Copyright (c) 2003 Association of Mizar Users
environ vocabulary FUNCT_1, BOOLE, ABSVALUE, EUCLID, PRE_TOPC, SQUARE_1, RELAT_1, SUBSET_1, ARYTM_3, METRIC_1, RCOMP_1, FUNCT_5, TOPMETR, COMPTS_1, ORDINAL2, TOPS_2, ARYTM_1, ARYTM, COMPLEX1, MCART_1, PCOMPS_1, JGRAPH_3, BORSUK_1, TOPREAL1, TOPREAL2, JORDAN3, PSCOMP_1, REALSET1, JORDAN5C, JORDAN6, JGRAPH_2, JGRAPH_6, RELAT_2, FINSEQ_1, FINSEQ_4, TARSKI, TOPS_1, FUNCT_4, JORDAN17; notation XBOOLE_0, ORDINAL1, ABSVALUE, EUCLID, TARSKI, RELAT_1, TOPS_2, FUNCT_1, FUNCT_2, SUBSET_1, FINSEQ_1, STRUCT_0, TOPMETR, PCOMPS_1, COMPTS_1, METRIC_1, SQUARE_1, RCOMP_1, PRE_TOPC, FUNCT_4, JGRAPH_3, JORDAN5C, JORDAN6, TOPREAL2, CONNSP_1, FINSEQ_4, TOPS_1, JORDAN17, JGRAPH_2, NUMBERS, XCMPLX_0, XREAL_0, TOPRNS_1, TOPREAL1, PSCOMP_1, REAL_1, NAT_1; constructors TOPS_1, RCOMP_1, JGRAPH_2, TOPREAL2, TOPGRP_1, CONNSP_1, WELLFND1, JGRAPH_3, JORDAN5C, JORDAN6, TOPRNS_1, TREAL_1, FINSEQ_4, TOPS_2, JORDAN17, TOPREAL1, PSCOMP_1, REAL_1, NAT_1; clusters STRUCT_0, RELSET_1, FUNCT_1, EUCLID, PRE_TOPC, TOPMETR, SQUARE_1, PSCOMP_1, BORSUK_1, TOPREAL2, BORSUK_2, TOPREAL1, JGRAPH_3, TOPS_1, JGRAPH_2, TOPREAL6, XREAL_0, NAT_1, MEMBERED, XBOOLE_0; requirements REAL, BOOLE, SUBSET, NUMERALS, ARITHM; definitions TARSKI, XBOOLE_0, TOPREAL1; theorems TARSKI, XBOOLE_0, XBOOLE_1, AXIOMS, RELAT_1, FUNCT_1, FUNCT_2, TOPS_1, TOPS_2, PRE_TOPC, TOPMETR, JORDAN6, EUCLID, REAL_1, REAL_2, JGRAPH_1, SQUARE_1, PSCOMP_1, METRIC_1, JGRAPH_2, RCOMP_1, COMPTS_1, RFUNCT_2, BORSUK_1, TOPREAL1, TOPREAL3, TOPREAL5, JGRAPH_3, ABSVALUE, JORDAN7, HEINE, JGRAPH_4, JORDAN5C, JGRAPH_5, GOBOARD6, JORDAN2C, TOPREAL2, TREAL_1, SEQ_2, FINSEQ_1, FINSEQ_3, FINSEQ_4, ZFMISC_1, NAT_1, ENUMSET1, UNIFORM1, BORSUK_4, TSEP_1, FUNCT_4, JORDAN1A, JORDAN17, JORDAN1, GOBOARD7, XREAL_0, TOPRNS_1, COMPLEX1, XCMPLX_0, XCMPLX_1; schemes FUNCT_2, JGRAPH_2, TOPREAL1, FRAENKEL, FUNCT_1, DOMAIN_1; begin :: Preliminaries canceled; theorem Th2: for a,b,r being real number st 0<=r & r<=1 & a<=b holds a<=(1-r)*a+r*b & (1-r)*a+r*b<=b proof let a,b,r be real number; assume A1: 0<=r & r<=1 & a<=b; then A2: 1-r>=0 by SQUARE_1:12; r*a<=r*b by A1,AXIOMS:25; then (1-r)*a+r*a<=(1-r)*a+r*b by REAL_1:55; then ((1-r)+r)*a<=(1-r)*a+r*b by XCMPLX_1:8; then 1*a<=(1-r)*a+r*b by XCMPLX_1:27; hence a<=(1-r)*a+r*b; (1-r)*a<=(1-r)*b by A1,A2,AXIOMS:25; then (1-r)*a+r*b<=(1-r)*b+r*b by REAL_1:55; then ((1-r)+r)*b>=(1-r)*a+r*b by XCMPLX_1:8; then 1*b>=(1-r)*a+r*b by XCMPLX_1:27; hence (1-r)*a+r*b<=b; end; theorem Th3: for a,b being real number st a>=0 & b>0 or a>0 & b>=0 holds a+b>0 proof let a,b be real number; assume A1: a>=0 & b>0 or a>0 & b>=0; now per cases by A1; case a>=0 & b>0; hence a+b>0 by REAL_1:69; case a>0 & b>=0; hence a+b>0 by REAL_1:69; end; hence a+b>0; end; theorem Th4: for a,b being real number st -1<=a & a<=1 & -1<=b & b<=1 holds a^2*b^2<=1 proof let a,b be real number; assume A1: -1<=a & a<=1 & -1<=b & b<=1; then A2: a^2<=1 by JGRAPH_2:7,SQUARE_1:59; A3: b^2<=1 by A1,JGRAPH_2:7,SQUARE_1:59; 0<=b^2 by SQUARE_1:72; then a^2*b^2 <= 1*b^2 by A2,AXIOMS:25; hence a^2*b^2<=1 by A3,AXIOMS:22; end; theorem Th5: for a,b being real number st a>=0 & b>=0 holds a*sqrt(b)=sqrt(a^2*b) proof let a,b be real number; assume A1: a>=0 & b>=0; then A2: sqrt(a^2)=a by SQUARE_1:89; a^2>=0 by SQUARE_1:72; hence a*sqrt(b)=sqrt(a^2*b) by A1,A2,SQUARE_1:97; end; Lm1: for a,b being real number st -1<=a & a<=1 & -1<=b & b<=1 holds (1+a^2)*b^2<=1+b^2 proof let a,b be real number; assume -1<=a & a<=1 & -1<=b & b<=1; then a^2*b^2<=1 by Th4; then 1*b^2+a^2*b^2<=1+b^2 by REAL_1:55; hence (1+a^2)*b^2<=1+b^2 by XCMPLX_1:8; end; theorem Th6: for a,b being real number st -1<=a & a<=1 & -1<=b & b<=1 holds (-b)*sqrt(1+a^2)<=sqrt(1+b^2) & -sqrt(1+b^2)<= b*sqrt(1+a^2) proof let a,b be real number; assume A1: -1<=a & a<=1 & -1<=b & b<=1; a^2>=0 by SQUARE_1:72; then 1+a^2>=1+0 by REAL_1:55; then A2: 1+a^2>=0 by AXIOMS:22; then A3: sqrt(1+a^2)>=0 by SQUARE_1:def 4; b^2>=0 by SQUARE_1:72; then 1+b^2>=1+0 by REAL_1:55; then 1+b^2>=0 by AXIOMS:22; then A4: sqrt(1+b^2)>=0 by SQUARE_1:def 4; A5: now per cases; case b>=0; then -b<=0 by REAL_1:66; hence (-b)*sqrt(1+a^2)<=sqrt(1+b^2) by A3,A4,SQUARE_1:23; case b<0; then -b>0 by REAL_1:66; then A6: (-b)*sqrt(1+a^2)=sqrt((-b)^2*(1+a^2)) by A2,Th5; (1+a^2)*b^2<=1+b^2 by A1,Lm1; then A7: (-b)^2*(1+a^2)<=1+b^2 by SQUARE_1:61; (-b)^2>=0 by SQUARE_1:72; then (-b)^2*(1+a^2)>=0 by A2,SQUARE_1:19; hence (-b)*sqrt(1+a^2)<=sqrt(1+b^2) by A6,A7,SQUARE_1:94; end; then -((-b)*sqrt(1+a^2)) >= - sqrt(1+b^2) by REAL_1:50; then ((--b)*sqrt(1+a^2)) >= - sqrt(1+b^2) by XCMPLX_1:175; hence (-b)*sqrt(1+a^2)<=sqrt(1+b^2) & -sqrt(1+b^2)<= b*sqrt(1+a^2) by A5; end; theorem Th7: for a,b being real number st -1<=a & a<=1 & -1<=b & b<=1 holds b*sqrt(1+a^2)<=sqrt(1+b^2) proof let a,b be real number; assume A1: -1<=a & a<=1 & -1<=b & b<=1; then A2: --1>=-b by REAL_1:50; -1<=-b by A1,REAL_1:50; then (--b)*sqrt(1+a^2)<=sqrt(1+(-b)^2) by A1,A2,Th6; hence b*sqrt(1+a^2)<=sqrt(1+b^2) by SQUARE_1:61; end; Lm2: for a,b being real number st b<=0 & a<=b holds a*sqrt(1+b^2)<= b*sqrt(1+a^2) proof let a,b be real number; assume A1: b<=0 & a<=b; a^2>=0 by SQUARE_1:72; then 1+a^2>=1+0 by REAL_1:55; then A2: 1+a^2>=0 by AXIOMS:22; b^2>=0 by SQUARE_1:72; then 1+b^2>=1+0 by REAL_1:55; then A3: 1+b^2>=0 by AXIOMS:22; --b<=0 by A1; then -b>=0 by REAL_1:66; then A4: (-b)*sqrt(1+a^2)=sqrt((-b)^2*(1+a^2)) by A2,Th5; --a<=0 by A1; then -a>=0 by REAL_1:66; then A5: (-a)*sqrt(1+b^2)=sqrt((-a)^2*(1+b^2)) by A3,Th5; A6: (-a)^2=a^2 by SQUARE_1:61; A7: (-b)^2=b^2 by SQUARE_1:61; a<b or a=b by A1,REAL_1:def 5; then b^2<a^2 or a=b by A1,JGRAPH_5:2; then b^2*1+b^2*a^2<=a^2*1+a^2*b^2 by REAL_1:55; then b^2*1+b^2*a^2<=a^2*(1+b^2) by XCMPLX_1:8; then A8: b^2*(1+a^2)<=a^2*(1+b^2) by XCMPLX_1:8; (b)^2>=0 by SQUARE_1:72; then (b)^2*(1+a^2)>=0 by A2,SQUARE_1:19; then sqrt((a)^2*(1+b^2))>=sqrt(b^2*(1+a^2)) by A8,SQUARE_1:94; then -(a*sqrt(1+b^2))>=(-b)*sqrt(1+a^2) by A4,A5,A6,A7,XCMPLX_1:175; then -(a*sqrt(1+b^2))>= -(b*sqrt(1+a^2)) by XCMPLX_1:175; hence (a)*sqrt(1+b^2)<=b*sqrt(1+a^2) by REAL_1:50; end; Lm3: for a,b being real number st a<=0 & a<=b holds a*sqrt(1+b^2)<= b*sqrt(1+a^2) proof let a,b be real number; assume A1: a<=0 & a<=b; now per cases; case b<=0; hence b*sqrt(1+a^2)>= a*sqrt(1+b^2) by A1,Lm2; case A2: b>0; A3: (b)^2 >=0 by SQUARE_1:72; 1+(b)^2 >(b)^2 by REAL_1:69; then sqrt(1+(b)^2)>0 by A3,SQUARE_1:93; then A4: a*sqrt(1+b^2)<=0 by A1,SQUARE_1:23; A5: (a)^2 >=0 by SQUARE_1:72; 1+(a)^2 >(a)^2 by REAL_1:69; then sqrt(1+(a)^2)>0 by A5,SQUARE_1:93; hence b*sqrt(1+a^2)>= a*sqrt(1+b^2) by A2,A4,REAL_2:121; end; hence thesis; end; Lm4: for a,b being real number st a>=0 & a>=b holds a*sqrt(1+b^2)>= b*sqrt(1+a^2) proof let a,b be real number; assume A1: a>=0 & a>=b; then A2: -a<=0 by REAL_1:66; -a <= -b by A1,REAL_1:50; then (-a)*sqrt(1+(-b)^2)<= (-b)*sqrt(1+(-a)^2) by A2,Lm3; then (-a)*sqrt(1+(b)^2)<= (-b)*sqrt(1+(-a)^2) by SQUARE_1:61; then (-a)*sqrt(1+(b)^2)<= (-b)*sqrt(1+(a)^2) by SQUARE_1:61; then -(a*sqrt(1+(b)^2))<= (-b)*sqrt(1+(a)^2) by XCMPLX_1:175; then -(a*sqrt(1+(b)^2))<= -(b*sqrt(1+(a)^2)) by XCMPLX_1:175; hence a*sqrt(1+b^2)>= b*sqrt(1+a^2) by REAL_1:50; end; theorem Th8: for a,b being real number st a>=b holds a*sqrt(1+b^2)>= b*sqrt(1+a^2) proof let a,b be real number; assume A1: a>=b; per cases; suppose a>=0; hence thesis by A1,Lm4; suppose a<0; hence thesis by A1,Lm2; end; theorem Th9: for a,c,d being real number,p being Point of TOP-REAL 2 st c <=d & p in LSeg(|[a,c]|,|[a,d]|) holds p`1=a & c <=p`2 & p`2<=d proof let a,c,d be real number,p be Point of TOP-REAL 2; assume A1: c <=d & p in LSeg(|[a,c]|,|[a,d]|); reconsider a2=a,c2=c,d2=d as Real by XREAL_0:def 1; p in LSeg(|[a2,c2]|,|[a2,d2]|) by A1; hence p`1=a by TOPREAL3:17; A2: (|[a,c]|)`2=c by EUCLID:56; (|[a,d]|)`2=d by EUCLID:56; hence c <=p`2 & p`2<=d by A1,A2,TOPREAL1:10; end; theorem Th10: for a,c,d being real number,p being Point of TOP-REAL 2 st c <d & p`1=a & c <=p`2 & p`2<=d holds p in LSeg(|[a,c]|,|[a,d]|) proof let a,c,d be real number,p be Point of TOP-REAL 2; assume A1: c <d & p`1=a & c <=p`2 & p`2<=d; then A2: d-c>0 by SQUARE_1:11; reconsider w=(p`2-c)/(d-c) as Real by XREAL_0:def 1; A3: (1-w)*(|[a,c]|)+w*(|[a,d]|) =|[(1-w)*a,(1-w)*c]|+w*(|[a,d]|) by EUCLID:62 .=|[(1-w)*a,(1-w)*c]|+(|[w*a,w*d]|) by EUCLID:62 .=|[(1-w)*a+w*a,(1-w)*c+w*d]| by EUCLID:60 .=|[((1-w)+w)*a,(1-w)*c+w*d]| by XCMPLX_1:8 .=|[(1)*a,(1-w)*c+w*d]| by XCMPLX_1:27 .=|[a,(1*c-w*c)+w*d]| by XCMPLX_1:40 .= |[a,c+w*d-w*c]| by XCMPLX_1:29 .= |[a,c+(w*d-w*c)]| by XCMPLX_1:29 .= |[a,c+w*(d-c)]| by XCMPLX_1:40 .= |[a,c+(p`2-c)]| by A2,XCMPLX_1:88 .= |[a,p`2]| by XCMPLX_1:27 .= p by A1,EUCLID:57; A4: p`2-c>=0 by A1,SQUARE_1:12; p`2-c <=d-c by A1,REAL_1:49; then w<=(d-c)/(d-c) by A2,REAL_1:73; then 0<=w & w<=1 by A2,A4,REAL_2:125,XCMPLX_1:60; then p in { (1-lambda)*(|[a,c]|) + lambda*(|[a,d]|) where lambda is Real : 0 <= lambda & lambda <= 1 } by A3; hence thesis by TOPREAL1:def 4; end; theorem Th11: for a,b,d being real number,p being Point of TOP-REAL 2 st a <=b & p in LSeg(|[a,d]|,|[b,d]|) holds p`2=d & a <=p`1 & p`1<=b proof let a,b,d be real number,p be Point of TOP-REAL 2; assume A1: a <=b & p in LSeg(|[a,d]|,|[b,d]|); reconsider a2=a,b2=b,d2=d as Real by XREAL_0:def 1; p in LSeg(|[a2,d2]|,|[b2,d2]|) by A1; hence p`2=d by TOPREAL3:18; A2: (|[a,d]|)`1=a by EUCLID:56; (|[b,d]|)`1=b by EUCLID:56; hence a <=p`1 & p`1<=b by A1,A2,TOPREAL1:9; end; theorem Th12: :: BORSUK_4:48 for a,b being real number,B being Subset of I[01] st B=[.a,b.] holds B is closed proof let a,b be real number,B be Subset of I[01]; assume A1: B=[.a,b.]; B c= the carrier of R^1 by BORSUK_1:83,TOPMETR:24,XBOOLE_1:1; then reconsider B2=B as Subset of R^1; A2: B2 is closed by A1,TREAL_1:4; reconsider I1=[.0,1.] as Subset of R^1 by TOPMETR:24; A3: [#](R^1|I1)=the carrier of I[01] by BORSUK_1:83,PRE_TOPC:def 10; A4: I[01]=R^1|I1 by TOPMETR:26,27; B=B2 /\ [#](R^1|I1) by A3,XBOOLE_1:28; hence B is closed by A2,A4,PRE_TOPC:43; end; theorem Th13: for X being TopStruct,Y,Z being non empty TopStruct, f being map of X,Y, g being map of X,Z holds dom f=dom g & dom f=the carrier of X & dom f=[#]X proof let X be TopStruct,Y,Z be non empty TopStruct, f be map of X,Y, g be map of X,Z; dom f=the carrier of X by FUNCT_2:def 1; hence dom f=dom g & dom f=the carrier of X & dom f=[#]X by FUNCT_2:def 1,PRE_TOPC:12; end; theorem Th14: for X being non empty TopSpace,B being non empty Subset of X ex f being map of X|B,X st (for p being Point of X|B holds f.p=p) & f is continuous proof let X be non empty TopSpace,B be non empty Subset of X; defpred P[set,set] means (for p being Point of X|B holds $2=$1); A1: the carrier of X|B = [#](X|B) by PRE_TOPC:12; A2: [#](X|B)= B by PRE_TOPC:def 10; A3: for x being Element of X|B ex y being Element of X st P[x,y] proof let x be Element of X|B; x in B by A1,A2; then reconsider px=x as Point of X; set y0=px; P[x,y0]; hence ex y being Element of X st P[x,y]; end; ex g being Function of the carrier of X|B,the carrier of X st for x being Element of X|B holds P[x,g.x] from FuncExD(A3); then consider g being Function of the carrier of X|B,the carrier of X such that A4: for x being Element of X|B holds P[x,g.x]; A5: for p being Point of X|B holds g.p=p by A4; A6: for r0 being Point of X|B,V being Subset of X st g.r0 in V & V is open holds ex W being Subset of X|B st r0 in W & W is open & g.:W c= V proof let r0 be Point of X|B,V be Subset of X; assume A7: g.r0 in V & V is open; V /\ [#](X|B) c= [#](X|B) by XBOOLE_1:17; then reconsider W2=V /\ [#](X|B) as Subset of X|B by A1; r0 in the carrier of (X|B); then A8: r0 in [#](X|B) by PRE_TOPC:12; g.r0=r0 by A4; then A9: r0 in W2 by A7,A8,XBOOLE_0:def 3; A10: W2 is open by A7,TOPS_2:32; g.:W2 c= V proof let y be set;assume y in g.:W2; then consider x being set such that A11: x in dom g & x in W2 & y=g.x by FUNCT_1:def 12; reconsider px=x as Point of X|B by A11; g.px=px by A4; hence y in V by A11,XBOOLE_0:def 3; end; hence ex W being Subset of X|B st r0 in W & W is open & g.:W c= V by A9,A10; end; reconsider g1=g as map of X|B,X ; g1 is continuous by A6,JGRAPH_2:20; hence thesis by A5; end; theorem Th15: for X being non empty TopSpace, f1 being map of X,R^1,a being real number st f1 is continuous holds ex g being map of X,R^1 st (for p being Point of X,r1 being real number st f1.p=r1 holds g.p=r1-a) & g is continuous proof let X be non empty TopSpace, f1 be map of X,R^1,a be real number; assume f1 is continuous; then consider g1 being map of X,R^1 such that A1: (for p being Point of X,r1 being real number st f1.p=r1 holds g1.p=r1+-a) & g1 is continuous by JGRAPH_2:34; for p being Point of X,r1 being real number st f1.p=r1 holds g1.p=r1-a proof let p be Point of X,r1 be real number; assume f1.p=r1; then g1.p=r1+-a by A1; hence g1.p=r1-a by XCMPLX_0:def 8; end; hence thesis by A1; end; theorem Th16: for X being non empty TopSpace, f1 being map of X,R^1,a being real number st f1 is continuous holds ex g being map of X,R^1 st (for p being Point of X,r1 being real number st f1.p=r1 holds g.p=a-r1) & g is continuous proof let X be non empty TopSpace, f1 be map of X,R^1,a be real number; assume f1 is continuous; then consider g1 being map of X,R^1 such that A1: (for p being Point of X,r1 being real number st f1.p=r1 holds g1.p=r1-a) & g1 is continuous by Th15; consider g2 being map of X,R^1 such that A2: (for p being Point of X,r1 being real number st g1.p=r1 holds g2.p= -r1) & g2 is continuous by A1,JGRAPH_4:13; for p being Point of X,r1 being real number st f1.p=r1 holds g2.p=a-r1 proof let p be Point of X,r1 be real number; assume f1.p=r1; then g1.p=r1-a by A1; then g2.p=-(r1-a) by A2 .=0-(r1-a) by XCMPLX_1:150 .=0-r1+a by XCMPLX_1:37 .=a+-r1 by XCMPLX_1:150 .=a-r1 by XCMPLX_0:def 8; hence g2.p=a-r1; end; hence thesis by A2; end; theorem Th17: for X being non empty TopSpace, n being Nat, p being Point of TOP-REAL n, f being map of X,R^1 st f is continuous ex g being map of X,TOP-REAL n st (for r being Point of X holds g.r=(f.r)*p) & g is continuous proof let X be non empty TopSpace, n be Nat, p be Point of TOP-REAL n, f be map of X,R^1; assume A1: f is continuous; defpred P[set,set] means $2=(f.$1)*p; A2: for x being Element of X ex y being Element of TOP-REAL n st P[x,y]; ex g being Function of the carrier of X,the carrier of TOP-REAL n st for x being Element of X holds P[x,g.x] from FuncExD(A2); then consider g being Function of the carrier of X,the carrier of TOP-REAL n such that A3: for x being Element of X holds P[x,g.x]; reconsider g as map of X,TOP-REAL n ; for r0 being Point of X,V being Subset of TOP-REAL n st g.r0 in V & V is open holds ex W being Subset of X st r0 in W & W is open & g.:W c= V proof let r0 be Point of X,V be Subset of TOP-REAL n; assume A4: g.r0 in V & V is open; then A5: g.r0 in Int V by TOPS_1:55; reconsider u=g.r0 as Point of Euclid n by TOPREAL3:13; consider s being real number such that A6: s>0 & Ball(u,s) c= V by A5,GOBOARD6:8; now per cases; case p <> 0.REAL n; then A7: |.p.| <> 0 by TOPRNS_1:25; A8: |.p.| >=0 by TOPRNS_1:26; set r2=s/|.p.|; reconsider G1=].f.r0-r2,f.r0+r2.[ as Subset of R^1 by TOPMETR:24; r2>0 by A6,A7,A8,SEQ_2:6; then A9: f.r0<f.r0+r2 by REAL_1:69; then f.r0-r2<f.r0 by REAL_1:84; then A10:f.r0 in G1 by A9,JORDAN6:45; G1 is open by JORDAN6:46; then consider W2 being Subset of X such that A11: r0 in W2 & W2 is open & f.:W2 c= G1 by A1,A10,JGRAPH_2:20; g.:W2 c= V proof let y be set;assume y in g.:W2; then consider r being set such that A12: r in dom g & r in W2 & y=g.r by FUNCT_1:def 12; reconsider r as Point of X by A12; dom f=the carrier of X by FUNCT_2:def 1; then f.r in f.:W2 by A12,FUNCT_1:def 12; then A13: abs(f.r - f.r0) <r2 by A11,RCOMP_1:8; reconsider t=f.r,t0=f.r0 as Real by XREAL_0:def 1; A14: abs(t0 - t)=abs(t-t0) by UNIFORM1:13; reconsider v=g.r as Point of Euclid n by TOPREAL3:13; g.r0=(f.r0)*p by A3; then A15: |.g.r0 -g.r.| = |.(f.r0)*p -(f.r)*p.| by A3 .= |.((f.r0)-(f.r))*p.| by EUCLID:54 .=abs(t0-t)*|.p.| by TOPRNS_1:8; abs(f.r - f.r0)*|.p.| < r2*|.p.| by A7,A8,A13,REAL_1:70; then |.g.r0 -g.r .|<s by A7,A14,A15,XCMPLX_1:88; then dist(u,v)<s by JGRAPH_1:45; then g.r in Ball(u,s) by METRIC_1:12; hence y in V by A6,A12; end; hence ex W being Subset of X st r0 in W & W is open & g.:W c= V by A11; case A16: p =0.REAL n; A17: for r being Point of X holds g.r=0.REAL n proof let r be Point of X; thus g.r=(f.r)*p by A3 .=0.REAL n by A16,EUCLID:32; end; then A18: 0.REAL n in V by A4; set W2=[#]X; r0 in the carrier of X; then A19: r0 in W2 by PRE_TOPC:12; g.:W2 c= V proof let y be set;assume y in g.:W2; then consider x being set such that A20: x in dom g & x in W2 & y=g.x by FUNCT_1:def 12; thus y in V by A17,A18,A20; end; hence ex W being Subset of X st r0 in W & W is open & g.:W c= V by A19; end; hence ex W being Subset of X st r0 in W & W is open & g.:W c= V; end; then g is continuous by JGRAPH_2:20; hence thesis by A3; end; theorem Th18: Sq_Circ.(|[-1,0]|)= |[-1,0]| proof set p= |[-1,0]|; A1: p`1=-1 & p`2=0 by EUCLID:56; then A2: p<>0.REAL 2 by EUCLID:56,58; p`2>=p`1 & p`2<=-p`1 by A1; then Sq_Circ.p= |[p`1/sqrt(1+(p`2/p`1)^2),p`2/sqrt(1+(p`2/p`1)^2)]| by A2,JGRAPH_3:def 1; hence thesis by A1,SQUARE_1:60,83; end; theorem for P being compact non empty Subset of TOP-REAL 2 st P={p where p is Point of TOP-REAL 2: |.p.|=1} holds Sq_Circ.(|[-1,0]|)=W-min(P) by Th18,JGRAPH_5:32; theorem Th20: for X being non empty TopSpace, n being Nat, g1,g2 being map of X,TOP-REAL n st g1 is continuous & g2 is continuous ex g being map of X,TOP-REAL n st (for r being Point of X holds g.r=g1.r + g2.r) & g is continuous proof let X being non empty TopSpace,n be Nat, g1,g2 be map of X,TOP-REAL n; assume A1: g1 is continuous & g2 is continuous; defpred P[set,set] means (for r1,r2 being Element of TOP-REAL n st g1.$1=r1 & g2.$1=r2 holds $2=r1+r2); A2:for x being Element of X ex y being Element of TOP-REAL n st P[x,y] proof let x be Element of X; set rr1=g1.x; set rr2=g2.x; set r3=rr1+rr2; for s1,s2 being Point of TOP-REAL n st g1.x=s1 & g2.x=s2 holds r3=s1+s2; hence thesis; end; ex f being Function of the carrier of X,the carrier of TOP-REAL n st for x being Element of X holds P[x,f.x] from FuncExD(A2); then consider f being Function of the carrier of X,the carrier of TOP-REAL n such that A3: for x being Element of X holds (for r1,r2 being Element of TOP-REAL n st g1.x=r1 & g2.x=r2 holds f.x=r1+r2); reconsider g0=f as map of X,TOP-REAL n ; A4: for r being Point of X holds g0.r=g1.r + g2.r by A3; for p being Point of X,V being Subset of TOP-REAL n st g0.p in V & V is open holds ex W being Subset of X st p in W & W is open & g0.:W c= V proof let p be Point of X,V be Subset of TOP-REAL n; assume g0.p in V & V is open; then A5: g0.p in Int V by TOPS_1:55; reconsider r=g0.p as Point of Euclid n by TOPREAL3:13; consider r0 being real number such that A6: r0>0 & Ball(r,r0) c= V by A5,GOBOARD6:8; reconsider r01=g1.p as Point of Euclid n by TOPREAL3:13; A7: the carrier of Euclid n=the carrier of TOP-REAL n by TOPREAL3:13; then reconsider G1=Ball(r01,r0/2) as Subset of TOP-REAL n ; A8: r0/2>0 by A6,SEQ_2:3; then A9:g1.p in G1 by GOBOARD6:4; TOP-REAL n=TopSpaceMetr(Euclid n) by EUCLID:def 8; then G1 is open by TOPMETR:21; then consider W1 being Subset of X such that A10: p in W1 & W1 is open & g1.:W1 c= G1 by A1,A9,JGRAPH_2:20; reconsider r02=g2.p as Point of Euclid n by TOPREAL3:13; reconsider G2=Ball(r02,r0/2) as Subset of TOP-REAL n by A7; A11:g2.p in G2 by A8,GOBOARD6:4; TOP-REAL n=TopSpaceMetr(Euclid n) by EUCLID:def 8; then G2 is open by TOPMETR:21; then consider W2 being Subset of X such that A12: p in W2 & W2 is open & g2.:W2 c= G2 by A1,A11,JGRAPH_2:20; set W=W1 /\ W2; A13:W is open by A10,A12,TOPS_1:38; A14:p in W by A10,A12,XBOOLE_0:def 3; g0.:W c= Ball(r,r0) proof let x be set;assume x in g0.:W; then consider z being set such that A15: z in dom g0 & z in W & g0.z=x by FUNCT_1:def 12; A16:z in W1 by A15,XBOOLE_0:def 3; reconsider pz=z as Point of X by A15; dom g1=the carrier of X by FUNCT_2:def 1; then A17: g1.pz in g1.:W1 by A16,FUNCT_1:def 12; reconsider aa1=g1.pz as Point of TOP-REAL n; reconsider bb1=aa1 as Point of Euclid n by TOPREAL3:13; dist(r01,bb1)<r0/2 by A10,A17,METRIC_1:12; then A18: |.g1.p - g1.pz .|<r0/2 by JGRAPH_1:45; A19:z in W2 by A15,XBOOLE_0:def 3; dom g2=the carrier of X by FUNCT_2:def 1; then A20: g2.pz in g2.:W2 by A19,FUNCT_1:def 12; reconsider aa2=g2.pz as Point of TOP-REAL n; reconsider bb2=aa2 as Point of Euclid n by TOPREAL3:13; dist(r02,bb2)<r0/2 by A12,A20,METRIC_1:12; then A21: |.g2.p - g2.pz .|<r0/2 by JGRAPH_1:45; A22: aa1+aa2=x by A3,A15; reconsider bb0=aa1+aa2 as Point of Euclid n by TOPREAL3:13; A23: g0.pz= g1.pz+g2.pz by A3; (g1.p +g2.p)-(g1.pz+g2.pz)=g1.p+g2.p-g1.pz-g2.pz by EUCLID:50 .= g1.p+g2.p+-g1.pz-g2.pz by EUCLID:45 .= g1.p+g2.p+-g1.pz+-g2.pz by EUCLID:45 .= g1.p+-g1.pz+g2.p+-g2.pz by EUCLID:30 .= g1.p+-g1.pz+(g2.p+-g2.pz) by EUCLID:30 .= g1.p-g1.pz+(g2.p+-g2.pz) by EUCLID:45 .= g1.p-g1.pz+(g2.p-g2.pz) by EUCLID:45; then A24: |.(g1.p +g2.p)-(g1.pz+g2.pz).| <= |.g1.p-g1.pz.| + |.g2.p-g2.pz.| by TOPRNS_1:30; |.g1.p-g1.pz.| + |.g2.p-g2.pz.| < r0/2 +r0/2 by A18,A21,REAL_1:67; then |.g1.p-g1.pz.| + |.g2.p-g2.pz.| < r0 by XCMPLX_1:66; then |.(g1.p +g2.p)-(g1.pz+g2.pz).|<r0 by A24,AXIOMS:22; then |.g0.p - g0.pz .|<r0 by A3,A23; then dist(r,bb0)<r0 by A15,A22,JGRAPH_1:45; hence x in Ball(r,r0) by A22,METRIC_1:12; end; then g0.:W c= V by A6,XBOOLE_1:1; hence ex W being Subset of X st p in W & W is open & g0.:W c= V by A13,A14; end; then g0 is continuous by JGRAPH_2:20; hence thesis by A4; end; theorem Th21: for X being non empty TopSpace, n being Nat, p1,p2 being Point of TOP-REAL n, f1,f2 being map of X,R^1 st f1 is continuous & f2 is continuous ex g being map of X,TOP-REAL n st (for r being Point of X holds g.r=(f1.r)*p1+(f2.r)*p2) & g is continuous proof let X be non empty TopSpace, n be Nat, p1,p2 be Point of TOP-REAL n, f1,f2 be map of X,R^1; assume A1: f1 is continuous & f2 is continuous; then consider g1 being map of X,TOP-REAL n such that A2: (for r being Point of X holds g1.r=(f1.r)*p1) & g1 is continuous by Th17; consider g2 being map of X,TOP-REAL n such that A3: (for r being Point of X holds g2.r=(f2.r)*p2) & g2 is continuous by A1,Th17; consider g being map of X,TOP-REAL n such that A4: (for r being Point of X holds g.r=g1.r + g2.r) & g is continuous by A2,A3,Th20; (for r being Point of X holds g.r=(f1.r)*p1+(f2.r)*p2) proof let r be Point of X; g.r=g1.r+g2.r by A4; then g.r=g1.r+(f2.r)*p2 by A3; hence g.r=(f1.r)*p1+(f2.r)*p2 by A2; end; hence thesis by A4; end; theorem Th22: for f being Function,A being set st f is one-to-one & A c= dom f holds f".:(f.:A)=A proof let f be Function,A be set; set B = f.:A; assume A1: f is one-to-one & A c= dom f; A2: f".:B c= A proof let y be set;assume y in f".:B; then consider x being set such that A3: x in dom (f") & x in B & y=f".x by FUNCT_1:def 12; consider y2 being set such that A4: y2 in dom f & y2 in A & x=f.y2 by A3,FUNCT_1:def 12; thus y in A by A1,A3,A4,FUNCT_1:54; end; A c= f".:B proof let x be set;assume A5: x in A; set y0=f.x; A6: f".y0=x by A1,A5,FUNCT_1:56; y0 in rng f by A1,A5,FUNCT_1:12; then A7: y0 in dom (f") by A1,FUNCT_1:55; y0 in B by A1,A5,FUNCT_1:def 12; hence x in f".:B by A6,A7,FUNCT_1:def 12; end; hence f".:B=A by A2,XBOOLE_0:def 10; end; begin :: General Fashoda Theorem for Unit Circle Lm5: (|[-1,0]|)`1 =-1 & (|[-1,0]|)`2=0 & (|[1,0]|)`1 =1 & (|[1,0]|)`2=0 & (|[0,-1]|)`1 =0 & (|[0,-1]|)`2=-1 & (|[0,1]|)`1 =0 & (|[0,1]|)`2=1 by EUCLID:56; Lm6: now thus |.(|[-1,0]|).|=sqrt((-1)^2+0^2) by Lm5,JGRAPH_3:10 .=1 by SQUARE_1:59,60,61,83; thus |.(|[1,0]|).|=sqrt(1^2+0^2) by Lm5,JGRAPH_3:10 .=1 by SQUARE_1:59,60,83; thus |.(|[0,-1]|).|=sqrt(0^2+(-1)^2) by Lm5,JGRAPH_3:10 .=1 by SQUARE_1:59,60,61,83; thus |.(|[0,1]|).|=sqrt(0^2+1^2) by Lm5,JGRAPH_3:10 .=1 by SQUARE_1:59,60,83; end; Lm7: 0 in [.0,1.] by TOPREAL5:1; Lm8: 1 in [.0,1.] by TOPREAL5:1; reserve p,p1,p2,p3,q,q1,q2 for Point of TOP-REAL 2,i,j for Nat, r,lambda for Real; theorem Th23: for f,g being map of I[01],TOP-REAL 2, C0,KXP,KXN,KYP,KYN being Subset of TOP-REAL 2, O,I being Point of I[01] st O=0 & I=1 & f is continuous one-to-one & g is continuous one-to-one & C0={p: |.p.|<=1}& KXP={q1 where q1 is Point of TOP-REAL 2: |.q1.|=1 & q1`2<=q1`1 & q1`2>=-q1`1} & KXN={q2 where q2 is Point of TOP-REAL 2: |.q2.|=1 & q2`2>=q2`1 & q2`2<=-q2`1} & KYP={q3 where q3 is Point of TOP-REAL 2: |.q3.|=1 & q3`2>=q3`1 & q3`2>=-q3`1} & KYN={q4 where q4 is Point of TOP-REAL 2: |.q4.|=1 & q4`2<=q4`1 & q4`2<=-q4`1} & f.O in KXP & f.I in KXN & g.O in KYP & g.I in KYN & rng f c= C0 & rng g c= C0 holds rng f meets rng g proof let f,g be map of I[01],TOP-REAL 2, C0,KXP,KXN,KYP,KYN be Subset of TOP-REAL 2, O,I be Point of I[01]; assume A1: O=0 & I=1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & C0={p: |.p.|<=1}& KXP={q1 where q1 is Point of TOP-REAL 2: |.q1.|=1 & q1`2<=q1`1 & q1`2>=-q1`1} & KXN={q2 where q2 is Point of TOP-REAL 2: |.q2.|=1 & q2`2>=q2`1 & q2`2<=-q2`1} & KYP={q3 where q3 is Point of TOP-REAL 2: |.q3.|=1 & q3`2>=q3`1 & q3`2>=-q3`1} & KYN={q4 where q4 is Point of TOP-REAL 2: |.q4.|=1 & q4`2<=q4`1 & q4`2<=-q4`1} & f.O in KXP & f.I in KXN & g.O in KYP & g.I in KYN & rng f c= C0 & rng g c= C0; then consider f2 being map of I[01],TOP-REAL 2 such that A2: f2.0=f.1 & f2.1=f.0 & rng f2=rng f & f2 is continuous & f2 is one-to-one by JGRAPH_5:15; thus rng f meets rng g by A1,A2,JGRAPH_5:16; end; theorem Th24: for f,g being map of I[01],TOP-REAL 2, C0,KXP,KXN,KYP,KYN being Subset of TOP-REAL 2, O,I being Point of I[01] st O=0 & I=1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & C0={p: |.p.|<=1}& KXP={q1 where q1 is Point of TOP-REAL 2: |.q1.|=1 & q1`2<=q1`1 & q1`2>=-q1`1} & KXN={q2 where q2 is Point of TOP-REAL 2: |.q2.|=1 & q2`2>=q2`1 & q2`2<=-q2`1} & KYP={q3 where q3 is Point of TOP-REAL 2: |.q3.|=1 & q3`2>=q3`1 & q3`2>=-q3`1} & KYN={q4 where q4 is Point of TOP-REAL 2: |.q4.|=1 & q4`2<=q4`1 & q4`2<=-q4`1} & f.O in KXP & f.I in KXN & g.O in KYN & g.I in KYP & rng f c= C0 & rng g c= C0 holds rng f meets rng g proof let f,g be map of I[01],TOP-REAL 2, C0,KXP,KXN,KYP,KYN be Subset of TOP-REAL 2, O,I be Point of I[01]; assume A1: O=0 & I=1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & C0={p: |.p.|<=1}& KXP={q1 where q1 is Point of TOP-REAL 2: |.q1.|=1 & q1`2<=q1`1 & q1`2>=-q1`1} & KXN={q2 where q2 is Point of TOP-REAL 2: |.q2.|=1 & q2`2>=q2`1 & q2`2<=-q2`1} & KYP={q3 where q3 is Point of TOP-REAL 2: |.q3.|=1 & q3`2>=q3`1 & q3`2>=-q3`1} & KYN={q4 where q4 is Point of TOP-REAL 2: |.q4.|=1 & q4`2<=q4`1 & q4`2<=-q4`1} & f.O in KXP & f.I in KXN & g.O in KYN & g.I in KYP & rng f c= C0 & rng g c= C0; then consider g2 being map of I[01],TOP-REAL 2 such that A2: g2.0=g.1 & g2.1=g.0 & rng g2=rng g & g2 is continuous & g2 is one-to-one by JGRAPH_5:15; thus rng f meets rng g by A1,A2,Th23; end; theorem Th25: for p1,p2,p3,p4 being Point of TOP-REAL 2, P being compact non empty Subset of TOP-REAL 2,C0 being Subset of TOP-REAL 2 st P={p where p is Point of TOP-REAL 2: |.p.|=1} & LE p1,p2,P & LE p2,p3,P & LE p3,p4,P holds (for f,g being map of I[01],TOP-REAL 2 st f is continuous one-to-one & g is continuous one-to-one & C0={p8 where p8 is Point of TOP-REAL 2: |.p8.|<=1}& f.0=p3 & f.1=p1 & g.0=p2 & g.1=p4 & rng f c= C0 & rng g c= C0 holds rng f meets rng g) proof let p1,p2,p3,p4 be Point of TOP-REAL 2, P be compact non empty Subset of TOP-REAL 2,C0 be Subset of TOP-REAL 2; assume A1: P={p where p is Point of TOP-REAL 2: |.p.|=1} & LE p1,p2,P & LE p2,p3,P & LE p3,p4,P; let f,g be map of I[01],TOP-REAL 2; assume A2:f is continuous one-to-one & g is continuous one-to-one & C0={p8 where p8 is Point of TOP-REAL 2: |.p8.|<=1}& f.0=p3 & f.1=p1 & g.0=p2 & g.1=p4 & rng f c= C0 & rng g c= C0; A3: dom f=the carrier of I[01] by FUNCT_2:def 1; A4: dom g=the carrier of I[01] by FUNCT_2:def 1; per cases; suppose A5: not (p1<>p2 & p2<>p3 & p3<>p4); now per cases by A5; case A6: p1=p2; thus rng f meets rng g proof A7: p1 in rng f by A2,A3,Lm8,BORSUK_1:83,FUNCT_1:def 5; p2 in rng g by A2,A4,Lm7,BORSUK_1:83,FUNCT_1:def 5; hence thesis by A6,A7,XBOOLE_0:3; end; case A8: p2=p3; thus rng f meets rng g proof A9: p3 in rng f by A2,A3,Lm7,BORSUK_1:83,FUNCT_1:def 5; p2 in rng g by A2,A4,Lm7,BORSUK_1:83,FUNCT_1:def 5; hence thesis by A8,A9,XBOOLE_0:3; end; case A10: p3=p4; thus rng f meets rng g proof A11: p3 in rng f by A2,A3,Lm7,BORSUK_1:83,FUNCT_1:def 5; p4 in rng g by A2,A4,Lm8,BORSUK_1:83,FUNCT_1:def 5; hence thesis by A10,A11,XBOOLE_0:3; end; end; hence thesis; suppose p1<>p2 & p2<>p3 & p3<>p4; then consider h being map of TOP-REAL 2,TOP-REAL 2 such that A12: h is_homeomorphism & (for q being Point of TOP-REAL 2 holds |.(h.q).|=|.q.|)& |[-1,0]|=h.p1 & |[0,1]|=h.p2 & |[1,0]|=h.p3 & |[0,-1]|=h.p4 by A1,JGRAPH_5:70; A13: h is one-to-one by A12,TOPS_2:def 5; reconsider f2=h*f as map of I[01],TOP-REAL 2; reconsider g2=h*g as map of I[01],TOP-REAL 2; A14: dom f2=the carrier of I[01] by FUNCT_2:def 1; A15: dom g2=the carrier of I[01] by FUNCT_2:def 1; A16: f2.1= |[-1,0]| by A2,A12,A14,Lm8,BORSUK_1:83,FUNCT_1:22; A17: g2.1= |[0,-1]| by A2,A12,A15,Lm8,BORSUK_1:83,FUNCT_1:22; A18: f2.0= |[1,0]| by A2,A12,A14,Lm7,BORSUK_1:83,FUNCT_1:22; A19: g2.0= |[0,1]| by A2,A12,A15,Lm7,BORSUK_1:83,FUNCT_1:22; A20: f2 is continuous one-to-one & g2 is continuous one-to-one & f2.1=|[-1,0]| & f2.0=|[1,0]| & g2.1=|[0,-1]| & g2.0= |[0,1]| by A2,A12,A14,A15,Lm7,Lm8,BORSUK_1:83,FUNCT_1:22, JGRAPH_5:8,9; A21: rng f2 c= C0 proof let y be set;assume y in rng f2; then consider x being set such that A22: x in dom f2 & y=f2.x by FUNCT_1:def 5; A23: f2.x=h.(f.x) by A22,FUNCT_1:22; A24: f.x in rng f by A3,A14,A22,FUNCT_1:def 5; then A25: f.x in C0 by A2; reconsider qf=f.x as Point of TOP-REAL 2 by A24; consider q5 being Point of TOP-REAL 2 such that A26: q5=f.x & |.q5.|<=1 by A2,A25; |.(h.qf).|=|.qf.| by A12; hence y in C0 by A2,A22,A23,A26; end; A27: rng g2 c= C0 proof let y be set;assume y in rng g2; then consider x being set such that A28: x in dom g2 & y=g2.x by FUNCT_1:def 5; A29: g2.x=h.(g.x) by A28,FUNCT_1:22; A30: g.x in rng g by A4,A15,A28,FUNCT_1:def 5; then A31: g.x in C0 by A2; reconsider qg=g.x as Point of TOP-REAL 2 by A30; consider q5 being Point of TOP-REAL 2 such that A32: q5=g.x & |.q5.|<=1 by A2,A31; |.(h.qg).|=|.qg.| by A12; hence y in C0 by A2,A28,A29,A32; end; defpred Q[Point of TOP-REAL 2] means |.$1.|=1 & $1`2<=$1`1 & $1`2>=-$1`1; {q1 where q1 is Point of TOP-REAL 2:Q[q1]} is Subset of TOP-REAL 2 from TopSubset; then reconsider KXP={q1 where q1 is Point of TOP-REAL 2: |.q1.|=1 & q1`2<=q1`1 & q1`2>=-q1`1} as Subset of TOP-REAL 2; defpred Q[Point of TOP-REAL 2] means |.$1.|=1 & $1`2>=$1`1 & $1`2<=-$1`1; {q2 where q2 is Point of TOP-REAL 2:Q[q2]} is Subset of TOP-REAL 2 from TopSubset; then reconsider KXN={q2 where q2 is Point of TOP-REAL 2: |.q2.|=1 & q2`2>=q2`1 & q2`2<=-q2`1} as Subset of TOP-REAL 2; defpred Q[Point of TOP-REAL 2] means |.$1.|=1 & $1`2>=$1`1 & $1`2>=-$1`1; {q3 where q3 is Point of TOP-REAL 2:Q[q3]} is Subset of TOP-REAL 2 from TopSubset; then reconsider KYP={q3 where q3 is Point of TOP-REAL 2: |.q3.|=1 & q3`2>=q3`1 & q3`2>=-q3`1} as Subset of TOP-REAL 2; defpred Q[Point of TOP-REAL 2] means |.$1.|=1 & $1`2<=$1`1 & $1`2<=-$1`1; {q4 where q4 is Point of TOP-REAL 2:Q[q4]} is Subset of TOP-REAL 2 from TopSubset; then reconsider KYN={q4 where q4 is Point of TOP-REAL 2: |.q4.|=1 & q4`2<=q4`1 & q4`2<=-q4`1} as Subset of TOP-REAL 2; reconsider O=0,I=1 as Point of I[01] by BORSUK_1:83,TOPREAL5:1; -(|[-1,0]|)`1=1 by Lm5; then A33: f2.I in KXN by A16,Lm5,Lm6; A34: f2.O in KXP by A18,Lm5,Lm6; -(|[0,-1]|)`1= 0 by Lm5; then A35: g2.I in KYN by A17,Lm5,Lm6; -(|[0,1]|)`1= 0 by Lm5; then g2.O in KYP by A19,Lm5,Lm6; then rng f2 meets rng g2 by A2,A20,A21,A27,A33,A34,A35,Th23; then consider x2 being set such that A36: x2 in rng f2 & x2 in rng g2 by XBOOLE_0:3; consider z2 being set such that A37: z2 in dom f2 & x2=f2.z2 by A36,FUNCT_1:def 5; consider z3 being set such that A38: z3 in dom g2 & x2=g2.z3 by A36,FUNCT_1:def 5; A39: dom h=the carrier of TOP-REAL 2 by FUNCT_2:def 1; A40: g.z3 in rng g by A4,A15,A38,FUNCT_1:def 5; A41: f.z2 in rng f by A3,A14,A37,FUNCT_1:def 5; reconsider h1=h as Function; A42: h1".x2=h1".(h.(f.z2)) by A37,FUNCT_1:22 .=f.z2 by A13,A39,A41,FUNCT_1:56; h1".x2=h1".(h.(g.z3)) by A38,FUNCT_1:22 .=g.z3 by A13,A39,A40,FUNCT_1:56; then h1".x2 in rng f & h1".x2 in rng g by A3,A4,A14,A15,A37,A38,A42,FUNCT_1 :def 5; hence thesis by XBOOLE_0:3; end; theorem Th26: for p1,p2,p3,p4 being Point of TOP-REAL 2, P being compact non empty Subset of TOP-REAL 2,C0 being Subset of TOP-REAL 2 st P={p where p is Point of TOP-REAL 2: |.p.|=1} & LE p1,p2,P & LE p2,p3,P & LE p3,p4,P holds (for f,g being map of I[01],TOP-REAL 2 st f is continuous one-to-one & g is continuous one-to-one & C0={p8 where p8 is Point of TOP-REAL 2: |.p8.|<=1}& f.0=p3 & f.1=p1 & g.0=p4 & g.1=p2 & rng f c= C0 & rng g c= C0 holds rng f meets rng g) proof let p1,p2,p3,p4 be Point of TOP-REAL 2, P be compact non empty Subset of TOP-REAL 2,C0 be Subset of TOP-REAL 2; assume A1: P={p where p is Point of TOP-REAL 2: |.p.|=1} & LE p1,p2,P & LE p2,p3,P & LE p3,p4,P; let f,g be map of I[01],TOP-REAL 2; assume A2:f is continuous one-to-one & g is continuous one-to-one & C0={p8 where p8 is Point of TOP-REAL 2: |.p8.|<=1}& f.0=p3 & f.1=p1 & g.0=p4 & g.1=p2 & rng f c= C0 & rng g c= C0; A3: dom f=the carrier of I[01] by FUNCT_2:def 1; A4: dom g=the carrier of I[01] by FUNCT_2:def 1; per cases; suppose A5: not (p1<>p2 & p2<>p3 & p3<>p4); now per cases by A5; case A6: p1=p2; thus rng f meets rng g proof A7: p1 in rng f by A2,A3,Lm8,BORSUK_1:83,FUNCT_1:def 5; p2 in rng g by A2,A4,Lm8,BORSUK_1:83,FUNCT_1:def 5; hence thesis by A6,A7,XBOOLE_0:3; end; case A8: p2=p3; thus rng f meets rng g proof A9: p3 in rng f by A2,A3,Lm7,BORSUK_1:83,FUNCT_1:def 5; p2 in rng g by A2,A4,Lm8,BORSUK_1:83,FUNCT_1:def 5; hence thesis by A8,A9,XBOOLE_0:3; end; case A10: p3=p4; thus rng f meets rng g proof A11: p3 in rng f by A2,A3,Lm7,BORSUK_1:83,FUNCT_1:def 5; p4 in rng g by A2,A4,Lm7,BORSUK_1:83,FUNCT_1:def 5; hence thesis by A10,A11,XBOOLE_0:3; end; end; hence thesis; suppose p1<>p2 & p2<>p3 & p3<>p4; then consider h being map of TOP-REAL 2,TOP-REAL 2 such that A12: h is_homeomorphism & (for q being Point of TOP-REAL 2 holds |.(h.q).|=|.q.|)& |[-1,0]|=h.p1 & |[0,1]|=h.p2 & |[1,0]|=h.p3 & |[0,-1]|=h.p4 by A1,JGRAPH_5:70; A13: h is one-to-one by A12,TOPS_2:def 5; reconsider f2=h*f as map of I[01],TOP-REAL 2; reconsider g2=h*g as map of I[01],TOP-REAL 2; A14: dom f2=the carrier of I[01] by FUNCT_2:def 1; A15: dom g2=the carrier of I[01] by FUNCT_2:def 1; A16: f2.1= |[-1,0]| by A2,A12,A14,Lm8,BORSUK_1:83,FUNCT_1:22; A17: g2.1= |[0,1]| by A2,A12,A15,Lm8,BORSUK_1:83,FUNCT_1:22; A18: f2.0= |[1,0]| by A2,A12,A14,Lm7,BORSUK_1:83,FUNCT_1:22; A19: g2.0= |[0,-1]| by A2,A12,A15,Lm7,BORSUK_1:83,FUNCT_1:22; A20: f2 is continuous one-to-one & g2 is continuous one-to-one & f2.1=|[-1,0]| & f2.0=|[1,0]| & g2.1=|[0,1]| & g2.0= |[0,-1]| by A2,A12,A14,A15,Lm7,Lm8,BORSUK_1:83,FUNCT_1:22, JGRAPH_5:8,9; A21: rng f2 c= C0 proof let y be set;assume y in rng f2; then consider x being set such that A22: x in dom f2 & y=f2.x by FUNCT_1:def 5; A23: f2.x=h.(f.x) by A22,FUNCT_1:22; A24: f.x in rng f by A3,A14,A22,FUNCT_1:def 5; then A25: f.x in C0 by A2; reconsider qf=f.x as Point of TOP-REAL 2 by A24; consider q5 being Point of TOP-REAL 2 such that A26: q5=f.x & |.q5.|<=1 by A2,A25; |.(h.qf).|=|.qf.| by A12; hence y in C0 by A2,A22,A23,A26; end; A27: rng g2 c= C0 proof let y be set;assume y in rng g2; then consider x being set such that A28: x in dom g2 & y=g2.x by FUNCT_1:def 5; A29: g2.x=h.(g.x) by A28,FUNCT_1:22; A30: g.x in rng g by A4,A15,A28,FUNCT_1:def 5; then A31: g.x in C0 by A2; reconsider qg=g.x as Point of TOP-REAL 2 by A30; consider q5 being Point of TOP-REAL 2 such that A32: q5=g.x & |.q5.|<=1 by A2,A31; |.(h.qg).|=|.qg.| by A12; hence y in C0 by A2,A28,A29,A32; end; defpred P[Point of TOP-REAL 2] means |.$1.|=1 & $1`2<=$1`1 & $1`2>=-$1`1; {q1 where q1 is Point of TOP-REAL 2:P[q1]} is Subset of TOP-REAL 2 from TopSubset; then reconsider KXP={q1 where q1 is Point of TOP-REAL 2: |.q1.|=1 & q1`2<=q1`1 & q1`2>=-q1`1} as Subset of TOP-REAL 2; defpred P[Point of TOP-REAL 2] means |.$1.|=1 & $1`2>=$1`1 & $1`2<=-$1`1; {q2 where q2 is Point of TOP-REAL 2:P[q2]} is Subset of TOP-REAL 2 from TopSubset; then reconsider KXN={q2 where q2 is Point of TOP-REAL 2: |.q2.|=1 & q2`2>=q2`1 & q2`2<=-q2`1} as Subset of TOP-REAL 2; defpred P[Point of TOP-REAL 2] means |.$1.|=1 & $1`2>=$1`1 & $1`2>=-$1`1; {q3 where q3 is Point of TOP-REAL 2:P[q3]} is Subset of TOP-REAL 2 from TopSubset; then reconsider KYP={q3 where q3 is Point of TOP-REAL 2: |.q3.|=1 & q3`2>=q3`1 & q3`2>=-q3`1} as Subset of TOP-REAL 2; defpred P[Point of TOP-REAL 2] means |.$1.|=1 & $1`2<=$1`1 & $1`2<=-$1`1; {q4 where q4 is Point of TOP-REAL 2:P[q4]} is Subset of TOP-REAL 2 from TopSubset; then reconsider KYN={q4 where q4 is Point of TOP-REAL 2: |.q4.|=1 & q4`2<=q4`1 & q4`2<=-q4`1} as Subset of TOP-REAL 2; reconsider O=0,I=1 as Point of I[01] by BORSUK_1:83,TOPREAL5:1; -(|[-1,0]|)`1=1 by Lm5; then A33: f2.I in KXN by A16,Lm5,Lm6; A34: f2.O in KXP by A18,Lm5,Lm6; -(|[0,-1]|)`1= 0 by Lm5; then A35: g2.I in KYP by A17,Lm5,Lm6; -(|[0,1]|)`1= 0 by Lm5; then g2.O in KYN by A19,Lm5,Lm6; then rng f2 meets rng g2 by A2,A20,A21,A27,A33,A34,A35,Th24; then consider x2 being set such that A36: x2 in rng f2 & x2 in rng g2 by XBOOLE_0:3; consider z2 being set such that A37: z2 in dom f2 & x2=f2.z2 by A36,FUNCT_1:def 5; consider z3 being set such that A38: z3 in dom g2 & x2=g2.z3 by A36,FUNCT_1:def 5; A39: dom h=the carrier of TOP-REAL 2 by FUNCT_2:def 1; A40: g.z3 in rng g by A4,A15,A38,FUNCT_1:def 5; A41: f.z2 in rng f by A3,A14,A37,FUNCT_1:def 5; reconsider h1=h as Function; A42: h1".x2=h1".(h.(f.z2)) by A37,FUNCT_1:22 .=f.z2 by A13,A39,A41,FUNCT_1:56; h1".x2=h1".(h.(g.z3)) by A38,FUNCT_1:22 .=g.z3 by A13,A39,A40,FUNCT_1:56; then h1".x2 in rng f & h1".x2 in rng g by A3,A4,A14,A15,A37,A38,A42,FUNCT_1 :def 5; hence thesis by XBOOLE_0:3; end; theorem Th27: for p1,p2,p3,p4 being Point of TOP-REAL 2, P being compact non empty Subset of TOP-REAL 2, C0 being Subset of TOP-REAL 2 st P={p where p is Point of TOP-REAL 2: |.p.|=1} & p1,p2,p3,p4 are_in_this_order_on P holds (for f,g being map of I[01],TOP-REAL 2 st f is continuous one-to-one & g is continuous one-to-one & C0={p8 where p8 is Point of TOP-REAL 2: |.p8.|<=1}& f.0=p1 & f.1=p3 & g.0=p2 & g.1=p4 & rng f c= C0 & rng g c= C0 holds rng f meets rng g) proof let p1,p2,p3,p4 be Point of TOP-REAL 2, P be compact non empty Subset of TOP-REAL 2,C0 be Subset of TOP-REAL 2; assume A1: P={p where p is Point of TOP-REAL 2: |.p.|=1} & p1,p2,p3,p4 are_in_this_order_on P; per cases by A1,JORDAN17:def 1; suppose LE p1,p2,P & LE p2,p3,P & LE p3,p4,P; hence thesis by A1,JGRAPH_5:71; suppose LE p2,p3,P & LE p3,p4,P & LE p4,p1,P; hence thesis by A1,JGRAPH_5:72; suppose LE p3,p4,P & LE p4,p1,P & LE p1,p2,P; hence thesis by A1,Th26; suppose LE p4,p1,P & LE p1,p2,P & LE p2,p3,P; hence thesis by A1,Th25; end; begin :: General Rectangles and Circles definition let a,b,c,d be real number; func rectangle(a,b,c,d) -> Subset of TOP-REAL 2 equals :Def1: {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b}; coherence proof defpred P[Point of TOP-REAL 2] means $1`1=a & c <=$1`2 & $1`2<=d or $1`2=d & a<=$1`1 & $1`1<=b or $1`1=b & c <=$1`2 & $1`2<=d or $1`2=c & a<=$1`1 & $1`1<=b; {p: P[p]} c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; theorem Th28: for a,b,c,d being real number, p being Point of TOP-REAL 2 st a<=b & c <=d & p in rectangle(a,b,c,d) holds a<=p`1 & p`1<=b & c <=p`2 & p`2<=d proof let a,b,c,d be real number, p be Point of TOP-REAL 2; assume A1: a<=b & c <=d & p in rectangle(a,b,c,d); then p in {p2: p2`1=a & c <=p2`2 & p2`2<=d or p2`2=d & a<=p2`1 & p2`1<=b or p2`1=b & c <=p2`2 & p2`2<=d or p2`2=c & a<=p2`1 & p2`1<=b} by Def1; then consider p2 such that A2: p2=p & (p2`1=a & c <=p2`2 & p2`2<=d or p2`2=d & a<=p2`1 & p2`1<=b or p2`1=b & c <=p2`2 & p2`2<=d or p2`2=c & a<=p2`1 & p2`1<=b); per cases by A2; suppose p`1=a & c <=p`2 & p`2<=d; hence thesis by A1; suppose p`2=d & a<=p`1 & p`1<=b; hence thesis by A1; suppose p`1=b & c <=p`2 & p`2<=d; hence thesis by A1; suppose p`2=c & a<=p`1 & p`1<=b; hence thesis by A1; end; definition let a,b,c,d be real number; func inside_of_rectangle(a,b,c,d) -> Subset of TOP-REAL 2 equals :Def2: {p: a <p`1 & p`1< b & c <p`2 & p`2< d}; coherence proof defpred P[Point of TOP-REAL 2] means a <$1`1 & $1`1< b & c <$1`2 & $1`2< d; {p: P[p]} c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; definition let a,b,c,d be real number; func closed_inside_of_rectangle(a,b,c,d) -> Subset of TOP-REAL 2 equals :Def3: {p: a <=p`1 & p`1<= b & c <=p`2 & p`2<= d}; coherence proof defpred P[Point of TOP-REAL 2] means a <=$1`1 & $1`1<= b & c <=$1`2 & $1`2<= d; {p: P[p]} c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; definition let a,b,c,d be real number; func outside_of_rectangle(a,b,c,d) -> Subset of TOP-REAL 2 equals :Def4: {p: not(a <=p`1 & p`1<= b & c <=p`2 & p`2<= d)}; coherence proof defpred P[Point of TOP-REAL 2] means not(a <=$1`1 & $1`1<= b & c <=$1`2 & $1`2<= d); {p: P[p] } c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; definition let a,b,c,d be real number; func closed_outside_of_rectangle(a,b,c,d) -> Subset of TOP-REAL 2 equals :Def5: {p: not(a <p`1 & p`1< b & c <p`2 & p`2< d)}; coherence proof defpred P[Point of TOP-REAL 2] means not(a <$1`1 & $1`1< b & c <$1`2 & $1`2< d); {p: P[p] } c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; theorem Th29: for a,b,r being real number,Kb,Cb being Subset of TOP-REAL 2 st r>=0 & Kb={q: |.q.|=1}& Cb={p2 where p2 is Point of TOP-REAL 2: |.(p2- |[a,b]|).|=r} holds AffineMap(r,a,r,b).:Kb=Cb proof let a,b,r be real number,Kb,Cb be Subset of TOP-REAL 2; assume A1: r>=0 & Kb={q: |.q.|=1}& Cb={p2 where p2 is Point of TOP-REAL 2: |.(p2- |[a,b]|).|=r}; reconsider rr=r as Real by XREAL_0:def 1; A2: AffineMap(r,a,r,b).:Kb c= Cb proof let y be set;assume y in AffineMap(r,a,r,b).:Kb; then consider x being set such that A3: x in dom (AffineMap(r,a,r,b)) & x in Kb & y=(AffineMap(r,a,r,b)).x by FUNCT_1:def 12; consider p being Point of TOP-REAL 2 such that A4: x=p & |.p.|=1 by A1,A3; A5: (AffineMap(r,a,r,b)).p=|[r*(p`1)+a,r*(p`2)+b]| by JGRAPH_2:def 2; then reconsider q=y as Point of TOP-REAL 2 by A3,A4; A6: q- |[a,b]|= |[r*(p`1)+a-a,r*(p`2)+b-b]| by A3,A4,A5,EUCLID:66 .= |[r*(p`1),r*(p`2)+b-b]| by XCMPLX_1:26 .= |[r*(p`1),r*(p`2)]| by XCMPLX_1:26 .= r*(|[(p`1),(p`2)]|) by EUCLID:62 .= r*p by EUCLID:57; |.r*p.|=abs(rr)*(|.p.|) by TOPRNS_1:8.=r by A1,A4,ABSVALUE:def 1; hence y in Cb by A1,A6; end; Cb c= AffineMap(r,a,r,b).:Kb proof let y be set;assume y in Cb; then consider p2 being Point of TOP-REAL 2 such that A7: y=p2 & |.(p2- |[a,b]|).|=r by A1; now per cases by A1; case A8: r>0; then r" >0 by REAL_1:72; then A9: 1/r >0 by XCMPLX_1:217; set p1=(1/r)*(p2- |[a,b]|); |.p1.|=abs(1/rr)*|.(p2- |[a,b]|).| by TOPRNS_1:8 .=(1/r)*r by A7,A9,ABSVALUE:def 1 .= 1 by A8,XCMPLX_1:88; then A10: p1 in Kb by A1; p1=|[(1/r)*(p2- |[a,b]|)`1,(1/r)*(p2- |[a,b]|)`2]| by EUCLID:61; then A11: p1`1=(1/r)*(p2- |[a,b]|)`1 & p1`2=(1/r)*(p2- |[a,b]|)`2 by EUCLID:56; then A12: r*p1`1=r*(1/r)*(p2- |[a,b]|)`1 by XCMPLX_1:4 .=1*(p2- |[a,b]|)`1 by A8,XCMPLX_1:88 .=p2`1 -(|[a,b]|)`1 by TOPREAL3:8 .=p2`1 - a by EUCLID:56; A13: r*p1`2=r*(1/r)*(p2- |[a,b]|)`2 by A11,XCMPLX_1:4 .=1*(p2- |[a,b]|)`2 by A8,XCMPLX_1:88 .=p2`2 -(|[a,b]|)`2 by TOPREAL3:8 .=p2`2 - b by EUCLID:56; A14: (AffineMap(r,a,r,b)).p1= |[r*(p1`1)+a,r*(p1`2)+b]| by JGRAPH_2:def 2 .= |[p2`1,p2`2 -b+b]| by A12,A13,XCMPLX_1:27 .= |[p2`1,p2`2]| by XCMPLX_1:27 .=p2 by EUCLID:57; dom (AffineMap(r,a,r,b))=the carrier of TOP-REAL 2 by FUNCT_2:def 1; hence y in AffineMap(r,a,r,b).:Kb by A7,A10,A14,FUNCT_1:def 12; case A15: r=0; set p1= |[1,0]|; p1`1=1 & p1`2=0 by EUCLID:56; then |.p1.|=sqrt(1^2+0) by JGRAPH_3:10,SQUARE_1:60 .=1 by SQUARE_1:89; then A16: p1 in Kb by A1; A17: (AffineMap(r,a,r,b)).p1= |[(0)*(p1`1)+a,(0)*(p1`2)+b]| by A15,JGRAPH_2:def 2 .=p2 by A7,A15,TOPRNS_1:29; dom (AffineMap(r,a,r,b))=the carrier of TOP-REAL 2 by FUNCT_2:def 1; hence y in AffineMap(r,a,r,b).:Kb by A7,A16,A17,FUNCT_1:def 12; end; hence y in AffineMap(r,a,r,b).:Kb; end; hence AffineMap(r,a,r,b).:Kb=Cb by A2,XBOOLE_0:def 10; end; theorem Th30: for P,Q being Subset of TOP-REAL 2 st (ex f being map of (TOP-REAL 2)|P,(TOP-REAL 2)|Q st f is_homeomorphism) & P is_simple_closed_curve holds Q is_simple_closed_curve proof let P,Q be Subset of TOP-REAL 2; assume A1: (ex f being map of (TOP-REAL 2)|P,(TOP-REAL 2)|Q st f is_homeomorphism) & P is_simple_closed_curve; then consider f being map of (TOP-REAL 2)|P,(TOP-REAL 2)|Q such that A2: f is_homeomorphism; consider g being map of (TOP-REAL 2)|R^2-unit_square, (TOP-REAL 2)|P such that A3: g is_homeomorphism by A1,TOPREAL2:def 1; (|[1,0]|)`1=1 & (|[1,0]|)`2=0 by EUCLID:56; then A4: |[1,0]| in R^2-unit_square by TOPREAL1:def 3; A5: dom g=[#]((TOP-REAL 2)|R^2-unit_square) & rng g=[#]((TOP-REAL 2)|P) by A3,TOPS_2:def 5; then dom g= R^2-unit_square by PRE_TOPC:def 10; then A6: g.(|[1,0]|) in rng g by A4,FUNCT_1:12; then A7: g.(|[1,0]|) in P by A5,PRE_TOPC:def 10; reconsider P1=P as non empty Subset of TOP-REAL 2 by A5,A6,PRE_TOPC:def 10; A8: dom f=[#]((TOP-REAL 2)|P) & rng f=[#]((TOP-REAL 2)|Q) by A2,TOPS_2:def 5; then dom f= P by PRE_TOPC:def 10; then f.(g.(|[1,0]|)) in rng f by A7,FUNCT_1:12; then reconsider Q1=Q as non empty Subset of TOP-REAL 2 by A8,PRE_TOPC:def 10 ; reconsider f1=f as map of (TOP-REAL 2)|P1,(TOP-REAL 2)|Q1; reconsider g1=g as map of (TOP-REAL 2)|R^2-unit_square,(TOP-REAL 2)|P1; reconsider h=f1*g1 as map of (TOP-REAL 2)|R^2-unit_square, (TOP-REAL 2)|Q1; h is_homeomorphism by A2,A3,TOPS_2:71; hence Q is_simple_closed_curve by TOPREAL2:def 1; end; theorem Th31: for P being Subset of TOP-REAL 2 st P is being_simple_closed_curve holds P is compact proof let P be Subset of TOP-REAL 2; assume P is being_simple_closed_curve; then reconsider P'=P as being_simple_closed_curve Subset of TOP-REAL 2; P' is compact; hence thesis; end; theorem Th32: for a,b,r be real number, Cb being Subset of TOP-REAL 2 st r>0 & Cb={p where p is Point of TOP-REAL 2: |.(p- |[a,b]|).|=r} holds Cb is_simple_closed_curve proof let a,b,r be real number, Cb be Subset of TOP-REAL 2; assume A1: r>0 & Cb={p where p is Point of TOP-REAL 2: |.(p- |[a,b]|).|=r}; A2:(|[r,0]|)`1=r & (|[r,0]|)`2=0 by EUCLID:56; |.(|[r+a,b]| - |[a,b]|).|=|.(|[r+a,0+b]| - |[a,b]|).| .=|.(|[r,0]|+|[a,b]|- |[a,b]|).| by EUCLID:60 .= |.(|[r,0]|+(|[a,b]|- |[a,b]|)).| by EUCLID:49 .=|.|[r,0]|+(0.REAL 2).| by EUCLID:46 .=|.|[r,0]|.| by EUCLID:31 .=sqrt(r^2+0) by A2,JGRAPH_3:10,SQUARE_1:60 .=r by A1,SQUARE_1:89; then |[r+a,b]| in Cb by A1; then reconsider Cbb=Cb as non empty Subset of TOP-REAL 2; set v= |[1,0]|; v`1=1 & v`2=0 by EUCLID:56; then |.v.|=sqrt(1^2+0) by JGRAPH_3:10,SQUARE_1:60 .=1 by SQUARE_1:89; then A3: |[1,0]| in {q: |.q.|=1}; defpred P[Point of TOP-REAL 2] means |.$1.|=1; {q where q is Element of TOP-REAL 2:P[q]} is Subset of TOP-REAL 2 from SubsetD; then reconsider Kb= {q: |.q.|=1} as non empty Subset of TOP-REAL 2 by A3; A4:the carrier of (TOP-REAL 2)|Kb=Kb by JORDAN1:1; set SC= AffineMap(r,a,r,b); A5: SC is one-to-one by A1,JGRAPH_2:54; A6:dom SC = the carrier of TOP-REAL 2 by FUNCT_2:def 1; A7:dom (SC|Kb)=(dom SC)/\ Kb by FUNCT_1:68 .=the carrier of ((TOP-REAL 2)|Kb) by A4,A6,XBOOLE_1:28; A8:rng (SC|Kb) c= rng (SC) by FUNCT_1:76; A9:rng (SC|Kb) c= (SC|Kb).:(the carrier of ((TOP-REAL 2)|Kb)) proof let u be set;assume u in rng (SC|Kb); then consider z being set such that A10: z in dom ((SC|Kb)) & u=(SC|Kb).z by FUNCT_1:def 5; thus u in (SC|Kb).:(the carrier of ((TOP-REAL 2)|Kb)) by A7,A10,FUNCT_1:def 12; end; (SC|Kb).: (the carrier of ((TOP-REAL 2)|Kb)) = SC.:Kb by A4,RFUNCT_2:5 .= Cb by A1,Th29 .=the carrier of (TOP-REAL 2)|Cbb by JORDAN1:1; then SC|Kb is Function of the carrier of (TOP-REAL 2)|Kb, the carrier of (TOP-REAL 2)|Cbb by A7,A9,FUNCT_2:4; then reconsider f0=SC|Kb as map of (TOP-REAL 2)|Kb, (TOP-REAL 2)|Cbb ; rng (SC|Kb) c= the carrier of (TOP-REAL 2) by A8,XBOOLE_1:1; then f0 is Function of the carrier of (TOP-REAL 2)|Kb, the carrier of TOP-REAL 2 by A7,FUNCT_2:4; then reconsider f00=f0 as map of (TOP-REAL 2)|Kb,TOP-REAL 2; A11:rng f0 = (SC|Kb).: (the carrier of ((TOP-REAL 2)|Kb)) by FUNCT_2:45 .= SC.:Kb by A4,RFUNCT_2:5 .= Cb by A1,Th29; A12:f0 is one-to-one by A5,FUNCT_1:84; A13:f00 is continuous by TOPMETR:10; A14: Kb is being_simple_closed_curve by JGRAPH_3:36; then Kb is compact by Th31; then (TOP-REAL 2)|Kb is compact by COMPTS_1:12; then ex f1 being map of (TOP-REAL 2)|Kb,(TOP-REAL 2)|Cbb st f00=f1 & f1 is_homeomorphism by A11,A12,A13,JGRAPH_1:64; hence thesis by A14,Th30; end; definition let a,b,r be real number; assume A1: r>0; func circle(a,b,r) -> compact non empty Subset of TOP-REAL 2 equals:Def6: {p where p is Point of TOP-REAL 2: |.p- |[a,b]| .|=r}; coherence proof defpred P[Point of TOP-REAL 2] means |.$1- |[a,b]| .|=r; {p where p is Point of TOP-REAL 2:P[p]} c= the carrier of TOP-REAL 2 from Fr_Set0; then reconsider Cb={p where p is Point of TOP-REAL 2: |.p- |[a,b]| .|=r} as Subset of TOP-REAL 2; A2:(|[r,0]|)`1=r & (|[r,0]|)`2=0 by EUCLID:56; |.(|[r+a,b]| - |[a,b]|).|=|.(|[r+a,0+b]| - |[a,b]|).| .=|.(|[r,0]|+|[a,b]|- |[a,b]|).| by EUCLID:60 .= |.(|[r,0]|+(|[a,b]|- |[a,b]|)).| by EUCLID:49 .=|.|[r,0]|+(0.REAL 2).| by EUCLID:46 .=|.|[r,0]|.| by EUCLID:31 .=sqrt(r^2+0^2) by A2,JGRAPH_3:10 .=r by A1,SQUARE_1:60,89; then A3: |[r+a,b]| in Cb; Cb is_simple_closed_curve by A1,Th32; hence thesis by A3,Th31; end; end; definition let a,b,r be real number; func inside_of_circle(a,b,r) -> Subset of TOP-REAL 2 equals :Def7: {p where p is Point of TOP-REAL 2: |.p- |[a,b]| .|<r}; coherence proof defpred P[Point of TOP-REAL 2] means |.$1- |[a,b]| .|<r; {p where p is Point of TOP-REAL 2: P[p]} c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; definition let a,b,r be real number; func closed_inside_of_circle(a,b,r) -> Subset of TOP-REAL 2 equals :Def8: {p where p is Point of TOP-REAL 2: |.p- |[a,b]| .|<=r}; coherence proof defpred P[Point of TOP-REAL 2] means |.$1- |[a,b]| .|<=r; {p where p is Point of TOP-REAL 2: P[p]} c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; definition let a,b,r be real number; func outside_of_circle(a,b,r) -> Subset of TOP-REAL 2 equals :Def9: {p where p is Point of TOP-REAL 2: |.p- |[a,b]| .|>r}; coherence proof defpred P[Point of TOP-REAL 2] means |.$1- |[a,b]| .|>r; {p where p is Point of TOP-REAL 2: P[p]} c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; definition let a,b,r be real number; func closed_outside_of_circle(a,b,r) -> Subset of TOP-REAL 2 equals :Def10: {p where p is Point of TOP-REAL 2: |.p- |[a,b]| .|>=r}; coherence proof defpred P[Point of TOP-REAL 2] means |.$1- |[a,b]| .|>=r; {p where p is Point of TOP-REAL 2: P[p]} c= the carrier of TOP-REAL 2 from Fr_Set0; hence thesis; end; end; theorem Th33: for r being real number holds inside_of_circle(0,0,r)={p : |.p.|<r} & (r>0 implies circle(0,0,r)={p2 : |.p2.|=r}) & outside_of_circle(0,0,r)={p3 : |.p3.|>r} & closed_inside_of_circle(0,0,r)={q : |.q.|<=r} & closed_outside_of_circle(0,0,r)={q2 : |.q2.|>=r} proof let r be real number; defpred P[Point of TOP-REAL 2] means |.$1- |[0,0]| .|<r; defpred Q[Point of TOP-REAL 2] means |.$1.|<r; deffunc F(set)=$1; A1: for p holds P[p] iff Q[p] by EUCLID:58,JORDAN2C:13; inside_of_circle(0,0,r) = {F(p) where p is Point of TOP-REAL 2: P[p]} by Def7 .= {F(p2) where p2 is Point of TOP-REAL 2: Q[p2]} from Fraenkel6'(A1); hence inside_of_circle(0,0,r)={p : |.p.|<r}; defpred P[Point of TOP-REAL 2] means |.$1- |[0,0]| .|=r; defpred Q[Point of TOP-REAL 2] means |.$1.|=r; A2: for p holds P[p] iff Q[p] by EUCLID:58,JORDAN2C:13; hereby assume r>0; then circle(0,0,r)= {F(p): P[p]} by Def6 .= {F(p2) where p2 is Point of TOP-REAL 2: Q[p2]} from Fraenkel6'(A2); hence circle(0,0,r)={p2 : |.p2.|=r}; end; defpred P[Point of TOP-REAL 2] means |.$1- |[0,0]| .|>r; defpred Q[Point of TOP-REAL 2] means |.$1.|>r; A3: for p holds P[p] iff Q[p] by EUCLID:58,JORDAN2C:13; outside_of_circle(0,0,r)= {F(p): P[p]} by Def9 .= {F(p2) where p2 is Point of TOP-REAL 2: Q[p2]} from Fraenkel6'(A3); hence outside_of_circle(0,0,r)={p3 : |.p3.|>r}; defpred P[Point of TOP-REAL 2] means |.$1- |[0,0]| .|<=r; defpred Q[Point of TOP-REAL 2] means |.$1.|<=r; A4: for p holds P[p] iff Q[p] by EUCLID:58,JORDAN2C:13; closed_inside_of_circle(0,0,r)= {F(p): P[p]} by Def8 .= {F(p2) where p2 is Point of TOP-REAL 2: Q[p2]} from Fraenkel6'(A4); hence closed_inside_of_circle(0,0,r)={p : |.p.|<=r}; defpred P[Point of TOP-REAL 2] means |.$1- |[0,0]| .|>=r; defpred Q[Point of TOP-REAL 2] means |.$1.|>=r; A5: for p holds P[p] iff Q[p] by EUCLID:58,JORDAN2C:13; closed_outside_of_circle(0,0,r)= {F(p): P[p]} by Def10 .= {F(p2) where p2 is Point of TOP-REAL 2: Q[p2]} from Fraenkel6'(A5); hence closed_outside_of_circle(0,0,r)={p3 : |.p3.|>=r}; end; theorem Th34: for Kb,Cb being Subset of TOP-REAL 2 st Kb={p: -1 <p`1 & p`1< 1 & -1 <p`2 & p`2< 1}& Cb={p2 where p2 is Point of TOP-REAL 2: |.p2.|<1} holds Sq_Circ.:Kb=Cb proof let Kb,Cb be Subset of TOP-REAL 2; assume A1:Kb={p: -1 <p`1 & p`1< 1 & -1 <p`2 & p`2< 1}& Cb={p2 where p2 is Point of TOP-REAL 2: |.p2.|<1}; thus Sq_Circ.:Kb c= Cb proof let y be set;assume y in Sq_Circ.:Kb; then consider x being set such that A2: x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by FUNCT_1:def 12; consider q being Point of TOP-REAL 2 such that A3:q=x & -1 <q`1 & q`1< 1 & -1 <q`2 & q`2< 1 by A1,A2; now per cases; case A4: q=0.REAL 2; then A5: Sq_Circ.q=q by JGRAPH_3:def 1; |.q.|=0 by A4,TOPRNS_1:24; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|<1 by A2,A3,A5; case A6:q<>0.REAL 2 & (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then A7:Sq_Circ.q=|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]| by JGRAPH_3:def 1; A8: (|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|)`1 = q`1/sqrt(1+(q`2/q`1)^2) & (|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|)`2 = q`2/sqrt(1+(q`2/q`1)^2) by EUCLID:56; 0<=(q`2/q`1)^2 by SQUARE_1:72; then A9:1+(q`2/q`1)^2>0 by Th3; A10: now assume A11: q`1=0; then q`2=0 by A6; hence contradiction by A6,A11,EUCLID:57,58; end; then A12: (q`1)^2>0 by SQUARE_1:74; A13: (q`1)^2+(q`2)^2<>0 by A10,COMPLEX1:2; (q`1)^2<1^2 by A3,JGRAPH_2:8; then A14: sqrt((q`1)^2)<1 by A12,SQUARE_1:59,83,95; A15: |.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).|^2 =((q`1)/sqrt(1+(q`2/(q`1))^2))^2+(q`2/sqrt(1+(q`2/(q`1))^2))^2 by A8,JGRAPH_3:10 .=(q`1)^2/(sqrt(1+(q`2/(q`1))^2))^2+(q`2/sqrt(1+(q`2/(q`1))^2))^2 by SQUARE_1:69 .=(q`1)^2/(sqrt(1+(q`2/(q`1))^2))^2 +(q`2)^2/(sqrt(1+(q`2/(q`1))^2))^2 by SQUARE_1:69 .=(q`1)^2/(1+(q`2/q`1)^2)+(q`2)^2/(sqrt(1+(q`2/q`1)^2))^2 by A9,SQUARE_1:def 4 .=(q`1)^2/(1+(q`2/q`1)^2)+(q`2)^2/(1+(q`2/q`1)^2) by A9,SQUARE_1:def 4 .=((q`1)^2+(q`2)^2)/(1+(q`2/q`1)^2) by XCMPLX_1:63 .=((q`1)^2+(q`2)^2)/(1+(q`2)^2/(q`1)^2) by SQUARE_1:69 .=((q`1)^2+(q`2)^2)/((q`1)^2/(q`1)^2+(q`2)^2/(q`1)^2) by A12,XCMPLX_1:60 .=((q`1)^2+(q`2)^2)/(((q`1)^2+(q`2)^2)/(q`1)^2) by XCMPLX_1:63 .=(q`1)^2*(((q`1)^2+(q`2)^2)/((q`1)^2+(q`2)^2)) by XCMPLX_1:82 .=(q`1)^2*1 by A13,XCMPLX_1:60 .=(q`1)^2; 0<=|.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).| by TOPRNS_1:26; then |.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).|<1 by A14,A15,SQUARE_1:89; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|<1 by A2,A3,A7; case A16:q<>0.REAL 2 & not(q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then A17:Sq_Circ.q=|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]| by JGRAPH_3:def 1; A18: (|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|)`1 = q`1/sqrt(1+(q`1/q`2)^2) & (|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|)`2 = q`2/sqrt(1+(q`1/q`2)^2) by EUCLID:56; 0<=(q`1/q`2)^2 by SQUARE_1:72; then A19:1+(q`1/q`2)^2>0 by Th3; A20: q`2 <> 0 by A16,REAL_1:66; then A21: (q`2)^2>0 by SQUARE_1:74; A22: (q`1)^2+(q`2)^2 <>0 by A20,COMPLEX1:2; (q`2)^2<1^2 by A3,JGRAPH_2:8; then A23: sqrt((q`2)^2)<1 by A21,SQUARE_1:59,83,95; A24: |.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).|^2 =((q`1)/sqrt(1+(q`1/(q`2))^2))^2+(q`2/sqrt(1+(q`1/(q`2))^2))^2 by A18,JGRAPH_3:10 .=(q`1)^2/(sqrt(1+(q`1/(q`2))^2))^2+(q`2/sqrt(1+(q`1/(q`2))^2))^2 by SQUARE_1:69 .=(q`1)^2/(sqrt(1+(q`1/(q`2))^2))^2 +(q`2)^2/(sqrt(1+(q`1/(q`2))^2))^2 by SQUARE_1:69 .=(q`1)^2/(1+(q`1/q`2)^2)+(q`2)^2/(sqrt(1+(q`1/q`2)^2))^2 by A19,SQUARE_1:def 4 .=(q`1)^2/(1+(q`1/q`2)^2)+(q`2)^2/(1+(q`1/q`2)^2) by A19,SQUARE_1:def 4 .=((q`1)^2+(q`2)^2)/(1+(q`1/q`2)^2) by XCMPLX_1:63 .=((q`1)^2+(q`2)^2)/(1+(q`1)^2/(q`2)^2) by SQUARE_1:69 .=((q`1)^2+(q`2)^2)/((q`1)^2/(q`2)^2+(q`2)^2/(q`2)^2) by A21,XCMPLX_1:60 .=((q`1)^2+(q`2)^2)/(((q`1)^2+(q`2)^2)/(q`2)^2) by XCMPLX_1:63 .=(q`2)^2*(((q`1)^2+(q`2)^2)/((q`1)^2+(q`2)^2)) by XCMPLX_1:82 .=(q`2)^2*1 by A22,XCMPLX_1:60 .=(q`2)^2; 0<=|.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).| by TOPRNS_1:26; then |.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).|<1 by A23,A24,SQUARE_1:89; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|<1 by A2,A3,A17; end; hence y in Cb by A1; end; let y be set;assume y in Cb; then consider p2 being Point of TOP-REAL 2 such that A25: p2=y & |.p2.|<1 by A1; set q=p2; now per cases; case A26: q=0.REAL 2; then q`1=0 & q`2=0 by EUCLID:56,58; then A27: y in Kb by A1,A25; A28: Sq_Circ".y=y by A25,A26,JGRAPH_3:38; A29: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; y=Sq_Circ.y by A25,A28,FUNCT_1:57,JGRAPH_3:54; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A27,A29; case A30:q<>0.REAL 2 & (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); set px=|[q`1*sqrt(1+(q`2/q`1)^2),q`2*sqrt(1+(q`2/q`1)^2)]|; A31: px`1 = q`1*sqrt(1+(q`2/q`1)^2) & px`2 = q`2*sqrt(1+(q`2/q`1)^2) by EUCLID:56; 0<=(q`2/q`1)^2 by SQUARE_1:72; then 1+(q`2/q`1)^2>0 by Th3; then A32:sqrt(1+(q`2/q`1)^2)>0 by SQUARE_1:93; 0<=(px`2/px`1)^2 by SQUARE_1:72; then A33:1+(px`2/px`1)^2>0 by Th3; A34:px`2/px`1=q`2/q`1 by A31,A32,XCMPLX_1:92; A35: q`1=q`1*sqrt(1+(q`2/q`1)^2)/(sqrt(1+(q`2/q`1)^2))by A32,XCMPLX_1: 90 .=px`1/(sqrt(1+(q`2/q`1)^2)) by EUCLID:56; A36: q`2=q`2*sqrt(1+(q`2/q`1)^2)/(sqrt(1+(q`2/q`1)^2))by A32,XCMPLX_1: 90 .=px`2/(sqrt(1+(q`2/q`1)^2)) by EUCLID:56; A37: |.q.|^2=q`1^2+q`2^2 by JGRAPH_3:10; |.q.| >=0 by TOPRNS_1:26; then A38: |.q.|^2<1 by A25,SQUARE_1:59,78; A39:now assume px`1=0 & px`2=0; then A40:q`1*sqrt(1+(q`2/q`1)^2)=0 & q`2*sqrt(1+(q`2/q`1)^2)=0 by EUCLID:56; then A41:q`1=0 by A32,XCMPLX_1:6; q`2=0 by A32,A40,XCMPLX_1:6; hence contradiction by A30,A41,EUCLID:57,58; end; q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2*sqrt(1+(q`2/q`1)^2) <= (-q`1)*sqrt(1+(q`2/q`1)^2) by A30,A32,AXIOMS:25; then q`2<=q`1 & (-q`1)*sqrt(1+(q`2/q`1)^2) <= q`2*sqrt(1+(q`2/q`1)^2) or px`2>=px`1 & px`2<=-px`1 by A31,A32,AXIOMS:25,XCMPLX_1:175; then A42:px`2<=px`1 & -px`1<=px`2 or px`2>=px`1 & px`2<=-px`1 by A31,A32,AXIOMS:25,XCMPLX_1:175; then A43:Sq_Circ.px=|[px`1/sqrt(1+(px`2/px`1)^2),px`2/sqrt(1+(px`2/px`1)^2) ]| by A39,JGRAPH_2:11,JGRAPH_3:def 1; px`2<=px`1 & --px`1>=-px`2 or px`2>=px`1 & px`2<=-px`1 by A42,REAL_1:50; then A44:px`2<=px`1 & px`1>=-px`2 or px`2>=px`1 & -px`2>=--px`1 by REAL_1:50; A45:px`1/sqrt(1+(px`2/px`1)^2)=q`1 by A31,A32,A34,XCMPLX_1:90; px`2/sqrt(1+(px`2/px`1)^2)=q`2 by A31,A32,A34,XCMPLX_1:90; then A46:q=Sq_Circ.px by A43,A45,EUCLID:57; A47: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; not px`1=0 by A39,A42; then A48: (px`1)^2>0 by SQUARE_1:74; A49: (px`2)^2>=0 by SQUARE_1:72; (px`1)^2/(sqrt(1+(px`2/px`1)^2))^2+(px`2/sqrt(1+(px`2/px`1)^2))^2<1 by A34,A35,A36,A37,A38,SQUARE_1:69; then (px`1)^2/(sqrt(1+(px`2/px`1)^2))^2+(px`2)^2/(sqrt(1+(px`2/px`1)^2)) ^2<1 by SQUARE_1:69; then (px`1)^2/(1+(px`2/px`1)^2)+(px`2)^2/(sqrt(1+(px`2/px`1)^2))^2<1 by A33,SQUARE_1:def 4; then (px`1)^2/(1+(px`2/px`1)^2)+(px`2)^2/(1+(px`2/px`1)^2)<1 by A33,SQUARE_1:def 4; then ((px`1)^2/(1+(px`2/px`1)^2) +(px`2)^2/(1+(px`2/px`1)^2))*(1+(px`2/px`1)^2)<1 *(1+(px`2/px`1)^2) by A33,REAL_1:70; then (px`1)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2) +(px`2)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2)<1 *(1+(px`2/px`1)^2) by XCMPLX_1:8; then (px`1)^2+(px`2)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2)<1 *(1+(px`2/px `1)^2) by A33,XCMPLX_1:88; then A50: (px`1)^2+(px`2)^2<1 *(1+(px`2/px`1)^2) by A33,XCMPLX_1:88; 1 *(1+(px`2/px`1)^2) =1+(px`2)^2/(px`1)^2 by SQUARE_1:69; then (px`1)^2+(px`2)^2-1<1+(px`2)^2/(px`1)^2-1 by A50,REAL_1:54; then (px`1)^2+(px`2)^2-1<(px`2)^2/(px`1)^2 by XCMPLX_1:26; then ((px`1)^2+(px`2)^2-1)*(px`1)^2<((px`2)^2/(px`1)^2)*(px`1)^2 by A48,REAL_1:70; then ((px`1)^2+(px`2)^2-1)*(px`1)^2<(px`2)^2 by A48,XCMPLX_1:88; then ((px`1)^2+((px`2)^2-1))*(px`1)^2<(px`2)^2 by XCMPLX_1:29; then (px`1)^2*(px`1)^2+((px`2)^2-1)*(px`1)^2<(px`2)^2 by XCMPLX_1:8; then (px`1)^2*(px`1)^2+(px`1)^2*((px`2)^2-1)-(px`2)^2<0 by REAL_2:105; then A51: 0>(px`1)^2*(px`1)^2+((px`1)^2*(px`2)^2-(px`1)^2*1)-(px`2)^2 by XCMPLX_1:40; (px`1)^2*(px`1)^2+((px`1)^2*(px`2)^2-(px`1)^2*1)-(px`2)^2 = (px`1)^2*(px`1)^2+(px`1)^2*(px`2)^2-(px`1)^2*1-(px`2)^2 by XCMPLX_1:29 .= (px`1)^2*(px`1)^2-(px`1)^2*1+(px`1)^2*(px`2)^2-1 *(px`2)^2 by XCMPLX_1:29 .= (px`1)^2*((px`1)^2-1)+(px`1)^2*(px`2)^2-1 *(px`2)^2 by XCMPLX_1:40 .= (px`1)^2*((px`1)^2-1)+((px`1)^2*(px`2)^2-1 *(px`2)^2) by XCMPLX_1: 29 .= (px`1)^2*((px`1)^2-1)+((px`1)^2-1)*(px`2)^2 by XCMPLX_1:40 .= ((px`1)^2-1)*((px`1)^2+(px`2)^2) by XCMPLX_1:8; then ((px`1)^2-1<0 or ((px`1)^2+(px`2)^2)<0) &((px`1)^2-1>0 or (px`1)^2+(px`2)^2>0) by A51,REAL_2:121; then (px`1)^2-1+1<0+1 & ((px`1)^2+(px`2)^2)>0 by A48,A49,Th3,REAL_1:53 ; then (px`1)^2<1 by XCMPLX_1:27; then A52:px`1<1 & px`1>-1 by JGRAPH_2:6,SQUARE_1:59; then px`2<1 & 1>-px`2 or px`2>=px`1 & -px`2>=px`1 by A44,AXIOMS:22; then px`2<1 & -1< --px`2 or px`2>-1 & -px`2> -1 by A52,AXIOMS:22,REAL_1:50; then px`2<1 & -1<px`2 or px`2>-1 & --px`2< --1 by REAL_1:50; then px in Kb by A1,A52; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A25,A46,A47; case A53:q<>0.REAL 2 & not(q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); set px=|[q`1*sqrt(1+(q`1/q`2)^2),q`2*sqrt(1+(q`1/q`2)^2)]|; A54:q<>0.REAL 2 & (q`1<=q`2 & -q`2<=q`1 or q`1>=q`2 & q`1<=-q`2) by A53,JGRAPH_2:23; A55: px`2 = q`2*sqrt(1+(q`1/q`2)^2) & px`1 = q`1*sqrt(1+(q`1/q`2)^2) by EUCLID:56; 0<=(q`1/q`2)^2 by SQUARE_1:72; then 1+(q`1/q`2)^2>0 by Th3; then A56:sqrt(1+(q`1/q`2)^2)>0 by SQUARE_1:93; 0<=(px`1/px`2)^2 by SQUARE_1:72; then A57:1+(px`1/px`2)^2>0 by Th3; A58:px`1/px`2=q`1/q`2 by A55,A56,XCMPLX_1:92; A59: q`2=q`2*sqrt(1+(q`1/q`2)^2)/(sqrt(1+(q`1/q`2)^2))by A56,XCMPLX_1: 90 .=px`2/(sqrt(1+(q`1/q`2)^2)) by EUCLID:56; A60: q`1=q`1*sqrt(1+(q`1/q`2)^2)/(sqrt(1+(q`1/q`2)^2))by A56,XCMPLX_1: 90 .=px`1/(sqrt(1+(q`1/q`2)^2)) by EUCLID:56; A61: |.q.|^2=q`2^2+q`1^2 by JGRAPH_3:10; |.q.| >=0 by TOPRNS_1:26; then A62: |.q.|^2<1 by A25,SQUARE_1:59,78; A63:now assume px`2=0 & px`1=0; then A64:q`2*sqrt(1+(q`1/q`2)^2)=0 & q`1*sqrt(1+(q`1/q`2)^2)=0 by EUCLID:56; then q`1=0 by A56,XCMPLX_1:6; hence contradiction by A53,A56,A64,XCMPLX_1:6; end; q`1<=q`2 & -q`2<=q`1 or q`1>=q`2 & q`1*sqrt(1+(q`1/q`2)^2) <= (-q`2)*sqrt(1+(q`1/q`2)^2) by A54,A56,AXIOMS:25; then q`1<=q`2 & (-q`2)*sqrt(1+(q`1/q`2)^2) <= q`1*sqrt(1+(q`1/q`2)^2) or px`1>=px`2 & px`1<=-px`2 by A55,A56,AXIOMS:25,XCMPLX_1:175; then A65:px`1<=px`2 & -px`2<=px`1 or px`1>=px`2 & px`1<=-px`2 by A55,A56,AXIOMS:25,XCMPLX_1:175; then A66:Sq_Circ.px=|[px`1/sqrt(1+(px`1/px`2)^2),px`2/sqrt(1+(px`1/px`2)^2) ]| by A63,JGRAPH_2:11,JGRAPH_3:14; px`1<=px`2 & --px`2>=-px`1 or px`1>=px`2 & px`1<=-px`2 by A65,REAL_1:50; then A67:px`1<=px`2 & px`2>=-px`1 or px`1>=px`2 & -px`1>=--px`2 by REAL_1:50; A68:px`2/sqrt(1+(px`1/px`2)^2)=q`2 by A55,A56,A58,XCMPLX_1:90; px`1/sqrt(1+(px`1/px`2)^2)=q`1 by A55,A56,A58,XCMPLX_1:90; then A69:q=Sq_Circ.px by A66,A68,EUCLID:57; A70: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; not px`2=0 by A63,A65; then A71: (px`2)^2>0 by SQUARE_1:74; A72: (px`1)^2>=0 by SQUARE_1:72; (px`2)^2/(sqrt(1+(px`1/px`2)^2))^2+(px`1/sqrt(1+(px`1/px`2)^2))^2<1 by A58,A59,A60,A61,A62,SQUARE_1:69; then (px`2)^2/(sqrt(1+(px`1/px`2)^2))^2+(px`1)^2/(sqrt(1+(px`1/px`2)^2)) ^2<1 by SQUARE_1:69; then (px`2)^2/(1+(px`1/px`2)^2)+(px`1)^2/(sqrt(1+(px`1/px`2)^2))^2<1 by A57,SQUARE_1:def 4; then (px`2)^2/(1+(px`1/px`2)^2)+(px`1)^2/(1+(px`1/px`2)^2)<1 by A57,SQUARE_1:def 4; then ((px`2)^2/(1+(px`1/px`2)^2) +(px`1)^2/(1+(px`1/px`2)^2))*(1+(px`1/px`2)^2)<1 *(1+(px`1/px`2)^2) by A57,REAL_1:70; then (px`2)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2) +(px`1)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2)<1 *(1+(px`1/px`2)^2) by XCMPLX_1:8; then (px`2)^2+(px`1)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2)<1 *(1+(px`1/px `2)^2) by A57,XCMPLX_1:88; then A73: (px`2)^2+(px`1)^2<1 *(1+(px`1/px`2)^2) by A57,XCMPLX_1:88; 1 *(1+(px`1/px`2)^2) =1+(px`1)^2/(px`2)^2 by SQUARE_1:69; then (px`2)^2+(px`1)^2-1<1+(px`1)^2/(px`2)^2-1 by A73,REAL_1:54; then (px`2)^2+(px`1)^2-1<(px`1)^2/(px`2)^2 by XCMPLX_1:26; then ((px`2)^2+(px`1)^2-1)*(px`2)^2<((px`1)^2/(px`2)^2)*(px`2)^2 by A71,REAL_1:70; then ((px`2)^2+(px`1)^2-1)*(px`2)^2<(px`1)^2 by A71,XCMPLX_1:88; then ((px`2)^2+((px`1)^2-1))*(px`2)^2<(px`1)^2 by XCMPLX_1:29; then (px`2)^2*(px`2)^2+((px`1)^2-1)*(px`2)^2<(px`1)^2 by XCMPLX_1:8; then (px`2)^2*(px`2)^2+(px`2)^2*((px`1)^2-1)-(px`1)^2<0 by REAL_2:105; then A74: 0>(px`2)^2*(px`2)^2+((px`2)^2*(px`1)^2-(px`2)^2*1)-(px`1)^2 by XCMPLX_1:40; (px`2)^2*(px`2)^2+((px`2)^2*(px`1)^2-(px`2)^2*1)-(px`1)^2 = (px`2)^2*(px`2)^2+(px`2)^2*(px`1)^2-(px`2)^2*1-(px`1)^2 by XCMPLX_1:29 .= (px`2)^2*(px`2)^2-(px`2)^2*1+(px`2)^2*(px`1)^2-1 *(px`1)^2 by XCMPLX_1:29 .= (px`2)^2*((px`2)^2-1)+(px`2)^2*(px`1)^2-1 *(px`1)^2 by XCMPLX_1:40 .= (px`2)^2*((px`2)^2-1)+((px`2)^2*(px`1)^2-1 *(px`1)^2) by XCMPLX_1: 29 .= (px`2)^2*((px`2)^2-1)+((px`2)^2-1)*(px`1)^2 by XCMPLX_1:40 .= ((px`2)^2-1)*((px`2)^2+(px`1)^2) by XCMPLX_1:8; then ((px`2)^2-1<0 or ((px`2)^2+(px`1)^2)<0) &((px`2)^2-1>0 or (px`2)^2+(px`1)^2>0) by A74,REAL_2:121; then (px`2)^2-1+1<0+1 & ((px`2)^2+(px`1)^2)>0 by A71,A72,Th3,REAL_1:53 ; then (px`2)^2<1 by XCMPLX_1:27; then A75:px`2<1 & px`2>-1 by JGRAPH_2:6,SQUARE_1:59; then px`1<1 & 1>-px`1 or px`1>=px`2 & -px`1>=px`2 by A67,AXIOMS:22; then px`1<1 & -1< --px`1 or px`1>-1 & -px`1> -1 by A75,AXIOMS:22,REAL_1:50; then px`1<1 & -1<px`1 or px`1>-1 & --px`1< --1 by REAL_1:50; then px in Kb by A1,A75; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A25,A69,A70; end; hence thesis by FUNCT_1:def 12; end; theorem Th35: for Kb,Cb being Subset of TOP-REAL 2 st Kb={p: not(-1 <=p`1 & p`1<= 1 & -1 <=p`2 & p`2<= 1)}& Cb={p2 where p2 is Point of TOP-REAL 2: |.p2.|>1} holds Sq_Circ.:Kb=Cb proof let Kb,Cb be Subset of TOP-REAL 2; assume A1:Kb={p: not(-1 <=p`1 & p`1<= 1 & -1 <=p`2 & p`2<= 1)}& Cb={p2 where p2 is Point of TOP-REAL 2: |.p2.|>1}; thus Sq_Circ.:Kb c= Cb proof let y be set;assume y in Sq_Circ.:Kb; then consider x being set such that A2: x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by FUNCT_1:def 12; consider q being Point of TOP-REAL 2 such that A3:q=x &( not(-1 <=q`1 & q`1<= 1 & -1 <=q`2 & q`2<= 1) ) by A1,A2; now per cases; case q=0.REAL 2; then q`1=0 & q`2=0 by EUCLID:56,58; hence contradiction by A3; case A4:q<>0.REAL 2 & (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then A5:Sq_Circ.q=|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]| by JGRAPH_3:def 1; A6: not(-1 <=q`2 & q`2<= 1) implies -1>q`1 or q`1>1 proof assume A7: not(-1 <=q`2 & q`2<= 1); now per cases by A7; case A8: -1>q`2; then -q`1< -1 or q`2>=q`1 & q`2<= -q`1 by A4,AXIOMS:22; hence -1>q`1 or q`1>1 by A8,AXIOMS:22,REAL_1:50; case q`2>1; then 1<q`1 or 1< -q`1 by A4,AXIOMS:22; then 1<q`1 or --q`1< -1 by REAL_1:50; hence -1>q`1 or q`1>1; end; hence -1>q`1 or q`1>1; end; A9: (|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|)`1 = q`1/sqrt(1+(q`2/q`1)^2) & (|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|)`2 = q`2/sqrt(1+(q`2/q`1)^2) by EUCLID:56; 0<=(q`2/q`1)^2 by SQUARE_1:72; then A10:1+(q`2/q`1)^2>0 by Th3; A11: now assume A12: q`1=0; then q`2=0 by A4; hence contradiction by A4,A12,EUCLID:57,58; end; then A13: (q`1)^2>0 by SQUARE_1:74; A14: (q`1)^2+(q`2)^2 <>0 by A11,COMPLEX1:2; (q`1)^2>1^2 by A3,A6,JGRAPH_2:5; then A15: sqrt((q`1)^2)>1 by SQUARE_1:59,83,95; A16: |.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).|^2 =((q`1)/sqrt(1+(q`2/(q`1))^2))^2+(q`2/sqrt(1+(q`2/(q`1))^2))^2 by A9,JGRAPH_3:10 .=(q`1)^2/(sqrt(1+(q`2/(q`1))^2))^2+(q`2/sqrt(1+(q`2/(q`1))^2))^2 by SQUARE_1:69 .=(q`1)^2/(sqrt(1+(q`2/(q`1))^2))^2 +(q`2)^2/(sqrt(1+(q`2/(q`1))^2))^2 by SQUARE_1:69 .=(q`1)^2/(1+(q`2/q`1)^2)+(q`2)^2/(sqrt(1+(q`2/q`1)^2))^2 by A10,SQUARE_1:def 4 .=(q`1)^2/(1+(q`2/q`1)^2)+(q`2)^2/(1+(q`2/q`1)^2) by A10,SQUARE_1:def 4 .=((q`1)^2+(q`2)^2)/(1+(q`2/q`1)^2) by XCMPLX_1:63 .=((q`1)^2+(q`2)^2)/(1+(q`2)^2/(q`1)^2) by SQUARE_1:69 .=((q`1)^2+(q`2)^2)/((q`1)^2/(q`1)^2+(q`2)^2/(q`1)^2) by A13,XCMPLX_1:60 .=((q`1)^2+(q`2)^2)/(((q`1)^2+(q`2)^2)/(q`1)^2) by XCMPLX_1:63 .=(q`1)^2*(((q`1)^2+(q`2)^2)/((q`1)^2+(q`2)^2)) by XCMPLX_1:82 .=(q`1)^2*1 by A14,XCMPLX_1:60 .=(q`1)^2; 0<=|.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).| by TOPRNS_1:26; then |.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).|>1 by A15,A16,SQUARE_1:89; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|>1 by A2,A3,A5; case A17:q<>0.REAL 2 & not(q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then A18:Sq_Circ.q=|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]| by JGRAPH_3:def 1; A19: (|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|)`1 = q`1/sqrt(1+(q`1/q`2)^2) & (|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|)`2 = q`2/sqrt(1+(q`1/q`2)^2) by EUCLID:56; 0<=(q`1/q`2)^2 by SQUARE_1:72; then A20:1+(q`1/q`2)^2>0 by Th3; A21: q`2 <> 0 by A17,REAL_1:66; then A22: (q`2)^2>0 by SQUARE_1:74; A23: (q`1)^2+(q`2)^2 <>0 by A21,COMPLEX1:2; not(-1 <=q`1 & q`1<= 1) implies -1>q`2 or q`2>1 proof assume A24: not(-1 <=q`1 & q`1<= 1); now per cases by A24; case A25: -1>q`1; then q`2< -1 or q`1<q`2 & -q`2< --q`1 by A17,AXIOMS:22,REAL_1:50; then -q`2< -1 or -1>q`2 by A25,AXIOMS:22; hence -1>q`2 or q`2>1 by REAL_1:50; case A26: q`1>1; --q`1< -q`2 & q`2<q`1 or q`2>q`1 & q`2> -q`1 by A17,REAL_1:50; then 1< -q`2 or q`2>q`1 & q`2> -q`1 by A26,AXIOMS:22; then -1> --q`2 or 1<q`2 by A26,AXIOMS:22,REAL_1:50; hence -1>q`2 or q`2>1; end; hence -1>q`2 or q`2>1; end; then (q`2)^2>1^2 by A3,JGRAPH_2:5; then A27: sqrt((q`2)^2)>1 by SQUARE_1:59,83,95; A28: |.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).|^2 =((q`1)/sqrt(1+(q`1/(q`2))^2))^2+(q`2/sqrt(1+(q`1/(q`2))^2))^2 by A19,JGRAPH_3:10 .=(q`1)^2/(sqrt(1+(q`1/(q`2))^2))^2+(q`2/sqrt(1+(q`1/(q`2))^2))^2 by SQUARE_1:69 .=(q`1)^2/(sqrt(1+(q`1/(q`2))^2))^2 +(q`2)^2/(sqrt(1+(q`1/(q`2))^2))^2 by SQUARE_1:69 .=(q`1)^2/(1+(q`1/q`2)^2)+(q`2)^2/(sqrt(1+(q`1/q`2)^2))^2 by A20,SQUARE_1:def 4 .=(q`1)^2/(1+(q`1/q`2)^2)+(q`2)^2/(1+(q`1/q`2)^2) by A20,SQUARE_1:def 4 .=((q`1)^2+(q`2)^2)/(1+(q`1/q`2)^2) by XCMPLX_1:63 .=((q`1)^2+(q`2)^2)/(1+(q`1)^2/(q`2)^2) by SQUARE_1:69 .=((q`1)^2+(q`2)^2)/((q`1)^2/(q`2)^2+(q`2)^2/(q`2)^2) by A22,XCMPLX_1:60 .=((q`1)^2+(q`2)^2)/(((q`1)^2+(q`2)^2)/(q`2)^2) by XCMPLX_1:63 .=(q`2)^2*(((q`1)^2+(q`2)^2)/((q`1)^2+(q`2)^2)) by XCMPLX_1:82 .=(q`2)^2*1 by A23,XCMPLX_1:60 .=(q`2)^2; 0<=|.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).| by TOPRNS_1:26; then |.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).|>1 by A27,A28,SQUARE_1:89; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|>1 by A2,A3,A18; end; hence y in Cb by A1; end; let y be set;assume y in Cb; then consider p2 being Point of TOP-REAL 2 such that A29: p2=y & |.p2.|>1 by A1; set q=p2; now per cases; case q=0.REAL 2; then |.q.|=0 by TOPRNS_1:24; hence contradiction by A29; case A30:q<>0.REAL 2 & (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); set px=|[q`1*sqrt(1+(q`2/q`1)^2),q`2*sqrt(1+(q`2/q`1)^2)]|; A31: px`1 = q`1*sqrt(1+(q`2/q`1)^2) & px`2 = q`2*sqrt(1+(q`2/q`1)^2) by EUCLID:56; 0<=(q`2/q`1)^2 by SQUARE_1:72; then 1+(q`2/q`1)^2>0 by Th3; then A32:sqrt(1+(q`2/q`1)^2)>0 by SQUARE_1:93; 0<=(px`2/px`1)^2 by SQUARE_1:72; then A33:1+(px`2/px`1)^2>0 by Th3; A34:px`2/px`1=q`2/q`1 by A31,A32,XCMPLX_1:92; A35: q`1=q`1*sqrt(1+(q`2/q`1)^2)/(sqrt(1+(q`2/q`1)^2))by A32,XCMPLX_1: 90 .=px`1/(sqrt(1+(q`2/q`1)^2)) by EUCLID:56; A36: q`2=q`2*sqrt(1+(q`2/q`1)^2)/(sqrt(1+(q`2/q`1)^2))by A32,XCMPLX_1: 90 .=px`2/(sqrt(1+(q`2/q`1)^2)) by EUCLID:56; A37: |.q.|^2=q`1^2+q`2^2 by JGRAPH_3:10; A38: |.q.|^2>1 by A29,SQUARE_1:59,78; A39:now assume px`1=0 & px`2=0; then A40:q`1*sqrt(1+(q`2/q`1)^2)=0 & q`2*sqrt(1+(q`2/q`1)^2)=0 by EUCLID:56; then A41:q`1=0 by A32,XCMPLX_1:6; q`2=0 by A32,A40,XCMPLX_1:6; hence contradiction by A30,A41,EUCLID:57,58; end; q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2*sqrt(1+(q`2/q`1)^2) <= (-q`1)*sqrt(1+(q`2/q`1)^2) by A30,A32,AXIOMS:25; then q`2<=q`1 & (-q`1)*sqrt(1+(q`2/q`1)^2) <= q`2*sqrt(1+(q`2/q`1)^2) or px`2>=px`1 & px`2<=-px`1 by A31,A32,AXIOMS:25,XCMPLX_1:175; then A42:px`2<=px`1 & -px`1<=px`2 or px`2>=px`1 & px`2<=-px`1 by A31,A32,AXIOMS:25,XCMPLX_1:175; then A43:Sq_Circ.px=|[px`1/sqrt(1+(px`2/px`1)^2),px`2/sqrt(1+(px`2/px`1)^2) ]| by A39,JGRAPH_2:11,JGRAPH_3:def 1; A44:px`1/sqrt(1+(px`2/px`1)^2)=q`1 by A31,A32,A34,XCMPLX_1:90; px`2/sqrt(1+(px`2/px`1)^2)=q`2 by A31,A32,A34,XCMPLX_1:90; then A45:q=Sq_Circ.px by A43,A44,EUCLID:57; A46: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; not px`1=0 by A39,A42; then A47: (px`1)^2>0 by SQUARE_1:74; A48: (px`2)^2>=0 by SQUARE_1:72; (px`1)^2/(sqrt(1+(px`2/px`1)^2))^2+(px`2/sqrt(1+(px`2/px`1)^2))^2>1 by A34,A35,A36,A37,A38,SQUARE_1:69; then (px`1)^2/(sqrt(1+(px`2/px`1)^2))^2+(px`2)^2/(sqrt(1+(px`2/px`1)^2)) ^2>1 by SQUARE_1:69; then (px`1)^2/(1+(px`2/px`1)^2)+(px`2)^2/(sqrt(1+(px`2/px`1)^2))^2>1 by A33,SQUARE_1:def 4; then (px`1)^2/(1+(px`2/px`1)^2)+(px`2)^2/(1+(px`2/px`1)^2)>1 by A33,SQUARE_1:def 4; then ((px`1)^2/(1+(px`2/px`1)^2) +(px`2)^2/(1+(px`2/px`1)^2))*(1+(px`2/px`1)^2)>1 *(1+(px`2/px`1)^2) by A33,REAL_1:70; then (px`1)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2) +(px`2)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2)>1 *(1+(px`2/px`1)^2) by XCMPLX_1:8; then (px`1)^2+(px`2)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2)>1 *(1+(px`2/px `1)^2) by A33,XCMPLX_1:88; then A49: (px`1)^2+(px`2)^2>1 *(1+(px`2/px`1)^2) by A33,XCMPLX_1:88; 1 *(1+(px`2/px`1)^2) =1+(px`2)^2/(px`1)^2 by SQUARE_1:69; then (px`1)^2+(px`2)^2-1>1+(px`2)^2/(px`1)^2-1 by A49,REAL_1:54; then (px`1)^2+(px`2)^2-1>(px`2)^2/(px`1)^2 by XCMPLX_1:26; then ((px`1)^2+(px`2)^2-1)*(px`1)^2>((px`2)^2/(px`1)^2)*(px`1)^2 by A47,REAL_1:70; then ((px`1)^2+(px`2)^2-1)*(px`1)^2>(px`2)^2 by A47,XCMPLX_1:88; then ((px`1)^2+((px`2)^2-1))*(px`1)^2>(px`2)^2 by XCMPLX_1:29; then (px`1)^2*(px`1)^2+((px`2)^2-1)*(px`1)^2>(px`2)^2 by XCMPLX_1:8; then (px`1)^2*(px`1)^2+(px`1)^2*((px`2)^2-1)-(px`2)^2>0 by SQUARE_1:11; then A50: 0<(px`1)^2*(px`1)^2+((px`1)^2*(px`2)^2-(px`1)^2*1)-(px`2)^2 by XCMPLX_1:40; (px`1)^2*(px`1)^2+((px`1)^2*(px`2)^2-(px`1)^2*1)-(px`2)^2 = (px`1)^2*(px`1)^2+(px`1)^2*(px`2)^2-(px`1)^2*1-(px`2)^2 by XCMPLX_1:29 .= (px`1)^2*(px`1)^2-(px`1)^2*1+(px`1)^2*(px`2)^2-1 *(px`2)^2 by XCMPLX_1:29 .= (px`1)^2*((px`1)^2-1)+(px`1)^2*(px`2)^2-1 *(px`2)^2 by XCMPLX_1:40 .= (px`1)^2*((px`1)^2-1)+((px`1)^2*(px`2)^2-1 *(px`2)^2) by XCMPLX_1: 29 .= (px`1)^2*((px`1)^2-1)+((px`1)^2-1)*(px`2)^2 by XCMPLX_1:40 .= ((px`1)^2-1)*((px`1)^2+(px`2)^2) by XCMPLX_1:8; then ( (px`1)^2-1<0 or (px`1)^2+(px`2)^2>0)& ((px`1)^2-1>0 or (px`1)^2+(px`2)^2<0) by A50,REAL_2:123; then (px`1)^2-1+1>0+1 & ((px`1)^2+(px`2)^2)>0 by A47,A48,Th3,REAL_1:53 ; then (px`1)^2>1 by XCMPLX_1:27; then px`1>1 or px`1< -1 by JGRAPH_2:7,SQUARE_1:59; then px in Kb by A1; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A29,A45,A46; case A51:q<>0.REAL 2 & not(q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); set px=|[q`1*sqrt(1+(q`1/q`2)^2),q`2*sqrt(1+(q`1/q`2)^2)]|; A52:q<>0.REAL 2 & (q`1<=q`2 & -q`2<=q`1 or q`1>=q`2 & q`1<=-q`2) by A51,JGRAPH_2:23; A53: px`2 = q`2*sqrt(1+(q`1/q`2)^2) & px`1 = q`1*sqrt(1+(q`1/q`2)^2) by EUCLID:56; 0<=(q`1/q`2)^2 by SQUARE_1:72; then 1+(q`1/q`2)^2>0 by Th3; then A54:sqrt(1+(q`1/q`2)^2)>0 by SQUARE_1:93; 0<=(px`1/px`2)^2 by SQUARE_1:72; then A55:1+(px`1/px`2)^2>0 by Th3; A56:px`1/px`2=q`1/q`2 by A53,A54,XCMPLX_1:92; A57: q`2=q`2*sqrt(1+(q`1/q`2)^2)/(sqrt(1+(q`1/q`2)^2))by A54,XCMPLX_1: 90 .=px`2/(sqrt(1+(q`1/q`2)^2)) by EUCLID:56; A58: q`1=q`1*sqrt(1+(q`1/q`2)^2)/(sqrt(1+(q`1/q`2)^2))by A54,XCMPLX_1: 90 .=px`1/(sqrt(1+(q`1/q`2)^2)) by EUCLID:56; A59: |.q.|^2=q`2^2+q`1^2 by JGRAPH_3:10; A60: |.q.|^2>1 by A29,SQUARE_1:59,78; A61:now assume px`2=0 & px`1=0; then A62:q`2*sqrt(1+(q`1/q`2)^2)=0 & q`1*sqrt(1+(q`1/q`2)^2)=0 by EUCLID:56; then q`1=0 by A54,XCMPLX_1:6; hence contradiction by A51,A54,A62,XCMPLX_1:6; end; q`1<=q`2 & -q`2<=q`1 or q`1>=q`2 & q`1*sqrt(1+(q`1/q`2)^2) <= (-q`2)*sqrt(1+(q`1/q`2)^2) by A52,A54,AXIOMS:25; then q`1<=q`2 & (-q`2)*sqrt(1+(q`1/q`2)^2) <= q`1*sqrt(1+(q`1/q`2)^2) or px`1>=px`2 & px`1<=-px`2 by A53,A54,AXIOMS:25,XCMPLX_1:175; then A63:px`1<=px`2 & -px`2<=px`1 or px`1>=px`2 & px`1<=-px`2 by A53,A54,AXIOMS:25,XCMPLX_1:175; then A64:Sq_Circ.px=|[px`1/sqrt(1+(px`1/px`2)^2),px`2/sqrt(1+(px`1/px`2)^2) ]| by A61,JGRAPH_2:11,JGRAPH_3:14; A65:px`2/sqrt(1+(px`1/px`2)^2)=q`2 by A53,A54,A56,XCMPLX_1:90; px`1/sqrt(1+(px`1/px`2)^2)=q`1 by A53,A54,A56,XCMPLX_1:90; then A66:q=Sq_Circ.px by A64,A65,EUCLID:57; A67: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; not px`2=0 by A61,A63; then A68: (px`2)^2>0 by SQUARE_1:74; A69: (px`1)^2>=0 by SQUARE_1:72; (px`2)^2/(sqrt(1+(px`1/px`2)^2))^2+(px`1/sqrt(1+(px`1/px`2)^2))^2>1 by A56,A57,A58,A59,A60,SQUARE_1:69; then (px`2)^2/(sqrt(1+(px`1/px`2)^2))^2+(px`1)^2/(sqrt(1+(px`1/px`2)^2)) ^2>1 by SQUARE_1:69; then (px`2)^2/(1+(px`1/px`2)^2)+(px`1)^2/(sqrt(1+(px`1/px`2)^2))^2>1 by A55,SQUARE_1:def 4; then (px`2)^2/(1+(px`1/px`2)^2)+(px`1)^2/(1+(px`1/px`2)^2)>1 by A55,SQUARE_1:def 4; then ((px`2)^2/(1+(px`1/px`2)^2) +(px`1)^2/(1+(px`1/px`2)^2))*(1+(px`1/px`2)^2)>1 *(1+(px`1/px`2)^2) by A55,REAL_1:70; then (px`2)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2) +(px`1)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2)>1 *(1+(px`1/px`2)^2) by XCMPLX_1:8; then (px`2)^2+(px`1)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2)>1 *(1+(px`1/px `2)^2) by A55,XCMPLX_1:88; then A70: (px`2)^2+(px`1)^2>1 *(1+(px`1/px`2)^2) by A55,XCMPLX_1:88; 1 *(1+(px`1/px`2)^2) =1+(px`1)^2/(px`2)^2 by SQUARE_1:69; then (px`2)^2+(px`1)^2-1>1+(px`1)^2/(px`2)^2-1 by A70,REAL_1:54; then (px`2)^2+(px`1)^2-1>(px`1)^2/(px`2)^2 by XCMPLX_1:26; then ((px`2)^2+(px`1)^2-1)*(px`2)^2>((px`1)^2/(px`2)^2)*(px`2)^2 by A68,REAL_1:70; then ((px`2)^2+(px`1)^2-1)*(px`2)^2>(px`1)^2 by A68,XCMPLX_1:88; then ((px`2)^2+((px`1)^2-1))*(px`2)^2>(px`1)^2 by XCMPLX_1:29; then (px`2)^2*(px`2)^2+((px`1)^2-1)*(px`2)^2>(px`1)^2 by XCMPLX_1:8; then (px`2)^2*(px`2)^2+(px`2)^2*((px`1)^2-1)-(px`1)^2>0 by SQUARE_1:11; then A71: 0<(px`2)^2*(px`2)^2+((px`2)^2*(px`1)^2-(px`2)^2*1)-(px`1)^2 by XCMPLX_1:40; (px`2)^2*(px`2)^2+((px`2)^2*(px`1)^2-(px`2)^2*1)-(px`1)^2 = (px`2)^2*(px`2)^2+(px`2)^2*(px`1)^2-(px`2)^2*1-(px`1)^2 by XCMPLX_1:29 .= (px`2)^2*(px`2)^2-(px`2)^2*1+(px`2)^2*(px`1)^2-1 *(px`1)^2 by XCMPLX_1:29 .= (px`2)^2*((px`2)^2-1)+(px`2)^2*(px`1)^2-1 *(px`1)^2 by XCMPLX_1:40 .= (px`2)^2*((px`2)^2-1)+((px`2)^2*(px`1)^2-1 *(px`1)^2) by XCMPLX_1: 29 .= (px`2)^2*((px`2)^2-1)+((px`2)^2-1)*(px`1)^2 by XCMPLX_1:40 .= ((px`2)^2-1)*((px`2)^2+(px`1)^2) by XCMPLX_1:8; then ( (px`2)^2-1<0 or (px`1)^2+(px`2)^2>0)& ((px`2)^2-1>0 or (px`1)^2+(px`2)^2<0) by A71,REAL_2:123; then (px`2)^2-1+1>0+1 & ((px`1)^2+(px`2)^2)>0 by A68,A69,Th3,REAL_1:53 ; then (px`2)^2>1 by XCMPLX_1:27; then px`2>1 or px`2< -1 by JGRAPH_2:7,SQUARE_1:59; then px in Kb by A1; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A29,A66,A67; end; hence thesis by FUNCT_1:def 12; end; theorem Th36: for Kb,Cb being Subset of TOP-REAL 2 st Kb={p: -1 <=p`1 & p`1<= 1 & -1 <=p`2 & p`2<= 1}& Cb={p2 where p2 is Point of TOP-REAL 2: |.p2.|<=1} holds Sq_Circ.:Kb=Cb proof let Kb,Cb be Subset of TOP-REAL 2; assume A1:Kb={p: -1 <=p`1 & p`1<= 1 & -1 <=p`2 & p`2<= 1}& Cb={p2 where p2 is Point of TOP-REAL 2: |.p2.|<=1}; thus Sq_Circ.:Kb c= Cb proof let y be set;assume y in Sq_Circ.:Kb; then consider x being set such that A2: x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by FUNCT_1:def 12; consider q being Point of TOP-REAL 2 such that A3:q=x &( -1 <=q`1 & q`1<= 1 & -1 <=q`2 & q`2<= 1 ) by A1,A2; now per cases; case A4: q=0.REAL 2; then A5: Sq_Circ.q=q by JGRAPH_3:def 1; |.q.|=0 by A4,TOPRNS_1:24; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|<=1 by A2,A3,A5; case A6:q<>0.REAL 2 & (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then A7:Sq_Circ.q=|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]| by JGRAPH_3:def 1; A8: (|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|)`1 = q`1/sqrt(1+(q`2/q`1)^2) & (|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|)`2 = q`2/sqrt(1+(q`2/q`1)^2) by EUCLID:56; 0<=(q`2/q`1)^2 by SQUARE_1:72; then A9:1+(q`2/q`1)^2>0 by Th3; A10: now assume A11: q`1=0; then q`2=0 by A6; hence contradiction by A6,A11,EUCLID:57,58; end; then A12: (q`1)^2>0 by SQUARE_1:74; A13: (q`1)^2+(q`2)^2 <>0 by A10,COMPLEX1:2; (q`1)^2<=1^2 by A3,JGRAPH_2:7; then A14: sqrt((q`1)^2)<=1 by A12,SQUARE_1:59,83,94; A15: |.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).|^2 =((q`1)/sqrt(1+(q`2/(q`1))^2))^2+(q`2/sqrt(1+(q`2/(q`1))^2))^2 by A8,JGRAPH_3:10 .=(q`1)^2/(sqrt(1+(q`2/(q`1))^2))^2+(q`2/sqrt(1+(q`2/(q`1))^2))^2 by SQUARE_1:69 .=(q`1)^2/(sqrt(1+(q`2/(q`1))^2))^2 +(q`2)^2/(sqrt(1+(q`2/(q`1))^2))^2 by SQUARE_1:69 .=(q`1)^2/(1+(q`2/q`1)^2)+(q`2)^2/(sqrt(1+(q`2/q`1)^2))^2 by A9,SQUARE_1:def 4 .=(q`1)^2/(1+(q`2/q`1)^2)+(q`2)^2/(1+(q`2/q`1)^2) by A9,SQUARE_1:def 4 .=((q`1)^2+(q`2)^2)/(1+(q`2/q`1)^2) by XCMPLX_1:63 .=((q`1)^2+(q`2)^2)/(1+(q`2)^2/(q`1)^2) by SQUARE_1:69 .=((q`1)^2+(q`2)^2)/((q`1)^2/(q`1)^2+(q`2)^2/(q`1)^2) by A12,XCMPLX_1:60 .=((q`1)^2+(q`2)^2)/(((q`1)^2+(q`2)^2)/(q`1)^2) by XCMPLX_1:63 .=(q`1)^2*(((q`1)^2+(q`2)^2)/((q`1)^2+(q`2)^2)) by XCMPLX_1:82 .=(q`1)^2*1 by A13,XCMPLX_1:60 .=(q`1)^2; 0<=|.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).| by TOPRNS_1:26; then |.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).|<=1 by A14,A15,SQUARE_1:89; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|<=1 by A2,A3,A7; case A16:q<>0.REAL 2 & not(q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then A17:Sq_Circ.q=|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]| by JGRAPH_3:def 1; A18: (|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|)`1 = q`1/sqrt(1+(q`1/q`2)^2) & (|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|)`2 = q`2/sqrt(1+(q`1/q`2)^2) by EUCLID:56; 0<=(q`1/q`2)^2 by SQUARE_1:72; then A19:1+(q`1/q`2)^2>0 by Th3; A20: q`2 <>0 by A16,REAL_1:66; then A21: (q`2)^2>0 by SQUARE_1:74; A22: (q`1)^2+(q`2)^2 <>0 by A20,COMPLEX1:2; (q`2)^2<=1 by A3,JGRAPH_2:7,SQUARE_1:59; then A23: sqrt((q`2)^2)<=1 by A21,SQUARE_1:83,94; A24: |.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).|^2 =((q`1)/sqrt(1+(q`1/(q`2))^2))^2+(q`2/sqrt(1+(q`1/(q`2))^2))^2 by A18,JGRAPH_3:10 .=(q`1)^2/(sqrt(1+(q`1/(q`2))^2))^2+(q`2/sqrt(1+(q`1/(q`2))^2))^2 by SQUARE_1:69 .=(q`1)^2/(sqrt(1+(q`1/(q`2))^2))^2 +(q`2)^2/(sqrt(1+(q`1/(q`2))^2))^2 by SQUARE_1:69 .=(q`1)^2/(1+(q`1/q`2)^2)+(q`2)^2/(sqrt(1+(q`1/q`2)^2))^2 by A19,SQUARE_1:def 4 .=(q`1)^2/(1+(q`1/q`2)^2)+(q`2)^2/(1+(q`1/q`2)^2) by A19,SQUARE_1:def 4 .=((q`1)^2+(q`2)^2)/(1+(q`1/q`2)^2) by XCMPLX_1:63 .=((q`1)^2+(q`2)^2)/(1+(q`1)^2/(q`2)^2) by SQUARE_1:69 .=((q`1)^2+(q`2)^2)/((q`1)^2/(q`2)^2+(q`2)^2/(q`2)^2) by A21,XCMPLX_1:60 .=((q`1)^2+(q`2)^2)/(((q`1)^2+(q`2)^2)/(q`2)^2) by XCMPLX_1:63 .=(q`2)^2*(((q`1)^2+(q`2)^2)/((q`1)^2+(q`2)^2)) by XCMPLX_1:82 .=(q`2)^2*1 by A22,XCMPLX_1:60 .=(q`2)^2; 0<=|.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).| by TOPRNS_1:26; then |.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).|<=1 by A23,A24,SQUARE_1:89; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|<=1 by A2,A3,A17; end; hence y in Cb by A1; end; let y be set;assume y in Cb; then consider p2 being Point of TOP-REAL 2 such that A25: p2=y & |.p2.|<=1 by A1; set q=p2; now per cases; case A26: q=0.REAL 2; then q`1=0 & q`2=0 by EUCLID:56,58; then A27: y in Kb by A1,A25; A28: Sq_Circ".y=y by A25,A26,JGRAPH_3:38; A29: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; y=Sq_Circ.y by A25,A28,FUNCT_1:57,JGRAPH_3:54; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A27,A29; case A30:q<>0.REAL 2 & (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); set px=|[q`1*sqrt(1+(q`2/q`1)^2),q`2*sqrt(1+(q`2/q`1)^2)]|; A31: px`1 = q`1*sqrt(1+(q`2/q`1)^2) & px`2 = q`2*sqrt(1+(q`2/q`1)^2) by EUCLID:56; 0<=(q`2/q`1)^2 by SQUARE_1:72; then 1+(q`2/q`1)^2>0 by Th3; then A32:sqrt(1+(q`2/q`1)^2)>0 by SQUARE_1:93; 0<=(px`2/px`1)^2 by SQUARE_1:72; then A33:1+(px`2/px`1)^2>0 by Th3; A34:px`2/px`1=q`2/q`1 by A31,A32,XCMPLX_1:92; A35: q`1=q`1*sqrt(1+(q`2/q`1)^2)/(sqrt(1+(q`2/q`1)^2))by A32,XCMPLX_1: 90 .=px`1/(sqrt(1+(q`2/q`1)^2)) by EUCLID:56; A36: q`2=q`2*sqrt(1+(q`2/q`1)^2)/(sqrt(1+(q`2/q`1)^2))by A32,XCMPLX_1: 90 .=px`2/(sqrt(1+(q`2/q`1)^2)) by EUCLID:56; A37: |.q.|^2=q`1^2+q`2^2 by JGRAPH_3:10; |.q.| >=0 by TOPRNS_1:26; then A38: |.q.|^2<=1 by A25,SQUARE_1:59,77; A39:now assume px`1=0 & px`2=0; then A40:q`1*sqrt(1+(q`2/q`1)^2)=0 & q`2*sqrt(1+(q`2/q`1)^2)=0 by EUCLID:56; then A41:q`1=0 by A32,XCMPLX_1:6; q`2=0 by A32,A40,XCMPLX_1:6; hence contradiction by A30,A41,EUCLID:57,58; end; q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2*sqrt(1+(q`2/q`1)^2) <= (-q`1)*sqrt(1+(q`2/q`1)^2) by A30,A32,AXIOMS:25; then q`2<=q`1 & (-q`1)*sqrt(1+(q`2/q`1)^2) <= q`2*sqrt(1+(q`2/q`1)^2) or px`2>=px`1 & px`2<=-px`1 by A31,A32,AXIOMS:25,XCMPLX_1:175; then A42:px`2<=px`1 & -px`1<=px`2 or px`2>=px`1 & px`2<=-px`1 by A31,A32,AXIOMS:25,XCMPLX_1:175; then A43:Sq_Circ.px=|[px`1/sqrt(1+(px`2/px`1)^2),px`2/sqrt(1+(px`2/px`1)^2) ]| by A39,JGRAPH_2:11,JGRAPH_3:def 1; px`2<=px`1 & --px`1>=-px`2 or px`2>=px`1 & px`2<=-px`1 by A42,REAL_1:50; then A44:px`2<=px`1 & px`1>=-px`2 or px`2>=px`1 & -px`2>=--px`1 by REAL_1:50; A45:px`1/sqrt(1+(px`2/px`1)^2)=q`1 by A31,A32,A34,XCMPLX_1:90; px`2/sqrt(1+(px`2/px`1)^2)=q`2 by A31,A32,A34,XCMPLX_1:90; then A46:q=Sq_Circ.px by A43,A45,EUCLID:57; A47: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; not px`1=0 by A39,A42; then A48: (px`1)^2>0 by SQUARE_1:74; A49: (px`2)^2>=0 by SQUARE_1:72; (px`1)^2/(sqrt(1+(px`2/px`1)^2))^2+(px`2/sqrt(1+(px`2/px`1)^2))^2 <=1 by A34,A35,A36,A37,A38,SQUARE_1:69; then (px`1)^2/(sqrt(1+(px`2/px`1)^2))^2+(px`2)^2/(sqrt(1+(px`2/px`1)^2)) ^2<=1 by SQUARE_1:69; then (px`1)^2/(1+(px`2/px`1)^2)+(px`2)^2/(sqrt(1+(px`2/px`1)^2))^2<=1 by A33,SQUARE_1:def 4; then (px`1)^2/(1+(px`2/px`1)^2)+(px`2)^2/(1+(px`2/px`1)^2)<=1 by A33,SQUARE_1:def 4; then ((px`1)^2/(1+(px`2/px`1)^2) +(px`2)^2/(1+(px`2/px`1)^2))*(1+(px`2/px`1)^2)<=1 *(1+(px`2/px`1)^2) by A33,AXIOMS:25; then (px`1)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2) +(px`2)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2)<=1 *(1+(px`2/px`1)^2) by XCMPLX_1:8; then (px`1)^2+(px`2)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2) <=1 *(1+(px`2/px`1)^2) by A33,XCMPLX_1:88; then A50: (px`1)^2+(px`2)^2<=1 *(1+(px`2/px`1)^2) by A33,XCMPLX_1:88; 1 *(1+(px`2/px`1)^2) =1+(px`2)^2/(px`1)^2 by SQUARE_1:69; then (px`1)^2+(px`2)^2-1<=1+(px`2)^2/(px`1)^2-1 by A50,REAL_1:49; then (px`1)^2+(px`2)^2-1<=(px`2)^2/(px`1)^2 by XCMPLX_1:26; then ((px`1)^2+(px`2)^2-1)*(px`1)^2<=((px`2)^2/(px`1)^2)*(px`1)^2 by A48,AXIOMS:25; then ((px`1)^2+(px`2)^2-1)*(px`1)^2<=(px`2)^2 by A48,XCMPLX_1:88; then ((px`1)^2+((px`2)^2-1))*(px`1)^2<=(px`2)^2 by XCMPLX_1:29; then (px`1)^2*(px`1)^2+((px`2)^2-1)*(px`1)^2<=(px`2)^2 by XCMPLX_1:8; then (px`1)^2*(px`1)^2+(px`1)^2*((px`2)^2-1)-(px`2)^2<=0 by REAL_2:106; then A51: 0>=(px`1)^2*(px`1)^2+((px`1)^2*(px`2)^2-(px`1)^2*1)-(px`2)^2 by XCMPLX_1:40; (px`1)^2*(px`1)^2+((px`1)^2*(px`2)^2-(px`1)^2*1)-(px`2)^2 = (px`1)^2*(px`1)^2+(px`1)^2*(px`2)^2-(px`1)^2*1-(px`2)^2 by XCMPLX_1:29 .= (px`1)^2*(px`1)^2-(px`1)^2*1+(px`1)^2*(px`2)^2-1 *(px`2)^2 by XCMPLX_1:29 .= (px`1)^2*((px`1)^2-1)+(px`1)^2*(px`2)^2-1 *(px`2)^2 by XCMPLX_1:40 .= (px`1)^2*((px`1)^2-1)+((px`1)^2*(px`2)^2-1 *(px`2)^2) by XCMPLX_1: 29 .= (px`1)^2*((px`1)^2-1)+((px`1)^2-1)*(px`2)^2 by XCMPLX_1:40 .= ((px`1)^2-1)*((px`1)^2+(px`2)^2) by XCMPLX_1:8; then (px`1)^2-1<=0 & (px`1)^2-1>=0 or (px`1)^2-1<=0 & (px`1)^2+(px`2)^2>=0 or (px`1)^2+(px`2)^2<=0 & (px`1)^2-1>=0 or (px`1)^2+(px`2)^2<=0 & (px`1)^2+(px`2)^2>=0 by A51,REAL_2:122; then (px`1)^2-1+1<=0+1 & ((px`1)^2+(px`2)^2)>=0 by A48,A49,Th3,REAL_1: 55; then (px`1)^2<=1 by XCMPLX_1:27; then A52:px`1<=1 & px`1>= -1 by JGRAPH_2:5,SQUARE_1:59; then px`2<=1 & 1>= -px`2 or px`2>= -1 & -px`2>=px`1 by A44,AXIOMS:22; then px`2<=1 & -1<= --px`2 or px`2>= -1 & -px`2>= -1 by A52,AXIOMS:22,REAL_1:50; then px`2<=1 & -1<=px`2 or px`2>= -1 & --px`2<= --1 by REAL_1:50; then px in Kb by A1,A52; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A25,A46,A47; case A53:q<>0.REAL 2 & not(q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); set px=|[q`1*sqrt(1+(q`1/q`2)^2),q`2*sqrt(1+(q`1/q`2)^2)]|; A54:q<>0.REAL 2 & (q`1<=q`2 & -q`2<=q`1 or q`1>=q`2 & q`1<=-q`2) by A53,JGRAPH_2:23; A55: px`2 = q`2*sqrt(1+(q`1/q`2)^2) & px`1 = q`1*sqrt(1+(q`1/q`2)^2) by EUCLID:56; 0<=(q`1/q`2)^2 by SQUARE_1:72; then 1+(q`1/q`2)^2>0 by Th3; then A56:sqrt(1+(q`1/q`2)^2)>0 by SQUARE_1:93; 0<=(px`1/px`2)^2 by SQUARE_1:72; then A57:1+(px`1/px`2)^2>0 by Th3; A58:px`1/px`2=q`1/q`2 by A55,A56,XCMPLX_1:92; A59: q`2=q`2*sqrt(1+(q`1/q`2)^2)/(sqrt(1+(q`1/q`2)^2))by A56,XCMPLX_1: 90 .=px`2/(sqrt(1+(q`1/q`2)^2)) by EUCLID:56; A60: q`1=q`1*sqrt(1+(q`1/q`2)^2)/(sqrt(1+(q`1/q`2)^2))by A56,XCMPLX_1: 90 .=px`1/(sqrt(1+(q`1/q`2)^2)) by EUCLID:56; A61: |.q.|^2=q`2^2+q`1^2 by JGRAPH_3:10; |.q.| >=0 by TOPRNS_1:26; then A62: |.q.|^2<=1 by A25,SQUARE_1:59,77; A63:now assume px`2=0 & px`1=0; then A64:q`2*sqrt(1+(q`1/q`2)^2)=0 & q`1*sqrt(1+(q`1/q`2)^2)=0 by EUCLID:56; then q`1=0 by A56,XCMPLX_1:6; hence contradiction by A53,A56,A64,XCMPLX_1:6; end; q`1<=q`2 & -q`2<=q`1 or q`1>=q`2 & q`1*sqrt(1+(q`1/q`2)^2) <= (-q`2)*sqrt(1+(q`1/q`2)^2) by A54,A56,AXIOMS:25; then q`1<=q`2 & (-q`2)*sqrt(1+(q`1/q`2)^2) <= q`1*sqrt(1+(q`1/q`2)^2) or px`1>=px`2 & px`1<=-px`2 by A55,A56,AXIOMS:25,XCMPLX_1:175; then A65:px`1<=px`2 & -px`2<=px`1 or px`1>=px`2 & px`1<=-px`2 by A55,A56,AXIOMS:25,XCMPLX_1:175; then A66:Sq_Circ.px=|[px`1/sqrt(1+(px`1/px`2)^2),px`2/sqrt(1+(px`1/px`2)^2) ]| by A63,JGRAPH_2:11,JGRAPH_3:14; px`1<=px`2 & --px`2>=-px`1 or px`1>=px`2 & px`1<=-px`2 by A65,REAL_1:50; then A67:px`1<=px`2 & px`2>=-px`1 or px`1>=px`2 & -px`1>=--px`2 by REAL_1:50; A68:px`2/sqrt(1+(px`1/px`2)^2)=q`2 by A55,A56,A58,XCMPLX_1:90; px`1/sqrt(1+(px`1/px`2)^2)=q`1 by A55,A56,A58,XCMPLX_1:90; then A69:q=Sq_Circ.px by A66,A68,EUCLID:57; A70: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; not px`2=0 by A63,A65; then A71: (px`2)^2>0 by SQUARE_1:74; A72: (px`1)^2>=0 by SQUARE_1:72; (px`2)^2/(sqrt(1+(px`1/px`2)^2))^2+(px`1/sqrt(1+(px`1/px`2)^2))^2<=1 by A58,A59,A60,A61,A62,SQUARE_1:69; then (px`2)^2/(sqrt(1+(px`1/px`2)^2))^2+(px`1)^2/(sqrt(1+(px`1/px`2)^2)) ^2<=1 by SQUARE_1:69; then (px`2)^2/(1+(px`1/px`2)^2)+(px`1)^2/(sqrt(1+(px`1/px`2)^2))^2<=1 by A57,SQUARE_1:def 4; then (px`2)^2/(1+(px`1/px`2)^2)+(px`1)^2/(1+(px`1/px`2)^2)<=1 by A57,SQUARE_1:def 4; then ((px`2)^2/(1+(px`1/px`2)^2) +(px`1)^2/(1+(px`1/px`2)^2))*(1+(px`1/px`2)^2)<=1 *(1+(px`1/px`2)^2) by A57,AXIOMS:25; then (px`2)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2) +(px`1)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2)<=1 *(1+(px`1/px`2)^2) by XCMPLX_1:8; then (px`2)^2+(px`1)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2) <=1 *(1+(px`1/px`2)^2) by A57,XCMPLX_1:88; then A73: (px`2)^2+(px`1)^2<=1 *(1+(px`1/px`2)^2) by A57,XCMPLX_1:88; 1 *(1+(px`1/px`2)^2) =1+(px`1)^2/(px`2)^2 by SQUARE_1:69; then (px`2)^2+(px`1)^2-1<=1+(px`1)^2/(px`2)^2-1 by A73,REAL_1:49; then (px`2)^2+(px`1)^2-1<=(px`1)^2/(px`2)^2 by XCMPLX_1:26; then ((px`2)^2+(px`1)^2-1)*(px`2)^2<=((px`1)^2/(px`2)^2)*(px`2)^2 by A71,AXIOMS:25; then ((px`2)^2+(px`1)^2-1)*(px`2)^2<=(px`1)^2 by A71,XCMPLX_1:88; then ((px`2)^2+((px`1)^2-1))*(px`2)^2<=(px`1)^2 by XCMPLX_1:29; then (px`2)^2*(px`2)^2+((px`1)^2-1)*(px`2)^2<=(px`1)^2 by XCMPLX_1:8; then (px`2)^2*(px`2)^2+(px`2)^2*((px`1)^2-1)-(px`1)^2<=0 by REAL_2:106; then A74: 0>=(px`2)^2*(px`2)^2+((px`2)^2*(px`1)^2-(px`2)^2*1)-(px`1)^2 by XCMPLX_1:40; (px`2)^2*(px`2)^2+((px`2)^2*(px`1)^2-(px`2)^2*1)-(px`1)^2 = (px`2)^2*(px`2)^2+(px`2)^2*(px`1)^2-(px`2)^2*1-(px`1)^2 by XCMPLX_1:29 .= (px`2)^2*(px`2)^2-(px`2)^2*1+(px`2)^2*(px`1)^2-1 *(px`1)^2 by XCMPLX_1:29 .= (px`2)^2*((px`2)^2-1)+(px`2)^2*(px`1)^2-1 *(px`1)^2 by XCMPLX_1:40 .= (px`2)^2*((px`2)^2-1)+((px`2)^2*(px`1)^2-1 *(px`1)^2) by XCMPLX_1: 29 .= (px`2)^2*((px`2)^2-1)+((px`2)^2-1)*(px`1)^2 by XCMPLX_1:40 .= ((px`2)^2-1)*((px`2)^2+(px`1)^2) by XCMPLX_1:8; then ((px`2)^2-1<=0 or ((px`2)^2+(px`1)^2)<=0) &((px`2)^2-1>=0 or (px`2)^2+(px`1)^2>=0) by A74,REAL_2:122; then (px`2)^2-1+1<=0+1 & ((px`2)^2+(px`1)^2)>=0 by A71,A72,Th3,REAL_1: 55; then (px`2)^2<=1 by XCMPLX_1:27; then A75:px`2<=1 & px`2>= -1 by JGRAPH_2:5,SQUARE_1:59; then px`1<=1 & 1>= -px`1 or px`1>= -1 & -px`1>=px`2 by A67,AXIOMS:22; then px`1<=1 & -1<= --px`1 or px`1>= -1 & -px`1>= -1 by A75,AXIOMS:22,REAL_1:50; then px`1<=1 & -1<=px`1 or px`1>= -1 & --px`1<= --1 by REAL_1:50; then px in Kb by A1,A75; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A25,A69,A70; end; hence thesis by FUNCT_1:def 12; end; theorem Th37: for Kb,Cb being Subset of TOP-REAL 2 st Kb={p: not(-1 <p`1 & p`1< 1 & -1 <p`2 & p`2< 1)}& Cb={p2 where p2 is Point of TOP-REAL 2: |.p2.|>=1} holds Sq_Circ.:Kb=Cb proof let Kb,Cb be Subset of TOP-REAL 2; assume A1: Kb={p: not(-1 <p`1 & p`1< 1 & -1 <p`2 & p`2< 1)}& Cb={p2 where p2 is Point of TOP-REAL 2: |.p2.|>=1}; thus Sq_Circ.:Kb c= Cb proof let y be set;assume y in Sq_Circ.:Kb; then consider x being set such that A2: x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by FUNCT_1:def 12; consider q being Point of TOP-REAL 2 such that A3:q=x &( not(-1 <q`1 & q`1< 1 & -1 <q`2 & q`2< 1) ) by A1,A2; now per cases; case q=0.REAL 2; then q`1=0 & q`2=0 by EUCLID:56,58; hence contradiction by A3; case A4:q<>0.REAL 2 & (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then A5:Sq_Circ.q=|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]| by JGRAPH_3:def 1; A6: not(-1 <q`2 & q`2< 1) implies -1>=q`1 or q`1>=1 proof assume A7: not(-1 <q`2 & q`2< 1); now per cases by A7; case A8: -1>=q`2; then -q`1<= -1 or q`2>=q`1 & q`2<= -q`1 by A4,AXIOMS:22; hence -1>=q`1 or q`1>=1 by A8,AXIOMS:22,REAL_1:50; case q`2>=1; then 1<=q`1 or 1<= -q`1 by A4,AXIOMS:22; then 1<=q`1 or --q`1<= -1 by REAL_1:50; hence -1>=q`1 or q`1>=1; end; hence -1>=q`1 or q`1>=1; end; A9: (|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|)`1 = q`1/sqrt(1+(q`2/q`1)^2) & (|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|)`2 = q`2/sqrt(1+(q`2/q`1)^2) by EUCLID:56; 0<=(q`2/q`1)^2 by SQUARE_1:72; then A10:1+(q`2/q`1)^2>0 by Th3; A11: now assume A12: q`1=0; then q`2=0 by A4; hence contradiction by A4,A12,EUCLID:57,58; end; then A13: (q`1)^2>0 by SQUARE_1:74; A14: (q`1)^2+(q`2)^2 <>0 by A11,COMPLEX1:2; (q`1)^2>=1^2 by A3,A6,JGRAPH_2:6; then A15: sqrt((q`1)^2)>=1 by SQUARE_1:59,83,94; A16: |.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).|^2 =((q`1)/sqrt(1+(q`2/(q`1))^2))^2+(q`2/sqrt(1+(q`2/(q`1))^2))^2 by A9,JGRAPH_3:10 .=(q`1)^2/(sqrt(1+(q`2/(q`1))^2))^2+(q`2/sqrt(1+(q`2/(q`1))^2))^2 by SQUARE_1:69 .=(q`1)^2/(sqrt(1+(q`2/(q`1))^2))^2 +(q`2)^2/(sqrt(1+(q`2/(q`1))^2))^2 by SQUARE_1:69 .=(q`1)^2/(1+(q`2/q`1)^2)+(q`2)^2/(sqrt(1+(q`2/q`1)^2))^2 by A10,SQUARE_1:def 4 .=(q`1)^2/(1+(q`2/q`1)^2)+(q`2)^2/(1+(q`2/q`1)^2) by A10,SQUARE_1:def 4 .=((q`1)^2+(q`2)^2)/(1+(q`2/q`1)^2) by XCMPLX_1:63 .=((q`1)^2+(q`2)^2)/(1+(q`2)^2/(q`1)^2) by SQUARE_1:69 .=((q`1)^2+(q`2)^2)/((q`1)^2/(q`1)^2+(q`2)^2/(q`1)^2) by A13,XCMPLX_1:60 .=((q`1)^2+(q`2)^2)/(((q`1)^2+(q`2)^2)/(q`1)^2) by XCMPLX_1:63 .=(q`1)^2*(((q`1)^2+(q`2)^2)/((q`1)^2+(q`2)^2)) by XCMPLX_1:82 .=(q`1)^2*1 by A14,XCMPLX_1:60 .=(q`1)^2; 0<=|.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).| by TOPRNS_1:26; then |.(|[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]|).|>=1 by A15,A16,SQUARE_1:89; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|>=1 by A2,A3,A5; case A17:q<>0.REAL 2 & not(q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then A18:Sq_Circ.q=|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]| by JGRAPH_3:def 1; A19: (|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|)`1 = q`1/sqrt(1+(q`1/q`2)^2) & (|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|)`2 = q`2/sqrt(1+(q`1/q`2)^2) by EUCLID:56; 0<=(q`1/q`2)^2 by SQUARE_1:72; then A20:1+(q`1/q`2)^2>0 by Th3; A21: q`2 <> 0 by A17,REAL_1:66; then A22: (q`2)^2>0 by SQUARE_1:74; A23: (q`1)^2+(q`2)^2 <>0 by A21,COMPLEX1:2; not(-1 <q`1 & q`1< 1) implies -1>=q`2 or q`2>=1 proof assume A24: not(-1 <q`1 & q`1< 1); now per cases by A24; case A25: -1>=q`1; then q`2<= -1 or q`1<q`2 & -q`2<= --q`1 by A17,AXIOMS:22,REAL_1:50; then -q`2<= -1 or -1>=q`2 by A25,AXIOMS:22; hence -1>=q`2 or q`2>=1 by REAL_1:50; case A26: q`1>=1; --q`1<= -q`2 & q`2<=q`1 or q`2>=q`1 & q`2>= -q`1 by A17,REAL_1:50; then 1<= -q`2 or q`2>=q`1 & q`2>= -q`1 by A26,AXIOMS:22; then -1>= --q`2 or 1<=q`2 by A26,AXIOMS:22,REAL_1:50; hence -1>=q`2 or q`2>=1; end; hence -1>=q`2 or q`2>=1; end; then (q`2)^2>=1^2 by A3,JGRAPH_2:6; then A27: sqrt((q`2)^2)>=1 by SQUARE_1:59,83,94; A28: |.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).|^2 =((q`1)/sqrt(1+(q`1/(q`2))^2))^2+(q`2/sqrt(1+(q`1/(q`2))^2))^2 by A19,JGRAPH_3:10 .=(q`1)^2/(sqrt(1+(q`1/(q`2))^2))^2+(q`2/sqrt(1+(q`1/(q`2))^2))^2 by SQUARE_1:69 .=(q`1)^2/(sqrt(1+(q`1/(q`2))^2))^2 +(q`2)^2/(sqrt(1+(q`1/(q`2))^2))^2 by SQUARE_1:69 .=(q`1)^2/(1+(q`1/q`2)^2)+(q`2)^2/(sqrt(1+(q`1/q`2)^2))^2 by A20,SQUARE_1:def 4 .=(q`1)^2/(1+(q`1/q`2)^2)+(q`2)^2/(1+(q`1/q`2)^2) by A20,SQUARE_1:def 4 .=((q`1)^2+(q`2)^2)/(1+(q`1/q`2)^2) by XCMPLX_1:63 .=((q`1)^2+(q`2)^2)/(1+(q`1)^2/(q`2)^2) by SQUARE_1:69 .=((q`1)^2+(q`2)^2)/((q`1)^2/(q`2)^2+(q`2)^2/(q`2)^2) by A22,XCMPLX_1:60 .=((q`1)^2+(q`2)^2)/(((q`1)^2+(q`2)^2)/(q`2)^2) by XCMPLX_1:63 .=(q`2)^2*(((q`1)^2+(q`2)^2)/((q`1)^2+(q`2)^2)) by XCMPLX_1:82 .=(q`2)^2*1 by A23,XCMPLX_1:60 .=(q`2)^2; 0<=|.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).| by TOPRNS_1:26; then |.(|[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]|).|>=1 by A27,A28,SQUARE_1:89; hence ex p2 being Point of TOP-REAL 2 st p2=y & |.p2.|>=1 by A2,A3,A18; end; hence y in Cb by A1; end; let y be set;assume y in Cb; then consider p2 being Point of TOP-REAL 2 such that A29: p2=y & |.p2.|>=1 by A1; set q=p2; now per cases; case q=0.REAL 2; then |.q.|=0 by TOPRNS_1:24; hence contradiction by A29; case A30:q<>0.REAL 2 & (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); set px=|[q`1*sqrt(1+(q`2/q`1)^2),q`2*sqrt(1+(q`2/q`1)^2)]|; A31: px`1 = q`1*sqrt(1+(q`2/q`1)^2) & px`2 = q`2*sqrt(1+(q`2/q`1)^2) by EUCLID:56; 0<=(q`2/q`1)^2 by SQUARE_1:72; then 1+(q`2/q`1)^2>0 by Th3; then A32:sqrt(1+(q`2/q`1)^2)>0 by SQUARE_1:93; 0<=(px`2/px`1)^2 by SQUARE_1:72; then A33:1+(px`2/px`1)^2>0 by Th3; A34:px`2/px`1=q`2/q`1 by A31,A32,XCMPLX_1:92; A35: q`1=q`1*sqrt(1+(q`2/q`1)^2)/(sqrt(1+(q`2/q`1)^2))by A32,XCMPLX_1: 90 .=px`1/(sqrt(1+(q`2/q`1)^2)) by EUCLID:56; A36: q`2=q`2*sqrt(1+(q`2/q`1)^2)/(sqrt(1+(q`2/q`1)^2))by A32,XCMPLX_1: 90 .=px`2/(sqrt(1+(q`2/q`1)^2)) by EUCLID:56; A37: |.q.|^2=q`1^2+q`2^2 by JGRAPH_3:10; A38: |.q.|^2>=1 by A29,SQUARE_1:59,77; A39:now assume px`1=0 & px`2=0; then A40:q`1*sqrt(1+(q`2/q`1)^2)=0 & q`2*sqrt(1+(q`2/q`1)^2)=0 by EUCLID:56; then A41:q`1=0 by A32,XCMPLX_1:6; q`2=0 by A32,A40,XCMPLX_1:6; hence contradiction by A30,A41,EUCLID:57,58; end; q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2*sqrt(1+(q`2/q`1)^2) <= (-q`1)*sqrt(1+(q`2/q`1)^2) by A30,A32,AXIOMS:25; then q`2<=q`1 & (-q`1)*sqrt(1+(q`2/q`1)^2) <= q`2*sqrt(1+(q`2/q`1)^2) or px`2>=px`1 & px`2<=-px`1 by A31,A32,AXIOMS:25,XCMPLX_1:175; then A42:px`2<=px`1 & -px`1<=px`2 or px`2>=px`1 & px`2<=-px`1 by A31,A32,AXIOMS:25,XCMPLX_1:175; then A43:Sq_Circ.px=|[px`1/sqrt(1+(px`2/px`1)^2),px`2/sqrt(1+(px`2/px`1)^2) ]| by A39,JGRAPH_2:11,JGRAPH_3:def 1; A44:px`1/sqrt(1+(px`2/px`1)^2)=q`1 by A31,A32,A34,XCMPLX_1:90; px`2/sqrt(1+(px`2/px`1)^2)=q`2 by A31,A32,A34,XCMPLX_1:90; then A45:q=Sq_Circ.px by A43,A44,EUCLID:57; A46: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; not px`1=0 by A39,A42; then A47: (px`1)^2>0 by SQUARE_1:74; (px`2)^2>=0 by SQUARE_1:72; then A48: (px`1)^2+(px`2)^2>0 by A47,Th3; (px`1)^2/(sqrt(1+(px`2/px`1)^2))^2+(px`2/sqrt(1+(px`2/px`1)^2))^2>=1 by A34,A35,A36,A37,A38,SQUARE_1:69; then (px`1)^2/(sqrt(1+(px`2/px`1)^2))^2+(px`2)^2/(sqrt(1+(px`2/px`1)^2)) ^2>=1 by SQUARE_1:69; then (px`1)^2/(1+(px`2/px`1)^2)+(px`2)^2/(sqrt(1+(px`2/px`1)^2))^2>=1 by A33,SQUARE_1:def 4; then (px`1)^2/(1+(px`2/px`1)^2)+(px`2)^2/(1+(px`2/px`1)^2)>=1 by A33,SQUARE_1:def 4; then ((px`1)^2/(1+(px`2/px`1)^2) +(px`2)^2/(1+(px`2/px`1)^2))*(1+(px`2/px`1)^2)>=1 *(1+(px`2/px`1)^2) by A33,AXIOMS:25; then (px`1)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2) +(px`2)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2)>=1 *(1+(px`2/px`1)^2) by XCMPLX_1:8; then (px`1)^2+(px`2)^2/(1+(px`2/px`1)^2)*(1+(px`2/px`1)^2) >=1 *(1+(px`2/px`1)^2) by A33,XCMPLX_1:88; then A49: (px`1)^2+(px`2)^2>=1 *(1+(px`2/px`1)^2) by A33,XCMPLX_1:88; 1 *(1+(px`2/px`1)^2) =1+(px`2)^2/(px`1)^2 by SQUARE_1:69; then (px`1)^2+(px`2)^2-1>=1+(px`2)^2/(px`1)^2-1 by A49,REAL_1:49; then (px`1)^2+(px`2)^2-1>=(px`2)^2/(px`1)^2 by XCMPLX_1:26; then ((px`1)^2+(px`2)^2-1)*(px`1)^2>=((px`2)^2/(px`1)^2)*(px`1)^2 by A47,AXIOMS:25; then ((px`1)^2+(px`2)^2-1)*(px`1)^2>=(px`2)^2 by A47,XCMPLX_1:88; then ((px`1)^2+((px`2)^2-1))*(px`1)^2>=(px`2)^2 by XCMPLX_1:29; then (px`1)^2*(px`1)^2+((px`2)^2-1)*(px`1)^2>=(px`2)^2 by XCMPLX_1:8; then (px`1)^2*(px`1)^2+(px`1)^2*((px`2)^2-1)-(px`2)^2>=0 by SQUARE_1:12; then A50: 0<=(px`1)^2*(px`1)^2+((px`1)^2*(px`2)^2-(px`1)^2*1)-(px`2)^2 by XCMPLX_1:40; (px`1)^2*(px`1)^2+((px`1)^2*(px`2)^2-(px`1)^2*1)-(px`2)^2 = (px`1)^2*(px`1)^2+(px`1)^2*(px`2)^2-(px`1)^2*1-(px`2)^2 by XCMPLX_1:29 .= (px`1)^2*(px`1)^2-(px`1)^2*1+(px`1)^2*(px`2)^2-1 *(px`2)^2 by XCMPLX_1:29 .= (px`1)^2*((px`1)^2-1)+(px`1)^2*(px`2)^2-1 *(px`2)^2 by XCMPLX_1:40 .= (px`1)^2*((px`1)^2-1)+((px`1)^2*(px`2)^2-1 *(px`2)^2) by XCMPLX_1: 29 .= (px`1)^2*((px`1)^2-1)+((px`1)^2-1)*(px`2)^2 by XCMPLX_1:40 .= ((px`1)^2-1)*((px`1)^2+(px`2)^2) by XCMPLX_1:8; then (px`1)^2-1>=0 & (px`1)^2+(px`2)^2>=0 by A48,A50,SQUARE_1:25; then (px`1)^2-1+1>=0+1 & ((px`1)^2+(px`2)^2)>=0 by REAL_1:55; then (px`1)^2>=1 by XCMPLX_1:27; then px`1>=1 or px`1<= -1 by JGRAPH_2:8,SQUARE_1:59; then px in Kb by A1; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A29,A45,A46; case A51:q<>0.REAL 2 & not(q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); set px=|[q`1*sqrt(1+(q`1/q`2)^2),q`2*sqrt(1+(q`1/q`2)^2)]|; A52:q<>0.REAL 2 & (q`1<=q`2 & -q`2<=q`1 or q`1>=q`2 & q`1<=-q`2) by A51,JGRAPH_2:23; A53: px`2 = q`2*sqrt(1+(q`1/q`2)^2) & px`1 = q`1*sqrt(1+(q`1/q`2)^2) by EUCLID:56; 0<=(q`1/q`2)^2 by SQUARE_1:72; then 1+(q`1/q`2)^2>0 by Th3; then A54:sqrt(1+(q`1/q`2)^2)>0 by SQUARE_1:93; 0<=(px`1/px`2)^2 by SQUARE_1:72; then A55:1+(px`1/px`2)^2>0 by Th3; A56:px`1/px`2=q`1/q`2 by A53,A54,XCMPLX_1:92; A57: q`2=q`2*sqrt(1+(q`1/q`2)^2)/(sqrt(1+(q`1/q`2)^2))by A54,XCMPLX_1: 90 .=px`2/(sqrt(1+(q`1/q`2)^2)) by EUCLID:56; A58: q`1=q`1*sqrt(1+(q`1/q`2)^2)/(sqrt(1+(q`1/q`2)^2))by A54,XCMPLX_1: 90 .=px`1/(sqrt(1+(q`1/q`2)^2)) by EUCLID:56; A59: |.q.|^2=q`2^2+q`1^2 by JGRAPH_3:10; A60: |.q.|^2>=1 by A29,SQUARE_1:59,77; A61:now assume px`2=0 & px`1=0; then A62:q`2*sqrt(1+(q`1/q`2)^2)=0 & q`1*sqrt(1+(q`1/q`2)^2)=0 by EUCLID:56; then q`1=0 by A54,XCMPLX_1:6; hence contradiction by A51,A54,A62,XCMPLX_1:6; end; q`1<=q`2 & -q`2<=q`1 or q`1>=q`2 & q`1*sqrt(1+(q`1/q`2)^2) <= (-q`2)*sqrt(1+(q`1/q`2)^2) by A52,A54,AXIOMS:25; then q`1<=q`2 & (-q`2)*sqrt(1+(q`1/q`2)^2) <= q`1*sqrt(1+(q`1/q`2)^2) or px`1>=px`2 & px`1<=-px`2 by A53,A54,AXIOMS:25,XCMPLX_1:175; then A63:px`1<=px`2 & -px`2<=px`1 or px`1>=px`2 & px`1<=-px`2 by A53,A54,AXIOMS:25,XCMPLX_1:175; then A64:Sq_Circ.px=|[px`1/sqrt(1+(px`1/px`2)^2),px`2/sqrt(1+(px`1/px`2)^2) ]| by A61,JGRAPH_2:11,JGRAPH_3:14; A65:px`2/sqrt(1+(px`1/px`2)^2)=q`2 by A53,A54,A56,XCMPLX_1:90; px`1/sqrt(1+(px`1/px`2)^2)=q`1 by A53,A54,A56,XCMPLX_1:90; then A66:q=Sq_Circ.px by A64,A65,EUCLID:57; A67: dom Sq_Circ=the carrier of TOP-REAL 2 by FUNCT_2:def 1; not px`2=0 by A61,A63; then A68: (px`2)^2>0 by SQUARE_1:74; A69: (px`1)^2>=0 by SQUARE_1:72; (px`2)^2/(sqrt(1+(px`1/px`2)^2))^2+(px`1/sqrt(1+(px`1/px`2)^2))^2>=1 by A56,A57,A58,A59,A60,SQUARE_1:69; then (px`2)^2/(sqrt(1+(px`1/px`2)^2))^2+(px`1)^2/(sqrt(1+(px`1/px`2)^2)) ^2>=1 by SQUARE_1:69; then (px`2)^2/(1+(px`1/px`2)^2)+(px`1)^2/(sqrt(1+(px`1/px`2)^2))^2>=1 by A55,SQUARE_1:def 4; then (px`2)^2/(1+(px`1/px`2)^2)+(px`1)^2/(1+(px`1/px`2)^2)>=1 by A55,SQUARE_1:def 4; then ((px`2)^2/(1+(px`1/px`2)^2) +(px`1)^2/(1+(px`1/px`2)^2))*(1+(px`1/px`2)^2)>=1 *(1+(px`1/px`2)^2) by A55,AXIOMS:25; then (px`2)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2) +(px`1)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2)>=1 *(1+(px`1/px`2)^2) by XCMPLX_1:8; then (px`2)^2+(px`1)^2/(1+(px`1/px`2)^2)*(1+(px`1/px`2)^2) >=1 *(1+(px`1/px`2)^2) by A55,XCMPLX_1:88; then A70: (px`2)^2+(px`1)^2>=1 *(1+(px`1/px`2)^2) by A55,XCMPLX_1:88; 1 *(1+(px`1/px`2)^2) =1+(px`1)^2/(px`2)^2 by SQUARE_1:69; then (px`2)^2+(px`1)^2-1>=1+(px`1)^2/(px`2)^2-1 by A70,REAL_1:49; then (px`2)^2+(px`1)^2-1>=(px`1)^2/(px`2)^2 by XCMPLX_1:26; then ((px`2)^2+(px`1)^2-1)*(px`2)^2>=((px`1)^2/(px`2)^2)*(px`2)^2 by A68,AXIOMS:25; then ((px`2)^2+(px`1)^2-1)*(px`2)^2>=(px`1)^2 by A68,XCMPLX_1:88; then ((px`2)^2+((px`1)^2-1))*(px`2)^2>=(px`1)^2 by XCMPLX_1:29; then (px`2)^2*(px`2)^2+((px`1)^2-1)*(px`2)^2>=(px`1)^2 by XCMPLX_1:8; then (px`2)^2*(px`2)^2+(px`2)^2*((px`1)^2-1)-(px`1)^2>=0 by SQUARE_1:12; then A71: 0<=(px`2)^2*(px`2)^2+((px`2)^2*(px`1)^2-(px`2)^2*1)-(px`1)^2 by XCMPLX_1:40; (px`2)^2*(px`2)^2+((px`2)^2*(px`1)^2-(px`2)^2*1)-(px`1)^2 = (px`2)^2*(px`2)^2+(px`2)^2*(px`1)^2-(px`2)^2*1-(px`1)^2 by XCMPLX_1:29 .= (px`2)^2*(px`2)^2-(px`2)^2*1+(px`2)^2*(px`1)^2-1 *(px`1)^2 by XCMPLX_1:29 .= (px`2)^2*((px`2)^2-1)+(px`2)^2*(px`1)^2-1 *(px`1)^2 by XCMPLX_1:40 .= (px`2)^2*((px`2)^2-1)+((px`2)^2*(px`1)^2-1 *(px`1)^2) by XCMPLX_1: 29 .= (px`2)^2*((px`2)^2-1)+((px`2)^2-1)*(px`1)^2 by XCMPLX_1:40 .= ((px`2)^2-1)*((px`2)^2+(px`1)^2) by XCMPLX_1:8; then ( (px`2)^2-1>=0 & (px`1)^2+(px`2)^2>=0 or (px`2)^2-1<=0 & (px`1)^2+(px`2)^2<=0) by A71,SQUARE_1:25; then (px`2)^2-1+1>=0+1 & ((px`1)^2+(px`2)^2)>=0 by A68,A69,Th3,REAL_1: 55; then (px`2)^2>=1^2 by SQUARE_1:59,XCMPLX_1:27; then px`2>=1 or px`2<= -1 by JGRAPH_2:8; then px in Kb by A1; hence ex x being set st x in dom Sq_Circ & x in Kb & y=Sq_Circ.x by A29,A66,A67; end; hence thesis by FUNCT_1:def 12; end; theorem for P0,P1,P01,P11,K0,K1,K01,K11 being Subset of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st P= circle(0,0,1) & P0= inside_of_circle(0,0,1) & P1= outside_of_circle(0,0,1) & P01= closed_inside_of_circle(0,0,1) & P11= closed_outside_of_circle(0,0,1) & K=rectangle(-1,1,-1,1) & K0=inside_of_rectangle(-1,1,-1,1) & K1=outside_of_rectangle(-1,1,-1,1) & K01=closed_inside_of_rectangle(-1,1,-1,1) & K11=closed_outside_of_rectangle(-1,1,-1,1) & f=Sq_Circ holds f.:K=P & f".:P=K & f.:K0=P0 & f".:P0=K0 & f.:K1=P1 & f".:P1=K1 & f.:K01=P01 & f.:K11=P11 & f".:P01=K01 & f".:P11=K11 proof let P0,P1,P01,P11,K0,K1,K01,K11 be Subset of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: P= circle(0,0,1) & P0= inside_of_circle(0,0,1) & P1= outside_of_circle(0,0,1) & P01= closed_inside_of_circle(0,0,1) & P11= closed_outside_of_circle(0,0,1) & K=rectangle(-1,1,-1,1) & K0=inside_of_rectangle(-1,1,-1,1) & K1=outside_of_rectangle(-1,1,-1,1)& K01=closed_inside_of_rectangle(-1,1,-1,1) & K11=closed_outside_of_rectangle(-1,1,-1,1) & f=Sq_Circ; then A2: K0={p: -1 <p`1 & p`1< 1 & -1 <p`2 & p`2< 1} by Def2; A3: P0={p: |.p.| <1} by A1,Th33; A4: K01={p: -1 <=p`1 & p`1<= 1 & -1 <=p`2 & p`2<= 1} by A1,Def3; A5: P01={p: |.p.| <=1} by A1,Th33; A6: K1={p: not(-1 <=p`1 & p`1<= 1 & -1 <=p`2 & p`2<= 1)} by A1,Def4; A7: P1={p: |.p.| >1} by A1,Th33; A8: K11={p: not(-1 <p`1 & p`1< 1 & -1 <p`2 & p`2< 1)} by A1,Def5; A9: P11={p: |.p.| >=1} by A1,Th33; defpred P[Point of TOP-REAL 2] means $1`1=-1 & -1 <=$1`2 & $1`2<=1 or $1`2=1 & -1<=$1`1 & $1`1<=1 or $1`1=1 & -1 <=$1`2 & $1`2<=1 or $1`2=-1 & -1<=$1`1 & $1`1<=1; defpred Q[Point of TOP-REAL 2] means -1=$1`1 & -1<=$1`2 & $1`2<=1 or $1`1=1 & -1<=$1`2 & $1`2<=1 or -1=$1`2 & -1<=$1`1 & $1`1<=1 or 1=$1`2 & -1<=$1`1 & $1`1<=1; deffunc F(set)=$1; A10: for p being Element of TOP-REAL 2 holds P[p] iff Q[p]; A11: K= {F(p): P[p]} by A1,Def1 .= {F(q):Q[q]} from Fraenkel6'(A10); defpred Q[Point of TOP-REAL 2] means |.$1.|=1; defpred P[Point of TOP-REAL 2] means |.$1- |[0,0]| .|=1; A12: for p holds P[p] iff Q[p] by EUCLID:58,JORDAN2C:13; A13: P= {F(p): P[p]} by A1,Def6 .= {F(p2) where p2 is Point of TOP-REAL 2: Q[p2]} from Fraenkel6'(A12); then A14: f.:K=P by A1,A11,JGRAPH_3:33; A16: dom f=the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A17: (f qua Function)".:P=K by A1,A14,Th22; f.:K0 = P0 by A1,A2,A3,Th34; then A18: (f qua Function)".:P0=K0 by A1,A16,Th22; f.:K1 = P1 by A1,A6,A7,Th35; then (f qua Function)".:P1=K1 by A1,A16,Th22; hence f.:K=P & f".:P=K & f.:K0=P0 & f".:P0=K0 & f.:K1=P1 & f".:P1=K1 by A1,A2,A3,A6,A7,A11,A13,A17,A18,Th34,Th35, JGRAPH_3:33; f.:K01 = P01 by A1,A4,A5,Th36; then A19: (f qua Function)".:P01=K01 by A1,A16,Th22; f.:K11 = P11 by A1,A8,A9,Th37; then (f qua Function)".:P11=K11 by A1,A16,Th22; hence thesis by A1,A4,A5,A8,A9,A19,Th36,Th37; end; begin :: Order of Points on Rectangle theorem Th39: for a,b,c,d being real number st a <= b & c <= d holds LSeg(|[ a,c ]|, |[ a,d ]|) = { p1 : p1`1 = a & p1`2 <= d & p1`2 >= c} & LSeg(|[ a,d ]|, |[ b,d ]|) = { p2 : p2`1 <= b & p2`1 >= a & p2`2 = d} & LSeg(|[ a,c ]|, |[ b,c ]|) = { q1 : q1`1 <= b & q1`1 >= a & q1`2 = c} & LSeg(|[ b,c ]|, |[ b,d ]|) = { q2 : q2`1 = b & q2`2 <= d & q2`2 >= c} proof let a,b,c,d be real number;assume A1: a <= b & c <= d; set L1 = { p : p`1 = a & p`2 <= d & p`2 >= c}, L2 = { p : p`1 <= b & p`1 >= a & p`2 = d}, L3 = { p : p`1 <= b & p`1 >= a & p`2 = c}, L4 = { p : p`1 = b & p`2 <= d & p`2 >= c}; set p0 = |[ a,c ]|, p01 = |[ a,d ]|, p10 = |[ b,c ]|, p1 = |[ b,d ]|; A2: p01`1 = a & p01`2 = d by EUCLID:56; A3: p10`1 = b & p10`2 = c by EUCLID:56; thus L1 = LSeg(p0,p01) proof A4: L1 c= LSeg(p0,p01) proof let a2 be set; assume a2 in L1; then consider p such that A5: a2 = p and A6: p`1 = a & p`2 <= d & p`2 >= c; now per cases; case A7: d <>c; reconsider lambda = (p`2-c)/(d-c) as Real by XREAL_0:def 1; d>=c by A6,AXIOMS:22; then d>c by A7,REAL_1:def 5; then A8: d-c>0 by SQUARE_1:11; p`2-c>=0 by A6,SQUARE_1:12; then A9: lambda>=0 by A8,REAL_2:125; d-c>=p`2-c by A6,REAL_1:49; then (d-c)/(d-c)>=(p`2-c)/(d-c) by A8,REAL_1:73; then A10: 1>=lambda by A8,XCMPLX_1:60; A11: (1-lambda)*c+lambda*d =((d-c)/(d-c)- (p`2-c)/(d-c))*c+(p`2-c)/(d-c)*d by A8,XCMPLX_1:60 .=(((d-c)- (p`2-c))/(d-c))*c+(p`2-c)/(d-c)*d by XCMPLX_1:121 .=((d- p`2)/(d-c))*c+(p`2-c)/(d-c)*d by XCMPLX_1:22 .=c*((d- p`2)/(d-c))+d*(p`2-c)/(d-c) by XCMPLX_1:75 .=c*(d- p`2)/(d-c)+d*(p`2-c)/(d-c) by XCMPLX_1:75 .=(c*d- c*p`2)/(d-c)+d*(p`2-c)/(d-c) by XCMPLX_1:40 .=(c*d- c*p`2)/(d-c)+(d*p`2-d*c)/(d-c) by XCMPLX_1:40 .=((c*d- c*p`2)+(d*p`2-d*c))/(d-c) by XCMPLX_1:63 .=((d*p`2-c*d)+c*d- c*p`2)/(d-c) by XCMPLX_1:29 .=(d*p`2- c*p`2)/(d-c) by XCMPLX_1:27 .=(d- c)*p`2/(d-c) by XCMPLX_1:40 .=p`2*((d- c)/(d-c)) by XCMPLX_1:75 .=p`2*1 by A8,XCMPLX_1:60 .=p`2; (1-lambda)*p0 + lambda*p01 =|[(1-lambda)*a,(1-lambda)*c]| + lambda*(|[a,d]|) by EUCLID:62 .=|[(1-lambda)*a,(1-lambda)*c]| +(|[ lambda*a, lambda*d]|) by EUCLID:62 .=|[(1-lambda)*a+lambda*a,(1-lambda)*c+lambda*d]| by EUCLID:60 .=|[((1-lambda)+lambda)*a,(1-lambda)*c+lambda*d]| by XCMPLX_1:8 .=|[1*a,(1-lambda)*c+lambda*d]| by XCMPLX_1:27 .= p by A6,A11,EUCLID:57; then a2 in {(1-r)*p0 + r*p01: 0 <= r & r <= 1 } by A5,A9,A10; hence a2 in LSeg(p0,p01) by TOPREAL1:def 4; case d =c; then A12: p`2=c by A6,AXIOMS:21; reconsider lambda = 0 as Real; (1-lambda)*p0 + lambda*p01 = |[(1-lambda)*a,(1-lambda)*c]| + lambda*(|[a,d]|) by EUCLID:62 .=|[(1-lambda)*a,(1-lambda)*c]| +(|[ lambda*a, lambda*d]|) by EUCLID:62 .=|[(1-lambda)*a+lambda*a,(1-lambda)*c+lambda*d]| by EUCLID:60 .= p by A6,A12,EUCLID:57; then a2 in {(1-r)*p0 + r*p01: 0 <= r & r <= 1 } by A5; hence a2 in LSeg(p0,p01) by TOPREAL1:def 4; end; hence a2 in LSeg(p0,p01); end; LSeg(p0,p01) c= L1 proof let a2 be set; assume a2 in LSeg(p0,p01); then a2 in {(1-lambda)*p0 + lambda*p01: 0 <= lambda & lambda <= 1 } by TOPREAL1:def 4; then consider lambda such that A13: a2 = (1-lambda)*p0 + lambda*p01 & 0 <= lambda & lambda <= 1; set q = (1-lambda)*p0 + lambda*p01; A14: q`1= ((1-lambda)*p0)`1 + (lambda*p01)`1 by TOPREAL3:7 .= (1-lambda)*(p0)`1 + (lambda*p01)`1 by TOPREAL3:9 .= (1-lambda)*(p0)`1 + lambda*(p01)`1 by TOPREAL3:9 .=(1-lambda)*a +lambda*a by A2,EUCLID:56 .=((1-lambda) +lambda)*a by XCMPLX_1:8 .=1*a by XCMPLX_1:27 .=a; q`2= ((1-lambda)*p0)`2 + (lambda*p01)`2 by TOPREAL3:7 .= (1-lambda)*(p0)`2 + (lambda*p01)`2 by TOPREAL3:9 .= (1-lambda)*(p0)`2 + lambda*(p01)`2 by TOPREAL3:9 .= (1-lambda)*c + lambda*d by A2,EUCLID:56; then q`1 = a & q`2 <= d & q`2 >= c by A1,A13,A14,Th2; hence a2 in L1 by A13; end; hence thesis by A4,XBOOLE_0:def 10; end; thus L2 = LSeg(p01,p1) proof A15: L2 c= LSeg(p01,p1) proof let a2 be set; assume a2 in L2; then consider p such that A16: a2 = p and A17: p`1 <= b & p`1 >= a & p`2=d; now per cases; case A18: b <>a; reconsider lambda = (p`1-a)/(b-a) as Real by XREAL_0:def 1; b>=a by A17,AXIOMS:22; then b>a by A18,REAL_1:def 5; then A19: b-a>0 by SQUARE_1:11; p`1-a>=0 by A17,SQUARE_1:12; then A20: lambda>=0 by A19,REAL_2:125; b-a>=p`1-a by A17,REAL_1:49; then (b-a)/(b-a)>=(p`1-a)/(b-a) by A19,REAL_1:73; then A21: 1>=lambda by A19,XCMPLX_1:60; A22: (1-lambda)*a+lambda*b =((b-a)/(b-a)- (p`1-a)/(b-a))*a+(p`1-a)/(b-a)*b by A19,XCMPLX_1:60 .=(((b-a)- (p`1-a))/(b-a))*a+(p`1-a)/(b-a)*b by XCMPLX_1:121 .=((b- p`1)/(b-a))*a+(p`1-a)/(b-a)*b by XCMPLX_1:22 .=a*((b- p`1)/(b-a))+b*(p`1-a)/(b-a) by XCMPLX_1:75 .=a*(b- p`1)/(b-a)+b*(p`1-a)/(b-a) by XCMPLX_1:75 .=(a*b- a*p`1)/(b-a)+b*(p`1-a)/(b-a) by XCMPLX_1:40 .=(a*b- a*p`1)/(b-a)+(b*p`1-b*a)/(b-a) by XCMPLX_1:40 .=((a*b- a*p`1)+(b*p`1-b*a))/(b-a) by XCMPLX_1:63 .=((b*p`1-a*b)+a*b- a*p`1)/(b-a) by XCMPLX_1:29 .=(b*p`1- a*p`1)/(b-a) by XCMPLX_1:27 .=(b- a)*p`1/(b-a) by XCMPLX_1:40 .=p`1*((b- a)/(b-a)) by XCMPLX_1:75 .=p`1*1 by A19,XCMPLX_1:60 .=p`1; (1-lambda)*p01 + lambda*p1 =|[(1-lambda)*a,(1-lambda)*d]| + lambda*(|[b,d]|) by EUCLID:62 .=|[(1-lambda)*a,(1-lambda)*d]| +(|[ lambda*b, lambda*d]|) by EUCLID:62 .=|[(1-lambda)*a+lambda*b,(1-lambda)*d+lambda*d]| by EUCLID:60 .=|[(1-lambda)*a+lambda*b,((1-lambda)+lambda)*d]| by XCMPLX_1:8 .=|[(1-lambda)*a+lambda*b,1*d]| by XCMPLX_1:27 .= p by A17,A22,EUCLID:57; then a2 in {(1-r)*p01 + r*p1: 0 <= r & r <= 1 } by A16,A20,A21; hence a2 in LSeg(p01,p1) by TOPREAL1:def 4; case b =a; then A23: p`1=a by A17,AXIOMS:21; reconsider lambda = 0 as Real; (1-lambda)*p01 + lambda*p1 =|[(1-lambda)*a,(1-lambda)*d]| + lambda*(|[b,d]|) by EUCLID:62 .=|[(1-lambda)*a,(1-lambda)*d]| +(|[ lambda*b, lambda*d]|) by EUCLID:62 .=|[(1-lambda)*a+lambda*b,(1-lambda)*d+lambda*d]| by EUCLID:60 .= p by A17,A23,EUCLID:57; then a2 in {(1-r)*p01 + r*p1: 0 <= r & r <= 1 } by A16; hence a2 in LSeg(p01,p1) by TOPREAL1:def 4; end; hence a2 in LSeg(p01,p1); end; LSeg(p01,p1) c= L2 proof let a2 be set; assume a2 in LSeg(p01,p1); then a2 in {(1-lambda)*p01 + lambda*p1: 0 <= lambda & lambda <= 1 } by TOPREAL1:def 4; then consider lambda such that A24: a2 = (1-lambda)*p01 + lambda*p1 & 0 <= lambda & lambda <= 1; set q = (1-lambda)*p01 + lambda*p1; A25: q`2= ((1-lambda)*p01)`2 + (lambda*p1)`2 by TOPREAL3:7 .= (1-lambda)*(p01)`2 + (lambda*p1)`2 by TOPREAL3:9 .= (1-lambda)*(p01)`2 + lambda*(p1)`2 by TOPREAL3:9 .=(1-lambda)*d +lambda*d by A2,EUCLID:56 .=((1-lambda) +lambda)*d by XCMPLX_1:8 .=1*d by XCMPLX_1:27 .=d; q`1= ((1-lambda)*p01)`1 + (lambda*p1)`1 by TOPREAL3:7 .= (1-lambda)*(p01)`1 + (lambda*p1)`1 by TOPREAL3:9 .= (1-lambda)*(p01)`1 + lambda*(p1)`1 by TOPREAL3:9 .= (1-lambda)*a + lambda*b by A2,EUCLID:56; then q`2 = d & q`1 <= b & q`1 >= a by A1,A24,A25,Th2; hence a2 in L2 by A24; end; hence thesis by A15,XBOOLE_0:def 10; end; thus L3 = LSeg(p0,p10) proof A26: L3 c= LSeg(p0,p10) proof let a2 be set; assume a2 in L3; then consider p such that A27: a2 = p and A28: p`1 <= b & p`1 >= a & p`2=c; now per cases; case A29: b <>a; reconsider lambda = (p`1-a)/(b-a) as Real by XREAL_0:def 1; b>=a by A28,AXIOMS:22; then b>a by A29,REAL_1:def 5; then A30: b-a>0 by SQUARE_1:11; p`1-a>=0 by A28,SQUARE_1:12; then A31: lambda>=0 by A30,REAL_2:125; b-a>=p`1-a by A28,REAL_1:49; then (b-a)/(b-a)>=(p`1-a)/(b-a) by A30,REAL_1:73; then A32: 1>=lambda by A30,XCMPLX_1:60; A33: (1-lambda)*a+lambda*b =((b-a)/(b-a)- (p`1-a)/(b-a))*a+(p`1-a)/(b-a)*b by A30,XCMPLX_1:60 .=(((b-a)- (p`1-a))/(b-a))*a+(p`1-a)/(b-a)*b by XCMPLX_1:121 .=((b- p`1)/(b-a))*a+(p`1-a)/(b-a)*b by XCMPLX_1:22 .=a*((b- p`1)/(b-a))+b*(p`1-a)/(b-a) by XCMPLX_1:75 .=a*(b- p`1)/(b-a)+b*(p`1-a)/(b-a) by XCMPLX_1:75 .=(a*b- a*p`1)/(b-a)+b*(p`1-a)/(b-a) by XCMPLX_1:40 .=(a*b- a*p`1)/(b-a)+(b*p`1-b*a)/(b-a) by XCMPLX_1:40 .=((a*b- a*p`1)+(b*p`1-b*a))/(b-a) by XCMPLX_1:63 .=((b*p`1-a*b)+a*b- a*p`1)/(b-a) by XCMPLX_1:29 .=(b*p`1- a*p`1)/(b-a) by XCMPLX_1:27 .=(b- a)*p`1/(b-a) by XCMPLX_1:40 .=p`1*((b- a)/(b-a)) by XCMPLX_1:75 .=p`1*1 by A30,XCMPLX_1:60 .=p`1; (1-lambda)*p0 + lambda*p10 =|[(1-lambda)*a,(1-lambda)*c]| + lambda*(|[b,c]|) by EUCLID:62 .=|[(1-lambda)*a,(1-lambda)*c]| +(|[ lambda*b, lambda*c]|) by EUCLID:62 .=|[(1-lambda)*a+lambda*b,(1-lambda)*c+lambda*c]| by EUCLID:60 .=|[(1-lambda)*a+lambda*b,((1-lambda)+lambda)*c]| by XCMPLX_1:8 .=|[(1-lambda)*a+lambda*b,1*c]| by XCMPLX_1:27 .= p by A28,A33,EUCLID:57; then a2 in {(1-r)*p0 + r*p10: 0 <= r & r <= 1 } by A27,A31,A32; hence a2 in LSeg(p0,p10) by TOPREAL1:def 4; case b =a; then A34: p`1=a by A28,AXIOMS:21; reconsider lambda = 0 as Real; (1-lambda)*p0 + lambda*p10 = |[(1-lambda)*a,(1-lambda)*c]| + lambda*(|[b,c]|) by EUCLID:62 .=|[(1-lambda)*a,(1-lambda)*c]| +(|[ lambda*b, lambda*c]|) by EUCLID:62 .=|[(1-lambda)*a+lambda*b,(1-lambda)*c+lambda*c]| by EUCLID:60 .= p by A28,A34,EUCLID:57; then a2 in {(1-r)*p0 + r*p10: 0 <= r & r <= 1 } by A27; hence a2 in LSeg(p0,p10) by TOPREAL1:def 4; end; hence a2 in LSeg(p0,p10); end; LSeg(p0,p10) c= L3 proof let a2 be set; assume a2 in LSeg(p0,p10); then a2 in {(1-lambda)*p0 + lambda*p10: 0 <= lambda & lambda <= 1 } by TOPREAL1:def 4; then consider lambda such that A35: a2 = (1-lambda)*p0 + lambda*p10 & 0 <= lambda & lambda <= 1; set q = (1-lambda)*p0 + lambda*p10; A36: q`2= ((1-lambda)*p0)`2 + (lambda*p10)`2 by TOPREAL3:7 .= (1-lambda)*(p0)`2 + (lambda*p10)`2 by TOPREAL3:9 .= (1-lambda)*(p0)`2 + lambda*(p10)`2 by TOPREAL3:9 .=(1-lambda)*c +lambda*c by A3,EUCLID:56 .=((1-lambda) +lambda)*c by XCMPLX_1:8 .=1*c by XCMPLX_1:27 .=c; q`1= ((1-lambda)*p0)`1 + (lambda*p10)`1 by TOPREAL3:7 .= (1-lambda)*(p0)`1 + (lambda*p10)`1 by TOPREAL3:9 .= (1-lambda)*(p0)`1 + lambda*(p10)`1 by TOPREAL3:9 .= (1-lambda)*a + lambda*b by A3,EUCLID:56; then q`2 = c & q`1 <= b & q`1 >= a by A1,A35,A36,Th2; hence a2 in L3 by A35; end; hence thesis by A26,XBOOLE_0:def 10; end; thus L4 = LSeg(p10,p1) proof A37: L4 c= LSeg(p10,p1) proof let a2 be set; assume a2 in L4; then consider p such that A38: a2 = p and A39: p`1 = b & p`2 <= d & p`2 >= c; now per cases; case A40: d <>c; reconsider lambda = (p`2-c)/(d-c) as Real by XREAL_0:def 1; d>=c by A39,AXIOMS:22; then d>c by A40,REAL_1:def 5; then A41: d-c>0 by SQUARE_1:11; p`2-c>=0 by A39,SQUARE_1:12; then A42: lambda>=0 by A41,REAL_2:125; d-c>=p`2-c by A39,REAL_1:49; then (d-c)/(d-c)>=(p`2-c)/(d-c) by A41,REAL_1:73; then A43: 1>=lambda by A41,XCMPLX_1:60; A44: (1-lambda)*c+lambda*d =((d-c)/(d-c)- (p`2-c)/(d-c))*c+(p`2-c)/(d-c)*d by A41,XCMPLX_1:60 .=(((d-c)- (p`2-c))/(d-c))*c+(p`2-c)/(d-c)*d by XCMPLX_1:121 .=((d- p`2)/(d-c))*c+(p`2-c)/(d-c)*d by XCMPLX_1:22 .=c*((d- p`2)/(d-c))+d*(p`2-c)/(d-c) by XCMPLX_1:75 .=c*(d- p`2)/(d-c)+d*(p`2-c)/(d-c) by XCMPLX_1:75 .=(c*d- c*p`2)/(d-c)+d*(p`2-c)/(d-c) by XCMPLX_1:40 .=(c*d- c*p`2)/(d-c)+(d*p`2-d*c)/(d-c) by XCMPLX_1:40 .=((c*d- c*p`2)+(d*p`2-d*c))/(d-c) by XCMPLX_1:63 .=((d*p`2-c*d)+c*d- c*p`2)/(d-c) by XCMPLX_1:29 .=(d*p`2- c*p`2)/(d-c) by XCMPLX_1:27 .=(d- c)*p`2/(d-c) by XCMPLX_1:40 .=p`2*((d- c)/(d-c)) by XCMPLX_1:75 .=p`2*1 by A41,XCMPLX_1:60 .=p`2; (1-lambda)*p10 + lambda*p1 =|[(1-lambda)*b,(1-lambda)*c]| + lambda*(|[b,d]|) by EUCLID:62 .=|[(1-lambda)*b,(1-lambda)*c]| +(|[ lambda*b, lambda*d]|) by EUCLID:62 .=|[(1-lambda)*b+lambda*b,(1-lambda)*c+lambda*d]| by EUCLID:60 .=|[((1-lambda)+lambda)*b,(1-lambda)*c+lambda*d]| by XCMPLX_1:8 .=|[1*b,(1-lambda)*c+lambda*d]| by XCMPLX_1:27 .= p by A39,A44,EUCLID:57; then a2 in {(1-r)*p10 + r*p1: 0 <= r & r <= 1 } by A38,A42,A43; hence a2 in LSeg(p10,p1) by TOPREAL1:def 4; case d =c; then A45: p`2=c by A39,AXIOMS:21; reconsider lambda = 0 as Real; (1-lambda)*p10 + lambda*p1 =|[(1-lambda)*b,(1-lambda)*c]| + lambda*(|[b,d]|) by EUCLID:62 .=|[(1-lambda)*b,(1-lambda)*c]| +(|[ lambda*b, lambda*d]|) by EUCLID:62 .=|[(1-lambda)*b+lambda*b,(1-lambda)*c+lambda*d]| by EUCLID:60 .= p by A39,A45,EUCLID:57; then a2 in {(1-r)*p10 + r*p1: 0 <= r & r <= 1 } by A38; hence a2 in LSeg(p10,p1) by TOPREAL1:def 4; end; hence a2 in LSeg(p10,p1); end; LSeg(p10,p1) c= L4 proof let a2 be set; assume a2 in LSeg(p10,p1); then a2 in {(1-lambda)*p10 + lambda*p1: 0 <= lambda & lambda <= 1 } by TOPREAL1:def 4; then consider lambda such that A46: a2 = (1-lambda)*p10 + lambda*p1 & 0 <= lambda & lambda <= 1; set q = (1-lambda)*p10 + lambda*p1; A47: q`1= ((1-lambda)*p10)`1 + (lambda*p1)`1 by TOPREAL3:7 .= (1-lambda)*(p10)`1 + (lambda*p1)`1 by TOPREAL3:9 .= (1-lambda)*(p10)`1 + lambda*(p1)`1 by TOPREAL3:9 .=(1-lambda)*b +lambda*b by A3,EUCLID:56 .=((1-lambda) +lambda)*b by XCMPLX_1:8 .=1*b by XCMPLX_1:27 .=b; q`2= ((1-lambda)*p10)`2 + (lambda*p1)`2 by TOPREAL3:7 .= (1-lambda)*(p10)`2 + (lambda*p1)`2 by TOPREAL3:9 .= (1-lambda)*(p10)`2 + lambda*(p1)`2 by TOPREAL3:9 .= (1-lambda)*c + lambda*d by A3,EUCLID:56; then q`1 = b & q`2 <= d & q`2 >= c by A1,A46,A47,Th2; hence a2 in L4 by A46; end; hence thesis by A37,XBOOLE_0:def 10; end; end; theorem Th40: for a,b,c,d being real number st a<=b & c <=d holds {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} = (LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|)) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) proof let a,b,c,d be real number; assume A1: a<=b & c <=d; set L1 = { p : p`1 = a & p`2 <= d & p`2 >= c}, L2 = { p : p`1 <= b & p`1 >= a & p`2 = d}, L3 = { p : p`1 <= b & p`1 >= a & p`2 = c}, L4 = { p : p`1 = b & p`2 <= d & p`2 >= c}; defpred P1[Point of TOP-REAL 2] means $1`1=a & c <=$1`2 & $1`2<=d; defpred P2[Point of TOP-REAL 2] means $1`2=d & a<=$1`1 & $1`1 <= b; defpred Q1[Point of TOP-REAL 2] means $1`1=b & c <=$1`2 & $1`2<=d; defpred Q2[Point of TOP-REAL 2] means $1`2=c & a<=$1`1 & $1`1<=b; set M1 = { p : P1[p]}, M2 = { p : P2[p]}, M3 = { p : Q2[p]}, M4 = { p : Q1[p]}; A2: L1 = M1 proof thus L1 c= M1 proof let x be set;assume x in L1; then consider p such that A3: x=p & p`1 = a & p`2 <= d & p`2 >= c; thus x in M1 by A3; end; thus M1 c= L1 proof let x be set;assume x in M1; then consider p such that A4: x=p & p`1 = a & c <=p`2 & p`2 <= d; thus x in L1 by A4; end; end; A5: L2 = M2 proof thus L2 c= M2 proof let x be set;assume x in L2; then consider p such that A6: x=p & p`1 <= b & p`1 >= a & p`2 = d; thus x in M2 by A6; end; thus M2 c= L2 proof let x be set;assume x in M2; then consider p such that A7: x=p & p`2=d & a<=p`1 & p`1 <= b; thus x in L2 by A7; end; end; A8: L3 = M3 proof thus L3 c= M3 proof let x be set;assume x in L3; then consider p such that A9: x=p & p`1 <= b & p`1 >= a & p`2 = c; thus x in M3 by A9; end; thus M3 c= L3 proof let x be set;assume x in M3; then consider p such that A10: x=p & p`2=c & a<=p`1 & p`1 <= b; thus x in L3 by A10; end; end; A11: L4 = M4 proof thus L4 c= M4 proof let x be set;assume x in L4; then consider p such that A12: x=p & p`1 = b & p`2 <= d & p`2 >= c; thus x in M4 by A12; end; thus M4 c= L4 proof let x be set;assume x in M4; then consider p such that A13: x=p & p`1 = b & c <=p`2 & p`2 <= d; thus x in L4 by A13; end; end; defpred P[Point of TOP-REAL 2] means $1`1=a & c <=$1`2 & $1`2<=d or $1`2=d & a<=$1`1 & $1`1<=b; defpred Q[Point of TOP-REAL 2] means $1`1=b & c <=$1`2 & $1`2<=d or $1`2=c & a<=$1`1 & $1`1<=b; {p2: P[p2] or Q[p2]} = {p: P[p]} \/ {q1: Q[q1]} from Fraenkel_Alt; then A14: {p2: p2`1=a & c <=p2`2 & p2`2<=d or p2`2=d & a<=p2`1 & p2`1<=b or p2`1=b & c <=p2`2 & p2`2<=d or p2`2=c & a<=p2`1 & p2`1<=b} = {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b} \/ {q1: q1`1=b & c <=q1`2 & q1`2<=d or q1`2=c & a<=q1`1 & q1`1<=b}; A15: {p: P1[p] or P2[p]} = M1 \/ M2 from Fraenkel_Alt .= LSeg(|[a,c]|,|[a,d]|) \/ L2 by A1,A2,A5,Th39 .= LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) by A1,Th39; {q1: Q1[q1] or Q2[q1]} = M4 \/ M3 from Fraenkel_Alt .= LSeg(|[ a,c ]|, |[ b,c ]|) \/ L4 by A1,A8,A11,Th39 .= LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|) by A1,Th39; hence thesis by A14,A15; end; theorem Th41: for a,b,c,d being real number st a <= b & c <= d holds LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,c]|,|[b,c]|) = {|[a,c]|} proof let a,b,c,d be real number; assume A1: a <= b & c <= d; for ax being set holds ax in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,c]|,|[b,c]|) iff ax = |[a,c]| proof let ax be set; thus ax in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,c]|,|[b,c]|) implies ax = |[a,c]| proof assume ax in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,c]|,|[b,c]|); then A2: ax in LSeg(|[a,c]|,|[a,d]|)& ax in LSeg(|[a,c]|,|[b,c]|) by XBOOLE_0:def 3; then ax in { p2 : p2`1 <= b & p2`1 >= a & p2`2 = c } by A1,Th39; then A3: ex p2 st p2 = ax & p2`1 <= b & p2`1 >= a & p2`2 = c; ax in { p2 : p2`1 = a & p2`2 <= d & p2`2 >= c } by A1,A2,Th39; then ex p st p = ax & p`1 = a & p`2 <= d & p`2 >= c; hence ax = |[a,c]| by A3,EUCLID:57; end; assume ax = |[a,c]|; then ax in LSeg(|[a,c]|,|[a,d]|) & ax in LSeg(|[a,c]|,|[b,c]|) by TOPREAL1:6; hence ax in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,c]|,|[b,c]|) by XBOOLE_0:def 3; end; hence thesis by TARSKI:def 1; end; theorem Th42: for a,b,c,d being real number st a <= b & c <= d holds LSeg(|[a,c]|,|[b,c]|) /\ LSeg(|[b,c]|,|[b,d]|) = {|[b,c]|} proof let a,b,c,d be real number; assume A1: a <= b & c <= d; for ax being set holds ax in LSeg(|[a,c]|,|[b,c]|) /\ LSeg(|[b,c]|,|[b,d]|) iff ax = |[b,c]| proof let ax be set; thus ax in LSeg(|[a,c]|,|[b,c]|) /\ LSeg(|[b,c]|,|[b,d]|) implies ax = |[b,c]| proof assume ax in LSeg(|[a,c]|,|[b,c]|) /\ LSeg(|[b,c]|,|[b,d]|); then A2: ax in LSeg(|[a,c]|,|[b,c]|)& ax in LSeg(|[b,c]|,|[b,d]|) by XBOOLE_0:def 3; then ax in { q1 : q1`1 <= b & q1`1 >= a & q1`2 = c} by A1,Th39; then A3: ex p2 st p2 = ax & p2`1 <= b & p2`1 >= a & p2`2 = c; ax in { q2 : q2`1 = b & q2`2 <= d & q2`2 >= c} by A1,A2,Th39; then ex p st p = ax & p`1 = b & p`2 <= d & p`2 >= c; hence ax = |[b,c]| by A3,EUCLID:57; end; assume ax = |[b,c]|; then ax in LSeg(|[a,c]|,|[b,c]|) & ax in LSeg(|[b,c]|,|[b,d]|) by TOPREAL1:6; hence ax in LSeg(|[a,c]|,|[b,c]|) /\ LSeg(|[b,c]|,|[b,d]|) by XBOOLE_0:def 3; end; hence thesis by TARSKI:def 1; end; theorem Th43: for a,b,c,d being real number st a <= b & c <= d holds LSeg(|[a,d]|,|[b,d]|) /\ LSeg(|[b,c]|,|[b,d]|) = {|[b,d]|} proof let a,b,c,d be real number;assume A1: a <= b & c <= d; for ax being set holds ax in LSeg(|[a,d]|,|[b,d]|) /\ LSeg(|[b,c]|,|[b,d]|) iff ax = |[b,d]| proof let ax be set; thus ax in LSeg(|[a,d]|,|[b,d]|) /\ LSeg(|[b,c]|,|[b,d]|) implies ax = |[b,d]| proof assume ax in LSeg(|[a,d]|,|[b,d]|) /\ LSeg(|[b,c]|,|[b,d]|); then A2: ax in LSeg(|[b,c]|,|[b,d]|) & ax in LSeg(|[a,d]|,|[b,d]|) by XBOOLE_0:def 3; then ax in { p : p`1 <= b & p`1 >= a & p`2 = d} by A1,Th39; then A3: ex p st p = ax & p`1 <= b & p`1 >= a & p`2 = d; ax in { p : p`1 = b & p`2 <= d & p`2 >= c} by A1,A2,Th39; then ex p2 st p2 = ax & p2`1 = b & p2`2 <= d & p2`2 >= c; hence ax = |[b,d]| by A3,EUCLID:57; end; assume ax = |[b,d]|; then ax in LSeg(|[a,d]|,|[b,d]|) & ax in LSeg(|[b,c]|,|[b,d]|) by TOPREAL1:6; hence ax in LSeg(|[a,d]|,|[b,d]|) /\ LSeg(|[b,c]|,|[b,d]|) by XBOOLE_0:def 3; end; hence thesis by TARSKI:def 1; end; theorem Th44: for a,b,c,d being real number st a <= b & c <= d holds LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|) = {|[a,d]|} proof let a,b,c,d be real number; assume A1: a <= b & c <= d; for ax being set holds ax in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|) iff ax = |[a,d]| proof let ax be set; thus ax in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|) implies ax = |[a,d]| proof assume ax in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|); then A2: ax in LSeg(|[a,c]|,|[a,d]|)& ax in LSeg(|[a,d]|,|[b,d]|) by XBOOLE_0:def 3; then ax in { p2 : p2`1 <= b & p2`1 >= a & p2`2 = d } by A1,Th39; then A3: ex p2 st p2 = ax & p2`1 <= b & p2`1 >= a & p2`2 = d; ax in { p2 : p2`1 = a & p2`2 <= d & p2`2 >= c } by A1,A2,Th39; then ex p st p = ax & p`1 = a & p`2 <= d & p`2 >= c; hence ax = |[a,d]| by A3,EUCLID:57; end; assume ax = |[a,d]|; then ax in LSeg(|[a,c]|,|[a,d]|) & ax in LSeg(|[a,d]|,|[b,d]|) by TOPREAL1:6; hence ax in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|) by XBOOLE_0:def 3; end; hence thesis by TARSKI:def 1; end; theorem Th45: {q: -1=q`1 & -1<=q`2 & q`2<=1 or q`1=1 & -1<=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1} = {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} proof thus {q: -1=q`1 & -1<=q`2 & q`2<=1 or q`1=1 & -1<=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1} c= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} proof let x be set;assume x in {q: -1=q`1 & -1<=q`2 & q`2<=1 or q`1=1 & -1<=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1}; then consider q such that A1: x=q & ( -1=q`1 & -1<=q`2 & q`2<=1 or q`1=1 & -1<=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1); thus x in {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1; end; thus {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} c= {q: -1=q`1 & -1<=q`2 & q`2<=1 or q`1=1 & -1<=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1} proof let x be set;assume x in {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1}; then consider p such that A2: p=x & ( p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1); thus x in {q: -1=q`1 & -1<=q`2 & q`2<=1 or q`1=1 & -1<=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1} by A2; end; end; theorem Th46: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds W-bound K = a proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; set X = K; reconsider Z = (proj1||X).:the carrier of ((TOP-REAL 2)|X) as Subset of REAL; A2: X = the carrier of ((TOP-REAL 2)|X) by JORDAN1:1; A3: for p be real number st p in Z holds p >= a proof let p be real number; assume p in Z; then consider p0 being set such that A4: p0 in the carrier of (TOP-REAL 2)|X and p0 in the carrier of (TOP-REAL 2)|X and A5: p = (proj1||X).p0 by FUNCT_2:115; reconsider p0 as Point of TOP-REAL 2 by A2,A4; X= {q : q`1=a & c <=q`2 & q`2<=d or q`2=d & a<=q`1 & q`1<=b or q`1=b & c <=q`2 & q`2<=d or q`2=c & a<=q`1 & q`1<=b} by A1,Def1; then ex q being Point of TOP-REAL 2 st p0 = q & ( q`1=a & c <=q`2 & q`2<=d or q`2=d & a<=q`1 & q`1<=b or q`1=b & c <=q`2 & q`2<=d or q`2=c & a<=q`1 & q`1<=b) by A2,A4; hence p >= a by A1,A2,A4,A5,PSCOMP_1:69; end; A6: for q being real number st for p being real number st p in Z holds p >= q holds a >= q proof let q be real number such that A7: for p being real number st p in Z holds p >= q; |[a,c]| in LSeg(|[ a,c ]|, |[ b,c ]|) by TOPREAL1:6; then A8: |[a,c]| in LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|) by XBOOLE_0:def 2; X= {q2 : q2`1=a & c <=q2`2 & q2`2<=d or q2`2=d & a<=q2`1 & q2`1<=b or q2`1=b & c <=q2`2 & q2`2<=d or q2`2=c & a<=q2`1 & q2`1<=b} by A1,Def1; then X= (LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|)) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40; then A9: |[a,c]| in X by A8,XBOOLE_0:def 2; then (proj1||X). |[a,c]| = |[a,c]|`1 by PSCOMP_1:69 .= a by EUCLID:56; then a in Z by A2,A9,FUNCT_2:43; hence thesis by A7; end; thus W-bound X = inf (proj1||X) by PSCOMP_1:def 30 .= inf Z by PSCOMP_1:def 20 .= a by A3,A6,PSCOMP_1:9; end; theorem Th47: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds N-bound K = d proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; set X = K; reconsider Z = (proj2||X).:the carrier of ((TOP-REAL 2)|X) as Subset of REAL; A2: X = the carrier of ((TOP-REAL 2)|X) by JORDAN1:1; A3: for p be real number st p in Z holds p <= d proof let p be real number; assume p in Z; then consider p0 being set such that A4: p0 in the carrier of (TOP-REAL 2)|X and p0 in the carrier of (TOP-REAL 2)|X and A5: p = (proj2||X).p0 by FUNCT_2:115; reconsider p0 as Point of TOP-REAL 2 by A2,A4; X= {q : q`1=a & c <=q`2 & q`2<=d or q`2=d & a<=q`1 & q`1<=b or q`1=b & c <=q`2 & q`2<=d or q`2=c & a<=q`1 & q`1<=b} by A1,Def1; then ex q being Point of TOP-REAL 2 st p0 = q & ( q`1=a & c <=q`2 & q`2<=d or q`2=d & a<=q`1 & q`1<=b or q`1=b & c <=q`2 & q`2<=d or q`2=c & a<=q`1 & q`1<=b) by A2,A4; hence p <= d by A1,A2,A4,A5,PSCOMP_1:70; end; A6: for q being real number st for p being real number st p in Z holds p <= q holds d <= q proof let q be real number such that A7: for p be real number st p in Z holds p <= q; |[b,d]| in LSeg(|[ b,c ]|, |[ b,d ]|) by TOPREAL1:6; then A8: |[b,d]| in LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|) by XBOOLE_0:def 2; X= {q2 : q2`1=a & c <=q2`2 & q2`2<=d or q2`2=d & a<=q2`1 & q2`1<=b or q2`1=b & c <=q2`2 & q2`2<=d or q2`2=c & a<=q2`1 & q2`1<=b} by A1,Def1; then X= (LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|)) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40; then A9: |[b,d]| in X by A8,XBOOLE_0:def 2; then (proj2||X). |[b,d]| = |[b,d]|`2 by PSCOMP_1:70 .= d by EUCLID:56; then d in Z by A2,A9,FUNCT_2:43; hence thesis by A7; end; thus N-bound X = sup (proj2||X) by PSCOMP_1:def 31 .= sup Z by PSCOMP_1:def 21 .= d by A3,A6,PSCOMP_1:11; end; theorem Th48: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds E-bound K = b proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; set X = K; reconsider Z = (proj1||X).:the carrier of ((TOP-REAL 2)|X) as Subset of REAL; A2: X = the carrier of ((TOP-REAL 2)|X) by JORDAN1:1; A3: for p be real number st p in Z holds p <= b proof let p be real number; assume p in Z; then consider p0 being set such that A4: p0 in the carrier of (TOP-REAL 2)|X and p0 in the carrier of (TOP-REAL 2)|X and A5: p = (proj1||X).p0 by FUNCT_2:115; reconsider p0 as Point of TOP-REAL 2 by A2,A4; X= {q : q`1=a & c <=q`2 & q`2<=d or q`2=d & a<=q`1 & q`1<=b or q`1=b & c <=q`2 & q`2<=d or q`2=c & a<=q`1 & q`1<=b} by A1,Def1; then ex q being Point of TOP-REAL 2 st p0 = q & ( q`1=a & c <=q`2 & q`2<=d or q`2=d & a<=q`1 & q`1<=b or q`1=b & c <=q`2 & q`2<=d or q`2=c & a<=q`1 & q`1<=b) by A2,A4; hence p <= b by A1,A2,A4,A5,PSCOMP_1:69; end; A6: for q being real number st for p being real number st p in Z holds p <= q holds b <= q proof let q be real number such that A7: for p be real number st p in Z holds p <= q; |[b,d]| in LSeg(|[ b,c ]|, |[ b,d ]|) by TOPREAL1:6; then A8: |[b,d]| in LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|) by XBOOLE_0:def 2; X= {q2 : q2`1=a & c <=q2`2 & q2`2<=d or q2`2=d & a<=q2`1 & q2`1<=b or q2`1=b & c <=q2`2 & q2`2<=d or q2`2=c & a<=q2`1 & q2`1<=b} by A1,Def1; then X= (LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|)) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40; then A9: |[b,d]| in X by A8,XBOOLE_0:def 2; then (proj1||X). |[b,d]| = |[b,d]|`1 by PSCOMP_1:69 .= b by EUCLID:56; then b in Z by A2,A9,FUNCT_2:43; hence thesis by A7; end; thus E-bound X = sup (proj1||X) by PSCOMP_1:def 32 .= sup Z by PSCOMP_1:def 21 .= b by A3,A6,PSCOMP_1:11; end; theorem Th49: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds S-bound K = c proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; set X = K; reconsider Z = (proj2||X).:the carrier of ((TOP-REAL 2)|X) as Subset of REAL; A2: X = the carrier of ((TOP-REAL 2)|X) by JORDAN1:1; A3: for p be real number st p in Z holds p >= c proof let p be real number; assume p in Z; then consider p0 being set such that A4: p0 in the carrier of (TOP-REAL 2)|X and p0 in the carrier of (TOP-REAL 2)|X and A5: p = (proj2||X).p0 by FUNCT_2:115; reconsider p0 as Point of TOP-REAL 2 by A2,A4; X= {q : q`1=a & c <=q`2 & q`2<=d or q`2=d & a<=q`1 & q`1<=b or q`1=b & c <=q`2 & q`2<=d or q`2=c & a<=q`1 & q`1<=b} by A1,Def1; then ex q being Point of TOP-REAL 2 st p0 = q & ( q`1=a & c <=q`2 & q`2<=d or q`2=d & a<=q`1 & q`1<=b or q`1=b & c <=q`2 & q`2<=d or q`2=c & a<=q`1 & q`1<=b) by A2,A4; hence p >= c by A1,A2,A4,A5,PSCOMP_1:70; end; A6: for q being real number st for p being real number st p in Z holds p >= q holds c >= q proof let q be real number such that A7: for p being real number st p in Z holds p >= q; |[b,c]| in LSeg(|[ b,c ]|, |[ b,d ]|) by TOPREAL1:6; then A8: |[b,c]| in LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|) by XBOOLE_0:def 2; X= {q2 : q2`1=a & c <=q2`2 & q2`2<=d or q2`2=d & a<=q2`1 & q2`1<=b or q2`1=b & c <=q2`2 & q2`2<=d or q2`2=c & a<=q2`1 & q2`1<=b} by A1,Def1; then X= (LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|)) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40; then A9: |[b,c]| in X by A8,XBOOLE_0:def 2; then (proj2||X). |[b,c]| = |[b,c]|`2 by PSCOMP_1:70 .= c by EUCLID:56; then c in Z by A2,A9,FUNCT_2:43; hence thesis by A7; end; thus S-bound X = inf (proj2||X) by PSCOMP_1:def 33 .= inf Z by PSCOMP_1:def 20 .= c by A3,A6,PSCOMP_1:9; end; theorem Th50: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds NW-corner K = |[a,d]| proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; A2: NW-corner K= |[W-bound K, N-bound K]| by PSCOMP_1:def 35; W-bound K=a by A1,Th46; hence NW-corner K = |[a,d]| by A1,A2,Th47; end; theorem Th51: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds NE-corner K = |[b,d]| proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; A2: NE-corner K= |[E-bound K, N-bound K]| by PSCOMP_1:def 36; E-bound K=b by A1,Th48; hence NE-corner K = |[b,d]| by A1,A2,Th47; end; theorem for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds SW-corner K = |[a,c]| proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; A2: SW-corner K= |[W-bound K, S-bound K]| by PSCOMP_1:def 34; W-bound K=a by A1,Th46; hence SW-corner K = |[a,c]| by A1,A2,Th49; end; theorem for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds SE-corner K = |[b,c]| proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; A2: SE-corner K= |[E-bound K, S-bound K]| by PSCOMP_1:def 37; E-bound K=b by A1,Th48; hence SE-corner K = |[b,c]| by A1,A2,Th49; end; theorem Th54: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds W-most K = LSeg(|[a,c]|,|[a,d]|) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; then K= {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} by Def1; then K= LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40; then A2: LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) c= K by XBOOLE_1:7; LSeg(|[a,c]|,|[a,d]|) c= LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) by XBOOLE_1:7; then A3: LSeg(|[a,c]|,|[a,d]|) c= K by A2,XBOOLE_1:1; A4: SW-corner K= |[W-bound K, S-bound K]| by PSCOMP_1:def 34; A5: NW-corner K = |[a,d]| by A1,Th50; A6: W-bound K=a by A1,Th46; A7: S-bound K= c by A1,Th49; thus W-most K = LSeg(SW-corner K, NW-corner K)/\K by PSCOMP_1:def 38 .= LSeg(|[a,c]|,|[a,d]|) by A3,A4,A5,A6,A7,XBOOLE_1:28; end; theorem Th55: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds E-most K = LSeg(|[b,c]|,|[b,d]|) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; then K= {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} by Def1; then K= LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40; then A2: LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|) c= K by XBOOLE_1:7; LSeg(|[b,c]|,|[b,d]|) c= LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|) by XBOOLE_1:7; then A3: LSeg(|[b,c]|,|[b,d]|) c= K by A2,XBOOLE_1:1; A4: SE-corner K= |[E-bound K, S-bound K]| by PSCOMP_1:def 37; A5: NE-corner K = |[b,d]| by A1,Th51; A6: E-bound K=b by A1,Th48; A7: S-bound K= c by A1,Th49; thus E-most K = LSeg(SE-corner K, NE-corner K)/\K by PSCOMP_1:def 40 .= LSeg(|[b,c]|,|[b,d]|) by A3,A4,A5,A6,A7,XBOOLE_1:28; end; theorem Th56: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<=b & c <=d holds W-min K=|[a,c]| & E-max K=|[b,d]| proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<=b & c <=d; A2: W-min K=|[a,c]| proof A3: inf (proj2||LSeg(|[a,c]|,|[a,d]|)) = c proof set X = LSeg(|[a,c]|,|[a,d]|); reconsider Z = (proj2||X).:the carrier of ((TOP-REAL 2)|X) as Subset of REAL; A4: X = the carrier of ((TOP-REAL 2)|X) by JORDAN1:1; A5: for p be real number st p in Z holds p >= c proof let p be real number; assume p in Z; then consider p0 being set such that A6: p0 in the carrier of (TOP-REAL 2)|X and p0 in the carrier of (TOP-REAL 2)|X and A7: p = (proj2||X).p0 by FUNCT_2:115; reconsider p0 as Point of TOP-REAL 2 by A4,A6; |[a,c]|`2 = c & |[a,d]|`2 = d by EUCLID:56; then p0`2 >= c by A1,A4,A6,TOPREAL1:10; hence p >= c by A4,A6,A7,PSCOMP_1:70; end; A8: for q being real number st for p being real number st p in Z holds p >= q holds c >= q proof let q be real number such that A9: for p being real number st p in Z holds p >= q; A10: |[a,c]| in X by TOPREAL1:6; then (proj2||X). |[a,c]| = |[a,c]|`2 by PSCOMP_1:70 .= c by EUCLID:56; then c in Z by A4,A10,FUNCT_2:43; hence thesis by A9; end; thus inf (proj2||X) = inf Z by PSCOMP_1:def 20 .= c by A5,A8,PSCOMP_1:9; end; A11: W-most K = LSeg(|[a,c]|,|[a,d]|) by A1,Th54; W-bound K = a by A1,Th46; hence W-min K= |[a,c]| by A3,A11,PSCOMP_1:def 42; end; E-max K=|[b,d]| proof A12: sup (proj2||LSeg(|[b,c]|,|[b,d]|)) = d proof set X = LSeg(|[b,c]|,|[b,d]|); reconsider Z = (proj2||X).:the carrier of ((TOP-REAL 2)|X) as Subset of REAL; A13: X = the carrier of ((TOP-REAL 2)|X) by JORDAN1:1; A14: for p be real number st p in Z holds p <= d proof let p be real number; assume p in Z; then consider p0 being set such that A15: p0 in the carrier of (TOP-REAL 2)|X and p0 in the carrier of (TOP-REAL 2)|X and A16: p = (proj2||X).p0 by FUNCT_2:115; reconsider p0 as Point of TOP-REAL 2 by A13,A15; |[b,c]|`2 = c & |[b,d]|`2 = d by EUCLID:56; then p0`2 <= d by A1,A13,A15,TOPREAL1:10; hence p <= d by A13,A15,A16,PSCOMP_1:70; end; A17: for q being real number st for p being real number st p in Z holds p <= q holds d <= q proof let q be real number such that A18: for p being real number st p in Z holds p <= q; A19: |[b,d]| in X by TOPREAL1:6; then (proj2||X). |[b,d]| = |[b,d]|`2 by PSCOMP_1:70 .= d by EUCLID:56; then d in Z by A13,A19,FUNCT_2:43; hence thesis by A18; end; thus sup (proj2||X) = sup Z by PSCOMP_1:def 21 .= d by A14,A17,PSCOMP_1:11; end; A20: E-most K = LSeg(|[b,c]|,|[b,d]|) by A1,Th55; E-bound K = b by A1,Th48; hence E-max K= |[b,d]| by A12,A20,PSCOMP_1:def 46; end; hence W-min K=|[a,c]| & E-max K=|[b,d]| by A2; end; theorem Th57: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<b & c <d holds LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) is_an_arc_of W-min(K),E-max(K) & LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) is_an_arc_of E-max(K),W-min(K) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<b & c <d; then A2: W-min(K)= |[a,c]| by Th56; A3: E-max(K)= |[b,d]| by A1,Th56; (|[a,c]|)`2=c by EUCLID:56; then A4: |[a,c]| <> |[a,d]| by A1,EUCLID:56; set p1= |[a,c]|,p2= |[a,d]|,q1=|[b,d]|; A5: LSeg(p1,p2) /\ LSeg(p2,q1) ={p2} by A1,Th44; (|[a,c]|)`1=a by EUCLID:56; then A6: |[a,c]| <> |[b,c]| by A1,EUCLID:56; set q2=|[b,c]|; LSeg(q1,q2) /\ LSeg(q2,p1) ={q2} by A1,Th42; hence LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) is_an_arc_of W-min(K),E-max(K) & LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) is_an_arc_of E-max(K),W-min(K) by A2,A3,A4,A5,A6,TOPREAL1:18; end; theorem Th58: for P,P1,P2 being Subset of TOP-REAL 2, a,b,c,d being real number, f1,f2 being FinSequence of TOP-REAL 2, p0,p1,p01,p10 being Point of TOP-REAL 2 st a < b & c < d & P={p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} & p0=|[a,c]| & p1=|[b,d]| & p01=|[a,d]| & p10=|[b,c]| & f1=<*p0,p01,p1*> & f2=<*p0,p10,p1*> holds f1 is_S-Seq & L~f1 = LSeg(p0,p01) \/ LSeg(p01,p1) & f2 is_S-Seq & L~f2 = LSeg(p0,p10) \/ LSeg(p10,p1) & P = L~f1 \/ L~f2 & L~f1 /\ L~f2 = {p0,p1} & f1/.1 = p0 & f1/.len f1=p1 & f2/.1 = p0 & f2/.len f2 = p1 proof let P,P1,P2 be Subset of TOP-REAL 2, a,b,c,d be real number, f1,f2 be FinSequence of TOP-REAL 2, p0,p1,p01,p10 be Point of TOP-REAL 2; assume A1: a < b & c < d & P={p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} & p0=|[a,c]| & p1=|[b,d]| & p01=|[a,d]| & p10=|[b,c]| & f1=<*p0,p01,p1*> & f2=<*p0,p10,p1*>; set L1 = { p : p`1 = a & p`2 <= d & p`2 >= c}; set L2 = { p : p`1 <= b & p`1 >= a & p`2 = d}; set L3 = { p : p`1 <= b & p`1 >= a & p`2 = c}; set L4 = { p : p`1 = b & p`2 <= d & p`2 >= c}; A2: p1`1 = b & p1`2 = d by A1,EUCLID:56; A3: p10`1 = b & p10`2 = c by A1,EUCLID:56; A4: p0`1 = a & p0`2 = c by A1,EUCLID:56; A5: len f1 = 1 + 2 by A1,FINSEQ_1:62; A6: f1/.1 = p0 & f1/.2 = p01 & f1/.3 = p1 by A1,FINSEQ_4:27; thus f1 is_S-Seq proof p0 <> p01 & p01 <> p1 & p0 <> p1 by A1,A2,A4,EUCLID:56; hence f1 is one-to-one by A1,FINSEQ_3:104; thus len f1 >= 2 by A5; thus f1 is unfolded proof let i be Nat; assume A7: 1 <= i & i + 2 <= len f1; then i <= 1 by A5,REAL_1:53; then A8: i = 1 by A7,AXIOMS:21; reconsider n2=1+1 as Nat; n2 in Seg len f1 by A5,FINSEQ_1:3; then A9: LSeg(f1,1) = LSeg(p0,p01) & LSeg(f1,n2) = LSeg(p01,p1) by A5,A6,TOPREAL1:def 5; for x being set holds x in LSeg(p0,p01) /\ LSeg(p01,p1) iff x = p01 proof let x be set; thus x in LSeg(p0,p01) /\ LSeg(p01,p1) implies x = p01 proof assume x in LSeg(p0,p01) /\ LSeg(p01,p1); then x in LSeg(p0,p01) & x in LSeg(p01,p1) by XBOOLE_0:def 3; then A10: x in {p : p`1 = a & p`2 <= d & p`2 >= c} & x in {p2 : p2`1 <= b & p2`1 >= a & p2`2 = d} by A1,Th39; then A11: ex p st p = x & p`1 = a & p`2 <= d & p`2 >= c; ex p2 st p2=x & p2`1<=b & p2`1>=a & p2`2=d by A10; hence x = p01 by A1,A11,EUCLID:57; end; assume x = p01; then x in LSeg(p0,p01) & x in LSeg(p01,p1) by TOPREAL1:6; hence x in LSeg(p0,p01) /\ LSeg(p01,p1) by XBOOLE_0:def 3; end; hence thesis by A6,A8,A9,TARSKI:def 1; end; thus f1 is s.n.c. proof let i,j be Nat such that A12: i+1 < j; now per cases; suppose 1 <= i; then A13: 1+1 <= i+1 by AXIOMS:24; now per cases; case 1 <= j & j+1 <= len f1; then j <= 2 by A5,REAL_1:53; hence contradiction by A12,A13,AXIOMS:22; case not (1 <= j & j+1 <= len f1); then LSeg(f1,j) = {} by TOPREAL1:def 5; hence LSeg(f1,i) /\ LSeg(f1,j) = {}; end; hence LSeg(f1,i) /\ LSeg(f1,j) = {}; suppose not (1 <= i & i+1 <= len f1); then LSeg(f1,i) = {} by TOPREAL1:def 5; hence LSeg(f1,i) /\ LSeg(f1,j) = {}; end; hence LSeg(f1,i) /\ LSeg(f1,j) = {}; end; let i be Nat; assume A14: 1 <= i & i + 1 <= len f1; then A15: i <= 1 + 1 by A5,REAL_1:53; now per cases by A14,A15,NAT_1:27; suppose A16: i = 1; then (f1/.i)`1 = p0`1 by A1,FINSEQ_4:27 .= a by A1,EUCLID:56 .= (f1/.(i+1))`1 by A1,A6,A16,EUCLID:56; hence (f1/.i)`1 = (f1/.(i+1))`1 or (f1/.i)`2 = (f1/.(i+1))`2; suppose A17: i = 2; then (f1/.i)`2 = p01`2 by A1,FINSEQ_4:27 .= d by A1,EUCLID:56 .= (f1/.(i+1))`2 by A1,A6,A17,EUCLID:56; hence (f1/.i)`1 = (f1/.(i+1))`1 or (f1/.i)`2 = (f1/.(i+1))`2; end; hence thesis; end; L~f1 = union {LSeg(p0,p01),LSeg(p01,p1)} proof len f1 = 2+1 & 1+1 in Seg len f1 by A5,FINSEQ_1:3; then 1+1 <= len f1 & LSeg(p0,p01) = LSeg(f1,1) by A6,TOPREAL1:def 5; then A18: LSeg(p0,p01) in {LSeg(f1,i): 1 <= i & i+1 <= len f1}; 2+1 <= len f1 & LSeg(p01,p1) = LSeg(f1,2) by A5,A6,TOPREAL1:def 5; then LSeg(p01,p1) in {LSeg(f1,i): 1 <= i & i+1 <= len f1}; then A19: {LSeg(p0,p01),LSeg(p01,p1)} c= {LSeg(f1,i):1<=i & i+1<=len f1} by A18,ZFMISC_1:38; {LSeg(f1,i): 1 <= i & i+1 <= len f1} c= {LSeg(p0,p01),LSeg(p01,p1)} proof let a be set; assume a in {LSeg(f1,i): 1 <= i & i+1 <= len f1}; then consider i such that A20: a = LSeg(f1,i) & 1<=i & i+1<=len f1; i+1 <= 2 + 1 by A1,A20,FINSEQ_1:62; then i <= 1 + 1 by REAL_1:53; then i = 1 or i = 2 by A20,NAT_1:27; then a = LSeg(p0,p01) or a = LSeg(p01,p1) by A6,A20,TOPREAL1:def 5; hence a in {LSeg(p0,p01),LSeg(p01,p1)} by TARSKI:def 2; end; hence union {LSeg(p0,p01),LSeg(p01,p1)} = union {LSeg(f1,i): 1 <= i & i+1 <= len f1} by A19,XBOOLE_0:def 10 .= L~f1 by TOPREAL1:def 6; end; hence A21: L~f1 = (LSeg(p0,p01) \/ LSeg(p01,p1)) by ZFMISC_1:93; then A22: L~f1=L1 \/ LSeg(p01,p1) by A1,Th39 .=L1 \/ L2 by A1,Th39; A23: len f2 = 1 + 2 by A1,FINSEQ_1:62; A24: f2/.1 = p0 & f2/.2 = p10 & f2/.3 = p1 by A1,FINSEQ_4:27; thus f2 is_S-Seq proof thus f2 is one-to-one by A1,A2,A3,A4,FINSEQ_3:104; thus len f2 >= 2 by A23; thus f2 is unfolded proof let i; assume A25: 1 <= i & i + 2 <= len f2; then i <= 1 by A23,REAL_1:53; then A26: i = 1 by A25,AXIOMS:21; 1+1 in Seg len f2 by A23,FINSEQ_1:3; then A27: LSeg(f2,1) = LSeg(p0,p10) & LSeg(f2,1+1) = LSeg(p10,p1) by A23,A24,TOPREAL1:def 5; for x being set holds x in LSeg(p0,p10) /\ LSeg(p10,p1) iff x = p10 proof let x be set; thus x in LSeg(p0,p10) /\ LSeg(p10,p1) implies x = p10 proof assume x in LSeg(p0,p10) /\ LSeg(p10,p1); then x in LSeg(p0,p10) & x in LSeg(p10,p1) by XBOOLE_0:def 3; then A28: x in { p : p`1 <= b & p`1 >= a & p`2 = c} & x in { p2 : p2`1 = b & p2`2 <= d & p2`2 >= c} by A1,Th39; then A29: ex p st p = x & p`1 <= b & p`1 >= a & p`2 = c; ex p2 st p2=x & p2`1=b & p2`2<=d & p2`2>=c by A28; hence x = p10 by A1,A29,EUCLID:57; end; assume x = p10; then x in LSeg(p0,p10) & x in LSeg(p10,p1) by TOPREAL1:6; hence x in LSeg(p0,p10) /\ LSeg(p10,p1) by XBOOLE_0:def 3; end; hence thesis by A24,A26,A27,TARSKI:def 1; end; thus f2 is s.n.c. proof let i,j such that A30: i+1 < j; now per cases; suppose 1 <= i; then A31: 1+1 <= i+1 by AXIOMS:24; now per cases; case 1 <= j & j+1 <= len f2; then j <= 2 by A23,REAL_1:53; hence contradiction by A30,A31,AXIOMS:22; case not (1 <= j & j+1 <= len f2); then LSeg(f2,j) = {} by TOPREAL1:def 5; hence LSeg(f2,i) /\ LSeg(f2,j) = {}; end; hence LSeg(f2,i) /\ LSeg(f2,j) = {}; suppose not (1 <= i & i+1 <= len f2); then LSeg(f2,i) = {} by TOPREAL1:def 5; hence LSeg(f2,i) /\ LSeg(f2,j) = {}; end; hence LSeg(f2,i) /\ LSeg(f2,j) = {}; end; let i; assume A32: 1 <= i & i + 1 <= len f2; then A33: i <= 1 + 1 by A23,REAL_1:53; per cases by A32,A33,NAT_1:27; suppose A34: i = 1; then (f2/.i)`2 = p0`2 by A1,FINSEQ_4:27 .= c by A1,EUCLID:56 .= (f2/.(i+1))`2 by A1,A24,A34,EUCLID:56; hence (f2/.i)`1 = (f2/.(i+1))`1 or (f2/.i)`2 = (f2/.(i+1))`2; suppose A35: i = 2; then (f2/.i)`1 = p10`1 by A1,FINSEQ_4:27 .= b by A1,EUCLID:56 .= (f2/.(i+1))`1 by A1,A24,A35,EUCLID:56; hence (f2/.i)`1 = (f2/.(i+1))`1 or (f2/.i)`2 = (f2/.(i+1))`2; end; A36: L~f2 = union {LSeg(p0,p10),LSeg(p10,p1)} proof len f2 = 2+1 & 1+1 in Seg len f2 by A23,FINSEQ_1:3; then 1+1 <= len f2 & LSeg(p0,p10) = LSeg(f2,1) by A24,TOPREAL1:def 5; then A37: LSeg(p0,p10) in {LSeg(f2,i): 1 <= i & i+1 <= len f2}; 2+1 <= len f2 & LSeg(p10,p1) = LSeg(f2,2) by A23,A24,TOPREAL1:def 5; then LSeg(p10,p1) in {LSeg(f2,i): 1 <= i & i+1 <= len f2}; then A38: {LSeg(p0,p10),LSeg(p10,p1)} c= {LSeg(f2,i):1<=i & i+1<=len f2} by A37,ZFMISC_1:38; {LSeg(f2,i): 1 <= i & i+1 <= len f2} c= {LSeg(p0,p10),LSeg(p10,p1)} proof let ax be set; assume ax in {LSeg(f2,i): 1 <= i & i+1 <= len f2}; then consider i such that A39: ax = LSeg(f2,i) & 1<=i & i+1<=len f2; i+1 <= 2 + 1 by A1,A39,FINSEQ_1:62; then i <= 1 + 1 by REAL_1:53; then i = 1 or i = 2 by A39,NAT_1:27; then ax = LSeg(p0,p10) or ax = LSeg(p10,p1) by A24,A39,TOPREAL1:def 5; hence ax in {LSeg(p0,p10),LSeg(p10,p1)} by TARSKI:def 2; end; hence union {LSeg(p0,p10),LSeg(p10,p1)} = union {LSeg(f2,i): 1 <= i & i+1 <= len f2} by A38,XBOOLE_0:def 10 .= L~f2 by TOPREAL1:def 6; end; hence L~f2 = LSeg(p0,p10) \/ LSeg(p10,p1) by ZFMISC_1:93; L~f2 = (LSeg(p0,p10) \/ LSeg(p10,p1)) by A36,ZFMISC_1:93; then A40: L~f2=L3 \/ LSeg(p10,p1) by A1,Th39 .=L3 \/ L4 by A1,Th39; P = LSeg(p0,p01) \/ LSeg(p01,p1) \/ (LSeg(p0,p10) \/ LSeg(p10,p1)) by A1,Th40; hence P = L~f1 \/ L~f2 by A21,A36,ZFMISC_1:93; now assume L2 meets L3; then consider x being set such that A41: x in L2 & x in L3 by XBOOLE_0:3; A42: ex p st p = x & p`1 <= b & p`1 >= a & p`2 = d by A41; ex p2 st p2 = x & p2`1 <= b & p2`1 >= a & p2`2 = c by A41; hence contradiction by A1,A42; end; then A43: L2 /\ L3 = {} by XBOOLE_0:def 7; A44: LSeg(|[ a,c ]|, |[ a,d ]|) = { p3 : p3`1 = a & p3`2 <= d & p3`2 >= c} & LSeg(|[ a,d ]|, |[ b,d ]|) = { p2 : p2`1 <= b & p2`1 >= a & p2`2 = d} & LSeg(|[ a,c ]|, |[ b,c ]|) = { q1 : q1`1 <= b & q1`1 >= a & q1`2 = c} & LSeg(|[ b,c ]|, |[ b,d ]|) = { q2 : q2`1 = b & q2`2 <= d & q2`2 >= c} & LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,c]|,|[b,c]|) = {|[a,c]|} & LSeg(|[a,d]|,|[b,d]|) /\ LSeg(|[b,c]|,|[b,d]|) = {|[b,d]|} by A1,Th39,Th41,Th43; now assume L1 meets L4; then consider x being set such that A45: x in L1 & x in L4 by XBOOLE_0:3; A46: ex p st p = x & p`1 = a & p`2 <= d & p`2 >= c by A45; ex p2 st p2 = x & p2`1 = b & p2`2 <= d & p2`2 >= c by A45; hence contradiction by A1,A46; end; then A47: L1 /\ L4 = {} by XBOOLE_0:def 7; thus L~f1 /\ L~f2 = (L1 \/ L2) /\ L3 \/ (L1 \/ L2) /\ L4 by A22,A40,XBOOLE_1:23 .= L1 /\ L3 \/ L2 /\ L3 \/ (L1 \/ L2) /\ L4 by XBOOLE_1:23 .= L1 /\ L3 \/ (L1 /\ L4 \/ L2 /\ L4) by A43,XBOOLE_1:23 .= {p0, p1} by A1,A44,A47,ENUMSET1:41; thus f1/.1 = p0 & f1/.len f1=p1 & f2/.1 = p0 & f2/.len f2 = p1 by A1,A5,A23,FINSEQ_4:27; end; theorem Th59: for P,P1,P2 being Subset of TOP-REAL 2, a,b,c,d being real number, f1,f2 being FinSequence of TOP-REAL 2,p1,p2 being Point of TOP-REAL 2 st a < b & c < d & P={p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} & p1=|[a,c]| & p2=|[b,d]| & f1=<*|[a,c]|,|[a,d]|,|[b,d]|*> & f2=<*|[a,c]|,|[b,c]|,|[b,d]|*> & P1=L~f1 & P2=L~f2 holds P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 is non empty & P2 is non empty & P = P1 \/ P2 & P1 /\ P2 = {p1,p2} proof let P,P1,P2 be Subset of TOP-REAL 2, a,b,c,d be real number, f1,f2 be FinSequence of TOP-REAL 2,p1,p2 be Point of TOP-REAL 2; assume A1: a < b & c < d & P={p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} & p1=|[a,c]| & p2=|[b,d]| & f1=<*|[a,c]|,|[a,d]|,|[b,d]|*> & f2=<*|[a,c]|,|[b,c]|,|[b,d]|*> & P1=L~f1 & P2=L~f2; (|[a,c]|)`2=c by EUCLID:56; then A2: |[a,c]|<>|[a,d]| or |[a,d]|<>|[b,d]| by A1,EUCLID:56; A3: P1=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th58; A4: LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|)={|[a,d]|} by A1,Th44; (|[b,c]|)`2=c by EUCLID:56; then A5: |[a,c]|<>|[b,c]| or |[b,c]|<>|[b,d]| by A1,EUCLID:56; A6: P2=LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) by A1,Th58; LSeg(|[a,c]|,|[b,c]|) /\ LSeg(|[b,c]|,|[b,d]|)={|[b,c]|} by A1,Th42; hence thesis by A1,A2,A3,A4,A5,A6,Th58,TOPREAL1:18; end; theorem Th60: for a,b,c,d being real number st a < b & c < d holds rectangle(a,b,c,d) is_simple_closed_curve proof let a,b,c,d be real number; assume A1: a < b & c < d; set P=rectangle(a,b,c,d); set p1=|[a,c]|,p2=|[b,d]|; reconsider f1=<*|[a,c]|,|[a,d]|,|[b,d]|*> as FinSequence of TOP-REAL 2; reconsider f2=<*|[a,c]|,|[b,c]|,|[b,d]|*> as FinSequence of TOP-REAL 2; set P1=L~f1,P2=L~f2; A2: a < b & c < d & P={p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} & p1=|[a,c]| & p2=|[b,d]| & f1=<*|[a,c]|,|[a,d]|,|[b,d]|*> & f2=<*|[a,c]|,|[b,c]|,|[b,d]|*> & P1=L~f1 & P2=L~f2 implies P1 is_an_arc_of p1,p2 & P2 is_an_arc_of p1,p2 & P1 is non empty & P2 is non empty & P = P1 \/ P2 & P1 /\ P2 = {p1,p2} by Th59; (|[a,c]|)`1=a by EUCLID:56; then A3: p1<>p2 by A1,EUCLID:56; p1 in P1 /\ P2 by A1,A2,Def1,TARSKI:def 2; then p1 in P1 by XBOOLE_0:def 3; then A4: p1 in P by A1,A2,Def1,XBOOLE_0:def 2; p2 in P1 /\ P2 by A1,A2,Def1,TARSKI:def 2; then p2 in P1 by XBOOLE_0:def 3; then p2 in P by A1,A2,Def1,XBOOLE_0:def 2; hence thesis by A1,A2,A3,A4,Def1,TOPREAL2:6; end; theorem Th61: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<b & c <d holds Upper_Arc(K)= LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<b & c <d; then A2: K is_simple_closed_curve by Th60; set P=K; A3: W-min(K)= |[a,c]| by A1,Th56; A4: E-max(K)= |[b,d]| by A1,Th56; reconsider U= LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) as non empty Subset of TOP-REAL 2; A5: U is_an_arc_of W-min(P),E-max(P) by A1,Th57; reconsider P3= LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) as non empty Subset of TOP-REAL 2; A6: P3 is_an_arc_of E-max(P),W-min(P) by A1,Th57; reconsider f1=<* |[a,c]|,|[a,d]|,|[b,d]| *>, f2=<* |[a,c]|,|[b,c]|,|[b,d]| *> as FinSequence of TOP-REAL 2; set p0=|[a,c]|,p01=|[a,d]|,p10=|[b,c]|,p1=|[b,d]|; A7: a < b & c < d & K={p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} & p0=|[a,c]| & p1=|[b,d]| & p01=|[a,d]| & p10=|[b,c]| & f1=<*p0,p01,p1*> & f2=<*p0,p10,p1*> implies f1 is_S-Seq & L~f1 = LSeg(p0,p01) \/ LSeg(p01,p1) & f2 is_S-Seq & L~f2 = LSeg(p0,p10) \/ LSeg(p10,p1) & K = L~f1 \/ L~f2 & L~f1 /\ L~f2 = {p0,p1} & f1/.1 = p0 & f1/.len f1=p1 & f2/.1 = p0 & f2/.len f2 = p1 by Th58; A8: Vertical_Line((W-bound(P)+E-bound(P))/2) = Vertical_Line((a+E-bound(P))/2) by A1,Th46 .= Vertical_Line((a+b)/2) by A1,Th48; set Q=Vertical_Line((W-bound(P)+E-bound(P))/2); reconsider a2=a,b2=b,c2=c,d2=d as Real by XREAL_0:def 1; A9: U /\ Vertical_Line((W-bound(P)+E-bound(P))/2) ={|[(a+b)/2,d]|} proof thus U /\ Vertical_Line((W-bound(P)+E-bound(P))/2) c= {|[(a+b)/2,d]|} proof let x be set;assume x in U /\ Vertical_Line((W-bound(P)+E-bound(P))/2); then A10: x in U & x in Vertical_Line((W-bound(P)+E-bound(P))/2) by XBOOLE_0:def 3; then x in {p where p is Point of TOP-REAL 2: p`1=(a+b)/2} by A8,JORDAN6:def 6; then consider p such that A11: x=p & p`1=(a+b)/2; now assume p in LSeg(|[a,c]|,|[a,d]|); then p in LSeg(|[a2,c2]|,|[a2,d2]|); then p`1=a by TOPREAL3:17; then a+a=(a+b)/2*2 by A11,XCMPLX_1:11 .=a+b by XCMPLX_1:88; then a+b-a=a by XCMPLX_1:26; hence contradiction by A1,XCMPLX_1:26; end; then p in LSeg(|[a2,d2]|,|[b2,d2]|) by A10,A11,XBOOLE_0:def 2; then p`2=d by TOPREAL3:18; then x=|[(a+b)/2,d]| by A11,EUCLID:57; hence x in {|[(a+b)/2,d]|} by TARSKI:def 1; end; let x be set;assume x in {|[(a+b)/2,d]|}; then A12: x= |[(a+b)/2,d]| by TARSKI:def 1; (|[(a+b)/2,d]|)`1= (a+b)/2 by EUCLID:56; then x in {p where p is Point of TOP-REAL 2: p`1=(a+b)/2} by A12; then A13: x in Vertical_Line((W-bound(P)+E-bound(P))/2) by A8,JORDAN6:def 6; A14: (|[b,d]|)`1=b & (|[b,d]|)`2=d by EUCLID:56; (|[a,d]|)`1=a & (|[a,d]|)`2=d by EUCLID:56; then x in LSeg(|[b,d]|,|[a,d]|) by A1,A12,A14,TOPREAL3:19; then x in U by XBOOLE_0:def 2; hence x in U /\ Vertical_Line((W-bound(P)+E-bound(P))/2) by A13,XBOOLE_0:def 3 ; end; then |[(a+b)/2,d]| in U /\ Q by TARSKI:def 1; then A15: U meets Q by XBOOLE_0:4; A16: Q is closed by JORDAN6:33; U is closed by A5,JORDAN6:12; then U /\ Q is closed by A16,TOPS_1:35; then First_Point(U,W-min(P),E-max(P), Vertical_Line((W-bound(P)+E-bound(P))/2)) in {|[(a+b)/2,d]|} by A5,A9,A15,JORDAN5C:def 1; then First_Point(U,W-min(P),E-max(P), Vertical_Line((W-bound(P)+E-bound(P))/2)) = |[(a+b)/2,d]| by TARSKI:def 1; then A17: First_Point(U,W-min(P),E-max(P), Vertical_Line((W-bound(P)+E-bound(P))/2))`2=d by EUCLID:56; A18: P3 /\ Vertical_Line((W-bound(P)+E-bound(P))/2) ={|[(a+b)/2,c]|} proof thus P3 /\ Vertical_Line((W-bound(P)+E-bound(P))/2) c= {|[(a+b)/2,c]|} proof let x be set;assume x in P3 /\ Vertical_Line((W-bound(P)+E-bound(P))/2); then A19: x in P3 & x in Vertical_Line((W-bound(P)+E-bound(P))/2) by XBOOLE_0:def 3; then x in {p where p is Point of TOP-REAL 2: p`1=(a+b)/2} by A8,JORDAN6:def 6; then consider p such that A20: x=p & p`1=(a+b)/2; now assume p in LSeg(|[b,c]|,|[b,d]|); then p in LSeg(|[b2,c2]|,|[b2,d2]|); then p`1= b by TOPREAL3:17; then b+b=(a+b)/2*2 by A20,XCMPLX_1:11 .=a+b by XCMPLX_1:88; then a+b-b=b by XCMPLX_1:26; hence contradiction by A1,XCMPLX_1:26; end; then p in LSeg(|[a2,c2]|,|[b2,c2]|) by A19,A20,XBOOLE_0:def 2; then p`2= c by TOPREAL3:18; then x=|[(a+b)/2,c]| by A20,EUCLID:57; hence x in {|[(a+b)/2,c]|} by TARSKI:def 1; end; let x be set;assume x in {|[(a+b)/2,c]|}; then A21: x= |[(a+b)/2,c]| by TARSKI:def 1; (|[(a+b)/2,c]|)`1= (a+b)/2 by EUCLID:56; then x in {p where p is Point of TOP-REAL 2: p`1=(a+b)/2} by A21; then A22: x in Vertical_Line((W-bound(P)+E-bound(P))/2) by A8,JORDAN6:def 6; A23: (|[b,c]|)`1=b & (|[b,c]|)`2=c by EUCLID:56; (|[a,c]|)`1=a & (|[a,c]|)`2=c by EUCLID:56; then |[(b+a)/2,c]| in LSeg(|[a,c]|,|[b,c]|) by A1,A23,TOPREAL3:19; then x in P3 by A21,XBOOLE_0:def 2; hence x in P3 /\ Vertical_Line((W-bound(P)+E-bound(P))/2) by A22,XBOOLE_0:def 3; end; then |[(a+b)/2,c]| in P3 /\ Q by TARSKI:def 1; then A24: P3 meets Q by XBOOLE_0:4; P3 is closed by A6,JORDAN6:12; then P3 /\ Q is closed by A16,TOPS_1:35; then Last_Point(P3,E-max(P),W-min(P), Vertical_Line((W-bound(P)+E-bound(P))/2)) in {|[(a+b)/2,c]|} by A6,A18,A24,JORDAN5C:def 2; then Last_Point(P3,E-max(P),W-min(P), Vertical_Line((W-bound(P)+E-bound(P))/2)) = |[(a+b)/2,c]| by TARSKI:def 1; then Last_Point(P3,E-max(P),W-min(P), Vertical_Line((W-bound(P)+E-bound(P))/2))`2 = c by EUCLID:56; hence Upper_Arc(K)= LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,A2,A3,A4,A5,A6,A7,A17,Def1,JORDAN6:def 8; end; theorem Th62: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number st K=rectangle(a,b,c,d) & a<b & c <d holds Lower_Arc(K)= LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number; assume A1: K=rectangle(a,b,c,d) & a<b & c <d; then A2: K is_simple_closed_curve by Th60; set P=K; A3: W-min(K)= |[a,c]| by A1,Th56; A4: E-max(K)= |[b,d]| by A1,Th56; reconsider U= LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) as non empty Subset of TOP-REAL 2; A5: U is_an_arc_of W-min(P),E-max(P) by A1,Th57; reconsider P3= LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) as non empty Subset of TOP-REAL 2; A6: P3 is_an_arc_of E-max(P),W-min(P) by A1,Th57; reconsider f1=<* |[a,c]|,|[a,d]|,|[b,d]| *>, f2=<* |[a,c]|,|[b,c]|,|[b,d]| *> as FinSequence of TOP-REAL 2; set p0=|[a,c]|,p01=|[a,d]|,p10=|[b,c]|,p1=|[b,d]|; A7: a < b & c < d & K={p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} & p0=|[a,c]| & p1=|[b,d]| & p01=|[a,d]| & p10=|[b,c]| & f1=<*p0,p01,p1*> & f2=<*p0,p10,p1*> implies f1 is_S-Seq & L~f1 = LSeg(p0,p01) \/ LSeg(p01,p1) & f2 is_S-Seq & L~f2 = LSeg(p0,p10) \/ LSeg(p10,p1) & K = L~f1 \/ L~f2 & L~f1 /\ L~f2 = {p0,p1} & f1/.1 = p0 & f1/.len f1=p1 & f2/.1 = p0 & f2/.len f2 = p1 by Th58; A8: Vertical_Line((W-bound(P)+E-bound(P))/2) = Vertical_Line((a+E-bound(P))/2) by A1,Th46 .= Vertical_Line((a+b)/2) by A1,Th48; set Q=Vertical_Line((W-bound(P)+E-bound(P))/2); reconsider a2=a,b2=b,c2=c,d2=d as Real by XREAL_0:def 1; A9: U /\ Vertical_Line((W-bound(P)+E-bound(P))/2) ={|[(a+b)/2,d]|} proof thus U /\ Vertical_Line((W-bound(P)+E-bound(P))/2) c= {|[(a+b)/2,d]|} proof let x be set;assume x in U /\ Vertical_Line((W-bound(P)+E-bound(P))/2); then A10: x in U & x in Vertical_Line((W-bound(P)+E-bound(P))/2) by XBOOLE_0:def 3; then x in {p where p is Point of TOP-REAL 2: p`1=(a+b)/2} by A8,JORDAN6:def 6; then consider p such that A11: x=p & p`1=(a+b)/2; now assume p in LSeg(|[a,c]|,|[a,d]|); then p in LSeg(|[a2,c2]|,|[a2,d2]|); then p`1=a by TOPREAL3:17; then a+a=(a+b)/2*2 by A11,XCMPLX_1:11 .=a+b by XCMPLX_1:88; then a+b-a=a by XCMPLX_1:26; hence contradiction by A1,XCMPLX_1:26; end; then p in LSeg(|[a2,d2]|,|[b2,d2]|) by A10,A11,XBOOLE_0:def 2; then p`2=d by TOPREAL3:18; then x=|[(a+b)/2,d]| by A11,EUCLID:57; hence x in {|[(a+b)/2,d]|} by TARSKI:def 1; end; let x be set;assume x in {|[(a+b)/2,d]|}; then A12: x= |[(a+b)/2,d]| by TARSKI:def 1; (|[(a+b)/2,d]|)`1= (a+b)/2 by EUCLID:56; then x in {p where p is Point of TOP-REAL 2: p`1=(a+b)/2} by A12; then A13: x in Vertical_Line((W-bound(P)+E-bound(P))/2) by A8,JORDAN6:def 6; A14: (|[b,d]|)`1=b & (|[b,d]|)`2=d by EUCLID:56; (|[a,d]|)`1=a & (|[a,d]|)`2=d by EUCLID:56; then x in LSeg(|[b,d]|,|[a,d]|) by A1,A12,A14,TOPREAL3:19; then x in U by XBOOLE_0:def 2; hence x in U /\ Vertical_Line((W-bound(P)+E-bound(P))/2) by A13,XBOOLE_0:def 3 ; end; then |[(a+b)/2,d]| in U /\ Q by TARSKI:def 1; then A15: U meets Q by XBOOLE_0:4; A16: Q is closed by JORDAN6:33; U is closed by A5,JORDAN6:12; then U /\ Q is closed by A16,TOPS_1:35; then First_Point(U,W-min(P),E-max(P), Vertical_Line((W-bound(P)+E-bound(P))/2)) in {|[(a+b)/2,d]|} by A5,A9,A15,JORDAN5C:def 1; then First_Point(U,W-min(P),E-max(P), Vertical_Line((W-bound(P)+E-bound(P))/2)) = |[(a+b)/2,d]| by TARSKI:def 1; then A17: First_Point(U,W-min(P),E-max(P), Vertical_Line((W-bound(P)+E-bound(P))/2))`2=d by EUCLID:56; A18: P3 /\ Vertical_Line((W-bound(P)+E-bound(P))/2) ={|[(a+b)/2,c]|} proof thus P3 /\ Vertical_Line((W-bound(P)+E-bound(P))/2) c= {|[(a+b)/2,c]|} proof let x be set;assume x in P3 /\ Vertical_Line((W-bound(P)+E-bound(P))/2); then A19: x in P3 & x in Vertical_Line((W-bound(P)+E-bound(P))/2) by XBOOLE_0:def 3; then x in {p where p is Point of TOP-REAL 2: p`1=(a+b)/2} by A8,JORDAN6:def 6; then consider p such that A20: x=p & p`1=(a+b)/2; now assume p in LSeg(|[b,c]|,|[b,d]|); then p in LSeg(|[b2,c2]|,|[b2,d2]|); then p`1= b by TOPREAL3:17; then b+b=(a+b)/2*2 by A20,XCMPLX_1:11 .=a+b by XCMPLX_1:88; then a+b-b=b by XCMPLX_1:26; hence contradiction by A1,XCMPLX_1:26; end; then p in LSeg(|[a2,c2]|,|[b2,c2]|) by A19,A20,XBOOLE_0:def 2; then p`2= c by TOPREAL3:18; then x=|[(a+b)/2,c]| by A20,EUCLID:57; hence x in {|[(a+b)/2,c]|} by TARSKI:def 1; end; let x be set;assume x in {|[(a+b)/2,c]|}; then A21: x= |[(a+b)/2,c]| by TARSKI:def 1; (|[(a+b)/2,c]|)`1= (a+b)/2 by EUCLID:56; then x in {p where p is Point of TOP-REAL 2: p`1=(a+b)/2} by A21; then A22: x in Vertical_Line((W-bound(P)+E-bound(P))/2) by A8,JORDAN6:def 6; A23: (|[b,c]|)`1=b & (|[b,c]|)`2=c by EUCLID:56; (|[a,c]|)`1=a & (|[a,c]|)`2=c by EUCLID:56; then |[(a+b)/2,c]| in LSeg(|[a,c]|,|[b,c]|) by A1,A23,TOPREAL3:19; then x in P3 by A21,XBOOLE_0:def 2; hence x in P3 /\ Vertical_Line((W-bound(P)+E-bound(P))/2) by A22,XBOOLE_0:def 3; end; then |[(a+b)/2,c]| in P3 /\ Q by TARSKI:def 1; then A24: P3 meets Q by XBOOLE_0:4; P3 is closed by A6,JORDAN6:12; then P3 /\ Q is closed by A16,TOPS_1:35; then Last_Point(P3,E-max(P),W-min(P), Vertical_Line((W-bound(P)+E-bound(P))/2)) in {|[(a+b)/2,c]|} by A6,A18,A24,JORDAN5C:def 2; then Last_Point(P3,E-max(P),W-min(P), Vertical_Line((W-bound(P)+E-bound(P))/2)) = |[(a+b)/2,c]| by TARSKI:def 1; then Last_Point(P3,E-max(P),W-min(P), Vertical_Line((W-bound(P)+E-bound(P))/2))`2 = c by EUCLID:56; then P3 is_an_arc_of E-max(P),W-min(P) & Upper_Arc(P) /\ P3={W-min(P),E-max(P)} & Upper_Arc(P) \/ P3=P & First_Point(Upper_Arc(P),W-min(P),E-max(P), Vertical_Line((W-bound(P)+E-bound(P))/2))`2> Last_Point(P3,E-max(P),W-min(P), Vertical_Line((W-bound(P)+E-bound(P))/2))`2 by A1,A3,A4,A7,A17,Def1, Th57,Th61; hence Lower_Arc(K)= LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) by A2,JORDAN6:def 9; end; theorem Th63: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d ex f being map of I[01],(TOP-REAL 2)|(Upper_Arc(K)) st f is_homeomorphism & f.0=W-min(K) & f.1=E-max(K) & rng f=Upper_Arc(K) & (for r being Real st r in [.0,1/2 .] holds f.r=(1-2*r)*|[a,c]|+(2*r)*|[a,d]|)& (for r being Real st r in [.1/2,1 .] holds f.r=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]|)& (for p being Point of TOP-REAL 2 st p in LSeg(|[a,c]|,|[a,d]|) holds 0<=((p`2)-c)/(d-c)/2 & ((p`2)-c)/(d-c)/2<=1 & f.(((p`2)-c)/(d-c)/2)=p)& (for p being Point of TOP-REAL 2 st p in LSeg(|[a,d]|,|[b,d]|) holds 0<=((p`1)-a)/(b-a)/2 + 1/2 & ((p`1)-a)/(b-a)/2 + 1/2<=1 & f.(((p`1)-a)/(b-a)/2 + 1/2)=p) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d; reconsider a2=a,b2=b,c2=c,d2=d as Real by XREAL_0:def 1; defpred P[set,set] means for r being Real st $1=r holds (r in [.0,1/2 .] implies $2=(1-2*r)*|[a,c]|+(2*r)*|[a,d]|) & (r in [.1/2,1 .] implies $2=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]|); A2: [.0,1.]=[.0,1/2 .] \/ [.1/2,1 .] by HEINE:2; A3: for x,y1,y2 being set st x in [.0,1.] & P[x,y1] & P[x,y2] holds y1 = y2 proof let x,y1,y2 be set; assume A4: x in [.0,1.] & P[x,y1] & P[x,y2]; now per cases by A2,A4,XBOOLE_0:def 2; case A5: x in [.0,1/2.]; then reconsider r=x as Real; y1= (1-2*r)*|[a,c]|+(2*r)*|[a,d]| by A4,A5; hence y1=y2 by A4,A5; case A6: x in [.1/2,1.]; then reconsider r=x as Real; y1= (1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]| by A4,A6; hence y1=y2 by A4,A6; end; hence y1 = y2; end; A7: for x being set st x in [.0,1.] ex y being set st P[x,y] proof let x be set;assume A8: x in [.0,1.]; now per cases by A2,A8,XBOOLE_0:def 2; case A9: x in [.0,1/2.]; then reconsider r=x as Real; A10: 0<=r & r<=1/2 by A9,TOPREAL5:1; set y0= (1-2*r)*|[a,c]|+(2*r)*|[a,d]|; r in [.1/2,1.] implies y0=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]| proof assume r in [.1/2,1.]; then 1/2 <=r & r<=1 by TOPREAL5:1; then A11: r=1/2 by A10,AXIOMS:21; then A12: y0= (0)*|[a,c]|+|[a,d]| by EUCLID:33 .= (0.REAL 2) + |[a,d]| by EUCLID:33 .= |[a,d]| by EUCLID:31; (1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]| = (1)*|[a,d]|+0.REAL 2 by A11,EUCLID:33 .= |[a,d]|+0.REAL 2 by EUCLID:33 .= |[a,d]| by EUCLID:31; hence y0=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]| by A12; end; then for r2 being Real st x=r2 holds (r2 in [.0,1/2.] implies y0=(1-2*r2)*|[a,c]|+(2*r2)*|[a,d]|) & (r2 in [.1/2,1.] implies y0=(1-(2*r2-1))*|[a,d]|+(2*r2-1)*|[b,d]|); hence ex y being set st P[x,y]; case A13: x in [.1/2,1.]; then reconsider r=x as Real; A14: 1/2<=r & r<=1 by A13,TOPREAL5:1; set y0= (1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]|; r in [.0,1/2.] implies y0=(1-2*r)*|[a,c]|+(2*r)*|[a,d]| proof assume r in [.0,1/2.]; then 0 <=r & r<=1/2 by TOPREAL5:1; then A15: r=1/2 by A14,AXIOMS:21; then A16: y0= |[a,d]|+(0)*|[b,d]| by EUCLID:33 .= |[a,d]|+(0.REAL 2) by EUCLID:33 .= |[a,d]| by EUCLID:31; (1-2*r)*|[a,c]|+(2*r)*|[a,d]| = 0.REAL 2+(1)*|[a,d]| by A15,EUCLID:33 .= 0.REAL 2+|[a,d]| by EUCLID:33 .= |[a,d]| by EUCLID:31; hence y0=(1-2*r)*|[a,c]|+(2*r)*|[a,d]| by A16; end; then for r2 being Real st x=r2 holds (r2 in [.0,1/2.] implies y0=(1-2*r2)*|[a,c]|+(2*r2)*|[a,d]|) & (r2 in [.1/2,1.] implies y0=(1-(2*r2-1))*|[a,d]|+(2*r2-1)*|[b,d]|); hence ex y being set st P[x,y]; end; hence ex y being set st P[x,y]; end; ex f2 being Function st dom f2 = [.0,1.] & for x being set st x in [.0,1.] holds P[x,f2.x] from FuncEx(A3,A7); then consider f2 being Function such that A17: dom f2 = [.0,1.] & for x being set st x in [.0,1.] holds P[x,f2.x]; rng f2 c= the carrier of (TOP-REAL 2)|(Upper_Arc(K)) proof let y be set;assume y in rng f2; then consider x being set such that A18: x in dom f2 & y=f2.x by FUNCT_1:def 5; now per cases by A2,A17,A18,XBOOLE_0:def 2; case A19: x in [.0,1/2.]; then reconsider r=x as Real; A20: 0<=r & r<=1/2 by A19,TOPREAL5:1; then A21: r*2<=1/2*2 by AXIOMS:25; A22: 2*0<=2*r by A20,AXIOMS:25; f2.x= (1-2*r)*|[a,c]|+(2*r)*|[a,d]| by A17,A18,A19; then y in { (1-lambda)*|[a,c]| + lambda*|[a,d]| where lambda is Real: 0 <= lambda & lambda <= 1 } by A18,A21,A22; then A23: y in LSeg(|[a,c]|,|[a,d]|) by TOPREAL1:def 4; Upper_Arc(K)= LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; then y in Upper_Arc(K) by A23,XBOOLE_0:def 2; hence y in the carrier of (TOP-REAL 2)|(Upper_Arc(K)) by JORDAN1:1; case A24: x in [.1/2,1.]; then reconsider r=x as Real; A25: 1/2<=r & r<=1 by A24,TOPREAL5:1; then r*2>=1/2*2 by AXIOMS:25; then A26: 2*r-1>=0 by SQUARE_1:12; 2*1>=2*r by A25,AXIOMS:25; then A27: 1+1-1>=2*r-1 by REAL_1:49; f2.x= (1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]| by A17,A18,A24; then y in { (1-lambda)*|[a,d]| + lambda*|[b,d]| where lambda is Real: 0 <= lambda & lambda <= 1 } by A18,A26,A27; then A28: y in LSeg(|[a,d]|,|[b,d]|) by TOPREAL1:def 4; Upper_Arc(K)= LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; then y in Upper_Arc(K) by A28,XBOOLE_0:def 2; hence y in the carrier of (TOP-REAL 2)|(Upper_Arc(K)) by JORDAN1:1; end; hence y in the carrier of (TOP-REAL 2)|(Upper_Arc(K)); end; then f2 is Function of the carrier of I[01], the carrier of (TOP-REAL 2)|(Upper_Arc(K)) by A17,BORSUK_1:83,FUNCT_2 :4; then reconsider f3=f2 as map of I[01],(TOP-REAL 2)|(Upper_Arc(K)) ; A29: 0 in [.0,1.] by TOPREAL5:1; 0 in [.0,1/2.] by TOPREAL5:1; then A30: f3.0= (1-2*0)*|[a,c]|+(2*0)*|[a,d]| by A17,A29 .= (1)*|[a,c]|+0.REAL 2 by EUCLID:33 .= |[a,c]|+0.REAL 2 by EUCLID:33 .= |[a,c]| by EUCLID:31 .= W-min(K) by A1,Th56; A31: 1 in [.0,1.] by TOPREAL5:1; 1 in [.1/2,1.] by TOPREAL5:1; then A32: f3.1= (1-(2*1-1))*|[a,d]|+(2*1-1)*|[b,d]| by A17,A31 .= (0)*|[a,d]|+|[b,d]| by EUCLID:33 .= (0.REAL 2) + |[b,d]| by EUCLID:33 .= |[b,d]| by EUCLID:31 .= E-max(K) by A1,Th56; A33: for r being Real st r in [.0,1/2.] holds f3.r=(1-2*r)*|[a,c]|+(2*r)*|[a,d]| proof let r be Real; assume A34: r in [.0,1/2.]; then A35: 0<=r & r<=1/2 by TOPREAL5:1; then r<=1 by AXIOMS:22; then r in [.0,1.] by A35,TOPREAL5:1; hence f3.r=(1-2*r)*|[a,c]|+(2*r)*|[a,d]| by A17,A34; end; A36: for r being Real st r in [.1/2,1.] holds f3.r=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]| proof let r be Real; assume A37: r in [.1/2,1.]; then A38: 1/2<=r & r<=1 by TOPREAL5:1; then 0<=r by AXIOMS:22; then r in [.0,1.] by A38,TOPREAL5:1; hence f3.r=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]| by A17,A37; end; A39: (for p being Point of TOP-REAL 2 st p in LSeg(|[a,c]|,|[a,d]|) holds 0<=((p`2)-c)/(d-c)/2 & ((p`2)-c)/(d-c)/2<=1 & f3.(((p`2)-c)/(d-c)/2)=p) proof let p be Point of TOP-REAL 2; assume A40: p in LSeg(|[a,c]|,|[a,d]|); then p in LSeg(|[a2,c2]|,|[a2,d2]|); then A41: p`1=a by TOPREAL3:17; A42: (|[a,c]|)`2= c by EUCLID:56; (|[a,d]|)`2= d by EUCLID:56; then A43: c <=p`2 & p`2<=d by A1,A40,A42,TOPREAL1:10; A44: d-c>0 by A1,SQUARE_1:11; (p`2) -c >=0 by A43,SQUARE_1:12; then ((p`2) -c)/(d-c) >=0/(d-c) by A44,REAL_1:73; then A45: ((p`2) -c)/(d-c)/2 >=0/2 by REAL_1:73; A46: d-c>0 by A1,SQUARE_1:11; (p`2) -c <=d-c by A43,REAL_1:49; then ((p`2) -c)/(d-c) <=(d-c)/(d-c) by A46,REAL_1:73; then ((p`2) -c)/(d-c) <=1 by A46,XCMPLX_1:60; then A47: ((p`2) -c)/(d-c)/2 <=1/2 by REAL_1:73; set r=((p`2)-c)/(d-c)/2; A48: ((2*r)*d)-(2*r)*c = (2*r)*(d-c) by XCMPLX_1:40; r in [.0,1/2.] by A45,A47,TOPREAL5:1; then f3.(((p`2)-c)/(d-c)/2)=(1-2*r)*|[a,c]|+(2*r)*|[a,d]| by A33 .=|[(1-2*r)*a,(1-2*r)*c]|+(2*r)*|[a,d]| by EUCLID:62 .=|[(1-2*r)*a,(1-2*r)*c]|+|[(2*r)*a,(2*r)*d]| by EUCLID:62 .=|[(1-2*r)*a+(2*r)*a,(1-2*r)*c+(2*r)*d]| by EUCLID:60 .=|[1*a-(2*r)*a+(2*r)*a,(1-2*r)*c+(2*r)*d]| by XCMPLX_1:40 .=|[1*a,(1-2*r)*c+(2*r)*d]| by XCMPLX_1:27 .=|[a,1*c-(2*r)*c+(2*r)*d]| by XCMPLX_1:40 .=|[a,1*c+-((2*r)*c)+(2*r)*d]| by XCMPLX_0:def 8 .=|[a,1*c+((-((2*r)*c))+(2*r)*d)]| by XCMPLX_1:1 .=|[a,1*c+((2*r)*(d-c))]| by A48,XCMPLX_0:def 8 .=|[a,1*c+(((p`2)-c)/(d-c))*(d-c)]| by XCMPLX_1:88 .=|[a,1*c+((p`2)-c)]| by A46,XCMPLX_1:88 .=|[p`1,p`2]| by A41,XCMPLX_1:27 .= p by EUCLID:57; hence 0<=((p`2)-c)/(d-c)/2 & ((p`2)-c)/(d-c)/2<=1 & f3.(((p`2)-c)/(d-c)/2)=p by A45,A47,AXIOMS:22; end; A49: for p being Point of TOP-REAL 2 st p in LSeg(|[a,d]|,|[b,d]|) holds 0<=((p`1)-a)/(b-a)/2+1/2 & ((p`1)-a)/(b-a)/2+1/2<=1 & f3.(((p`1)-a)/(b-a)/2+1/2)=p proof let p be Point of TOP-REAL 2; assume A50: p in LSeg(|[a,d]|,|[b,d]|); then p in LSeg(|[a2,d2]|,|[b2,d2]|); then A51: p`2=d by TOPREAL3:18; A52: (|[a,d]|)`1= a by EUCLID:56; (|[b,d]|)`1= b by EUCLID:56; then A53: a <=p`1 & p`1<=b by A1,A50,A52,TOPREAL1:9; A54: b-a>0 by A1,SQUARE_1:11; (p`1) -a >=0 by A53,SQUARE_1:12; then ((p`1) -a)/(b-a) >=0/(b-a) by A54,REAL_1:73; then ((p`1) -a)/(b-a)/2 >=0/2 by REAL_1:73; then A55: ((p`1) -a)/(b-a)/2+1/2 >=0+1/2 by REAL_1:55; A56: b-a>0 by A1,SQUARE_1:11; (p`1) -a <=b-a by A53,REAL_1:49; then ((p`1) -a)/(b-a) <=(b-a)/(b-a) by A56,REAL_1:73; then ((p`1) -a)/(b-a) <=1 by A56,XCMPLX_1:60; then ((p`1) -a)/(b-a)/2 <=1/2 by REAL_1:73; then A57: ((p`1) -a)/(b-a)/2+1/2 <=1/2+1/2 by REAL_1:55; set r=((p`1)-a)/(b-a)/2+1/2; A58: r= (((p`1)-a)/(b-a)+1)/2 by XCMPLX_1:63; r in [.1/2,1.] by A55,A57,TOPREAL5:1; then f3.(((p`1)-a)/(b-a)/2+1/2)=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]| by A36 .=|[(1-(2*r-1))*a,(1-(2*r-1))*d]|+((2*r-1))*|[b,d]| by EUCLID:62 .=|[(1-(2*r-1))*a,(1-(2*r-1))*d]|+|[((2*r-1))*b,((2*r-1))*d]| by EUCLID:62 .=|[(1-(2*r-1))*a+((2*r-1))*b,(1-(2*r-1))*d+((2*r-1))*d]| by EUCLID:60 .=|[(1-(2*r-1))*a+((2*r-1))*b,1*d-(2*r-1)*d+((2*r-1))*d]| by XCMPLX_1:40 .=|[(1-(2*r-1))*a+((2*r-1))*b,1*d]| by XCMPLX_1:27 .=|[1*a-(2*r-1)*a+((2*r-1))*b,d]| by XCMPLX_1:40 .=|[1*a+-(((2*r-1))*a)+((2*r-1))*b,d]| by XCMPLX_0:def 8 .=|[1*a+((-(((2*r-1))*a))+((2*r-1))*b),d]| by XCMPLX_1:1 .=|[1*a+((((2*r-1))*b)-((2*r-1))*a),d]| by XCMPLX_0:def 8 .=|[1*a+(((2*r-1))*(b-a)),d]| by XCMPLX_1:40 .=|[1*a+(((p`1)-a)/(b-a)+1-1)*(b-a),d]| by A58,XCMPLX_1:88 .=|[1*a+(((p`1)-a)/(b-a))*(b-a),d]| by XCMPLX_1:26 .=|[1*a+((p`1)-a),d]| by A56,XCMPLX_1:88 .=|[p`1,p`2]| by A51,XCMPLX_1:27 .= p by EUCLID:57; hence 0<=((p`1)-a)/(b-a)/2+1/2 & ((p`1)-a)/(b-a)/2+1/2<=1 & f3.(((p`1)-a)/(b-a)/2+1/2)=p by A55,A57,AXIOMS:22; end; reconsider B00=[.0,1.] as Subset of R^1 by TOPMETR:24; reconsider B01=B00 as non empty Subset of R^1 by TOPREAL5:1; I[01]=(R^1)|B01 by TOPMETR:26,27; then consider h1 being map of I[01],R^1 such that A59: (for p being Point of I[01] holds h1.p=p) & h1 is continuous by Th14; consider h2 being map of I[01],R^1 such that A60: (for p being Point of I[01],r1 being real number st h1.p=r1 holds h2.p=2*r1) & h2 is continuous by A59,JGRAPH_2:33; consider h5 being map of I[01],R^1 such that A61: (for p being Point of I[01],r1 being real number st h2.p=r1 holds h5.p=1-r1) & h5 is continuous by A60,Th16; consider h3 being map of I[01],R^1 such that A62: (for p being Point of I[01],r1 being real number st h2.p=r1 holds h3.p=r1-1) & h3 is continuous by A60,Th15; consider h4 being map of I[01],R^1 such that A63: (for p being Point of I[01],r1 being real number st h3.p=r1 holds h4.p=1-r1) & h4 is continuous by A62,Th16; consider g1 being map of I[01],TOP-REAL 2 such that A64: (for r being Point of I[01] holds g1.r=(h5.r)*|[a,c]|+(h2.r)*|[a,d]|) & g1 is continuous by A60,A61,Th21; A65: for r being Point of I[01],s being real number st r=s holds g1.r=(1-2*s)*|[a,c]|+(2*s)*|[a,d]| proof let r be Point of I[01],s be real number; assume A66: r=s; g1.r=(h5.r)*|[a,c]|+(h2.r)*|[a,d]| by A64 .=(1-(h2.r))*|[a,c]|+(h2.r)*|[a,d]| by A61 .=(1-2*(h1.r))*|[a,c]|+(h2.r)*|[a,d]| by A60 .=(1-2*(h1.r))*|[a,c]|+(2*(h1.r))*|[a,d]| by A60 .=(1-2*s)*|[a,c]|+(2*(h1.r))*|[a,d]| by A59,A66 .=(1-2*s)*|[a,c]|+(2*s)*|[a,d]| by A59,A66; hence g1.r=(1-2*s)*|[a,c]|+(2*s)*|[a,d]|; end; consider g2 being map of I[01],TOP-REAL 2 such that A67: (for r being Point of I[01] holds g2.r=(h4.r)*|[a,d]|+(h3.r)*|[b,d]|) & g2 is continuous by A62,A63,Th21; A68: for r being Point of I[01],s being real number st r=s holds g2.r=(1-(2*s-1))*|[a,d]|+(2*s-1)*|[b,d]| proof let r be Point of I[01],s be real number; assume A69: r=s; g2.r=(h4.r)*|[a,d]|+(h3.r)*|[b,d]| by A67 .=(1-h3.r)*|[a,d]|+(h3.r)*|[b,d]| by A63 .=(1-((h2.r)-1))*|[a,d]|+(h3.r)*|[b,d]| by A62 .=(1-((h2.r)-1))*|[a,d]|+((h2.r)-1)*|[b,d]| by A62 .=(1-(2*(h1.r)-1))*|[a,d]|+((h2.r)-1)*|[b,d]| by A60 .=(1-(2*(h1.r)-1))*|[a,d]|+(2*(h1.r)-1)*|[b,d]| by A60 .=(1-(2*s-1))*|[a,d]|+(2*(h1.r)-1)*|[b,d]| by A59,A69 .=(1-(2*s-1))*|[a,d]|+(2*s-1)*|[b,d]| by A59,A69; hence g2.r=(1-(2*s-1))*|[a,d]|+(2*s-1)*|[b,d]|; end; [.0,1/2.] c= [.0,1.] by A2,XBOOLE_1:7; then reconsider B11=[.0,1/2.] as non empty Subset of I[01] by BORSUK_1:83,TOPREAL5:1; A70: dom (g1|B11)=dom g1 /\ B11 by FUNCT_1:68 .= (the carrier of I[01]) /\ B11 by FUNCT_2:def 1 .=B11 by XBOOLE_1:28 .=the carrier of (I[01]|B11) by JORDAN1:1; rng (g1|B11) c= rng g1 by FUNCT_1:76; then rng (g1|B11) c= the carrier of TOP-REAL 2 by XBOOLE_1:1; then g1|B11 is Function of the carrier of (I[01]|B11),the carrier of TOP-REAL 2 by A70,FUNCT_2:4; then reconsider g11=g1|B11 as map of I[01]|B11,TOP-REAL 2 ; A71: TOP-REAL 2=(TOP-REAL 2)|([#](TOP-REAL 2)) by TSEP_1:3; then A72: g11 is continuous by A64,BORSUK_4:69; [.1/2,1.] c= the carrier of I[01] by A2,BORSUK_1:83,XBOOLE_1:7; then reconsider B22=[.1/2,1.] as non empty Subset of I[01] by TOPREAL5:1; A73: dom (g2|B22)=dom g2 /\ B22 by FUNCT_1:68 .= (the carrier of I[01]) /\ B22 by FUNCT_2:def 1 .=B22 by XBOOLE_1:28 .=the carrier of (I[01]|B22) by JORDAN1:1; rng (g2|B22) c= rng g2 by FUNCT_1:76; then rng (g2|B22) c= the carrier of TOP-REAL 2 by XBOOLE_1:1; then g2|B22 is Function of the carrier of (I[01]|B22),the carrier of TOP-REAL 2 by A73,FUNCT_2:4; then reconsider g22=g2|B22 as map of I[01]|B22,TOP-REAL 2 ; A74: g22 is continuous by A67,A71,BORSUK_4:69; A75: B11=[#](I[01]|B11) by PRE_TOPC:def 10; A76: B22=[#](I[01]|B22) by PRE_TOPC:def 10; A77: B11 is closed by Th12; A78: B22 is closed by Th12; B11 \/ B22=[.0,1.] by HEINE:2; then A79: [#](I[01]|B11) \/ [#](I[01]|B22)=[#]I[01] by A75,A76,BORSUK_1:83,PRE_TOPC:12; for p being set st p in ([#](I[01]|B11)) /\ ([#](I[01]|B22)) holds g11.p = g22.p proof let p be set;assume p in ([#](I[01]|B11)) /\ ([#](I[01]|B22)); then p in [#](I[01]|B11) & p in [#](I[01]|B22) by XBOOLE_0:def 3; then A80: p in B11 & p in B22 by PRE_TOPC:def 10; then reconsider rp=p as Real; A81: rp<=1/2 by A80,TOPREAL5:1; rp>=1/2 by A80,TOPREAL5:1; then rp=1/2 by A81,AXIOMS:21; then A82: 2*rp=1; thus g11.p=g1.p by A80,FUNCT_1:72 .= (1-1)*|[a,c]|+(1)*|[a,d]| by A65,A80,A82 .=0.REAL 2 +1*|[a,d]| by EUCLID:33 .=(1-0)*|[a,d]| +(1-1)*|[b,d]| by EUCLID:33 .=g2.p by A68,A80,A82 .=g22.p by A80,FUNCT_1:72; end; then consider h being map of I[01],TOP-REAL 2 such that A83: h=g11+*g22 & h is continuous by A72,A74,A75,A76,A77,A78,A79,JGRAPH_2:9; A84: dom f3=dom h & dom f3=the carrier of I[01] by Th13; for x being set st x in dom f2 holds f3.x=h.x proof let x be set; assume A85: x in dom f2; then reconsider rx=x as Real by A84,BORSUK_1:83; A86: 0<=rx & rx<=1 by A84,A85,BORSUK_1:83,TOPREAL5:1; now per cases; case A87: rx<1/2; then A88: rx in [.0,1/2.] by A86,TOPREAL5:1; now assume rx in dom g22; then rx in B22 by A76,Th13; hence contradiction by A87,TOPREAL5:1; end; then h.rx=g11.rx by A83,FUNCT_4:12 .=g1.rx by A88,FUNCT_1:72 .=(1-(2*rx))*|[a,c]|+(2*rx)*|[a,d]| by A65,A84,A85 .=f3.rx by A33,A88; hence f3.x=h.x; case rx >=1/2; then A89: rx in [.1/2,1.] by A86,TOPREAL5:1; then rx in [#](I[01]|B22) by PRE_TOPC:def 10; then h.rx=g22.rx by A73,A83,FUNCT_4:14 .=g2.rx by A89,FUNCT_1:72 .=(1-(2*rx-1))*|[a,d]|+(2*rx-1)*|[b,d]| by A68,A84,A85 .=f3.rx by A36,A89; hence f3.x=h.x; end; hence f3.x=h.x; end; then f2=h by A84,FUNCT_1:9; then A90: f3 is continuous by A83,JGRAPH_1:63; A91: dom f3=[#](I[01]) by A17,BORSUK_1:83,PRE_TOPC:12; for x1,x2 being set st x1 in dom f3 & x2 in dom f3 & f3.x1=f3.x2 holds x1=x2 proof let x1,x2 be set; assume A92: x1 in dom f3 & x2 in dom f3 & f3.x1=f3.x2; then reconsider r1=x1 as Real by A17; reconsider r2=x2 as Real by A17,A92; A93: LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|) = {|[a,d]|} by A1,Th44; now per cases by A2,A17,A92,XBOOLE_0:def 2; case A94: x1 in [.0,1/2.] & x2 in [.0,1/2.]; then f3.r1=(1-2*r1)*|[a,c]|+(2*r1)*|[a,d]| by A33; then (1-2*r2)*|[a,c]|+(2*r2)*|[a,d]|= (1-2*r1)*|[a,c]|+(2*r1)*|[a,d]| by A33,A92,A94; then (1-2*r2)*|[a,c]|+(2*r2)*|[a,d]| -(2*r1)*|[a,d]| = (1-2*r1)*|[a,c]| by EUCLID:52; then (1-2*r2)*|[a,c]|+((2*r2)*|[a,d]| -(2*r1)*|[a,d]|) = (1-2*r1)*|[a,c]| by EUCLID:49; then (1-2*r2)*|[a,c]|+(2*r2-2*r1)*(|[a,d]|) = (1-2*r1)*|[a,c]| by EUCLID:54; then (2*r2-2*r1)*(|[a,d]|)+((1-2*r2)*|[a,c]|-(1-2*r1)*|[a,c]|) = (1-2*r1)*|[a,c]|-(1-2*r1)*|[a,c]| by EUCLID:49; then (2*r2-2*r1)*(|[a,d]|)+((1-2*r2)*|[a,c]|-(1-2*r1)*|[a,c]|) = 0.REAL 2 by EUCLID:46; then (2*r2-2*r1)*(|[a,d]|)+((1-2*r2)-(1-2*r1))*|[a,c]| = 0.REAL 2 by EUCLID:54; then (2*r2-2*r1)*(|[a,d]|)+(-(2*r2-2*r1))*|[a,c]| = 0.REAL 2 by XCMPLX_1:149; then (2*r2-2*r1)*(|[a,d]|)+-((2*r2-2*r1)*|[a,c]|) = 0.REAL 2 by EUCLID:44; then (2*r2-2*r1)*(|[a,d]|)-((2*r2-2*r1)*|[a,c]|) = 0.REAL 2 by EUCLID:45; then (2*r2-2*r1)*((|[a,d]|)-(|[a,c]|)) = 0.REAL 2 by EUCLID:53; then (2*r2-2*r1)=0 or (|[a,d]|)-(|[a,c]|)=0.REAL 2 by EUCLID:35; then (2*r2-2*r1)=0 or |[a,d]|=|[a,c]| by EUCLID:47; then (2*r2-2*r1)=0 or d =|[a,c]|`2 by EUCLID:56; then 2*r2=2*r1 by A1,EUCLID:56,XCMPLX_1:15; then r2=r1*2/2 by XCMPLX_1:90; hence x1=x2 by XCMPLX_1:90; case A95: x1 in [.0,1/2.] & x2 in [.1/2,1.]; then A96: f3.r1=(1-2*r1)*|[a,c]|+(2*r1)*|[a,d]| by A33; A97: 0<=r1 & r1<=1/2 by A95,TOPREAL5:1; then A98: r1*2<=1/2*2 by AXIOMS:25; 2*0<=2*r1 by A97,AXIOMS:25; then f3.r1 in { (1-lambda)*|[a,c]| + lambda*|[a,d]| where lambda is Real : 0 <= lambda & lambda <= 1 } by A96,A98; then A99: f3.r1 in LSeg(|[a,c]|,|[a,d]|) by TOPREAL1:def 4; A100: f3.r2=(1-(2*r2-1))*|[a,d]|+(2*r2-1)*|[b,d]| by A36,A95; A101: 1/2<=r2 & r2<=1 by A95,TOPREAL5:1; then r2*2>=1/2*2 by AXIOMS:25; then A102: 2*r2-1>=0 by SQUARE_1:12; 2*1>=2*r2 by A101,AXIOMS:25; then 1+1-1>=2*r2-1 by REAL_1:49; then f3.r2 in { (1-lambda)*|[a,d]| + lambda*|[b,d]| where lambda is Real : 0 <= lambda & lambda <= 1 } by A100,A102; then f3.r2 in LSeg(|[a,d]|,|[b,d]|) by TOPREAL1:def 4; then f3.r1 in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|) by A92,A99,XBOOLE_0:def 3; then A103: f3.r1= |[a,d]| by A93,TARSKI:def 1; then (1-2*r1)*|[a,c]|+(2*r1)*|[a,d]|+-(|[a,d]|)=0.REAL 2 by A96,EUCLID:40; then (1-2*r1)*|[a,c]|+(2*r1)*|[a,d]|+(-1)*|[a,d]|=0.REAL 2 by EUCLID:43; then (1-2*r1)*|[a,c]|+((2*r1)*|[a,d]|+(-1)*|[a,d]|)=0.REAL 2 by EUCLID:30; then (1-2*r1)*|[a,c]|+((2*r1)+(-1))*|[a,d]|=0.REAL 2 by EUCLID:37; then (1-2*r1)*|[a,c]|+(-(1-(2*r1)))*|[a,d]|=0.REAL 2 by XCMPLX_1:162; then (1-2*r1)*|[a,c]|+-((1-(2*r1))*|[a,d]|)=0.REAL 2 by EUCLID:44; then (1-2*r1)*|[a,c]|-((1-(2*r1))*|[a,d]|)=0.REAL 2 by EUCLID:45; then (1-2*r1)*(|[a,c]|-(|[a,d]|))=0.REAL 2 by EUCLID:53; then 1-2*r1=0 or (|[a,c]|-(|[a,d]|))=0.REAL 2 by EUCLID:35; then 1-2*r1=0 or |[a,c]|=|[a,d]| by EUCLID:47; then 1-2*r1=0 or c =|[a,d]|`2 by EUCLID:56; then 1=2*r1 by A1,EUCLID:56,XCMPLX_1:15; then A104: r1=1/2 by XCMPLX_1:90; (1-(2*r2-1))*|[a,d]|+(2*r2-1)*|[b,d]|+-(|[a,d]|)=0.REAL 2 by A92,A100,A103,EUCLID:40; then (1-(2*r2-1))*|[a,d]|+((2*r2-1))*|[b,d]|+(-1)*|[a,d]|=0.REAL 2 by EUCLID:43; then ((2*r2-1))*|[b,d]|+((1-(2*r2-1))*|[a,d]|+(-1)*|[a,d]|)=0.REAL 2 by EUCLID:30; then ((2*r2-1))*|[b,d]|+((1-(2*r2-1))+(-1))*|[a,d]|=0.REAL 2 by EUCLID:37; then ((2*r2-1))*|[b,d]|+(-1+1-(2*r2-1))*|[a,d]|=0.REAL 2 by XCMPLX_1:29; then ((2*r2-1))*|[b,d]|+(-(2*r2-1))*|[a,d]|=0.REAL 2 by XCMPLX_1:150; then ((2*r2-1))*|[b,d]|+-((2*r2-1)*|[a,d]|)=0.REAL 2 by EUCLID:44; then ((2*r2-1))*|[b,d]|-((2*r2-1)*|[a,d]|)=0.REAL 2 by EUCLID:45; then ((2*r2-1))*(|[b,d]|-(|[a,d]|))=0.REAL 2 by EUCLID:53; then (2*r2-1)=0 or (|[b,d]|-(|[a,d]|))=0.REAL 2 by EUCLID:35; then (2*r2-1)=0 or |[b,d]|=|[a,d]| by EUCLID:47; then (2*r2-1)=0 or b =|[a,d]|`1 by EUCLID:56; then 1=2*r2 by A1,EUCLID:56,XCMPLX_1:15; hence x1=x2 by A104,XCMPLX_1:90; case A105: x1 in [.1/2,1.] & x2 in [.0,1/2.]; then A106: f3.r2=(1-2*r2)*|[a,c]|+(2*r2)*|[a,d]| by A33; A107: 0<=r2 & r2<=1/2 by A105,TOPREAL5:1; then A108: r2*2<=1/2*2 by AXIOMS:25; 2*0<=2*r2 by A107,AXIOMS:25; then f3.r2 in { (1-lambda)*|[a,c]| + lambda*|[a,d]| where lambda is Real : 0 <= lambda & lambda <= 1 } by A106,A108; then A109: f3.r2 in LSeg(|[a,c]|,|[a,d]|) by TOPREAL1:def 4; A110: f3.r1=(1-(2*r1-1))*|[a,d]|+(2*r1-1)*|[b,d]| by A36,A105; A111: 1/2<=r1 & r1<=1 by A105,TOPREAL5:1; then r1*2>=1/2*2 by AXIOMS:25; then A112: 2*r1-1>=0 by SQUARE_1:12; 2*1>=2*r1 by A111,AXIOMS:25; then 1+1-1>=2*r1-1 by REAL_1:49; then f3.r1 in { (1-lambda)*|[a,d]| + lambda*|[b,d]| where lambda is Real : 0 <= lambda & lambda <= 1 } by A110,A112; then f3.r1 in LSeg(|[a,d]|,|[b,d]|) by TOPREAL1:def 4; then f3.r2 in LSeg(|[a,c]|,|[a,d]|) /\ LSeg(|[a,d]|,|[b,d]|) by A92,A109,XBOOLE_0:def 3; then A113: f3.r2= |[a,d]| by A93,TARSKI:def 1; then (1-2*r2)*|[a,c]|+(2*r2)*|[a,d]|+-(|[a,d]|)=0.REAL 2 by A106,EUCLID:40; then (1-2*r2)*|[a,c]|+(2*r2)*|[a,d]|+(-1)*|[a,d]|=0.REAL 2 by EUCLID:43; then (1-2*r2)*|[a,c]|+((2*r2)*|[a,d]|+(-1)*|[a,d]|)=0.REAL 2 by EUCLID:30; then (1-2*r2)*|[a,c]|+((2*r2)+(-1))*|[a,d]|=0.REAL 2 by EUCLID:37; then (1-2*r2)*|[a,c]|+(-(1-(2*r2)))*|[a,d]|=0.REAL 2 by XCMPLX_1:162; then (1-2*r2)*|[a,c]|+-((1-(2*r2))*|[a,d]|)=0.REAL 2 by EUCLID:44; then (1-2*r2)*|[a,c]|-((1-(2*r2))*|[a,d]|)=0.REAL 2 by EUCLID:45; then (1-2*r2)*(|[a,c]|-(|[a,d]|))=0.REAL 2 by EUCLID:53; then 1-2*r2=0 or (|[a,c]|-(|[a,d]|))=0.REAL 2 by EUCLID:35; then 1-2*r2=0 or |[a,c]|=|[a,d]| by EUCLID:47; then 1-2*r2=0 or c =|[a,d]|`2 by EUCLID:56; then 1=2*r2 by A1,EUCLID:56,XCMPLX_1:15; then A114: r2=1/2 by XCMPLX_1:90; (1-(2*r1-1))*|[a,d]|+(2*r1-1)*|[b,d]|+-(|[a,d]|)=0.REAL 2 by A92,A110,A113,EUCLID:40; then (1-(2*r1-1))*|[a,d]|+((2*r1-1))*|[b,d]|+(-1)*|[a,d]|=0.REAL 2 by EUCLID:43; then ((2*r1-1))*|[b,d]|+((1-(2*r1-1))*|[a,d]|+(-1)*|[a,d]|)=0.REAL 2 by EUCLID:30; then ((2*r1-1))*|[b,d]|+(-1+(1-(2*r1-1)))*|[a,d]|=0.REAL 2 by EUCLID:37; then ((2*r1-1))*|[b,d]|+(1+-1-(2*r1-1))*|[a,d]|=0.REAL 2 by XCMPLX_1:29; then ((2*r1-1))*|[b,d]|+(-(2*r1-1))*|[a,d]|=0.REAL 2 by XCMPLX_1:150; then ((2*r1-1))*|[b,d]|+-((2*r1-1)*|[a,d]|)=0.REAL 2 by EUCLID:44; then ((2*r1-1))*|[b,d]|-((2*r1-1)*|[a,d]|)=0.REAL 2 by EUCLID:45; then ((2*r1-1))*(|[b,d]|-(|[a,d]|))=0.REAL 2 by EUCLID:53; then (2*r1-1)=0 or (|[b,d]|-(|[a,d]|))=0.REAL 2 by EUCLID:35; then (2*r1-1)=0 or |[b,d]|=|[a,d]| by EUCLID:47; then (2*r1-1)=0 or b =|[a,d]|`1 by EUCLID:56; then 1=2*r1 by A1,EUCLID:56,XCMPLX_1:15; hence x1=x2 by A114,XCMPLX_1:90; case A115: x1 in [.1/2,1.] & x2 in [.1/2,1.]; then f3.r1=(1-(2*r1-1))*|[a,d]|+((2*r1-1))*|[b,d]| by A36; then (1-(2*r2-1))*|[a,d]|+((2*r2-1))*|[b,d]| = (1-(2*r1-1))*|[a,d]|+((2*r1-1))*|[b,d]| by A36,A92,A115; then (1-(2*r2-1))*|[a,d]|+((2*r2-1))*|[b,d]| -((2*r1-1))*|[b,d]| = (1-(2*r1-1))*|[a,d]| by EUCLID:52; then (1-(2*r2-1))*|[a,d]|+(((2*r2-1))*|[b,d]| -((2*r1-1))*|[b,d]|) = (1-(2*r1-1))*|[a,d]| by EUCLID:49; then (1-(2*r2-1))*|[a,d]|+((2*r2-1)-(2*r1-1))*(|[b,d]|) = (1-(2*r1-1))*|[a,d]| by EUCLID:54; then ((2*r2-1)-(2*r1-1))*(|[b,d]|) +((1-(2*r2-1))*|[a,d]|-(1-(2*r1-1))*|[a,d]|) = (1-(2*r1-1))*|[a,d]|-(1-(2*r1-1))*|[a,d]| by EUCLID:49; then ((2*r2-1)-(2*r1-1))*(|[b,d]|) +((1-(2*r2-1))*|[a,d]|-(1-(2*r1-1))*|[a,d]|) = 0.REAL 2 by EUCLID:46; then ((2*r2-1)-(2*r1-1))*(|[b,d]|)+((1-(2*r2-1))-(1-(2*r1-1)))*|[a,d]| = 0.REAL 2 by EUCLID:54; then ((2*r2-1)-(2*r1-1))*(|[b,d]|)+(-((2*r2-1)-(2*r1-1)))*|[a,d]| = 0.REAL 2 by XCMPLX_1:149; then ((2*r2-1)-(2*r1-1))*(|[b,d]|)+-(((2*r2-1)-(2*r1-1))*|[a,d]|) = 0.REAL 2 by EUCLID:44; then ((2*r2-1)-(2*r1-1))*(|[b,d]|)-(((2*r2-1)-(2*r1-1))*|[a,d]|) = 0.REAL 2 by EUCLID:45; then ((2*r2-1)-(2*r1-1))*((|[b,d]|)-(|[a,d]|)) = 0.REAL 2 by EUCLID:53; then ((2*r2-1)-(2*r1-1))=0 or (|[b,d]|)-(|[a,d]|)=0.REAL 2 by EUCLID:35; then ((2*r2-1)-(2*r1-1))=0 or |[b,d]|=|[a,d]| by EUCLID:47; then ((2*r2-1)-(2*r1-1))=0 or b =|[a,d]|`1 by EUCLID:56; then (2*r2-1)=(2*r1-1) by A1,EUCLID:56,XCMPLX_1:15; then 2*r2=2*r1-1+1 by XCMPLX_1:27; then 2*r2=2*r1 by XCMPLX_1:27; then r2=r1*2/2 by XCMPLX_1:90; hence x1=x2 by XCMPLX_1:90; end; hence x1=x2; end; then A116: f3 is one-to-one by FUNCT_1:def 8; A117: the carrier of ((TOP-REAL 2)|(Upper_Arc(K))) =[#]((TOP-REAL 2)|(Upper_Arc(K))) by PRE_TOPC:12; [#]((TOP-REAL 2)|(Upper_Arc(K))) c= rng f3 proof let y be set;assume y in [#]((TOP-REAL 2)|(Upper_Arc(K))); then A118: y in Upper_Arc(K) by PRE_TOPC:def 10; then reconsider q=y as Point of TOP-REAL 2; A119: Upper_Arc(K)=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; now per cases by A118,A119,XBOOLE_0:def 2; case q in LSeg(|[a,c]|,|[a,d]|); then A120: 0<=((q`2)-c)/(d-c)/2 & ((q`2)-c)/(d-c)/2<=1 & f3.(((q`2)-c)/(d-c)/2)=q by A39; then ((q`2)-c)/(d-c)/2 in [.0,1.] by TOPREAL5:1; hence y in rng f3 by A17,A120,FUNCT_1:def 5; case q in LSeg(|[a,d]|,|[b,d]|); then A121: 0<=((q`1)-a)/(b-a)/2+1/2 & ((q`1)-a)/(b-a)/2+1/2<=1 & f3.(((q`1)-a)/(b-a)/2+1/2)=q by A49; then ((q`1)-a)/(b-a)/2+1/2 in [.0,1.] by TOPREAL5:1; hence y in rng f3 by A17,A121,FUNCT_1:def 5; end; hence y in rng f3; end; then A122: rng f3=[#]((TOP-REAL 2)|(Upper_Arc(K))) by A117,XBOOLE_0:def 10; A123: I[01] is compact by HEINE:11,TOPMETR:27; ((TOP-REAL 2)|(Upper_Arc(K))) is_T2 by TOPMETR:3; then A124: f3 is_homeomorphism by A90,A91,A116,A122,A123,COMPTS_1:26; rng f3=Upper_Arc(K) by A122,PRE_TOPC:def 10; hence ex f being map of I[01],(TOP-REAL 2)|(Upper_Arc(K)) st f is_homeomorphism & f.0=W-min(K) & f.1=E-max(K) & rng f=Upper_Arc(K) & (for r being Real st r in [.0,1/2.] holds f.r=(1-2*r)*|[a,c]|+(2*r)*|[a,d]|)& (for r being Real st r in [.1/2,1.] holds f.r=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]|)& (for p being Point of TOP-REAL 2 st p in LSeg(|[a,c]|,|[a,d]|) holds 0<=((p`2)-c)/(d-c)/2 & ((p`2)-c)/(d-c)/2<=1 & f.(((p`2)-c)/(d-c)/2)=p)& (for p being Point of TOP-REAL 2 st p in LSeg(|[a,d]|,|[b,d]|) holds 0<=((p`1)-a)/(b-a)/2+1/2 & ((p`1)-a)/(b-a)/2+1/2<=1 & f.(((p`1)-a)/(b-a)/2+1/2)=p) by A30,A32,A33,A36,A39,A49,A124; end; theorem Th64: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d ex f being map of I[01],(TOP-REAL 2)|(Lower_Arc(K)) st f is_homeomorphism & f.0=E-max(K) & f.1=W-min(K) & rng f=Lower_Arc(K) & (for r being Real st r in [.0,1/2.] holds f.r=(1-2*r)*|[b,d]|+(2*r)*|[b,c]|)& (for r being Real st r in [.1/2,1.] holds f.r=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]|)& (for p being Point of TOP-REAL 2 st p in LSeg(|[b,d]|,|[b,c]|) holds 0<=((p`2)-d)/(c-d)/2 & ((p`2)-d)/(c-d)/2<=1 & f.(((p`2)-d)/(c-d)/2)=p)& (for p being Point of TOP-REAL 2 st p in LSeg(|[b,c]|,|[a,c]|) holds 0<=((p`1)-b)/(a-b)/2+1/2 & ((p`1)-b)/(a-b)/2+1/2<=1 & f.(((p`1)-b)/(a-b)/2+1/2)=p) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d; reconsider a2=a,b2=b,c2=c,d2=d as Real by XREAL_0:def 1; defpred P[set,set] means for r being Real st $1=r holds (r in [.0,1/2.] implies $2=(1-2*r)*|[b,d]|+(2*r)*|[b,c]|) & (r in [.1/2,1.] implies $2=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]|); A2: [.0,1.]=[.0,1/2.] \/ [.1/2,1.] by HEINE:2; A3: for x,y1,y2 being set st x in [.0,1.] & P[x,y1] & P[x,y2] holds y1 = y2 proof let x,y1,y2 be set; assume A4: x in [.0,1.] & P[x,y1] & P[x,y2]; now per cases by A2,A4,XBOOLE_0:def 2; case A5: x in [.0,1/2.]; then reconsider r=x as Real; y1= (1-2*r)*|[b,d]|+(2*r)*|[b,c]| by A4,A5; hence y1=y2 by A4,A5; case A6: x in [.1/2,1.]; then reconsider r=x as Real; y1= (1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]| by A4,A6; hence y1=y2 by A4,A6; end; hence y1 = y2; end; A7: for x being set st x in [.0,1.] ex y being set st P[x,y] proof let x be set;assume A8: x in [.0,1.]; now per cases by A2,A8,XBOOLE_0:def 2; case A9: x in [.0,1/2.]; then reconsider r=x as Real; A10: 0<=r & r<=1/2 by A9,TOPREAL5:1; set y0= (1-2*r)*|[b,d]|+(2*r)*|[b,c]|; r in [.1/2,1.] implies y0=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]| proof assume r in [.1/2,1.]; then 1/2 <=r & r<=1 by TOPREAL5:1; then A11: r=1/2 by A10,AXIOMS:21; then A12: y0= (0)*|[b,d]|+|[b,c]| by EUCLID:33 .= (0.REAL 2) + |[b,c]| by EUCLID:33 .= |[b,c]| by EUCLID:31; (1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]| = (1)*|[b,c]|+0.REAL 2 by A11,EUCLID:33 .= |[b,c]|+0.REAL 2 by EUCLID:33 .= |[b,c]| by EUCLID:31; hence y0=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]| by A12; end; then for r2 being Real st x=r2 holds (r2 in [.0,1/2.] implies y0=(1-2*r2)*|[b,d]|+(2*r2)*|[b,c]|) & (r2 in [.1/2,1.] implies y0=(1-(2*r2-1))*|[b,c]|+(2*r2-1)*|[a,c]|); hence ex y being set st P[x,y]; case A13: x in [.1/2,1.]; then reconsider r=x as Real; A14: 1/2<=r & r<=1 by A13,TOPREAL5:1; set y0= (1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]|; r in [.0,1/2.] implies y0=(1-2*r)*|[b,d]|+(2*r)*|[b,c]| proof assume r in [.0,1/2.]; then 0 <=r & r<=1/2 by TOPREAL5:1; then A15: r=1/2 by A14,AXIOMS:21; then A16: y0= |[b,c]|+(0)*|[a,c]| by EUCLID:33 .= |[b,c]|+(0.REAL 2) by EUCLID:33 .= |[b,c]| by EUCLID:31; (1-2*r)*|[b,d]|+(2*r)*|[b,c]| = 0.REAL 2+(1)*|[b,c]| by A15,EUCLID:33 .= 0.REAL 2+|[b,c]| by EUCLID:33 .= |[b,c]| by EUCLID:31; hence y0=(1-2*r)*|[b,d]|+(2*r)*|[b,c]| by A16; end; then for r2 being Real st x=r2 holds (r2 in [.0,1/2.] implies y0=(1-2*r2)*|[b,d]|+(2*r2)*|[b,c]|) & (r2 in [.1/2,1.] implies y0=(1-(2*r2-1))*|[b,c]|+(2*r2-1)*|[a,c]|); hence ex y being set st P[x,y]; end; hence ex y being set st P[x,y]; end; ex f2 being Function st dom f2 = [.0,1.] & for x being set st x in [.0,1.] holds P[x,f2.x] from FuncEx(A3,A7); then consider f2 being Function such that A17: dom f2 = [.0,1.] & for x being set st x in [.0,1.] holds P[x,f2.x]; rng f2 c= the carrier of (TOP-REAL 2)|(Lower_Arc(K)) proof let y be set;assume y in rng f2; then consider x being set such that A18: x in dom f2 & y=f2.x by FUNCT_1:def 5; now per cases by A2,A17,A18,XBOOLE_0:def 2; case A19: x in [.0,1/2.]; then reconsider r=x as Real; A20: 0<=r & r<=1/2 by A19,TOPREAL5:1; then A21: r*2<=1/2*2 by AXIOMS:25; A22: 2*0<=2*r by A20,AXIOMS:25; f2.x= (1-2*r)*|[b,d]|+(2*r)*|[b,c]| by A17,A18,A19; then y in { (1-lambda)*|[b,d]| + lambda*|[b,c]| where lambda is Real: 0 <= lambda & lambda <= 1 } by A18,A21,A22; then A23: y in LSeg(|[b,d]|,|[b,c]|) by TOPREAL1:def 4; Lower_Arc(K)= LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) by A1,Th62; then y in Lower_Arc(K) by A23,XBOOLE_0:def 2; hence y in the carrier of (TOP-REAL 2)|(Lower_Arc(K)) by JORDAN1:1; case A24: x in [.1/2,1.]; then reconsider r=x as Real; A25: 1/2<=r & r<=1 by A24,TOPREAL5:1; then r*2>=1/2*2 by AXIOMS:25; then A26: 2*r-1>=0 by SQUARE_1:12; 2*1>=2*r by A25,AXIOMS:25; then A27: 1+1-1>=2*r-1 by REAL_1:49; f2.x= (1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]| by A17,A18,A24; then y in { (1-lambda)*|[b,c]| + lambda*|[a,c]| where lambda is Real: 0 <= lambda & lambda <= 1 } by A18,A26,A27; then A28: y in LSeg(|[b,c]|,|[a,c]|) by TOPREAL1:def 4; Lower_Arc(K)= LSeg(|[a,c]|,|[b,c]|) \/ LSeg(|[b,c]|,|[b,d]|) by A1,Th62; then y in Lower_Arc(K) by A28,XBOOLE_0:def 2; hence y in the carrier of (TOP-REAL 2)|(Lower_Arc(K)) by JORDAN1:1; end; hence y in the carrier of (TOP-REAL 2)|(Lower_Arc(K)); end; then f2 is Function of the carrier of I[01], the carrier of (TOP-REAL 2)|(Lower_Arc(K)) by A17,BORSUK_1:83,FUNCT_2 :4; then reconsider f3=f2 as map of I[01],(TOP-REAL 2)|(Lower_Arc(K)) ; A29: 0 in [.0,1.] by TOPREAL5:1; 0 in [.0,1/2.] by TOPREAL5:1; then A30: f3.0= (1-2*0)*|[b,d]|+(2*0)*|[b,c]| by A17,A29 .= (1)*|[b,d]|+0.REAL 2 by EUCLID:33 .= |[b,d]|+0.REAL 2 by EUCLID:33 .= |[b,d]| by EUCLID:31 .= E-max(K) by A1,Th56; A31: 1 in [.0,1.] by TOPREAL5:1; 1 in [.1/2,1.] by TOPREAL5:1; then A32: f3.1= (1-(2*1-1))*|[b,c]|+(2*1-1)*|[a,c]| by A17,A31 .= (0)*|[b,c]|+|[a,c]| by EUCLID:33 .= (0.REAL 2) + |[a,c]| by EUCLID:33 .= |[a,c]| by EUCLID:31 .= W-min(K) by A1,Th56; A33: for r being Real st r in [.0,1/2.] holds f3.r=(1-2*r)*|[b,d]|+(2*r)*|[b,c]| proof let r be Real; assume A34: r in [.0,1/2.]; then A35: 0<=r & r<=1/2 by TOPREAL5:1; then r<=1 by AXIOMS:22; then r in [.0,1.] by A35,TOPREAL5:1; hence f3.r=(1-2*r)*|[b,d]|+(2*r)*|[b,c]| by A17,A34; end; A36: for r being Real st r in [.1/2,1.] holds f3.r=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]| proof let r be Real; assume A37: r in [.1/2,1.]; then A38: 1/2<=r & r<=1 by TOPREAL5:1; then 0<=r by AXIOMS:22; then r in [.0,1.] by A38,TOPREAL5:1; hence f3.r=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]| by A17,A37; end; A39: (for p being Point of TOP-REAL 2 st p in LSeg(|[b,d]|,|[b,c]|) holds 0<=((p`2)-d)/(c-d)/2 & ((p`2)-d)/(c-d)/2<=1 & f3.(((p`2)-d)/(c-d)/2)=p) proof let p be Point of TOP-REAL 2; assume A40: p in LSeg(|[b,d]|,|[b,c]|); then p in LSeg(|[b2,d2]|,|[b2,c2]|); then A41: p`1=b by TOPREAL3:17; A42: (|[b,d]|)`2= d by EUCLID:56; (|[b,c]|)`2= c by EUCLID:56; then A43: c <=p`2 & p`2<=d by A1,A40,A42,TOPREAL1:10; d-c>0 by A1,SQUARE_1:11; then -(d-c)< -0 by REAL_1:50; then 0-(d-c) < 0 by XCMPLX_1:150; then 0-d+c <0 by XCMPLX_1:37; then -d+c <0 by XCMPLX_1:150; then A44: c -d <0 by XCMPLX_0:def 8; d-(p`2) >=0 by A43,SQUARE_1:12; then -(d-(p`2)) <= -0 by REAL_1:50; then 0-(d-(p`2)) <= 0 by XCMPLX_1:150; then 0-d+p`2 <=0 by XCMPLX_1:37; then -d+p`2 <=0 by XCMPLX_1:150; then (p`2) -d <=0 by XCMPLX_0:def 8; then ((p`2) -d)/(c-d) >=0/(c-d) by A44,REAL_1:74; then A45: ((p`2) -d)/(c-d)/2 >=0/2 by REAL_1:73; (p`2) -d >=c-d by A43,REAL_1:49; then ((p`2) -d)/(c-d) <=(c-d)/(c-d) by A44,REAL_1:74; then ((p`2) -d)/(c-d) <=1 by A44,XCMPLX_1:60; then A46: ((p`2) -d)/(c-d)/2 <=1/2 by REAL_1:73; set r=((p`2)-d)/(c-d)/2; r in [.0,1/2.] by A45,A46,TOPREAL5:1; then f3.(((p`2)-d)/(c-d)/2)=(1-2*r)*|[b,d]|+(2*r)*|[b,c]| by A33 .=|[(1-2*r)*b,(1-2*r)*d]|+(2*r)*|[b,c]| by EUCLID:62 .=|[(1-2*r)*b,(1-2*r)*d]|+|[(2*r)*b,(2*r)*c]| by EUCLID:62 .=|[(1-2*r)*b+(2*r)*b,(1-2*r)*d+(2*r)*c]| by EUCLID:60 .=|[1*b-(2*r)*b+(2*r)*b,(1-2*r)*d+(2*r)*c]| by XCMPLX_1:40 .=|[1*b,(1-2*r)*d+(2*r)*c]| by XCMPLX_1:27 .=|[b,1*d-(2*r)*d+(2*r)*c]| by XCMPLX_1:40 .=|[b,1*d+-((2*r)*d)+(2*r)*c]| by XCMPLX_0:def 8 .=|[b,1*d+((-((2*r)*d))+(2*r)*c)]| by XCMPLX_1:1 .=|[b,1*d+(((2*r)*c)-(2*r)*d)]| by XCMPLX_0:def 8 .=|[b,1*d+((2*r)*(c-d))]| by XCMPLX_1:40 .=|[b,1*d+(((p`2)-d)/(c-d))*(c-d)]| by XCMPLX_1:88 .=|[b,1*d+((p`2)-d)]| by A44,XCMPLX_1:88 .=|[p`1,p`2]| by A41,XCMPLX_1:27 .= p by EUCLID:57; hence 0<=((p`2)-d)/(c-d)/2 & ((p`2)-d)/(c-d)/2<=1 & f3.(((p`2)-d)/(c-d)/2)=p by A45,A46,AXIOMS:22; end; A47: for p being Point of TOP-REAL 2 st p in LSeg(|[b,c]|,|[a,c]|) holds 0<=((p`1)-b)/(a-b)/2+1/2 & ((p`1)-b)/(a-b)/2+1/2<=1 & f3.(((p`1)-b)/(a-b)/2+1/2)=p proof let p be Point of TOP-REAL 2; assume A48: p in LSeg(|[b,c]|,|[a,c]|); then p in LSeg(|[b2,c2]|,|[a2,c2]|); then A49: p`2=c by TOPREAL3:18; A50: (|[b,c]|)`1= b by EUCLID:56; (|[a,c]|)`1= a by EUCLID:56; then A51: a <=p`1 & p`1<=b by A1,A48,A50,TOPREAL1:9; b-a>0 by A1,SQUARE_1:11; then -(b-a)< -0 by REAL_1:50; then 0-(b-a) < 0 by XCMPLX_1:150; then 0-b+a <0 by XCMPLX_1:37; then -b+a <0 by XCMPLX_1:150; then A52: a -b <0 by XCMPLX_0:def 8; b-(p`1) >=0 by A51,SQUARE_1:12; then -(b-(p`1)) <= -0 by REAL_1:50; then 0-(b-(p`1)) <= 0 by XCMPLX_1:150; then 0-b+p`1 <=0 by XCMPLX_1:37; then -b+p`1 <=0 by XCMPLX_1:150; then (p`1) -b <=0 by XCMPLX_0:def 8; then ((p`1) -b)/(a-b) >=0/(a-b) by A52,REAL_1:74; then ((p`1) -b)/(a-b)/2 >=0/2 by REAL_1:73; then A53: ((p`1) -b)/(a-b)/2+1/2 >=0+1/2 by REAL_1:55; (p`1) -b >=a-b by A51,REAL_1:49; then ((p`1) -b)/(a-b) <=(a-b)/(a-b) by A52,REAL_1:74; then ((p`1) -b)/(a-b) <=1 by A52,XCMPLX_1:60; then ((p`1) -b)/(a-b)/2 <=1/2 by REAL_1:73; then A54: ((p`1) -b)/(a-b)/2+1/2 <=1/2+1/2 by REAL_1:55; set r=((p`1)-b)/(a-b)/2+1/2; A55: r= (((p`1)-b)/(a-b)+1)/2 by XCMPLX_1:63; r in [.1/2,1.] by A53,A54,TOPREAL5:1; then f3.(((p`1)-b)/(a-b)/2+1/2)=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]| by A36 .=|[(1-(2*r-1))*b,(1-(2*r-1))*c]|+((2*r-1))*|[a,c]| by EUCLID:62 .=|[(1-(2*r-1))*b,(1-(2*r-1))*c]|+|[((2*r-1))*a,((2*r-1))*c]| by EUCLID:62 .=|[(1-(2*r-1))*b+((2*r-1))*a,(1-(2*r-1))*c+((2*r-1))*c]| by EUCLID:60 .=|[(1-(2*r-1))*b+((2*r-1))*a,1*c-(2*r-1)*c+((2*r-1))*c]| by XCMPLX_1:40 .=|[(1-(2*r-1))*b+((2*r-1))*a,1*c]| by XCMPLX_1:27 .=|[1*b-(2*r-1)*b+((2*r-1))*a,c]| by XCMPLX_1:40 .=|[1*b+-(((2*r-1))*b)+((2*r-1))*a,c]| by XCMPLX_0:def 8 .=|[1*b+((-(((2*r-1))*b))+((2*r-1))*a),c]| by XCMPLX_1:1 .=|[1*b+((((2*r-1))*a)-((2*r-1))*b),c]| by XCMPLX_0:def 8 .=|[1*b+(((2*r-1))*(a-b)),c]| by XCMPLX_1:40 .=|[1*b+(((p`1)-b)/(a-b)+1-1)*(a-b),c]| by A55,XCMPLX_1:88 .=|[1*b+(((p`1)-b)/(a-b))*(a-b),c]| by XCMPLX_1:26 .=|[1*b+((p`1)-b),c]| by A52,XCMPLX_1:88 .=|[p`1,p`2]| by A49,XCMPLX_1:27 .= p by EUCLID:57; hence 0<=((p`1)-b)/(a-b)/2+1/2 & ((p`1)-b)/(a-b)/2+1/2<=1 & f3.(((p`1)-b)/(a-b)/2+1/2)=p by A53,A54,AXIOMS:22; end; reconsider B00=[.0,1.] as Subset of R^1 by TOPMETR:24; reconsider B01=B00 as non empty Subset of R^1 by TOPREAL5:1; I[01]=(R^1)|B01 by TOPMETR:26,27; then consider h1 being map of I[01],R^1 such that A56: (for p being Point of I[01] holds h1.p=p) & h1 is continuous by Th14; consider h2 being map of I[01],R^1 such that A57: (for p being Point of I[01],r1 being real number st h1.p=r1 holds h2.p=2*r1) & h2 is continuous by A56,JGRAPH_2:33; consider h5 being map of I[01],R^1 such that A58: (for p being Point of I[01],r1 being real number st h2.p=r1 holds h5.p=1-r1) & h5 is continuous by A57,Th16; consider h3 being map of I[01],R^1 such that A59: (for p being Point of I[01],r1 being real number st h2.p=r1 holds h3.p=r1-1) & h3 is continuous by A57,Th15; consider h4 being map of I[01],R^1 such that A60: (for p being Point of I[01],r1 being real number st h3.p=r1 holds h4.p=1-r1) & h4 is continuous by A59,Th16; consider g1 being map of I[01],TOP-REAL 2 such that A61: (for r being Point of I[01] holds g1.r=(h5.r)*|[b,d]|+(h2.r)*|[b,c]|) & g1 is continuous by A57,A58,Th21; A62: for r being Point of I[01],s being real number st r=s holds g1.r=(1-2*s)*|[b,d]|+(2*s)*|[b,c]| proof let r be Point of I[01],s be real number; assume A63: r=s; g1.r=(h5.r)*|[b,d]|+(h2.r)*|[b,c]| by A61 .=(1-(h2.r))*|[b,d]|+(h2.r)*|[b,c]| by A58 .=(1-2*(h1.r))*|[b,d]|+(h2.r)*|[b,c]| by A57 .=(1-2*(h1.r))*|[b,d]|+(2*(h1.r))*|[b,c]| by A57 .=(1-2*s)*|[b,d]|+(2*(h1.r))*|[b,c]| by A56,A63 .=(1-2*s)*|[b,d]|+(2*s)*|[b,c]| by A56,A63; hence g1.r=(1-2*s)*|[b,d]|+(2*s)*|[b,c]|; end; consider g2 being map of I[01],TOP-REAL 2 such that A64: (for r being Point of I[01] holds g2.r=(h4.r)*|[b,c]|+(h3.r)*|[a,c]|) & g2 is continuous by A59,A60,Th21; A65: for r being Point of I[01],s being real number st r=s holds g2.r=(1-(2*s-1))*|[b,c]|+(2*s-1)*|[a,c]| proof let r be Point of I[01],s be real number; assume A66: r=s; g2.r=(h4.r)*|[b,c]|+(h3.r)*|[a,c]| by A64 .=(1-h3.r)*|[b,c]|+(h3.r)*|[a,c]| by A60 .=(1-((h2.r)-1))*|[b,c]|+(h3.r)*|[a,c]| by A59 .=(1-((h2.r)-1))*|[b,c]|+((h2.r)-1)*|[a,c]| by A59 .=(1-(2*(h1.r)-1))*|[b,c]|+((h2.r)-1)*|[a,c]| by A57 .=(1-(2*(h1.r)-1))*|[b,c]|+(2*(h1.r)-1)*|[a,c]| by A57 .=(1-(2*s-1))*|[b,c]|+(2*(h1.r)-1)*|[a,c]| by A56,A66 .=(1-(2*s-1))*|[b,c]|+(2*s-1)*|[a,c]| by A56,A66; hence g2.r=(1-(2*s-1))*|[b,c]|+(2*s-1)*|[a,c]|; end; [.0,1/2.] c= [.0,1.] by A2,XBOOLE_1:7; then reconsider B11=[.0,1/2.] as non empty Subset of I[01] by BORSUK_1:83,TOPREAL5:1; A67: dom (g1|B11)=dom g1 /\ B11 by FUNCT_1:68 .= (the carrier of I[01]) /\ B11 by FUNCT_2:def 1 .=B11 by XBOOLE_1:28 .=the carrier of (I[01]|B11) by JORDAN1:1; rng (g1|B11) c= rng g1 by FUNCT_1:76; then rng (g1|B11) c= the carrier of TOP-REAL 2 by XBOOLE_1:1; then g1|B11 is Function of the carrier of (I[01]|B11),the carrier of TOP-REAL 2 by A67,FUNCT_2:4; then reconsider g11=g1|B11 as map of I[01]|B11,TOP-REAL 2 ; A68: TOP-REAL 2=(TOP-REAL 2)|([#](TOP-REAL 2)) by TSEP_1:3; then A69: g11 is continuous by A61,BORSUK_4:69; [.1/2,1.] c= [.0,1.] by A2,XBOOLE_1:7; then reconsider B22=[.1/2,1.] as non empty Subset of I[01] by BORSUK_1:83,TOPREAL5:1; A70: dom (g2|B22)=dom g2 /\ B22 by FUNCT_1:68 .= (the carrier of I[01]) /\ B22 by FUNCT_2:def 1 .=B22 by XBOOLE_1:28 .=the carrier of (I[01]|B22) by JORDAN1:1; rng (g2|B22) c= rng g2 by FUNCT_1:76; then rng (g2|B22) c= the carrier of TOP-REAL 2 by XBOOLE_1:1; then g2|B22 is Function of the carrier of (I[01]|B22),the carrier of TOP-REAL 2 by A70,FUNCT_2:4; then reconsider g22=g2|B22 as map of I[01]|B22,TOP-REAL 2 ; A71: g22 is continuous by A64,A68,BORSUK_4:69; A72: B11=[#](I[01]|B11) by PRE_TOPC:def 10; A73: B22=[#](I[01]|B22) by PRE_TOPC:def 10; A74: B11 is closed by Th12; A75: B22 is closed by Th12; B11 \/ B22=[.0,1.] by HEINE:2; then A76: [#](I[01]|B11) \/ [#](I[01]|B22)=[#]I[01] by A72,A73,BORSUK_1:83,PRE_TOPC:12; for p being set st p in ([#](I[01]|B11)) /\ ([#](I[01]|B22)) holds g11.p = g22.p proof let p be set;assume p in ([#](I[01]|B11)) /\ ([#](I[01]|B22)); then p in [#](I[01]|B11) & p in [#](I[01]|B22) by XBOOLE_0:def 3; then A77: p in B11 & p in B22 by PRE_TOPC:def 10; then reconsider rp=p as Real; A78: rp<=1/2 by A77,TOPREAL5:1; rp>=1/2 by A77,TOPREAL5:1; then rp=1/2 by A78,AXIOMS:21; then A79: 2*rp=1; thus g11.p=g1.p by A77,FUNCT_1:72 .= (1-1)*|[b,d]|+(1)*|[b,c]| by A62,A77,A79 .=0.REAL 2 +1*|[b,c]| by EUCLID:33 .=(1-0)*|[b,c]| +(1-1)*|[a,c]| by EUCLID:33 .=g2.p by A65,A77,A79 .=g22.p by A77,FUNCT_1:72; end; then consider h being map of I[01],TOP-REAL 2 such that A80: h=g11+*g22 & h is continuous by A69,A71,A72,A73,A74,A75,A76,JGRAPH_2:9; A81: dom f3=dom h & dom f3=the carrier of I[01] by Th13; for x being set st x in dom f2 holds f3.x=h.x proof let x be set; assume A82: x in dom f2; then reconsider rx=x as Real by A81,BORSUK_1:83; A83: 0<=rx & rx<=1 by A81,A82,BORSUK_1:83,TOPREAL5:1; now per cases; case A84: rx<1/2; then A85: rx in [.0,1/2.] by A83,TOPREAL5:1; now assume rx in dom g22; then rx in B22 by A73,Th13; hence contradiction by A84,TOPREAL5:1; end; then h.rx=g11.rx by A80,FUNCT_4:12 .=g1.rx by A85,FUNCT_1:72 .=(1-(2*rx))*|[b,d]|+(2*rx)*|[b,c]| by A62,A81,A82 .=f3.rx by A33,A85; hence f3.x=h.x; case rx >=1/2; then A86: rx in [.1/2,1.] by A83,TOPREAL5:1; then rx in [#](I[01]|B22) by PRE_TOPC:def 10; then h.rx=g22.rx by A70,A80,FUNCT_4:14 .=g2.rx by A86,FUNCT_1:72 .=(1-(2*rx-1))*|[b,c]|+(2*rx-1)*|[a,c]| by A65,A81,A82 .=f3.rx by A36,A86; hence f3.x=h.x; end; hence f3.x=h.x; end; then f2=h by A81,FUNCT_1:9; then A87: f3 is continuous by A80,JGRAPH_1:63; A88: dom f3=[#](I[01]) by A17,BORSUK_1:83,PRE_TOPC:12; for x1,x2 being set st x1 in dom f3 & x2 in dom f3 & f3.x1=f3.x2 holds x1=x2 proof let x1,x2 be set; assume A89: x1 in dom f3 & x2 in dom f3 & f3.x1=f3.x2; then reconsider r1=x1 as Real by A17; reconsider r2=x2 as Real by A17,A89; A90: LSeg(|[b,d]|,|[b,c]|) /\ LSeg(|[b,c]|,|[a,c]|) = {|[b,c]|} by A1,Th42; now per cases by A2,A17,A89,XBOOLE_0:def 2; case A91: x1 in [.0,1/2.] & x2 in [.0,1/2.]; then f3.r1=(1-2*r1)*|[b,d]|+(2*r1)*|[b,c]| by A33; then (1-2*r2)*|[b,d]|+(2*r2)*|[b,c]|= (1-2*r1)*|[b,d]|+(2*r1)*|[b,c]| by A33,A89,A91; then (1-2*r2)*|[b,d]|+(2*r2)*|[b,c]| -(2*r1)*|[b,c]| = (1-2*r1)*|[b,d]| by EUCLID:52; then (1-2*r2)*|[b,d]|+((2*r2)*|[b,c]| -(2*r1)*|[b,c]|) = (1-2*r1)*|[b,d]| by EUCLID:49; then (1-2*r2)*|[b,d]|+(2*r2-2*r1)*(|[b,c]|) = (1-2*r1)*|[b,d]| by EUCLID:54; then (2*r2-2*r1)*(|[b,c]|)+((1-2*r2)*|[b,d]|-(1-2*r1)*|[b,d]|) = (1-2*r1)*|[b,d]|-(1-2*r1)*|[b,d]| by EUCLID:49; then (2*r2-2*r1)*(|[b,c]|)+((1-2*r2)*|[b,d]|-(1-2*r1)*|[b,d]|) = 0.REAL 2 by EUCLID:46; then (2*r2-2*r1)*(|[b,c]|)+((1-2*r2)-(1-2*r1))*|[b,d]| = 0.REAL 2 by EUCLID:54; then (2*r2-2*r1)*(|[b,c]|)+(-(2*r2-2*r1))*|[b,d]| = 0.REAL 2 by XCMPLX_1:149; then (2*r2-2*r1)*(|[b,c]|)+-((2*r2-2*r1)*|[b,d]|) = 0.REAL 2 by EUCLID:44; then (2*r2-2*r1)*(|[b,c]|)-((2*r2-2*r1)*|[b,d]|) = 0.REAL 2 by EUCLID:45; then (2*r2-2*r1)*((|[b,c]|)-(|[b,d]|)) = 0.REAL 2 by EUCLID:53; then (2*r2-2*r1)=0 or (|[b,c]|)-(|[b,d]|)=0.REAL 2 by EUCLID:35; then (2*r2-2*r1)=0 or |[b,c]|=|[b,d]| by EUCLID:47; then (2*r2-2*r1)=0 or d =|[b,c]|`2 by EUCLID:56; then 2*r2=2*r1 by A1,EUCLID:56,XCMPLX_1:15; then r2=r1*2/2 by XCMPLX_1:90; hence x1=x2 by XCMPLX_1:90; case A92: x1 in [.0,1/2.] & x2 in [.1/2,1.]; then A93: f3.r1=(1-2*r1)*|[b,d]|+(2*r1)*|[b,c]| by A33; A94: 0<=r1 & r1<=1/2 by A92,TOPREAL5:1; then A95: r1*2<=1/2*2 by AXIOMS:25; 2*0<=2*r1 by A94,AXIOMS:25; then f3.r1 in { (1-lambda)*|[b,d]| + lambda*|[b,c]| where lambda is Real : 0 <= lambda & lambda <= 1 } by A93,A95; then A96: f3.r1 in LSeg(|[b,d]|,|[b,c]|) by TOPREAL1:def 4; A97: f3.r2=(1-(2*r2-1))*|[b,c]|+(2*r2-1)*|[a,c]| by A36,A92; A98: 1/2<=r2 & r2<=1 by A92,TOPREAL5:1; then r2*2>=1/2*2 by AXIOMS:25; then A99: 2*r2-1>=0 by SQUARE_1:12; 2*1>=2*r2 by A98,AXIOMS:25; then 1+1-1>=2*r2-1 by REAL_1:49; then f3.r2 in { (1-lambda)*|[b,c]| + lambda*|[a,c]| where lambda is Real : 0 <= lambda & lambda <= 1 } by A97,A99; then f3.r2 in LSeg(|[b,c]|,|[a,c]|) by TOPREAL1:def 4; then f3.r1 in LSeg(|[b,d]|,|[b,c]|) /\ LSeg(|[b,c]|,|[a,c]|) by A89,A96,XBOOLE_0:def 3; then A100: f3.r1= |[b,c]| by A90,TARSKI:def 1; then (1-2*r1)*|[b,d]|+(2*r1)*|[b,c]|+-(|[b,c]|)=0.REAL 2 by A93,EUCLID:40; then (1-2*r1)*|[b,d]|+(2*r1)*|[b,c]|+(-1)*|[b,c]|=0.REAL 2 by EUCLID:43; then (1-2*r1)*|[b,d]|+((2*r1)*|[b,c]|+(-1)*|[b,c]|)=0.REAL 2 by EUCLID:30; then (1-2*r1)*|[b,d]|+((2*r1)+(-1))*|[b,c]|=0.REAL 2 by EUCLID:37; then (1-2*r1)*|[b,d]|+(-(1-(2*r1)))*|[b,c]|=0.REAL 2 by XCMPLX_1:162; then (1-2*r1)*|[b,d]|+-((1-(2*r1))*|[b,c]|)=0.REAL 2 by EUCLID:44; then (1-2*r1)*|[b,d]|-((1-(2*r1))*|[b,c]|)=0.REAL 2 by EUCLID:45; then (1-2*r1)*(|[b,d]|-(|[b,c]|))=0.REAL 2 by EUCLID:53; then 1-2*r1=0 or (|[b,d]|-(|[b,c]|))=0.REAL 2 by EUCLID:35; then 1-2*r1=0 or |[b,d]|=|[b,c]| by EUCLID:47; then 1-2*r1=0 or d =|[b,c]|`2 by EUCLID:56; then 1=2*r1 by A1,EUCLID:56,XCMPLX_1:15; then A101: r1=1/2 by XCMPLX_1:90; (1-(2*r2-1))*|[b,c]|+(2*r2-1)*|[a,c]|+-(|[b,c]|)=0.REAL 2 by A89,A97,A100,EUCLID:40; then (1-(2*r2-1))*|[b,c]|+((2*r2-1))*|[a,c]|+(-1)*|[b,c]|=0.REAL 2 by EUCLID:43; then ((2*r2-1))*|[a,c]|+((1-(2*r2-1))*|[b,c]|+(-1)*|[b,c]|)=0.REAL 2 by EUCLID:30; then ((2*r2-1))*|[a,c]|+((1-(2*r2-1))+(-1))*|[b,c]|=0.REAL 2 by EUCLID:37; then ((2*r2-1))*|[a,c]|+(-1+1-(2*r2-1))*|[b,c]|=0.REAL 2 by XCMPLX_1:29; then ((2*r2-1))*|[a,c]|+(-(2*r2-1))*|[b,c]|=0.REAL 2 by XCMPLX_1:150; then ((2*r2-1))*|[a,c]|+-((2*r2-1)*|[b,c]|)=0.REAL 2 by EUCLID:44; then ((2*r2-1))*|[a,c]|-((2*r2-1)*|[b,c]|)=0.REAL 2 by EUCLID:45; then ((2*r2-1))*(|[a,c]|-(|[b,c]|))=0.REAL 2 by EUCLID:53; then (2*r2-1)=0 or (|[a,c]|-(|[b,c]|))=0.REAL 2 by EUCLID:35; then (2*r2-1)=0 or |[a,c]|=|[b,c]| by EUCLID:47; then (2*r2-1)=0 or a =|[b,c]|`1 by EUCLID:56; then 1=2*r2 by A1,EUCLID:56,XCMPLX_1:15; hence x1=x2 by A101,XCMPLX_1:90; case A102: x1 in [.1/2,1.] & x2 in [.0,1/2.]; then A103: f3.r2=(1-2*r2)*|[b,d]|+(2*r2)*|[b,c]| by A33; A104: 0<=r2 & r2<=1/2 by A102,TOPREAL5:1; then A105: r2*2<=1/2*2 by AXIOMS:25; 2*0<=2*r2 by A104,AXIOMS:25; then f3.r2 in { (1-lambda)*|[b,d]| + lambda*|[b,c]| where lambda is Real : 0 <= lambda & lambda <= 1 } by A103,A105; then A106: f3.r2 in LSeg(|[b,d]|,|[b,c]|) by TOPREAL1:def 4; A107: f3.r1=(1-(2*r1-1))*|[b,c]|+(2*r1-1)*|[a,c]| by A36,A102; A108: 1/2<=r1 & r1<=1 by A102,TOPREAL5:1; then r1*2>=1/2*2 by AXIOMS:25; then A109: 2*r1-1>=0 by SQUARE_1:12; 2*1>=2*r1 by A108,AXIOMS:25; then 1+1-1>=2*r1-1 by REAL_1:49; then f3.r1 in { (1-lambda)*|[b,c]| + lambda*|[a,c]| where lambda is Real : 0 <= lambda & lambda <= 1 } by A107,A109; then f3.r1 in LSeg(|[b,c]|,|[a,c]|) by TOPREAL1:def 4; then f3.r2 in LSeg(|[b,d]|,|[b,c]|) /\ LSeg(|[b,c]|,|[a,c]|) by A89,A106,XBOOLE_0:def 3; then A110: f3.r2= |[b,c]| by A90,TARSKI:def 1; then (1-2*r2)*|[b,d]|+(2*r2)*|[b,c]|+-(|[b,c]|)=0.REAL 2 by A103,EUCLID:40; then (1-2*r2)*|[b,d]|+(2*r2)*|[b,c]|+(-1)*|[b,c]|=0.REAL 2 by EUCLID:43; then (1-2*r2)*|[b,d]|+((2*r2)*|[b,c]|+(-1)*|[b,c]|)=0.REAL 2 by EUCLID:30; then (1-2*r2)*|[b,d]|+((2*r2)+(-1))*|[b,c]|=0.REAL 2 by EUCLID:37; then (1-2*r2)*|[b,d]|+(-(1-(2*r2)))*|[b,c]|=0.REAL 2 by XCMPLX_1:162; then (1-2*r2)*|[b,d]|+-((1-(2*r2))*|[b,c]|)=0.REAL 2 by EUCLID:44; then (1-2*r2)*|[b,d]|-((1-(2*r2))*|[b,c]|)=0.REAL 2 by EUCLID:45; then (1-2*r2)*(|[b,d]|-(|[b,c]|))=0.REAL 2 by EUCLID:53; then 1-2*r2=0 or (|[b,d]|-(|[b,c]|))=0.REAL 2 by EUCLID:35; then 1-2*r2=0 or |[b,d]|=|[b,c]| by EUCLID:47; then 1-2*r2=0 or d =|[b,c]|`2 by EUCLID:56; then 1=2*r2 by A1,EUCLID:56,XCMPLX_1:15; then A111: r2=1/2 by XCMPLX_1:90; (1-(2*r1-1))*|[b,c]|+(2*r1-1)*|[a,c]|+-(|[b,c]|)=0.REAL 2 by A89,A107,A110,EUCLID:40; then (1-(2*r1-1))*|[b,c]|+((2*r1-1))*|[a,c]|+(-1)*|[b,c]|=0.REAL 2 by EUCLID:43; then ((2*r1-1))*|[a,c]|+((1-(2*r1-1))*|[b,c]|+(-1)*|[b,c]|)=0.REAL 2 by EUCLID:30; then ((2*r1-1))*|[a,c]|+((1-(2*r1-1))+(-1))*|[b,c]|=0.REAL 2 by EUCLID:37; then ((2*r1-1))*|[a,c]|+(-1+1-(2*r1-1))*|[b,c]|=0.REAL 2 by XCMPLX_1:29; then ((2*r1-1))*|[a,c]|+(-(2*r1-1))*|[b,c]|=0.REAL 2 by XCMPLX_1:150; then ((2*r1-1))*|[a,c]|+-((2*r1-1)*|[b,c]|)=0.REAL 2 by EUCLID:44; then ((2*r1-1))*|[a,c]|-((2*r1-1)*|[b,c]|)=0.REAL 2 by EUCLID:45; then ((2*r1-1))*(|[a,c]|-(|[b,c]|))=0.REAL 2 by EUCLID:53; then (2*r1-1)=0 or (|[a,c]|-(|[b,c]|))=0.REAL 2 by EUCLID:35; then (2*r1-1)=0 or |[a,c]|=|[b,c]| by EUCLID:47; then (2*r1-1)=0 or a =|[b,c]|`1 by EUCLID:56; then 1=2*r1 by A1,EUCLID:56,XCMPLX_1:15; hence x1=x2 by A111,XCMPLX_1:90; case A112: x1 in [.1/2,1.] & x2 in [.1/2,1.]; then f3.r1=(1-(2*r1-1))*|[b,c]|+((2*r1-1))*|[a,c]| by A36; then (1-(2*r2-1))*|[b,c]|+((2*r2-1))*|[a,c]| = (1-(2*r1-1))*|[b,c]|+((2*r1-1))*|[a,c]| by A36,A89,A112; then (1-(2*r2-1))*|[b,c]|+((2*r2-1))*|[a,c]| -((2*r1-1))*|[a,c]| = (1-(2*r1-1))*|[b,c]| by EUCLID:52; then (1-(2*r2-1))*|[b,c]|+(((2*r2-1))*|[a,c]| -((2*r1-1))*|[a,c]|) = (1-(2*r1-1))*|[b,c]| by EUCLID:49; then (1-(2*r2-1))*|[b,c]|+((2*r2-1)-(2*r1-1))*(|[a,c]|) = (1-(2*r1-1))*|[b,c]| by EUCLID:54; then ((2*r2-1)-(2*r1-1))*(|[a,c]|) +((1-(2*r2-1))*|[b,c]|-(1-(2*r1-1))*|[b,c]|) = (1-(2*r1-1))*|[b,c]|-(1-(2*r1-1))*|[b,c]| by EUCLID:49; then ((2*r2-1)-(2*r1-1))*(|[a,c]|) +((1-(2*r2-1))*|[b,c]|-(1-(2*r1-1))*|[b,c]|) = 0.REAL 2 by EUCLID:46; then ((2*r2-1)-(2*r1-1))*(|[a,c]|)+((1-(2*r2-1))-(1-(2*r1-1)))*|[b,c]| = 0.REAL 2 by EUCLID:54; then ((2*r2-1)-(2*r1-1))*(|[a,c]|)+(-((2*r2-1)-(2*r1-1)))*|[b,c]| = 0.REAL 2 by XCMPLX_1:149; then ((2*r2-1)-(2*r1-1))*(|[a,c]|)+-(((2*r2-1)-(2*r1-1))*|[b,c]|) = 0.REAL 2 by EUCLID:44; then ((2*r2-1)-(2*r1-1))*(|[a,c]|)-(((2*r2-1)-(2*r1-1))*|[b,c]|) = 0.REAL 2 by EUCLID:45; then ((2*r2-1)-(2*r1-1))*((|[a,c]|)-(|[b,c]|)) = 0.REAL 2 by EUCLID:53; then ((2*r2-1)-(2*r1-1))=0 or (|[a,c]|)-(|[b,c]|)=0.REAL 2 by EUCLID:35; then ((2*r2-1)-(2*r1-1))=0 or |[a,c]|=|[b,c]| by EUCLID:47; then ((2*r2-1)-(2*r1-1))=0 or a =|[b,c]|`1 by EUCLID:56; then (2*r2-1)=(2*r1-1) by A1,EUCLID:56,XCMPLX_1:15; then 2*r2=2*r1-1+1 by XCMPLX_1:27; then 2*r2=2*r1 by XCMPLX_1:27; then r2=r1*2/2 by XCMPLX_1:90; hence x1=x2 by XCMPLX_1:90; end; hence x1=x2; end; then A113: f3 is one-to-one by FUNCT_1:def 8; A114: the carrier of ((TOP-REAL 2)|(Lower_Arc(K))) =[#]((TOP-REAL 2)|(Lower_Arc(K))) by PRE_TOPC:12; [#]((TOP-REAL 2)|(Lower_Arc(K))) c= rng f3 proof let y be set;assume y in [#]((TOP-REAL 2)|(Lower_Arc(K))); then A115: y in Lower_Arc(K) by PRE_TOPC:def 10; then reconsider q=y as Point of TOP-REAL 2; A116: Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1, Th62 ; now per cases by A115,A116,XBOOLE_0:def 2; case q in LSeg(|[b,d]|,|[b,c]|); then A117: 0<=((q`2)-d)/(c-d)/2 & ((q`2)-d)/(c-d)/2<=1 & f3.(((q`2)-d)/(c-d)/2)=q by A39; then ((q`2)-d)/(c-d)/2 in [.0,1.] by TOPREAL5:1; hence y in rng f3 by A17,A117,FUNCT_1:def 5; case q in LSeg(|[b,c]|,|[a,c]|); then A118: 0<=((q`1)-b)/(a-b)/2+1/2 & ((q`1)-b)/(a-b)/2+1/2<=1 & f3.(((q`1)-b)/(a-b)/2+1/2)=q by A47; then ((q`1)-b)/(a-b)/2+1/2 in [.0,1.] by TOPREAL5:1; hence y in rng f3 by A17,A118,FUNCT_1:def 5; end; hence y in rng f3; end; then A119: rng f3=[#]((TOP-REAL 2)|(Lower_Arc(K))) by A114,XBOOLE_0:def 10; A120: I[01] is compact by HEINE:11,TOPMETR:27; ((TOP-REAL 2)|(Lower_Arc(K))) is_T2 by TOPMETR:3; then A121: f3 is_homeomorphism by A87,A88,A113,A119,A120,COMPTS_1:26; rng f3=Lower_Arc(K) by A119,PRE_TOPC:def 10; hence ex f being map of I[01],(TOP-REAL 2)|(Lower_Arc(K)) st f is_homeomorphism & f.0=E-max(K) & f.1=W-min(K) & rng f=Lower_Arc(K) & (for r being Real st r in [.0,1/2.] holds f.r=(1-2*r)*|[b,d]|+(2*r)*|[b,c]|)& (for r being Real st r in [.1/2,1.] holds f.r=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]|)& (for p being Point of TOP-REAL 2 st p in LSeg(|[b,d]|,|[b,c]|) holds 0<=((p`2)-d)/(c-d)/2 & ((p`2)-d)/(c-d)/2<=1 & f.(((p`2)-d)/(c-d)/2)=p)& (for p being Point of TOP-REAL 2 st p in LSeg(|[b,c]|,|[a,c]|) holds 0<=((p`1)-b)/(a-b)/2+1/2 & ((p`1)-b)/(a-b)/2+1/2<=1 & f.(((p`1)-b)/(a-b)/2+1/2)=p) by A30,A32,A33,A36,A39,A47,A121; end; theorem Th65: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,c]|,|[a,d]|) & p2 in LSeg(|[a,c]|,|[a,d]|) holds LE p1,p2,K iff p1`2<=p2`2 proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,c]|,|[a,d]|) & p2 in LSeg(|[a,c]|,|[a,d]|); then A2: K is_simple_closed_curve by Th60; A3: p1`1=a & c <=p1`2 & p1`2 <= d by A1,Th9; A4: p2`1=a & c <=p2`2 & p2`2 <= d by A1,Th9; A5: E-max(K)= |[b,d]| by A1,Th56; A6: Upper_Arc(K)=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; then A7: LSeg(|[a,c]|,|[a,d]|) c= Upper_Arc(K) by XBOOLE_1:7; A8: Upper_Arc(K) /\ Lower_Arc(K)={W-min(K),E-max(K)} by A2,JORDAN6:def 9; reconsider a2=a,c2=c,d2=d as Real by XREAL_0:def 1; A9: now assume p2 in Lower_Arc(K); then A10: p2 in Upper_Arc(K) /\ Lower_Arc(K) by A1,A7,XBOOLE_0:def 3; now assume p2=E-max(K); then A11: p2`1=b by A5,EUCLID:56; p2 in LSeg(|[a2,c2]|,|[a2,d2]|) by A1; hence contradiction by A1,A11,TOPREAL3:17; end; hence p2=W-min(K) by A8,A10,TARSKI:def 2; end; thus LE p1,p2,K implies p1`2<=p2`2 proof assume LE p1,p2,K; then A12: p1 in Upper_Arc(K) & p2 in Lower_Arc(K)& not p2=W-min(K) or p1 in Upper_Arc(K) & p2 in Upper_Arc(K) & LE p1,p2,Upper_Arc(K),W-min(K),E-max(K) or p1 in Lower_Arc(K) & p2 in Lower_Arc(K)& not p2=W-min(K) & LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) by JORDAN6:def 10; consider f being map of I[01],(TOP-REAL 2)|(Upper_Arc(K)) such that A13: f is_homeomorphism & f.0=W-min(K) & f.1=E-max(K) & rng f=Upper_Arc(K) & (for r being Real st r in [.0,1/2.] holds f.r=(1-2*r)*|[a,c]|+(2*r)*|[a,d]|)& (for r being Real st r in [.1/2,1.] holds f.r=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]|)& (for p being Point of TOP-REAL 2 st p in LSeg(|[a,c]|,|[a,d]|) holds 0<=((p`2)-c)/(d-c)/2 & ((p`2)-c)/(d-c)/2<=1 & f.(((p`2)-c)/(d-c)/2)=p)& (for p being Point of TOP-REAL 2 st p in LSeg(|[a,d]|,|[b,d]|) holds 0<=((p`1)-a)/(b-a)/2+1/2 & ((p`1)-a)/(b-a)/2+1/2<=1 & f.(((p`1)-a)/(b-a)/2+1/2)=p) by A1,Th63; reconsider s1=((p1`2)-c)/(d-c)/2,s2=((p2`2)-c)/(d-c)/2 as Real by XREAL_0:def 1; A14: f.s1=p1 by A1,A13; A15: f.s2=p2 by A1,A13; A16: d-c >0 by A1,SQUARE_1:11; A17: 0<=s1 & s1<=1 by A1,A13; 0<=s2 & s2<=1 by A1,A13; then s1<=s2 by A9,A12,A13,A14,A15,A17,JORDAN5C:def 3; then ((p1`2)-c)/(d-c)/2*2<=((p2`2)-c)/(d-c)/2*2 by AXIOMS:25; then ((p1`2)-c)/(d-c)<= ((p2`2)-c)/(d-c)/2*2 by XCMPLX_1:88; then ((p1`2)-c)/(d-c)<= ((p2`2)-c)/(d-c) by XCMPLX_1:88; then ((p1`2)-c)/(d-c)*(d-c)<= ((p2`2)-c)/(d-c)*(d-c) by A16,AXIOMS:25; then ((p1`2)-c)<= ((p2`2)-c)/(d-c)*(d-c) by A16,XCMPLX_1:88; then ((p1`2)-c)<= ((p2`2)-c) by A16,XCMPLX_1:88; then ((p1`2)-c)+c <= ((p2`2)-c)+c by REAL_1:55; then (p1`2) <= ((p2`2)-c)+c by XCMPLX_1:27; hence p1`2<=p2`2 by XCMPLX_1:27; end; thus p1`2<=p2`2 implies LE p1,p2,K proof assume A18: p1`2<=p2`2; for g being map of I[01], (TOP-REAL 2)|Upper_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = W-min(K) & g.1 = E-max(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Upper_Arc(K), s1, s2 be Real; assume A19: g is_homeomorphism & g.0 = W-min(K) & g.1 = E-max(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A20: dom g=the carrier of I[01] by FUNCT_2:def 1; A21: g is one-to-one by A19,TOPS_2:def 5; A22: the carrier of ((TOP-REAL 2)|Upper_Arc(K)) =Upper_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A19,TOPS_2:def 5; then A23: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A24: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A25: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A24,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A26: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A25,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A27: k is continuous map of I[01],R^1 by A23,A26,TOPS_2:58; A28: W-min K=|[a,c]| by A1,Th56; now assume A29: s1>s2; A30: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A31: k.0=h.(W-min(K)) by A19,A30,FUNCT_1:23 .=h1.(W-min(K))+h2.(W-min(K)) by A26 .=(W-min(K))`1+proj2.(W-min(K)) by PSCOMP_1:def 28 .=(W-min(K))`1+(W-min(K))`2 by PSCOMP_1:def 29 .=a+(W-min(K))`2 by A28,EUCLID:56 .=a+c by A28,EUCLID:56; s1 in [.0,1.] by A19,TOPREAL5:1; then A32: k.s1=h.p1 by A19,A30,FUNCT_1:23 .=h1.p1+h2.p1 by A26 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=a+p1`2 by A3,PSCOMP_1:def 29; A33: s2 in [.0,1.] by A19,TOPREAL5:1; then k.s2=h.p2 by A19,A30,FUNCT_1:23 .=h1.p2+h2.p2 by A26 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=a+p2`2 by A4,PSCOMP_1:def 29; then A34: k.0<=k.s1 & k.s1<=k.s2 by A3,A18,A31,A32,REAL_1:55; A35: 0 in [.0,1.] by TOPREAL5:1; then A36: [.0,s2.] c= [.0,1.] by A33,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A37: B is connected by A19,A33,A35,BORSUK_1:83,BORSUK_4:49; A38: 0 in B by A19,TOPREAL5:1; A39: s2 in B by A19,TOPREAL5:1; A40: k.0 is Real by XREAL_0:def 1; A41: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A42: xc in B & k.xc =k.s1 by A27,A34,A37,A38,A39,A40,A41,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A43: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A44: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A44,FUNCT_2:def 1; A45: k.x1=h.(g1.x1) by A44,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A26 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A46: k.x2=h.(g1.x2) by A44,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A26 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A47: g.r1 in Upper_Arc(K) by A22; A48: g.r2 in Upper_Arc(K) by A22; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A47; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A48; now per cases by A6,A22,XBOOLE_0:def 2; case A49: g.r1 in LSeg(|[a,c]|,|[a,d]|) & g.r2 in LSeg(|[a,c]|,|[a,d]|); then A50: (gr1)`1=a & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A51: (gr2)`1=a & c <=(gr2)`2 & (gr2)`2 <=d by A1,A49,Th9; then (gr1)`2=(gr2)`2 by A44,A45,A46,A50,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A50,A51,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A20,A21,FUNCT_1:def 8; case A52: g.r1 in LSeg(|[a,c]|,|[a,d]|) & g.r2 in LSeg(|[a,d]|,|[b,d]|); then A53: (gr1)`1=a & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A54: (gr2)`2=d & a <=(gr2)`1 & (gr2)`1 <=b by A1,A52,Th11; A55: a+(gr1)`2=(gr2)`1 +d by A1,A44,A45,A46,A52,A53,Th11; A56: now assume a<>gr2`1; then a<gr2`1 by A54,REAL_1:def 5; hence contradiction by A53,A55,REAL_1:67; end; now assume gr1`2<>d; then d>gr1`2 by A53,REAL_1:def 5; hence contradiction by A44,A45,A46,A53,A54,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A53,A54,A56,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A20,A21,FUNCT_1:def 8; case A57: g.r1 in LSeg(|[a,d]|,|[b,d]|) & g.r2 in LSeg(|[a,c]|,|[a,d]|); then A58: (gr2)`1=a & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A59: (gr1)`2=d & a <=(gr1)`1 & (gr1)`1 <=b by A1,A57,Th11; A60: a+(gr2)`2=(gr1)`1 +d by A1,A44,A45,A46,A57,A58,Th11; A61: now assume a<>gr1`1; then a<gr1`1 by A59,REAL_1:def 5; hence contradiction by A58,A60,REAL_1:67; end; now assume gr2`2<>d; then d>gr2`2 by A58,REAL_1:def 5; hence contradiction by A44,A45,A46,A58,A59,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A58,A59,A61,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A20,A21,FUNCT_1:def 8; case A62: g.r1 in LSeg(|[a,d]|,|[b,d]|) & g.r2 in LSeg(|[a,d]|,|[b,d]|); then A63: (gr1)`2=d & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A64: (gr2)`2=d & a <=(gr2)`1 & (gr2)`1 <=b by A1,A62,Th11; then (gr1)`1=(gr2)`1 by A44,A45,A46,A63,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A63,A64,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A20,A21,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A65: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A19,TOPREAL5:1; then rxc=s1 by A36,A42,A43,A65,FUNCT_1:def 8; hence contradiction by A29,A42,TOPREAL5:1; end; hence s1 <= s2; end; then p1 in Upper_Arc(K) & p2 in Upper_Arc(K) & LE p1,p2,Upper_Arc(K),W-min(K),E-max(K) by A1,A7,JORDAN5C:def 3; hence LE p1,p2,K by JORDAN6:def 10; end; end; theorem Th66: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,d]|,|[b,d]|) & p2 in LSeg(|[a,d]|,|[b,d]|) holds LE p1,p2,K iff p1`1<=p2`1 proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,d]|,|[b,d]|) & p2 in LSeg(|[a,d]|,|[b,d]|); then A2: K is_simple_closed_curve by Th60; A3: p1`2=d & a <=p1`1 & p1`1 <= b by A1,Th11; A4: p2`2=d & a <=p2`1 & p2`1 <= b by A1,Th11; A5: W-min(K)= |[a,c]| by A1,Th56; A6: E-max(K)= |[b,d]| by A1,Th56; A7: Upper_Arc(K)=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; then A8: LSeg(|[a,d]|,|[b,d]|) c= Upper_Arc(K) by XBOOLE_1:7; A9: Upper_Arc(K) /\ Lower_Arc(K)={W-min(K),E-max(K)} by A2,JORDAN6:def 9; reconsider a2=a,b2=b,d2=d as Real by XREAL_0:def 1; A10: now assume p2 in Lower_Arc(K); then A11: p2 in Upper_Arc(K) /\ Lower_Arc(K) by A1,A8,XBOOLE_0:def 3; now assume p2=W-min(K); then A12: p2`2=c by A5,EUCLID:56; p2 in LSeg(|[a2,d2]|,|[b2,d2]|) by A1; hence contradiction by A1,A12,TOPREAL3:18; end; hence p2=E-max(K) by A9,A11,TARSKI:def 2; end; thus LE p1,p2,K implies p1`1<=p2`1 proof assume LE p1,p2,K; then A13: p1 in Upper_Arc(K) & p2 in Lower_Arc(K)& not p2=W-min(K) or p1 in Upper_Arc(K) & p2 in Upper_Arc(K) & LE p1,p2,Upper_Arc(K),W-min(K),E-max(K) or p1 in Lower_Arc(K) & p2 in Lower_Arc(K)& not p2=W-min(K) & LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) by JORDAN6:def 10; now per cases; case p2=E-max(K); hence p1`1<=p2`1 by A3,A6,EUCLID:56; case A14: p2<>E-max(K); consider f being map of I[01],(TOP-REAL 2)|(Upper_Arc(K)) such that A15: f is_homeomorphism & f.0=W-min(K) & f.1=E-max(K) & rng f=Upper_Arc(K) & (for r being Real st r in [.0,1/2.] holds f.r=(1-2*r)*|[a,c]|+(2*r)*|[a,d]|)& (for r being Real st r in [.1/2,1.] holds f.r=(1-(2*r-1))*|[a,d]|+(2*r-1)*|[b,d]|)& (for p being Point of TOP-REAL 2 st p in LSeg(|[a,c]|,|[a,d]|) holds 0<=((p`2)-c)/(d-c)/2 & ((p`2)-c)/(d-c)/2<=1 & f.(((p`2)-c)/(d-c)/2)=p)& (for p being Point of TOP-REAL 2 st p in LSeg(|[a,d]|,|[b,d]|) holds 0<=((p`1)-a)/(b-a)/2+1/2 & ((p`1)-a)/(b-a)/2+1/2<=1 & f.(((p`1)-a)/(b-a)/2+1/2)=p) by A1,Th63; reconsider s1=((p1`1)-a)/(b-a)/2+1/2,s2=((p2`1)-a)/(b-a)/2+1/2 as Real by XREAL_0:def 1; A16: f.s1=p1 by A1,A15; A17: f.s2=p2 by A1,A15; A18: b-a >0 by A1,SQUARE_1:11; A19: 0<=s1 & s1<=1 by A1,A15; 0<=s2 & s2<=1 by A1,A15; then s1<=s2 by A10,A13,A14,A15,A16,A17,A19,JORDAN5C:def 3; then ((p1`1)-a)/(b-a)/2<= ((p2`1)-a)/(b-a)/2 by REAL_1:53; then ((p1`1)-a)/(b-a)/2*2<=((p2`1)-a)/(b-a)/2*2 by AXIOMS:25; then ((p1`1)-a)/(b-a)<= ((p2`1)-a)/(b-a)/2*2 by XCMPLX_1:88; then ((p1`1)-a)/(b-a)<= ((p2`1)-a)/(b-a) by XCMPLX_1:88; then ((p1`1)-a)/(b-a)*(b-a)<= ((p2`1)-a)/(b-a)*(b-a) by A18,AXIOMS:25; then ((p1`1)-a)<= ((p2`1)-a)/(b-a)*(b-a) by A18,XCMPLX_1:88; then ((p1`1)-a)<= ((p2`1)-a) by A18,XCMPLX_1:88; then ((p1`1)-a)+a <= ((p2`1)-a)+a by REAL_1:55; then (p1`1) <= ((p2`1)-a)+a by XCMPLX_1:27; hence p1`1<=p2`1 by XCMPLX_1:27; end; hence thesis; end; thus p1`1<=p2`1 implies LE p1,p2,K proof assume A20: p1`1<=p2`1; for g being map of I[01], (TOP-REAL 2)|Upper_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = W-min(K) & g.1 = E-max(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Upper_Arc(K), s1, s2 be Real; assume A21: g is_homeomorphism & g.0 = W-min(K) & g.1 = E-max(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A22: dom g=the carrier of I[01] by FUNCT_2:def 1; A23: g is one-to-one by A21,TOPS_2:def 5; A24: the carrier of ((TOP-REAL 2)|Upper_Arc(K)) =Upper_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A21,TOPS_2:def 5; then A25: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A26: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A27: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A26,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A28: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A27,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A29: k is continuous map of I[01],R^1 by A25,A28,TOPS_2:58; A30: W-min K=|[a,c]| by A1,Th56; now assume A31: s1>s2; A32: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A33: k.0=h.(W-min(K)) by A21,A32,FUNCT_1:23 .=h1.(W-min(K))+h2.(W-min(K)) by A28 .=(W-min(K))`1+proj2.(W-min(K)) by PSCOMP_1:def 28 .=(W-min(K))`1+(W-min(K))`2 by PSCOMP_1:def 29 .=(W-min(K))`1+c by A30,EUCLID:56 .=a+c by A30,EUCLID:56; s1 in [.0,1.] by A21,TOPREAL5:1; then A34: k.s1=h.p1 by A21,A32,FUNCT_1:23 .=h1.p1+h2.p1 by A28 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=p1`1 +d by A3,PSCOMP_1:def 29; A35: s2 in [.0,1.] by A21,TOPREAL5:1; then k.s2=h.p2 by A21,A32,FUNCT_1:23 .=h1.p2+h2.p2 by A28 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=p2`1 +d by A4,PSCOMP_1:def 29; then A36: k.0<=k.s1 & k.s1<=k.s2 by A1,A3,A20,A33,A34,REAL_1:55; A37: 0 in [.0,1.] by TOPREAL5:1; then A38: [.0,s2.] c= [.0,1.] by A35,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A39: B is connected by A21,A35,A37,BORSUK_1:83,BORSUK_4:49; A40: 0 in B by A21,TOPREAL5:1; A41: s2 in B by A21,TOPREAL5:1; A42: k.0 is Real by XREAL_0:def 1; A43: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A44: xc in B & k.xc =k.s1 by A29,A36,A39,A40,A41,A42,A43,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A45: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A46: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A46,FUNCT_2:def 1; A47: k.x1=h.(g1.x1) by A46,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A28 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A48: k.x2=h.(g1.x2) by A46,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A28 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A49: g.r1 in Upper_Arc(K) by A24; A50: g.r2 in Upper_Arc(K) by A24; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A49; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A50; now per cases by A7,A24,XBOOLE_0:def 2; case A51: g.r1 in LSeg(|[a,c]|,|[a,d]|) & g.r2 in LSeg(|[a,c]|,|[a,d]|); then A52: (gr1)`1=a & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A53: (gr2)`1=a & c <=(gr2)`2 & (gr2)`2 <=d by A1,A51,Th9; then (gr1)`2=(gr2)`2 by A46,A47,A48,A52,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A52,A53,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A22,A23,FUNCT_1:def 8; case A54: g.r1 in LSeg(|[a,c]|,|[a,d]|) & g.r2 in LSeg(|[a,d]|,|[b,d]|); then A55: (gr1)`1=a & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A56: (gr2)`2=d & a <=(gr2)`1 & (gr2)`1 <=b by A1,A54,Th11; A57: a+(gr1)`2=(gr2)`1 +d by A1,A46,A47,A48,A54,A55,Th11; A58: now assume a<>gr2`1; then a<gr2`1 by A56,REAL_1:def 5; hence contradiction by A55,A57,REAL_1:67; end; now assume gr1`2<>d; then d>gr1`2 by A55,REAL_1:def 5; hence contradiction by A46,A47,A48,A55,A56,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A55,A56,A58,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A22,A23,FUNCT_1:def 8; case A59: g.r1 in LSeg(|[a,d]|,|[b,d]|) & g.r2 in LSeg(|[a,c]|,|[a,d]|); then A60: (gr2)`1=a & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A61: (gr1)`2=d & a <=(gr1)`1 & (gr1)`1 <=b by A1,A59,Th11; A62: a+(gr2)`2=(gr1)`1 +d by A1,A46,A47,A48,A59,A60,Th11; A63: now assume a<>gr1`1; then a<gr1`1 by A61,REAL_1:def 5; hence contradiction by A60,A62,REAL_1:67; end; now assume gr2`2<>d; then d>gr2`2 by A60,REAL_1:def 5; hence contradiction by A46,A47,A48,A60,A61,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A60,A61,A63,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A22,A23,FUNCT_1:def 8; case A64: g.r1 in LSeg(|[a,d]|,|[b,d]|) & g.r2 in LSeg(|[a,d]|,|[b,d]|); then A65: (gr1)`2=d & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A66: (gr2)`2=d & a <=(gr2)`1 & (gr2)`1 <=b by A1,A64,Th11; then (gr1)`1=(gr2)`1 by A46,A47,A48,A65,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A65,A66,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A22,A23,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A67: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A21,TOPREAL5:1; then rxc=s1 by A38,A44,A45,A67,FUNCT_1:def 8; hence contradiction by A31,A44,TOPREAL5:1; end; hence s1 <= s2; end; then p1 in Upper_Arc(K) & p2 in Upper_Arc(K) & LE p1,p2,Upper_Arc(K),W-min(K),E-max(K) by A1,A8,JORDAN5C:def 3; hence LE p1,p2,K by JORDAN6:def 10; end; end; theorem Th67: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[b,c]|,|[b,d]|) & p2 in LSeg(|[b,c]|,|[b,d]|) holds LE p1,p2,K iff p1`2>=p2`2 proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[b,c]|,|[b,d]|) & p2 in LSeg(|[b,c]|,|[b,d]|); then A2: K is_simple_closed_curve by Th60; A3: p1`1=b & c <=p1`2 & p1`2 <= d by A1,Th9; A4: p2`1=b & c <=p2`2 & p2`2 <= d by A1,Th9; A5: W-min(K)= |[a,c]| by A1,Th56; A6: E-max(K)= |[b,d]| by A1,Th56; A7: Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62 ; then A8: LSeg(|[b,d]|,|[b,c]|) c= Lower_Arc(K) by XBOOLE_1:7; A9: Upper_Arc(K) /\ Lower_Arc(K)={W-min(K),E-max(K)} by A2,JORDAN6:def 9; reconsider b2=b,c2=c,d2=d as Real by XREAL_0:def 1; A10: now assume p1 in Upper_Arc(K); then A11: p1 in Upper_Arc(K) /\ Lower_Arc(K) by A1,A8,XBOOLE_0:def 3; now assume p1=W-min(K); then A12: p1`1=a by A5,EUCLID:56; p1 in LSeg(|[b2,c2]|,|[b2,d2]|) by A1; hence contradiction by A1,A12,TOPREAL3:17; end; hence p1=E-max(K) by A9,A11,TARSKI:def 2; end; thus LE p1,p2,K implies p1`2>=p2`2 proof assume LE p1,p2,K; then A13: p1 in Upper_Arc(K) & p2 in Lower_Arc(K)& not p2=W-min(K) or p1 in Upper_Arc(K) & p2 in Upper_Arc(K) & LE p1,p2,Upper_Arc(K),W-min(K),E-max(K) or p1 in Lower_Arc(K) & p2 in Lower_Arc(K)& not p2=W-min(K) & LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) by JORDAN6:def 10; now per cases; case p1=E-max(K); hence p1`2>=p2`2 by A4,A6,EUCLID:56; case A14: p1<>E-max(K); consider f being map of I[01],(TOP-REAL 2)|(Lower_Arc(K)) such that A15: f is_homeomorphism & f.0=E-max(K) & f.1=W-min(K) & rng f=Lower_Arc(K) & (for r being Real st r in [.0,1/2.] holds f.r=(1-2*r)*|[b,d]|+(2*r)*|[b,c]|)& (for r being Real st r in [.1/2,1.] holds f.r=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]|)& (for p being Point of TOP-REAL 2 st p in LSeg(|[b,d]|,|[b,c]|) holds 0<=((p`2)-d)/(c-d)/2 & ((p`2)-d)/(c-d)/2<=1 & f.(((p`2)-d)/(c-d)/2)=p)& (for p being Point of TOP-REAL 2 st p in LSeg(|[b,c]|,|[a,c]|) holds 0<=((p`1)-b)/(a-b)/2+1/2 & ((p`1)-b)/(a-b)/2+1/2<=1 & f.(((p`1)-b)/(a-b)/2+1/2)=p) by A1,Th64; reconsider s1=((p1`2)-d)/(c-d)/2,s2=((p2`2)-d)/(c-d)/2 as Real by XREAL_0:def 1; A16: f.s1=p1 by A1,A15; A17: f.s2=p2 by A1,A15; d-c>0 by A1,SQUARE_1:11; then -(d-c)< -0 by REAL_1:50; then 0-(d-c) < 0 by XCMPLX_1:150; then 0-d+c <0 by XCMPLX_1:37; then -d+c <0 by XCMPLX_1:150; then A18: c -d <0 by XCMPLX_0:def 8; A19: 0<=s1 & s1<=1 by A1,A15; 0<=s2 & s2<=1 by A1,A15; then s1<=s2 by A10,A13,A14,A15,A16,A17,A19,JORDAN5C:def 3; then ((p1`2)-d)/(c-d)/2*2<=((p2`2)-d)/(c-d)/2*2 by AXIOMS:25; then ((p1`2)-d)/(c-d)<= ((p2`2)-d)/(c-d)/2*2 by XCMPLX_1:88; then ((p1`2)-d)/(c-d)<= ((p2`2)-d)/(c-d) by XCMPLX_1:88; then ((p1`2)-d)/(c-d)*(c-d)>= ((p2`2)-d)/(c-d)*(c-d) by A18,REAL_1:52; then ((p1`2)-d)>= ((p2`2)-d)/(c-d)*(c-d) by A18,XCMPLX_1:88; then ((p1`2)-d)>= ((p2`2)-d) by A18,XCMPLX_1:88; then ((p1`2)-d)+d >= ((p2`2)-d)+d by REAL_1:55; then (p1`2) >= ((p2`2)-d)+d by XCMPLX_1:27; hence p1`2>=p2`2 by XCMPLX_1:27; end; hence thesis; end; thus p1`2>=p2`2 implies LE p1,p2,K proof assume A20: p1`2>=p2`2; now per cases; case p2=W-min (K); then p2=|[a,c]| by A1,Th56; hence contradiction by A1,A4,EUCLID:56; case A21: p2<>W-min(K); for g being map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 be Real; assume A22: g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A23: dom g=the carrier of I[01] by FUNCT_2:def 1; A24: g is one-to-one by A22,TOPS_2:def 5; A25: the carrier of ((TOP-REAL 2)|Lower_Arc(K)) =Lower_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A22,TOPS_2:def 5; then A26: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A27: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A28: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A27,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A29: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A28,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A30: k is continuous map of I[01],R^1 by A26,A29,TOPS_2:58; A31: E-max K=|[b,d]| by A1,Th56; now assume A32: s1>s2; A33: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A34: k.0=h.(E-max(K)) by A22,A33,FUNCT_1:23 .=h1.(E-max(K))+h2.(E-max(K)) by A29 .=(E-max(K))`1+proj2.(E-max(K)) by PSCOMP_1:def 28 .=(E-max(K))`1+(E-max(K))`2 by PSCOMP_1:def 29 .=b+(E-max(K))`2 by A31,EUCLID:56 .=b+d by A31,EUCLID:56; s1 in [.0,1.] by A22,TOPREAL5:1; then A35: k.s1=h.p1 by A22,A33,FUNCT_1:23 .=h1.p1+h2.p1 by A29 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=b+p1`2 by A3,PSCOMP_1:def 29; A36: s2 in [.0,1.] by A22,TOPREAL5:1; then k.s2=h.p2 by A22,A33,FUNCT_1:23 .=proj1.p2 +proj2.p2 by A29 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=b+p2`2 by A4,PSCOMP_1:def 29; then A37: k.0>=k.s1 & k.s1>=k.s2 by A3,A20,A34,A35,REAL_1:55; A38: 0 in [.0,1.] by TOPREAL5:1; then A39: [.0,s2.] c= [.0,1.] by A36,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A40: B is connected by A22,A36,A38,BORSUK_1:83,BORSUK_4:49; A41: 0 in B by A22,TOPREAL5:1; A42: s2 in B by A22,TOPREAL5:1; A43: k.0 is Real by XREAL_0:def 1; A44: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A45: xc in B & k.xc =k.s1 by A30,A37,A40,A41,A42,A43,A44,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A46: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A47: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A47,FUNCT_2:def 1; A48: k.x1=h.(g1.x1) by A47,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A29 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A49: k.x2=h.(g1.x2) by A47,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A29 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A50: g.r1 in Lower_Arc(K) by A25; A51: g.r2 in Lower_Arc(K) by A25; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A50; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A51; now per cases by A7,A25,XBOOLE_0:def 2; case A52: g.r1 in LSeg(|[b,c]|,|[b,d]|) & g.r2 in LSeg(|[b,c]|,|[b,d]|); then A53: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A54: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,A52,Th9; then (gr1)`2=(gr2)`2 by A47,A48,A49,A53,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A53,A54,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A23,A24,FUNCT_1:def 8; case A55: g.r1 in LSeg(|[b,c]|,|[b,d]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A56: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A57: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A55,Th11; A58: b+(gr1)`2=(gr2)`1 +c by A1,A47,A48,A49,A55,A56,Th11; A59: now assume b<>gr2`1; then b>gr2`1 by A57,REAL_1:def 5; hence contradiction by A56,A58,REAL_1:67; end; now assume gr1`2<>c; then c <gr1`2 by A56,REAL_1:def 5; hence contradiction by A47,A48,A49,A56,A57,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A56,A57,A59,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A23,A24,FUNCT_1:def 8; case A60: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,c]|,|[b,d]|); then A61: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A62: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,A60,Th11; A63: b+(gr2)`2=(gr1)`1 +c by A1,A47,A48,A49,A60,A61,Th11; A64: now assume b<>gr1`1; then b> gr1`1 by A62,REAL_1:def 5; hence contradiction by A61,A63,REAL_1:67; end; now assume gr2`2<> c; then c <gr2`2 by A61,REAL_1:def 5; hence contradiction by A47,A48,A49,A61,A62,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A61,A62,A64,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A23,A24,FUNCT_1:def 8; case A65: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A66: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A67: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A65,Th11; then (gr1)`1=(gr2)`1 by A47,A48,A49,A66,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A66,A67,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A23,A24,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A68: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A22,TOPREAL5:1; then rxc=s1 by A39,A45,A46,A68,FUNCT_1:def 8; hence contradiction by A32,A45,TOPREAL5:1; end; hence s1 <= s2; end; then p1 in Lower_Arc(K) & p2 in Lower_Arc(K) & not p2=W-min(K) & LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) by A1,A8,A21,JORDAN5C:def 3; hence LE p1,p2,K by JORDAN6:def 10; end; hence thesis; end; end; theorem Th68: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,c]|,|[b,c]|) & p2 in LSeg(|[a,c]|,|[b,c]|) holds LE p1,p2,K & p1<>W-min(K) iff p1`1>=p2`1 & p2<>W-min(K) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,c]|,|[b,c]|) & p2 in LSeg(|[a,c]|,|[b,c]|); then A2: K is_simple_closed_curve by Th60; A3: p1`2=c & a <=p1`1 & p1`1 <= b by A1,Th11; A4: p2`2=c & a <=p2`1 & p2`1 <= b by A1,Th11; A5: W-min(K)= |[a,c]| by A1,Th56; A6: E-max(K)= |[b,d]| by A1,Th56; A7: Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62 ; then A8: LSeg(|[b,c]|,|[a,c]|) c= Lower_Arc(K) by XBOOLE_1:7; then A9: p1 in Lower_Arc(K) by A1; A10: Lower_Arc(K) c= K by A2,JORDAN1A:16; A11: Upper_Arc(K) /\ Lower_Arc(K)={W-min(K),E-max(K)} by A2,JORDAN6:def 9; A12: now assume p1 in Upper_Arc(K); then p1 in Upper_Arc(K) /\ Lower_Arc(K) by A1,A8,XBOOLE_0:def 3; then p1=W-min(K) or p1=E-max(K) by A11,TARSKI:def 2; hence p1=W-min(K) by A1,A3,A6,EUCLID:56; end; thus LE p1,p2,K & p1<>W-min(K) implies p1`1>=p2`1 & p2<>W-min(K) proof assume A13: LE p1,p2,K & p1<>W-min(K); then A14: p1 in Upper_Arc(K) & p2 in Lower_Arc(K)& not p2=W-min(K) or p1 in Upper_Arc(K) & p2 in Upper_Arc(K) & LE p1,p2,Upper_Arc(K),W-min(K),E-max(K) or p1 in Lower_Arc(K) & p2 in Lower_Arc(K)& not p2=W-min(K) & LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) by JORDAN6:def 10; consider f being map of I[01],(TOP-REAL 2)|(Lower_Arc(K)) such that A15: f is_homeomorphism & f.0=E-max(K) & f.1=W-min(K) & rng f=Lower_Arc(K) & (for r being Real st r in [.0,1/2.] holds f.r=(1-2*r)*|[b,d]|+(2*r)*|[b,c]|)& (for r being Real st r in [.1/2,1.] holds f.r=(1-(2*r-1))*|[b,c]|+(2*r-1)*|[a,c]|)& (for p being Point of TOP-REAL 2 st p in LSeg(|[b,d]|,|[b,c]|) holds 0<=((p`2)-d)/(c-d)/2 & ((p`2)-d)/(c-d)/2<=1 & f.(((p`2)-d)/(c-d)/2)=p)& (for p being Point of TOP-REAL 2 st p in LSeg(|[b,c]|,|[a,c]|) holds 0<=((p`1)-b)/(a-b)/2+1/2 & ((p`1)-b)/(a-b)/2+1/2<=1 & f.(((p`1)-b)/(a-b)/2+1/2)=p) by A1,Th64; reconsider s1=((p1`1)-b)/(a-b)/2+1/2,s2=((p2`1)-b)/(a-b)/2+1/2 as Real by XREAL_0:def 1; A16: f.s1=p1 by A1,A15; A17: f.s2=p2 by A1,A15; b-a>0 by A1,SQUARE_1:11; then -(b-a)< -0 by REAL_1:50; then 0-(b-a) < 0 by XCMPLX_1:150; then 0-b+a <0 by XCMPLX_1:37; then -b+a <0 by XCMPLX_1:150; then A18: a -b <0 by XCMPLX_0:def 8; A19: 0<=s1 & s1<=1 by A1,A15; 0<=s2 & s2<=1 by A1,A15; then s1<=s2 by A12,A13,A14,A15,A16,A17,A19,JORDAN5C:def 3; then ((p1`1)-b)/(a-b)/2<= ((p2`1)-b)/(a-b)/2 by REAL_1:53; then ((p1`1)-b)/(a-b)/2*2<=((p2`1)-b)/(a-b)/2*2 by AXIOMS:25; then ((p1`1)-b)/(a-b)<= ((p2`1)-b)/(a-b)/2*2 by XCMPLX_1:88; then ((p1`1)-b)/(a-b)<= ((p2`1)-b)/(a-b) by XCMPLX_1:88; then ((p1`1)-b)/(a-b)*(a-b)>= ((p2`1)-b)/(a-b)*(a-b) by A18,REAL_1:52; then ((p1`1)-b)>= ((p2`1)-b)/(a-b)*(a-b) by A18,XCMPLX_1:88; then ((p1`1)-b)>= ((p2`1)-b) by A18,XCMPLX_1:88; then ((p1`1)-b)+b >= ((p2`1)-b)+b by REAL_1:55; then (p1`1) >= ((p2`1)-b)+b by XCMPLX_1:27; hence p1`1>=p2`1 by XCMPLX_1:27; now assume A20: p2=W-min(K); then LE p2,p1,K by A2,A9,A10,JORDAN7:3; hence contradiction by A2,A13,A20,JORDAN6:72; end; hence thesis; end; thus p1`1>=p2`1 & p2<>W-min(K) implies LE p1,p2,K & p1<>W-min(K) proof assume A21: p1`1>=p2`1 & p2<>W-min(K); A22: for g being map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 be Real; assume A23: g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A24: dom g=the carrier of I[01] by FUNCT_2:def 1; A25: g is one-to-one by A23,TOPS_2:def 5; A26: the carrier of ((TOP-REAL 2)|Lower_Arc(K)) =Lower_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A23,TOPS_2:def 5; then A27: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A28: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A29: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A28,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A30: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A29,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A31: k is continuous map of I[01],R^1 by A27,A30,TOPS_2:58; A32: E-max K=|[b,d]| by A1,Th56; now assume A33: s1>s2; A34: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A35: k.0=h.(E-max(K)) by A23,A34,FUNCT_1:23 .=h1.(E-max(K))+h2.(E-max(K)) by A30 .=(E-max(K))`1+proj2.(E-max(K)) by PSCOMP_1:def 28 .=(E-max(K))`1+(E-max(K))`2 by PSCOMP_1:def 29 .=(E-max(K))`1+d by A32,EUCLID:56 .=b+d by A32,EUCLID:56; s1 in [.0,1.] by A23,TOPREAL5:1; then A36: k.s1=h.p1 by A23,A34,FUNCT_1:23 .=proj1.p1 +proj2.p1 by A30 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=p1`1 +c by A3,PSCOMP_1:def 29; A37: s2 in [.0,1.] by A23,TOPREAL5:1; then k.s2=h.p2 by A23,A34,FUNCT_1:23 .=h1.p2+h2.p2 by A30 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=p2`1 +c by A4,PSCOMP_1:def 29; then A38: k.0>=k.s1 & k.s1>=k.s2 by A1,A3,A21,A35,A36,REAL_1:55; A39: 0 in [.0,1.] by TOPREAL5:1; then A40: [.0,s2.] c= [.0,1.] by A37,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A41: B is connected by A23,A37,A39,BORSUK_1:83,BORSUK_4:49; A42: 0 in B by A23,TOPREAL5:1; A43: s2 in B by A23,TOPREAL5:1; A44: k.0 is Real by XREAL_0:def 1; A45: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A46: xc in B & k.xc =k.s1 by A31,A38,A41,A42,A43,A44,A45,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A47: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A48: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A48,FUNCT_2:def 1; A49: k.x1=h.(g1.x1) by A48,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A30 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A50: k.x2=h.(g1.x2) by A48,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A30 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A51: g.r1 in Lower_Arc(K) by A26; A52: g.r2 in Lower_Arc(K) by A26; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A51; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A52; now per cases by A7,A26,XBOOLE_0:def 2; case A53: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A54: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A55: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,A53,Th9; then (gr1)`2=(gr2)`2 by A48,A49,A50,A54,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A54,A55,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A24,A25,FUNCT_1:def 8; case A56: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A57: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A58: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A56,Th11; A59: b+(gr1)`2=(gr2)`1 +c by A1,A48,A49,A50,A56,A57,Th11; A60: now assume b<>gr2`1; then b>gr2`1 by A58,REAL_1:def 5; hence contradiction by A57,A59,REAL_1:67; end; now assume gr1`2<>c; then c <gr1`2 by A57,REAL_1:def 5; hence contradiction by A48,A49,A50,A57,A58,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A57,A58,A60,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A24,A25,FUNCT_1:def 8; case A61: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A62: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A63: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,A61,Th11; A64: b+(gr2)`2=(gr1)`1 +c by A1,A48,A49,A50,A61,A62,Th11; A65: now assume b<>gr1`1; then b>gr1`1 by A63,REAL_1:def 5; hence contradiction by A62,A64,REAL_1:67; end; now assume gr2`2<>c; then c <gr2`2 by A62,REAL_1:def 5; hence contradiction by A48,A49,A50,A62,A63,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A62,A63,A65,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A24,A25,FUNCT_1:def 8; case A66: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A67: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A68: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A66,Th11; then (gr1)`1=(gr2)`1 by A48,A49,A50,A67,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A67,A68,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A24,A25,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A69: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A23,TOPREAL5:1; then rxc=s1 by A40,A46,A47,A69,FUNCT_1:def 8; hence contradiction by A33,A46,TOPREAL5:1; end; hence s1 <= s2; end; A70: now assume A71: p1=W-min(K); then p1`1=a & p1`2=c by A5,EUCLID:56; then p1`1=p2`1 by A4,A21,AXIOMS:21; then |[(p1)`1,(p1)`2]|=p2 by A3,A4,EUCLID:57; hence contradiction by A21,A71,EUCLID:57; end; p1 in Lower_Arc(K) & p2 in Lower_Arc(K) & not p2=W-min(K) & LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) by A1,A8,A21,A22,JORDAN5C:def 3; hence LE p1,p2,K by JORDAN6:def 10; thus thesis by A70; end; end; theorem Th69: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,c]|,|[a,d]|) holds LE p1,p2,K iff p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,c]|,|[a,d]|); then A2: K is_simple_closed_curve by Th60; Upper_Arc(K)=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; then A3: LSeg(|[a,c]|,|[a,d]|) c= Upper_Arc(K) by XBOOLE_1:7; A4: p1`1=a & c <=p1`2 & p1`2 <= d by A1,Th9; thus LE p1,p2,K implies p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) proof assume A5: LE p1,p2,K; then A6: p1 in K & p2 in K by A2,JORDAN7:5; K= {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} by A1,Def1; then K= LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40 .=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) \/ LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by XBOOLE_1:4; then p2 in LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) \/ LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) by A6,XBOOLE_0:def 2; then A7: p2 in LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) by XBOOLE_0:def 2; now per cases by A7,XBOOLE_0:def 2; case p2 in LSeg(|[a,c]|,|[a,d]|); hence p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A5,Th65; case p2 in LSeg(|[a,d]|,|[b,d]|); hence p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); case p2 in LSeg(|[b,d]|,|[b,c]|); hence p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); case A8: p2 in LSeg(|[b,c]|,|[a,c]|); now per cases; case p2=W-min(K); then LE p2,p1,K by A2,A6,JORDAN7:3; hence p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A2,A5,JORDAN6:72; case p2<>W-min(K); hence p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A8; end; hence p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); end; hence p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); end; A9: W-min(K)= |[a,c]| by A1,Th56; thus p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) implies LE p1,p2,K proof assume A10: p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2 or p2 in LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); now per cases by A10; case p2 in LSeg(|[a,c]|,|[a,d]|) & p1`2<=p2`2; hence LE p1,p2,K by A1,Th65; case A11: p2 in LSeg(|[a,d]|,|[b,d]|); then A12: p2`2=d & a <=p2`1 & p2`1 <= b by A1,Th11; A13: Upper_Arc(K)=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; then A14: p2 in Upper_Arc(K) by A11,XBOOLE_0:def 2; A15: p1 in Upper_Arc(K) by A1,A13,XBOOLE_0:def 2; LE p1,p2,Upper_Arc(K),W-min(K),E-max(K) proof for g being map of I[01], (TOP-REAL 2)|Upper_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = W-min(K) & g.1 = E-max(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Upper_Arc(K), s1, s2 be Real; assume A16: g is_homeomorphism & g.0 = W-min(K) & g.1 = E-max(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A17: dom g=the carrier of I[01] by FUNCT_2:def 1; A18: g is one-to-one by A16,TOPS_2:def 5; A19: the carrier of ((TOP-REAL 2)|Upper_Arc(K)) =Upper_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A16,TOPS_2:def 5; then A20: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A21: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A22: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A21,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A23: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A22,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A24: k is continuous map of I[01],R^1 by A20,A23,TOPS_2:58; A25: W-min K=|[a,c]| by A1,Th56; now assume A26: s1>s2; A27: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A28: k.0=h.(W-min(K)) by A16,A27,FUNCT_1:23 .=h1.(W-min(K))+h2.(W-min(K)) by A23 .=(W-min(K))`1+proj2.(W-min(K)) by PSCOMP_1:def 28 .=(W-min(K))`1+(W-min(K))`2 by PSCOMP_1:def 29 .=(W-min(K))`1+c by A25,EUCLID:56 .=a+c by A25,EUCLID:56; s1 in [.0,1.] by A16,TOPREAL5:1; then A29: k.s1=h.p1 by A16,A27,FUNCT_1:23 .=proj1.p1 +proj2.p1 by A23 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=a +p1`2 by A4,PSCOMP_1:def 29; A30: s2 in [.0,1.] by A16,TOPREAL5:1; then k.s2=h.p2 by A16,A27,FUNCT_1:23 .=proj1.p2 +proj2.p2 by A23 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=p2`1 +d by A12,PSCOMP_1:def 29; then A31: k.0<=k.s1 & k.s1<=k.s2 by A4,A12,A28,A29,REAL_1:55; A32: 0 in [.0,1.] by TOPREAL5:1; then A33: [.0,s2.] c= [.0,1.] by A30,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A34: B is connected by A16,A30,A32,BORSUK_1:83,BORSUK_4:49; A35: 0 in B by A16,TOPREAL5:1; A36: s2 in B by A16,TOPREAL5:1; A37: k.0 is Real by XREAL_0:def 1; A38: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A39: xc in B & k.xc =k.s1 by A24,A31,A34,A35,A36,A37,A38,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A40: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A41: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A41,FUNCT_2:def 1; A42: k.x1=h.(g1.x1) by A41,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A23 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A43: k.x2=h.(g1.x2) by A41,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A23 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A44: g.r1 in Upper_Arc(K) by A19; A45: g.r2 in Upper_Arc(K) by A19; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A44; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A45; now per cases by A13,A19,XBOOLE_0:def 2; case A46: g.r1 in LSeg(|[a,c]|,|[a,d]|) & g.r2 in LSeg(|[a,c]|,|[a,d]|); then A47: (gr1)`1=a & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A48: (gr2)`1=a & c <=(gr2)`2 & (gr2)`2 <=d by A1,A46,Th9; then (gr1)`2=(gr2)`2 by A41,A42,A43,A47,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A47,A48,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A17,A18,FUNCT_1:def 8; case A49: g.r1 in LSeg(|[a,c]|,|[a,d]|) & g.r2 in LSeg(|[a,d]|,|[b,d]|); then A50: (gr1)`1=a & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A51: (gr2)`2=d & a <=(gr2)`1 & (gr2)`1 <=b by A1,A49,Th11; A52: a+(gr1)`2=(gr2)`1 +d by A1,A41,A42,A43,A49,A50,Th11; A53: now assume a<>gr2`1; then a<gr2`1 by A51,REAL_1:def 5; hence contradiction by A50,A52,REAL_1:67; end; now assume gr1`2<>d; then d>gr1`2 by A50,REAL_1:def 5; hence contradiction by A41,A42,A43,A50,A51,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A50,A51,A53,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A17,A18,FUNCT_1:def 8; case A54: g.r1 in LSeg(|[a,d]|,|[b,d]|) & g.r2 in LSeg(|[a,c]|,|[a,d]|); then A55: (gr2)`1=a & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A56: (gr1)`2=d & a <=(gr1)`1 & (gr1)`1 <=b by A1,A54,Th11; A57: a+(gr2)`2=(gr1)`1 +d by A1,A41,A42,A43,A54,A55,Th11; A58: now assume a<>gr1`1; then a<gr1`1 by A56,REAL_1:def 5; hence contradiction by A55,A57,REAL_1:67; end; now assume gr2`2<>d; then d>gr2`2 by A55,REAL_1:def 5; hence contradiction by A41,A42,A43,A55,A56,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A55,A56,A58,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A17,A18,FUNCT_1:def 8; case A59: g.r1 in LSeg(|[a,d]|,|[b,d]|) & g.r2 in LSeg(|[a,d]|,|[b,d]|); then A60: (gr1)`2=d & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A61: (gr2)`2=d & a <=(gr2)`1 & (gr2)`1 <=b by A1,A59,Th11; then (gr1)`1=(gr2)`1 by A41,A42,A43,A60,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A60,A61,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A17,A18,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A62: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A16,TOPREAL5:1; then rxc=s1 by A33,A39,A40,A62,FUNCT_1:def 8; hence contradiction by A26,A39,TOPREAL5:1; end; hence s1 <= s2; end; hence thesis by A14,A15,JORDAN5C:def 3; end; hence LE p1,p2,K by A14,A15,JORDAN6:def 10; case A63: p2 in LSeg(|[b,d]|,|[b,c]|); reconsider b2=b,c2=c,d2=d as Real by XREAL_0:def 1; p2 in LSeg(|[b2,d2]|,|[b2,c2]|) by A63; then A64: p2`1 =b by TOPREAL3:17; Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62; then A65: LSeg(|[b,d]|,|[b,c]|) c= Lower_Arc(K) by XBOOLE_1:7; p2 <> W-min(K) by A1,A9,A64,EUCLID:56; hence LE p1,p2,K by A1,A3,A63,A65,JORDAN6:def 10; case A66: p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62; then LSeg(|[b,c]|,|[a,c]|) c= Lower_Arc(K) by XBOOLE_1:7; hence LE p1,p2,K by A1,A3,A66,JORDAN6:def 10; end; hence LE p1,p2,K; end; end; theorem Th70: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,d]|,|[b,d]|) holds LE p1,p2,K iff p2 in LSeg(|[a,d]|,|[b,d]|) & p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[a,d]|,|[b,d]|); then A2: K is_simple_closed_curve by Th60; Upper_Arc(K)=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; then A3: LSeg(|[a,d]|,|[b,d]|) c= Upper_Arc(K) by XBOOLE_1:7; A4: p1`2=d & a <=p1`1 & p1`1 <= b by A1,Th11; thus LE p1,p2,K implies p2 in LSeg(|[a,d]|,|[b,d]|) & p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) proof assume A5: LE p1,p2,K; then A6: p1 in K & p2 in K by A2,JORDAN7:5; K= {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} by A1,Def1; then K= LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40 .=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) \/ LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by XBOOLE_1:4; then p2 in LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) \/ LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) by A6,XBOOLE_0:def 2; then A7: p2 in LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) by XBOOLE_0:def 2; now per cases by A7,XBOOLE_0:def 2; case p2 in LSeg(|[a,c]|,|[a,d]|); then LE p2,p1,K by A1,Th69; hence p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A2,A5,JORDAN6:72; case p2 in LSeg(|[a,d]|,|[b,d]|); hence p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A5,Th66; case p2 in LSeg(|[b,d]|,|[b,c]|); hence p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); case A8: p2 in LSeg(|[b,c]|,|[a,c]|); now per cases; case p2=W-min(K); then LE p2,p1,K by A2,A6,JORDAN7:3; hence p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A2,A5,JORDAN6:72; case p2<>W-min(K); hence p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A8; end; hence p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); end; hence p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); end; A9: W-min(K)= |[a,c]| by A1,Th56; thus p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) implies LE p1,p2,K proof assume A10: p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1 or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); now per cases by A10; case A11: p2 in LSeg(|[a,d]|,|[b,d]|)& p1`1<=p2`1; then A12: p2`2=d & a <=p2`1 & p2`1 <= b by A1,Th11; A13: Upper_Arc(K)=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) by A1,Th61; then A14: p2 in Upper_Arc(K) by A11,XBOOLE_0:def 2; A15: p1 in Upper_Arc(K) by A1,A13,XBOOLE_0:def 2; LE p1,p2,Upper_Arc(K),W-min(K),E-max(K) proof for g being map of I[01], (TOP-REAL 2)|Upper_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = W-min(K) & g.1 = E-max(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Upper_Arc(K), s1, s2 be Real; assume A16: g is_homeomorphism & g.0 = W-min(K) & g.1 = E-max(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A17: dom g=the carrier of I[01] by FUNCT_2:def 1; A18: g is one-to-one by A16,TOPS_2:def 5; A19: the carrier of ((TOP-REAL 2)|Upper_Arc(K)) =Upper_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A16,TOPS_2:def 5; then A20: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A21: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A22: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A21,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A23: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A22,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A24: k is continuous map of I[01],R^1 by A20,A23,TOPS_2:58; A25: W-min K=|[a,c]| by A1,Th56; now assume A26: s1>s2; A27: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A28: k.0=h.(W-min(K)) by A16,A27,FUNCT_1:23 .=h1.(W-min(K))+h2.(W-min(K)) by A23 .=(W-min(K))`1+proj2.(W-min(K)) by PSCOMP_1:def 28 .=(W-min(K))`1+(W-min(K))`2 by PSCOMP_1:def 29 .=(W-min(K))`1+c by A25,EUCLID:56 .=a+c by A25,EUCLID:56; s1 in [.0,1.] by A16,TOPREAL5:1; then A29: k.s1=h.p1 by A16,A27,FUNCT_1:23 .=proj1.p1 +proj2.p1 by A23 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=p1`1+d by A4,PSCOMP_1:def 29; A30: s2 in [.0,1.] by A16,TOPREAL5:1; then k.s2=h.p2 by A16,A27,FUNCT_1:23 .=proj1.p2 +proj2.p2 by A23 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=p2`1 +d by A12,PSCOMP_1:def 29; then A31: k.0<=k.s1 & k.s1<=k.s2 by A1,A4,A11,A28,A29,REAL_1:55; A32: 0 in [.0,1.] by TOPREAL5:1; then A33: [.0,s2.] c= [.0,1.] by A30,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A34: B is connected by A16,A30,A32,BORSUK_1:83,BORSUK_4:49; A35: 0 in B by A16,TOPREAL5:1; A36: s2 in B by A16,TOPREAL5:1; A37: k.0 is Real by XREAL_0:def 1; A38: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A39: xc in B & k.xc =k.s1 by A24,A31,A34,A35,A36,A37,A38,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A40: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A41: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A41,FUNCT_2:def 1; A42: k.x1=h.(g1.x1) by A41,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A23 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A43: k.x2=h.(g1.x2) by A41,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A23 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A44: g.r1 in Upper_Arc(K) by A19; A45: g.r2 in Upper_Arc(K) by A19; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A44; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A45; now per cases by A13,A19,XBOOLE_0:def 2; case A46: g.r1 in LSeg(|[a,c]|,|[a,d]|) & g.r2 in LSeg(|[a,c]|,|[a,d]|); then A47: (gr1)`1=a & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A48: (gr2)`1=a & c <=(gr2)`2 & (gr2)`2 <=d by A1,A46,Th9; then (gr1)`2=(gr2)`2 by A41,A42,A43,A47,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A47,A48,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A17,A18,FUNCT_1:def 8; case A49: g.r1 in LSeg(|[a,c]|,|[a,d]|) & g.r2 in LSeg(|[a,d]|,|[b,d]|); then A50: (gr1)`1=a & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A51: (gr2)`2=d & a <=(gr2)`1 & (gr2)`1 <=b by A1,A49,Th11; A52: a+(gr1)`2=(gr2)`1 +d by A1,A41,A42,A43,A49,A50,Th11; A53: now assume a<>gr2`1; then a<gr2`1 by A51,REAL_1:def 5; hence contradiction by A50,A52,REAL_1:67; end; now assume gr1`2<>d; then d>gr1`2 by A50,REAL_1:def 5; hence contradiction by A41,A42,A43,A50,A51,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A50,A51,A53,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A17,A18,FUNCT_1:def 8; case A54: g.r1 in LSeg(|[a,d]|,|[b,d]|) & g.r2 in LSeg(|[a,c]|,|[a,d]|); then A55: (gr2)`1=a & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A56: (gr1)`2=d & a <=(gr1)`1 & (gr1)`1 <=b by A1,A54,Th11; A57: a+(gr2)`2=(gr1)`1 +d by A1,A41,A42,A43,A54,A55,Th11; A58: now assume a<>gr1`1; then a<gr1`1 by A56,REAL_1:def 5; hence contradiction by A55,A57,REAL_1:67; end; now assume gr2`2<>d; then d>gr2`2 by A55,REAL_1:def 5; hence contradiction by A41,A42,A43,A55,A56,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A55,A56,A58,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A17,A18,FUNCT_1:def 8; case A59: g.r1 in LSeg(|[a,d]|,|[b,d]|) & g.r2 in LSeg(|[a,d]|,|[b,d]|); then A60: (gr1)`2=d & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A61: (gr2)`2=d & a <=(gr2)`1 & (gr2)`1 <=b by A1,A59,Th11; then (gr1)`1=(gr2)`1 by A41,A42,A43,A60,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A60,A61,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A17,A18,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A62: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A16,TOPREAL5:1; then rxc=s1 by A33,A39,A40,A62,FUNCT_1:def 8; hence contradiction by A26,A39,TOPREAL5:1; end; hence s1 <= s2; end; hence thesis by A14,A15,JORDAN5C:def 3; end; hence LE p1,p2,K by A14,A15,JORDAN6:def 10; case A63: p2 in LSeg(|[b,d]|,|[b,c]|); reconsider b2=b,c2=c,d2=d as Real by XREAL_0:def 1; p2 in LSeg(|[b2,d2]|,|[b2,c2]|) by A63; then A64: p2`1 =b by TOPREAL3:17; Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62; then A65: LSeg(|[b,d]|,|[b,c]|) c= Lower_Arc(K) by XBOOLE_1:7; p2 <> W-min(K) by A1,A9,A64,EUCLID:56; hence LE p1,p2,K by A1,A3,A63,A65,JORDAN6:def 10; case A66: p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62; then LSeg(|[b,c]|,|[a,c]|) c= Lower_Arc(K) by XBOOLE_1:7; hence LE p1,p2,K by A1,A3,A66,JORDAN6:def 10; end; hence LE p1,p2,K; end; end; theorem Th71: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[b,d]|,|[b,c]|) holds LE p1,p2,K iff p2 in LSeg(|[b,d]|,|[b,c]|) & p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[b,d]|,|[b,c]|); then A2: K is_simple_closed_curve by Th60; A3: p1`1=b & c <=p1`2 & p1`2 <= d by A1,Th9; thus LE p1,p2,K implies p2 in LSeg(|[b,d]|,|[b,c]|) & p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) proof assume A4: LE p1,p2,K; then A5: p1 in K & p2 in K by A2,JORDAN7:5; K= {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} by A1,Def1; then K= LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40 .=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) \/ LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by XBOOLE_1:4; then p2 in LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) \/ LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) by A5,XBOOLE_0:def 2; then A6: p2 in LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) by XBOOLE_0:def 2; now per cases by A6,XBOOLE_0:def 2; case p2 in LSeg(|[a,c]|,|[a,d]|); then LE p2,p1,K by A1,Th69; hence p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A2,A4,JORDAN6:72; case p2 in LSeg(|[a,d]|,|[b,d]|); then LE p2,p1,K by A1,Th70; hence p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A2,A4,JORDAN6:72; case p2 in LSeg(|[b,d]|,|[b,c]|); hence p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A4,Th67; case A7: p2 in LSeg(|[b,c]|,|[a,c]|); now per cases; case p2=W-min(K); then LE p2,p1,K by A2,A5,JORDAN7:3; hence p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A1,A2,A4,JORDAN6:72; case p2<>W-min(K); hence p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) by A7; end; hence p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); end; hence p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); end; thus p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K) implies LE p1,p2,K proof assume A8: p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2 or p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); now per cases by A8; case A9: p2 in LSeg(|[b,d]|,|[b,c]|)& p1`2>=p2`2; then A10: p2`1=b & c <=p2`2 & p2`2 <= d by A1,Th9; W-min K=|[a,c]| by A1,Th56; then A11: p2 <> W-min(K) by A1,A10,EUCLID:56; A12: Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62; then A13: p2 in Lower_Arc(K) by A9,XBOOLE_0:def 2; A14: p1 in Lower_Arc(K) by A1,A12,XBOOLE_0:def 2; LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) proof for g being map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 be Real; assume A15: g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A16: dom g=the carrier of I[01] by FUNCT_2:def 1; A17: g is one-to-one by A15,TOPS_2:def 5; A18: the carrier of ((TOP-REAL 2)|Lower_Arc(K)) =Lower_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A15,TOPS_2:def 5; then A19: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A20: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A21: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A20,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A22: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A21,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A23: k is continuous map of I[01],R^1 by A19,A22,TOPS_2:58; A24: E-max K=|[b,d]| by A1,Th56; now assume A25: s1>s2; A26: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A27: k.0=h.(E-max(K)) by A15,A26,FUNCT_1:23 .=h1.(E-max(K))+h2.(E-max(K)) by A22 .=(E-max(K))`1+proj2.(E-max(K)) by PSCOMP_1:def 28 .=(E-max(K))`1+(E-max(K))`2 by PSCOMP_1:def 29 .=(E-max(K))`1+d by A24,EUCLID:56 .=b+d by A24,EUCLID:56; s1 in [.0,1.] by A15,TOPREAL5:1; then A28: k.s1=h.p1 by A15,A26,FUNCT_1:23 .=proj1.p1 +proj2.p1 by A22 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=b+p1`2 by A3,PSCOMP_1:def 29; A29: s2 in [.0,1.] by A15,TOPREAL5:1; then k.s2=h.p2 by A15,A26,FUNCT_1:23 .=proj1.p2 +proj2.p2 by A22 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=b+p2`2 by A10,PSCOMP_1:def 29; then A30: k.0>=k.s1 & k.s1>=k.s2 by A3,A9,A27,A28,REAL_1:55; A31: 0 in [.0,1.] by TOPREAL5:1; then A32: [.0,s2.] c= [.0,1.] by A29,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A33: B is connected by A15,A29,A31,BORSUK_1:83,BORSUK_4:49; A34: 0 in B by A15,TOPREAL5:1; A35: s2 in B by A15,TOPREAL5:1; A36: k.0 is Real by XREAL_0:def 1; A37: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A38: xc in B & k.xc =k.s1 by A23,A30,A33,A34,A35,A36,A37,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A39: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A40: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A40,FUNCT_2:def 1; A41: k.x1=h.(g1.x1) by A40,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A22 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A42: k.x2=h.(g1.x2) by A40,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A22 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A43: g.r1 in Lower_Arc(K) by A18; A44: g.r2 in Lower_Arc(K) by A18; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A43; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A44; now per cases by A12,A18,XBOOLE_0:def 2; case A45: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A46: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A47: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,A45,Th9; then (gr1)`2=(gr2)`2 by A40,A41,A42,A46,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A46,A47,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A16,A17,FUNCT_1:def 8; case A48: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A49: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A50: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A48,Th11; then A51: b+(gr1)`2=(gr2)`1 +c by A1,A40,A41,A42,A48,Th9; A52: now assume b<>gr2`1; then b>gr2`1 by A50,REAL_1:def 5; hence contradiction by A40,A41,A42,A49,A50,REAL_1:67; end; now assume gr1`2<> c; then c <gr1`2 by A49,REAL_1:def 5; hence contradiction by A50,A51,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A49,A50,A52,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A16,A17,FUNCT_1:def 8; case A53: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A54: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A55: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,A53,Th11; A56: b+(gr2)`2=(gr1)`1 +c by A1,A40,A41,A42,A53,A54,Th11; A57: now assume b<>gr1`1; then b>gr1`1 by A55,REAL_1:def 5; hence contradiction by A54,A56,REAL_1:67; end; now assume gr2`2<> c; then c < gr2`2 by A54,REAL_1:def 5; hence contradiction by A40,A41,A42,A54,A55,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A54,A55,A57,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A16,A17,FUNCT_1:def 8; case A58: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A59: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A60: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A58,Th11; then (gr1)`1=(gr2)`1 by A40,A41,A42,A59,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A59,A60,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A16,A17,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A61: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A15,TOPREAL5:1; then rxc=s1 by A32,A38,A39,A61,FUNCT_1:def 8; hence contradiction by A25,A38,TOPREAL5:1; end; hence s1 <= s2; end; hence thesis by A13,A14,JORDAN5C:def 3; end; hence LE p1,p2,K by A11,A13,A14,JORDAN6:def 10; case A62: p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); then A63: p2`2=c & a <=p2`1 & p2`1 <= b by A1,Th11; A64: Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62; then A65: p2 in Lower_Arc(K) by A62,XBOOLE_0:def 2; A66: p1 in Lower_Arc(K) by A1,A64,XBOOLE_0:def 2; LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) proof for g being map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 be Real; assume A67: g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A68: dom g=the carrier of I[01] by FUNCT_2:def 1; A69: g is one-to-one by A67,TOPS_2:def 5; A70: the carrier of ((TOP-REAL 2)|Lower_Arc(K)) =Lower_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A67,TOPS_2:def 5; then A71: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A72: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A73: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A72,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A74: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A73,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A75: k is continuous map of I[01],R^1 by A71,A74,TOPS_2:58; A76: E-max K=|[b,d]| by A1,Th56; now assume A77: s1>s2; A78: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A79: k.0=h.(E-max(K)) by A67,A78,FUNCT_1:23 .=h1.(E-max(K))+h2.(E-max(K)) by A74 .=(E-max(K))`1+proj2.(E-max(K)) by PSCOMP_1:def 28 .=(E-max(K))`1+(E-max(K))`2 by PSCOMP_1:def 29 .=(E-max(K))`1+d by A76,EUCLID:56 .=b+d by A76,EUCLID:56; s1 in [.0,1.] by A67,TOPREAL5:1; then A80: k.s1=h.p1 by A67,A78,FUNCT_1:23 .=proj1.p1 +proj2.p1 by A74 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=b+p1`2 by A3,PSCOMP_1:def 29; A81: s2 in [.0,1.] by A67,TOPREAL5:1; then k.s2=h.p2 by A67,A78,FUNCT_1:23 .=proj1.p2 +proj2.p2 by A74 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=p2`1+c by A63,PSCOMP_1:def 29; then A82: k.0>=k.s1 & k.s1>=k.s2 by A3,A63,A79,A80,REAL_1:55; A83: 0 in [.0,1.] by TOPREAL5:1; then A84: [.0,s2.] c= [.0,1.] by A81,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A85: B is connected by A67,A81,A83,BORSUK_1:83,BORSUK_4:49; A86: 0 in B by A67,TOPREAL5:1; A87: s2 in B by A67,TOPREAL5:1; A88: k.0 is Real by XREAL_0:def 1; A89: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A90: xc in B & k.xc =k.s1 by A75,A82,A85,A86,A87,A88,A89,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A91: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A92: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A92,FUNCT_2:def 1; A93: k.x1=h.(g1.x1) by A92,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A74 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A94: k.x2=h.(g1.x2) by A92,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A74 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A95: g.r1 in Lower_Arc(K) by A70; A96: g.r2 in Lower_Arc(K) by A70; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A95; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A96; now per cases by A64,A70,XBOOLE_0:def 2; case A97: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A98: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A99: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,A97,Th9; then (gr1)`2=(gr2)`2 by A92,A93,A94,A98,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A98,A99,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A68,A69,FUNCT_1:def 8; case A100: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A101: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A102: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A100,Th11; then A103: b+(gr1)`2=(gr2)`1 +c by A1,A92,A93,A94,A100,Th9; A104: now assume b<>gr2`1; then b>gr2`1 by A102,REAL_1:def 5; hence contradiction by A92,A93,A94,A101,A102,REAL_1:67; end; now assume gr1`2<> c; then c <gr1`2 by A101,REAL_1:def 5; hence contradiction by A102,A103,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A101,A102,A104,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A68,A69,FUNCT_1:def 8; case A105: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A106: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A107: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,A105,Th11; A108: b+(gr2)`2=(gr1)`1 +c by A1,A92,A93,A94,A105,A106,Th11; A109: now assume b<>gr1`1; then b>gr1`1 by A107,REAL_1:def 5; hence contradiction by A106,A108,REAL_1:67; end; now assume gr2`2<> c; then c < gr2`2 by A106,REAL_1:def 5; hence contradiction by A92,A93,A94,A106,A107,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A106,A107,A109,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A68,A69,FUNCT_1:def 8; case A110: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A111: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A112: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A110,Th11; then (gr1)`1=(gr2)`1 by A92,A93,A94,A111,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A111,A112,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A68,A69,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A113: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A67,TOPREAL5:1; then rxc=s1 by A84,A90,A91,A113,FUNCT_1:def 8; hence contradiction by A77,A90,TOPREAL5:1; end; hence s1 <= s2; end; hence thesis by A65,A66,JORDAN5C:def 3; end; hence LE p1,p2,K by A62,A65,A66,JORDAN6:def 10; end; hence LE p1,p2,K; end; end; theorem Th72: for K being non empty compact Subset of TOP-REAL 2, a,b,c,d being real number,p1,p2 being Point of TOP-REAL 2 st K=rectangle(a,b,c,d) & a<b & c < d & p1 in LSeg(|[b,c]|,|[a,c]|)& p1<>W-min(K) holds LE p1,p2,K iff p2 in LSeg(|[b,c]|,|[a,c]|) & p1`1>=p2`1 & p2<>W-min(K) proof let K be non empty compact Subset of TOP-REAL 2, a,b,c,d be real number,p1,p2 be Point of TOP-REAL 2; assume A1: K=rectangle(a,b,c,d) & a<b & c <d & p1 in LSeg(|[b,c]|,|[a,c]|) & p1<>W-min(K); then A2: K is_simple_closed_curve by Th60; A3: p1`2=c & a <=p1`1 & p1`1 <= b by A1,Th11; thus LE p1,p2,K implies p2 in LSeg(|[b,c]|,|[a,c]|) & p1`1>=p2`1 & p2<>W-min(K) proof assume A4: LE p1,p2,K; then A5: p1 in K & p2 in K by A2,JORDAN7:5; K= {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} by A1,Def1; then K= LSeg(|[ a,c ]|, |[ a,d ]|) \/ LSeg(|[ a,d ]|, |[ b,d ]|) \/ (LSeg(|[ a,c ]|, |[ b,c ]|) \/ LSeg(|[ b,c ]|, |[ b,d ]|)) by A1,Th40 .=LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) \/ LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by XBOOLE_1:4; then p2 in LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) \/ LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) by A5,XBOOLE_0:def 2; then A6: p2 in LSeg(|[a,c]|,|[a,d]|) \/ LSeg(|[a,d]|,|[b,d]|) or p2 in LSeg(|[b,d]|,|[b,c]|) or p2 in LSeg(|[b,c]|,|[a,c]|) by XBOOLE_0:def 2; now per cases by A6,XBOOLE_0:def 2; case p2 in LSeg(|[a,c]|,|[a,d]|); then LE p2,p1,K by A1,Th69; hence p2 in LSeg(|[b,c]|,|[a,c]|)& p1`1>=p2`1 & p2<>W-min(K) by A1,A2,A4,JORDAN6:72; case p2 in LSeg(|[a,d]|,|[b,d]|); then LE p2,p1,K by A1,Th70; hence p2 in LSeg(|[b,c]|,|[a,c]|)& p1`1>=p2`1 & p2<>W-min(K) by A1,A2,A4,JORDAN6:72; case p2 in LSeg(|[b,d]|,|[b,c]|); then LE p2,p1,K by A1,Th71; hence p2 in LSeg(|[b,c]|,|[a,c]|)& p1`1>=p2`1 & p2<>W-min(K) by A1,A2,A4,JORDAN6:72; case p2 in LSeg(|[b,c]|,|[a,c]|); hence p2 in LSeg(|[b,c]|,|[a,c]|)& p1`1>=p2`1 & p2<>W-min(K) by A1,A4,Th68; end; hence p2 in LSeg(|[b,c]|,|[a,c]|)& p1`1>=p2`1 & p2<>W-min(K); end; thus p2 in LSeg(|[b,c]|,|[a,c]|)& p1`1>=p2`1 & p2<>W-min(K) implies LE p1,p2,K proof assume A7: p2 in LSeg(|[b,c]|,|[a,c]|)& p1`1>=p2`1 & p2<>W-min(K); now per cases by A7; case A8: p2 in LSeg(|[b,c]|,|[a,c]|)& p1`1>=p2`1; then A9: p2`2=c & a <=p2`1 & p2`1 <= b by A1,Th11; A10: Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62; then A11: p2 in Lower_Arc(K) by A8,XBOOLE_0:def 2; A12: p1 in Lower_Arc(K) by A1,A10,XBOOLE_0:def 2; LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) proof for g being map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 be Real; assume A13: g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A14: dom g=the carrier of I[01] by FUNCT_2:def 1; A15: g is one-to-one by A13,TOPS_2:def 5; A16: the carrier of ((TOP-REAL 2)|Lower_Arc(K)) =Lower_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A13,TOPS_2:def 5; then A17: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A18: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A19: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A18,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A20: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A19,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A21: k is continuous map of I[01],R^1 by A17,A20,TOPS_2:58; A22: E-max K=|[b,d]| by A1,Th56; now assume A23: s1>s2; A24: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A25: k.0=h.(E-max(K)) by A13,A24,FUNCT_1:23 .=h1.(E-max(K))+h2.(E-max(K)) by A20 .=(E-max(K))`1+proj2.(E-max(K)) by PSCOMP_1:def 28 .=(E-max(K))`1+(E-max(K))`2 by PSCOMP_1:def 29 .=(E-max(K))`1+d by A22,EUCLID:56 .=b+d by A22,EUCLID:56; s1 in [.0,1.] by A13,TOPREAL5:1; then A26: k.s1=h.p1 by A13,A24,FUNCT_1:23 .=proj1.p1 +proj2.p1 by A20 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=p1`1+c by A3,PSCOMP_1:def 29; A27: s2 in [.0,1.] by A13,TOPREAL5:1; then k.s2=h.p2 by A13,A24,FUNCT_1:23 .=proj1.p2 +proj2.p2 by A20 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=p2`1+c by A9,PSCOMP_1:def 29; then A28: k.0>=k.s1 & k.s1>=k.s2 by A1,A3,A8,A25,A26,REAL_1:55; A29: 0 in [.0,1.] by TOPREAL5:1; then A30: [.0,s2.] c= [.0,1.] by A27,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A31: B is connected by A13,A27,A29,BORSUK_1:83,BORSUK_4:49; A32: 0 in B by A13,TOPREAL5:1; A33: s2 in B by A13,TOPREAL5:1; A34: k.0 is Real by XREAL_0:def 1; A35: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A36: xc in B & k.xc =k.s1 by A21,A28,A31,A32,A33,A34,A35,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A37: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A38: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A38,FUNCT_2:def 1; A39: k.x1=h.(g1.x1) by A38,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A20 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A40: k.x2=h.(g1.x2) by A38,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A20 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A41: g.r1 in Lower_Arc(K) by A16; A42: g.r2 in Lower_Arc(K) by A16; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A41; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A42; now per cases by A10,A16,XBOOLE_0:def 2; case A43: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A44: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A45: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,A43,Th9; then (gr1)`2=(gr2)`2 by A38,A39,A40,A44,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A44,A45,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A14,A15,FUNCT_1:def 8; case A46: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A47: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A48: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A46,Th11; then A49: b+(gr1)`2=(gr2)`1 +c by A1,A38,A39,A40,A46,Th9; A50: now assume b<>gr2`1; then b>gr2`1 by A48,REAL_1:def 5; hence contradiction by A38,A39,A40,A47,A48,REAL_1:67; end; now assume gr1`2<> c; then c <gr1`2 by A47,REAL_1:def 5; hence contradiction by A48,A49,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A47,A48,A50,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A14,A15,FUNCT_1:def 8; case A51: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A52: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A53: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,A51,Th11; A54: b+(gr2)`2=(gr1)`1 +c by A1,A38,A39,A40,A51,A52,Th11; A55: now assume b<>gr1`1; then b>gr1`1 by A53,REAL_1:def 5; hence contradiction by A52,A54,REAL_1:67; end; now assume gr2`2<> c; then c < gr2`2 by A52,REAL_1:def 5; hence contradiction by A38,A39,A40,A52,A53,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A52,A53,A55,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A14,A15,FUNCT_1:def 8; case A56: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A57: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A58: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A56,Th11; then (gr1)`1=(gr2)`1 by A38,A39,A40,A57,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A57,A58,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A14,A15,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A59: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A13,TOPREAL5:1; then rxc=s1 by A30,A36,A37,A59,FUNCT_1:def 8; hence contradiction by A23,A36,TOPREAL5:1; end; hence s1 <= s2; end; hence thesis by A11,A12,JORDAN5C:def 3; end; hence LE p1,p2,K by A7,A11,A12,JORDAN6:def 10; case A60: p2 in LSeg(|[b,c]|,|[a,c]|) & p2<>W-min(K); then A61: p2`2=c & a <=p2`1 & p2`1 <= b by A1,Th11; A62: Lower_Arc(K)=LSeg(|[b,d]|,|[b,c]|) \/ LSeg(|[b,c]|,|[a,c]|) by A1,Th62; then A63: p2 in Lower_Arc(K) by A60,XBOOLE_0:def 2; A64: p1 in Lower_Arc(K) by A1,A62,XBOOLE_0:def 2; LE p1,p2,Lower_Arc(K),E-max(K),W-min(K) proof for g being map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 being Real st g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1 holds s1 <= s2 proof let g be map of I[01], (TOP-REAL 2)|Lower_Arc(K), s1, s2 be Real; assume A65: g is_homeomorphism & g.0 = E-max(K) & g.1 = W-min(K) & g.s1 = p1 & 0 <= s1 & s1 <= 1 & g.s2 = p2 & 0 <= s2 & s2 <= 1; A66: dom g=the carrier of I[01] by FUNCT_2:def 1; A67: g is one-to-one by A65,TOPS_2:def 5; A68: the carrier of ((TOP-REAL 2)|Lower_Arc(K)) =Lower_Arc(K) by JORDAN1:1; then g is Function of the carrier of I[01], the carrier of TOP-REAL 2 by FUNCT_2:9; then reconsider g1=g as map of I[01],TOP-REAL 2 ; g is continuous by A65,TOPS_2:def 5; then A69: g1 is continuous by TOPMETR:7; reconsider h1=proj1 as map of TOP-REAL 2,R^1 by JGRAPH_2:16; reconsider h2=proj2 as map of TOP-REAL 2,R^1 by JGRAPH_2:17; A70: (TOP-REAL 2)|([#](TOP-REAL 2))=TOP-REAL 2 by TSEP_1:3; then A71: (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h1.p=proj1.p) implies h1 is continuous by JGRAPH_2:39; (for p being Point of (TOP-REAL 2)|([#](TOP-REAL 2)) holds h2.p=proj2.p) implies h2 is continuous by A70,JGRAPH_2:40; then consider h being map of TOP-REAL 2,R^1 such that A72: (for p being Point of TOP-REAL 2, r1,r2 being real number st h1.p=r1 & h2.p=r2 holds h.p=r1+r2) & h is continuous by A71,JGRAPH_2:29; reconsider k=h*g1 as map of I[01],R^1; A73: k is continuous map of I[01],R^1 by A69,A72,TOPS_2:58; A74: E-max K=|[b,d]| by A1,Th56; now assume A75: s1>s2; A76: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; 0 in [.0,1.] by TOPREAL5:1; then A77: k.0=h.(E-max(K)) by A65,A76,FUNCT_1:23 .=h1.(E-max(K))+h2.(E-max(K)) by A72 .=(E-max(K))`1+proj2.(E-max(K)) by PSCOMP_1:def 28 .=(E-max(K))`1+(E-max(K))`2 by PSCOMP_1:def 29 .=(E-max(K))`1+d by A74,EUCLID:56 .=b+d by A74,EUCLID:56; s1 in [.0,1.] by A65,TOPREAL5:1; then A78: k.s1=h.p1 by A65,A76,FUNCT_1:23 .=proj1.p1 +proj2.p1 by A72 .=p1`1+proj2.p1 by PSCOMP_1:def 28 .=p1`1+c by A3,PSCOMP_1:def 29; A79: s2 in [.0,1.] by A65,TOPREAL5:1; then k.s2=h.p2 by A65,A76,FUNCT_1:23 .=proj1.p2 +proj2.p2 by A72 .=p2`1+proj2.p2 by PSCOMP_1:def 28 .=p2`1+c by A61,PSCOMP_1:def 29; then A80: k.0>=k.s1 & k.s1>=k.s2 by A1,A3,A7,A77,A78,REAL_1:55; A81: 0 in [.0,1.] by TOPREAL5:1; then A82: [.0,s2.] c= [.0,1.] by A79,RCOMP_1:16; then reconsider B=[.0,s2.] as Subset of I[01] by BORSUK_1:83 ; A83: B is connected by A65,A79,A81,BORSUK_1:83,BORSUK_4:49; A84: 0 in B by A65,TOPREAL5:1; A85: s2 in B by A65,TOPREAL5:1; A86: k.0 is Real by XREAL_0:def 1; A87: k.s2 is Real by XREAL_0:def 1; k.s1 is Real by XREAL_0:def 1; then consider xc being Point of I[01] such that A88: xc in B & k.xc =k.s1 by A73,A80,A83,A84,A85,A86,A87,TOPREAL5:11; xc in [.0,1.] by BORSUK_1:83; then reconsider rxc=xc as Real; A89: k is one-to-one proof for x1,x2 being set st x1 in dom k & x2 in dom k & k.x1=k.x2 holds x1=x2 proof let x1,x2 be set; assume A90: x1 in dom k & x2 in dom k & k.x1=k.x2; then reconsider r1=x1 as Point of I[01] by FUNCT_2:def 1; reconsider r2=x2 as Point of I[01] by A90,FUNCT_2:def 1; A91: k.x1=h.(g1.x1) by A90,FUNCT_1:22 .=h1.(g1.r1)+h2.(g1.r1) by A72 .=(g1.r1)`1+proj2.(g1.r1) by PSCOMP_1:def 28 .=(g1.r1)`1+(g1.r1)`2 by PSCOMP_1:def 29; A92: k.x2=h.(g1.x2) by A90,FUNCT_1:22 .=h1.(g1.r2)+h2.(g1.r2) by A72 .=(g1.r2)`1+proj2.(g1.r2) by PSCOMP_1:def 28 .=(g1.r2)`1+(g1.r2)`2 by PSCOMP_1:def 29; A93: g.r1 in Lower_Arc(K) by A68; A94: g.r2 in Lower_Arc(K) by A68; reconsider gr1=g.r1 as Point of TOP-REAL 2 by A93; reconsider gr2=g.r2 as Point of TOP-REAL 2 by A94; now per cases by A62,A68,XBOOLE_0:def 2; case A95: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A96: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A97: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,A95,Th9; then (gr1)`2=(gr2)`2 by A90,A91,A92,A96,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A96,A97,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A66,A67,FUNCT_1:def 8; case A98: g.r1 in LSeg(|[b,d]|,|[b,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A99: (gr1)`1=b & c <=(gr1)`2 & (gr1)`2 <=d by A1,Th9; A100: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A98,Th11; then A101: b+(gr1)`2=(gr2)`1 +c by A1,A90,A91,A92,A98,Th9; A102: now assume b<>gr2`1; then b>gr2`1 by A100,REAL_1:def 5; hence contradiction by A90,A91,A92,A99,A100,REAL_1:67; end; now assume gr1`2<> c; then c <gr1`2 by A99,REAL_1:def 5; hence contradiction by A100,A101,REAL_1:67; end; then |[(gr1)`1,(gr1)`2]|=g.r2 by A99,A100,A102,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A66,A67,FUNCT_1:def 8; case A103: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,d]|,|[b,c]|); then A104: (gr2)`1=b & c <=(gr2)`2 & (gr2)`2 <=d by A1,Th9; A105: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,A103,Th11; A106: b+(gr2)`2=(gr1)`1 +c by A1,A90,A91,A92,A103,A104,Th11; A107: now assume b<>gr1`1; then b>gr1`1 by A105,REAL_1:def 5; hence contradiction by A104,A106,REAL_1:67; end; now assume gr2`2<> c; then c < gr2`2 by A104,REAL_1:def 5; hence contradiction by A90,A91,A92,A104,A105,REAL_1:67; end; then |[(gr2)`1,(gr2)`2]|=g.r1 by A104,A105,A107,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A66,A67,FUNCT_1:def 8; case A108: g.r1 in LSeg(|[b,c]|,|[a,c]|) & g.r2 in LSeg(|[b,c]|,|[a,c]|); then A109: (gr1)`2=c & a <=(gr1)`1 & (gr1)`1 <=b by A1,Th11; A110: (gr2)`2=c & a <=(gr2)`1 & (gr2)`1 <=b by A1,A108,Th11; then (gr1)`1=(gr2)`1 by A90,A91,A92,A109,XCMPLX_1:2; then |[(gr1)`1,(gr1)`2]|=g.r2 by A109,A110,EUCLID:57; then g.r1=g.r2 by EUCLID:57; hence x1=x2 by A66,A67,FUNCT_1:def 8; end; hence x1=x2; end; hence thesis by FUNCT_1:def 8; end; A111: dom k=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then s1 in dom k by A65,TOPREAL5:1; then rxc=s1 by A82,A88,A89,A111,FUNCT_1:def 8; hence contradiction by A75,A88,TOPREAL5:1; end; hence s1 <= s2; end; hence thesis by A63,A64,JORDAN5C:def 3; end; hence LE p1,p2,K by A60,A63,A64,JORDAN6:def 10; end; hence LE p1,p2,K; end; end; theorem Th73: for x being set,a,b,c,d being real number st x in rectangle(a,b,c,d) & a<b & c <d holds x in LSeg(|[a,c]|,|[a,d]|) or x in LSeg(|[a,d]|,|[b,d]|) or x in LSeg(|[b,d]|,|[b,c]|) or x in LSeg(|[b,c]|,|[a,c]|) proof let x be set,a,b,c,d be real number;assume A1: x in rectangle(a,b,c,d) & a<b & c <d; then x in {p: p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b} by Def1; then consider p such that A2: p=x &( p`1=a & c <=p`2 & p`2<=d or p`2=d & a<=p`1 & p`1<=b or p`1=b & c <=p`2 & p`2<=d or p`2=c & a<=p`1 & p`1<=b); now per cases by A2; case A3: p`1=a & c <=p`2 & p`2<=d; A4: d-c >0 by A1,SQUARE_1:11; then A5: (d-c)">0 by REAL_1:72; A6: p`2 -c >=0 by A3,SQUARE_1:12; A7: d-p`2 >=0 by A3,SQUARE_1:12; (p`2-c)/(d-c)=(p`2 -c)*(d-c)" by XCMPLX_0:def 9; then A8: (p`2-c)/(d-c)>=0 by A5,A6,REAL_2:121; reconsider r=(p`2-c)/(d-c) as Real by XREAL_0:def 1; A9: 1-r=(d-c)/(d-c)-(p`2-c)/(d-c) by A4,XCMPLX_1:60 .=((d-c)-(p`2 -c))/(d-c) by XCMPLX_1:121 .=(d-p`2)/(d-c) by XCMPLX_1:22; then 1-r=(d-p`2)*(d-c)" by XCMPLX_0:def 9; then 1-r >=0 by A5,A7,REAL_2:121; then 1-r+r>=0+r by REAL_1:55; then A10: 1>=r by XCMPLX_1:27; A11: ((1-r)*(|[a,c]|)+r*(|[a,d]|))`1 =((1-r)*(|[a,c]|))`1+(r*(|[a,d]|))`1 by TOPREAL3:7 .=(1-r)*((|[a,c]|)`1)+(r*(|[a,d]|))`1 by TOPREAL3:9 .=(1-r)*a+(r*(|[a,d]|))`1 by EUCLID:56 .=(1-r)*a+r*((|[a,d]|)`1) by TOPREAL3:9 .=(1-r)*a+r*a by EUCLID:56 .=(1-r+r)*a by XCMPLX_1:8 .=1*a by XCMPLX_1:27 .=p`1 by A3; ((1-r)*(|[a,c]|)+r*(|[a,d]|))`2 =((1-r)*(|[a,c]|))`2+(r*(|[a,d]|))`2 by TOPREAL3:7 .=(1-r)*((|[a,c]|)`2)+(r*(|[a,d]|))`2 by TOPREAL3:9 .=(1-r)*c+(r*(|[a,d]|))`2 by EUCLID:56 .=(1-r)*c+r*((|[a,d]|)`2) by TOPREAL3:9 .=(d-p`2)/(d-c)*c+(p`2-c)/(d-c)*d by A9,EUCLID:56 .=(d-p`2)*(d-c)"*c + (p`2-c)/(d-c)*d by XCMPLX_0:def 9 .=(d-p`2)*(d-c)"*c + (p`2-c)*(d-c)"*d by XCMPLX_0:def 9 .=(d-c)"*((d-p`2)*c)+ (d-c)"*(p`2-c)*d by XCMPLX_1:4 .=(d-c)"*((d-p`2)*c)+ (d-c)"*((p`2-c)*d) by XCMPLX_1:4 .=(d-c)"*(((d-p`2)*c)+ ((p`2-c)*d)) by XCMPLX_1:8 .=(d-c)"*((d*c -p`2*c)+ ((p`2-c)*d)) by XCMPLX_1:40 .=(d-c)"*((d*c -p`2*c)+ (p`2*d-c*d)) by XCMPLX_1:40 .=(d-c)"*(d*c+ (p`2*d-c*d) -p`2*c) by XCMPLX_1:29 .=(d-c)"*(d*c+ p`2*d-c*d -p`2*c) by XCMPLX_1:29 .=(d-c)"*( p`2*d -p`2*c) by XCMPLX_1:26 .=(d-c)"*( p`2*(d -c)) by XCMPLX_1:40 .=(d-c)"*(d -c)*p`2 by XCMPLX_1:4 .=1*p`2 by A4,XCMPLX_0:def 7 .=p`2; then p=|[((1-r)*(|[a,c]|)+r*(|[a,d]|))`1, ((1-r)*(|[a,c]|)+r*(|[a,d]|))`2]| by A11,EUCLID:57 .=(1-r)*(|[a,c]|)+r*(|[a,d]|) by EUCLID:57; then x in {(1-l)*(|[a,c]|)+l*(|[a,d]|) where l is Real: 0<=l & l<=1} by A2,A8,A10; hence x in LSeg(|[a,c]|,|[a,d]|) or x in LSeg(|[a,d]|,|[b,d]|) or x in LSeg(|[b,d]|,|[b,c]|) or x in LSeg(|[b,c]|,|[a,c]|) by TOPREAL1:def 4; case A12: p`2=d & a<=p`1 & p`1<=b; A13: b-a >0 by A1,SQUARE_1:11; then A14: (b-a)">0 by REAL_1:72; A15: p`1 -a >=0 by A12,SQUARE_1:12; A16: b-p`1 >=0 by A12,SQUARE_1:12; (p`1-a)/(b-a)=(p`1 -a)*(b-a)" by XCMPLX_0:def 9; then A17: (p`1-a)/(b-a)>=0 by A14,A15,REAL_2:121; reconsider r=(p`1-a)/(b-a) as Real by XREAL_0:def 1; A18: 1-r=(b-a)/(b-a)-(p`1-a)/(b-a) by A13,XCMPLX_1:60 .=((b-a)-(p`1 -a))/(b-a) by XCMPLX_1:121 .=(b-p`1)/(b-a) by XCMPLX_1:22; then 1-r=(b-p`1)*(b-a)" by XCMPLX_0:def 9; then 1-r >=0 by A14,A16,REAL_2:121; then 1-r+r>=0+r by REAL_1:55; then A19: 1>=r by XCMPLX_1:27; A20: ((1-r)*(|[a,d]|)+r*(|[b,d]|))`1 =((1-r)*(|[a,d]|))`1+(r*(|[b,d]|))`1 by TOPREAL3:7 .=(1-r)*((|[a,d]|)`1)+(r*(|[b,d]|))`1 by TOPREAL3:9 .=(1-r)*a+(r*(|[b,d]|))`1 by EUCLID:56 .=(1-r)*a+r*((|[b,d]|)`1) by TOPREAL3:9 .=(b-p`1)/(b-a)*a+(p`1-a)/(b-a)*b by A18,EUCLID:56 .=(b-p`1)*(b-a)"*a + (p`1-a)/(b-a)*b by XCMPLX_0:def 9 .=(b-p`1)*(b-a)"*a + (p`1-a)*(b-a)"*b by XCMPLX_0:def 9 .=(b-a)"*((b-p`1)*a)+ (b-a)"*(p`1-a)*b by XCMPLX_1:4 .=(b-a)"*((b-p`1)*a)+ (b-a)"*((p`1-a)*b) by XCMPLX_1:4 .=(b-a)"*(((b-p`1)*a)+ ((p`1-a)*b)) by XCMPLX_1:8 .=(b-a)"*((b*a -p`1*a)+ ((p`1-a)*b)) by XCMPLX_1:40 .=(b-a)"*((b*a -p`1*a)+ (p`1*b-a*b)) by XCMPLX_1:40 .=(b-a)"*(b*a+ (p`1*b-a*b) -p`1*a) by XCMPLX_1:29 .=(b-a)"*(b*a+ p`1*b-a*b -p`1*a) by XCMPLX_1:29 .=(b-a)"*( p`1*b -p`1*a) by XCMPLX_1:26 .=(b-a)"*( p`1*(b -a)) by XCMPLX_1:40 .=(b-a)"*(b -a)*p`1 by XCMPLX_1:4 .=1*p`1 by A13,XCMPLX_0:def 7 .=p`1; ((1-r)*(|[a,d]|)+r*(|[b,d]|))`2 =((1-r)*(|[a,d]|))`2+(r*(|[b,d]|))`2 by TOPREAL3:7 .=(1-r)*((|[a,d]|)`2)+(r*(|[b,d]|))`2 by TOPREAL3:9 .=(1-r)*d+(r*(|[b,d]|))`2 by EUCLID:56 .=(1-r)*d+r*((|[b,d]|)`2) by TOPREAL3:9 .=(1-r)*d+r*d by EUCLID:56 .=(1-r+r)*d by XCMPLX_1:8 .=1*d by XCMPLX_1:27 .=p`2 by A12; then p=|[((1-r)*(|[a,d]|)+r*(|[b,d]|))`1, ((1-r)*(|[a,d]|)+r*(|[b,d]|))`2]| by A20,EUCLID:57 .=(1-r)*(|[a,d]|)+r*(|[b,d]|) by EUCLID:57; then x in {(1-l)*(|[a,d]|)+l*(|[b,d]|) where l is Real: 0<=l & l<=1} by A2,A17,A19; hence x in LSeg(|[a,c]|,|[a,d]|) or x in LSeg(|[a,d]|,|[b,d]|) or x in LSeg(|[b,d]|,|[b,c]|) or x in LSeg(|[b,c]|,|[a,c]|) by TOPREAL1:def 4; case A21: p`1=b & c <=p`2 & p`2<=d; A22: d-c >0 by A1,SQUARE_1:11; then A23: (d-c)">0 by REAL_1:72; A24: p`2 -c >=0 by A21,SQUARE_1:12; A25: d-p`2 >=0 by A21,SQUARE_1:12; (d-p`2)/(d-c)=(d-p`2)*(d-c)" by XCMPLX_0:def 9; then A26: (d-p`2)/(d-c)>=0 by A23,A25,REAL_2:121; reconsider r=(d-p`2)/(d-c) as Real by XREAL_0:def 1; A27: 1-r=(d-c)/(d-c)-(d-p`2)/(d-c) by A22,XCMPLX_1:60 .=((d-c)-(d-p`2))/(d-c) by XCMPLX_1:121 .=((d-c)-d+p`2)/(d-c) by XCMPLX_1:37 .= ((d+-c)-d+p`2)/(d-c) by XCMPLX_0:def 8 .= (-c+p`2)/(d-c) by XCMPLX_1:26 .=(p`2-c)/(d-c) by XCMPLX_0:def 8; then 1-r=(p`2-c)*(d-c)" by XCMPLX_0:def 9; then 1-r >=0 by A23,A24,REAL_2:121; then 1-r+r>=0+r by REAL_1:55; then A28: 1>=r by XCMPLX_1:27; A29: ((1-r)*(|[b,d]|)+r*(|[b,c]|))`1 =((1-r)*(|[b,d]|))`1+(r*(|[b,c]|))`1 by TOPREAL3:7 .=(1-r)*((|[b,d]|)`1)+(r*(|[b,c]|))`1 by TOPREAL3:9 .=(1-r)*b+(r*(|[b,c]|))`1 by EUCLID:56 .=(1-r)*b+r*((|[b,c]|)`1) by TOPREAL3:9 .=(1-r)*b+r*b by EUCLID:56 .=(1-r+r)*b by XCMPLX_1:8 .=1*b by XCMPLX_1:27 .=p`1 by A21; ((1-r)*(|[b,d]|)+r*(|[b,c]|))`2 =((1-r)*(|[b,d]|))`2+(r*(|[b,c]|))`2 by TOPREAL3:7 .=(1-r)*((|[b,d]|)`2)+(r*(|[b,c]|))`2 by TOPREAL3:9 .=(1-r)*d+(r*(|[b,c]|))`2 by EUCLID:56 .=(1-r)*d+r*((|[b,c]|)`2) by TOPREAL3:9 .=(p`2-c)/(d-c)*d+(d-p`2)/(d-c)*c by A27,EUCLID:56 .=(p`2-c)*(d-c)"*d + (d-p`2)/(d-c)*c by XCMPLX_0:def 9 .=(p`2-c)*(d-c)"*d + (d-p`2)*(d-c)"*c by XCMPLX_0:def 9 .=(d-c)"*((p`2-c)*d)+ (d-c)"*(d-p`2)*c by XCMPLX_1:4 .=(d-c)"*((p`2-c)*d)+ (d-c)"*((d-p`2)*c) by XCMPLX_1:4 .=(d-c)"*(((p`2-c)*d)+ ((d-p`2)*c)) by XCMPLX_1:8 .=(d-c)"*((p`2*d -c*d)+ ((d-p`2)*c)) by XCMPLX_1:40 .=(d-c)"*((p`2*d -d*c )+ (d*c-p`2*c)) by XCMPLX_1:40 .=(d-c)"*(p`2*d -d*c+ d*c-p`2*c) by XCMPLX_1:29 .=(d-c)"*(p`2*d -p`2*c) by XCMPLX_1:27 .=(d-c)"*( p`2*(d -c)) by XCMPLX_1:40 .=(d-c)"*(d -c)*p`2 by XCMPLX_1:4 .=1*p`2 by A22,XCMPLX_0:def 7 .=p`2; then p=|[((1-r)*(|[b,d]|)+r*(|[b,c]|))`1, ((1-r)*(|[b,d]|)+r*(|[b,c]|))`2]| by A29,EUCLID:57 .=(1-r)*(|[b,d]|)+r*(|[b,c]|) by EUCLID:57; then x in {(1-l)*(|[b,d]|)+l*(|[b,c]|) where l is Real: 0<=l & l<=1} by A2,A26,A28; hence x in LSeg(|[a,c]|,|[a,d]|) or x in LSeg(|[a,d]|,|[b,d]|) or x in LSeg(|[b,d]|,|[b,c]|) or x in LSeg(|[b,c]|,|[a,c]|) by TOPREAL1:def 4; case A30: p`2=c & a<=p`1 & p`1<=b; A31: b-a >0 by A1,SQUARE_1:11; then A32: (b-a)">0 by REAL_1:72; A33: p`1 -a >=0 by A30,SQUARE_1:12; A34: b-p`1 >=0 by A30,SQUARE_1:12; (b-p`1)/(b-a)=(b-p`1)*(b-a)" by XCMPLX_0:def 9; then A35: (b-p`1)/(b-a)>=0 by A32,A34,REAL_2:121; reconsider r=(b-p`1)/(b-a) as Real by XREAL_0:def 1; A36: 1-r=(b-a)/(b-a)-(b-p`1)/(b-a) by A31,XCMPLX_1:60 .=((b-a)-(b-p`1))/(b-a) by XCMPLX_1:121 .=((b-a)-b+p`1)/(b-a) by XCMPLX_1:37 .= ((b+-a)-b+p`1)/(b-a) by XCMPLX_0:def 8 .= (-a+p`1)/(b-a) by XCMPLX_1:26 .=(p`1-a)/(b-a) by XCMPLX_0:def 8; then 1-r=(p`1-a)*(b-a)" by XCMPLX_0:def 9; then 1-r >=0 by A32,A33,REAL_2:121; then 1-r+r>=0+r by REAL_1:55; then A37: 1>=r by XCMPLX_1:27; A38: ((1-r)*(|[b,c]|)+r*(|[a,c]|))`1 =((1-r)*(|[b,c]|))`1+(r*(|[a,c]|))`1 by TOPREAL3:7 .=(1-r)*((|[b,c]|)`1)+(r*(|[a,c]|))`1 by TOPREAL3:9 .=(1-r)*b+(r*(|[a,c]|))`1 by EUCLID:56 .=(1-r)*b+r*((|[a,c]|)`1) by TOPREAL3:9 .=(p`1-a)/(b-a)*b+(b-p`1)/(b-a)*a by A36,EUCLID:56 .=(p`1-a)*(b-a)"*b + (b-p`1)/(b-a)*a by XCMPLX_0:def 9 .=(p`1-a)*(b-a)"*b + (b-p`1)*(b-a)"*a by XCMPLX_0:def 9 .=(b-a)"*((p`1-a)*b)+ (b-a)"*(b-p`1)*a by XCMPLX_1:4 .=(b-a)"*((p`1-a)*b)+ (b-a)"*((b-p`1)*a) by XCMPLX_1:4 .=(b-a)"*(((p`1-a)*b)+ ((b-p`1)*a)) by XCMPLX_1:8 .=(b-a)"*((p`1*b -a*b)+ ((b-p`1)*a)) by XCMPLX_1:40 .=(b-a)"*((p`1*b -a*b)+ (b*a-p`1*a)) by XCMPLX_1:40 .=(b-a)"*((p`1*b -a*b)+ b*a-p`1*a) by XCMPLX_1:29 .=(b-a)"*(p`1*b -p`1*a) by XCMPLX_1:27 .=(b-a)"*( p`1*(b -a)) by XCMPLX_1:40 .=(b-a)"*(b -a)*p`1 by XCMPLX_1:4 .=1*p`1 by A31,XCMPLX_0:def 7 .=p`1; ((1-r)*(|[b,c]|)+r*(|[a,c]|))`2 =((1-r)*(|[b,c]|))`2+(r*(|[a,c]|))`2 by TOPREAL3:7 .=(1-r)*((|[b,c]|)`2)+(r*(|[a,c]|))`2 by TOPREAL3:9 .=(1-r)*c+(r*(|[a,c]|))`2 by EUCLID:56 .=(1-r)*c+r*((|[a,c]|)`2) by TOPREAL3:9 .=(1-r)*c+r*c by EUCLID:56 .=(1-r+r)*c by XCMPLX_1:8 .=1*c by XCMPLX_1:27 .=p`2 by A30; then p=|[((1-r)*(|[b,c]|)+r*(|[a,c]|))`1, ((1-r)*(|[b,c]|)+r*(|[a,c]|))`2]| by A38,EUCLID:57 .=(1-r)*(|[b,c]|)+r*(|[a,c]|) by EUCLID:57; then x in {(1-l)*(|[b,c]|)+l*(|[a,c]|) where l is Real: 0<=l & l<=1} by A2,A35,A37; hence x in LSeg(|[a,c]|,|[a,d]|) or x in LSeg(|[a,d]|,|[b,d]|) or x in LSeg(|[b,d]|,|[b,c]|) or x in LSeg(|[b,c]|,|[a,c]|) by TOPREAL1:def 4; end; hence x in LSeg(|[a,c]|,|[a,d]|) or x in LSeg(|[a,d]|,|[b,d]|) or x in LSeg(|[b,d]|,|[b,c]|) or x in LSeg(|[b,c]|,|[a,c]|); end; begin :: General Fashoda Theorem for Unit Square theorem Th74: for p1,p2 being Point of TOP-REAL 2, K being non empty compact Subset of TOP-REAL 2 st K=rectangle(-1,1,-1,1) & LE p1,p2,K & p1 in LSeg(|[-1,-1]|,|[-1,1]|) holds p2 in LSeg(|[-1,-1]|,|[-1,1]|)& p2`2>=p1`2 or p2 in LSeg(|[-1,1]|,|[1,1]|) or p2 in LSeg(|[1,1]|,|[1,-1]|) or p2 in LSeg(|[1,-1]|,|[-1,-1]|)& p2<>|[-1,-1]| proof let p1,p2 be Point of TOP-REAL 2, K be non empty compact Subset of TOP-REAL 2; assume A1: K=rectangle(-1,1,-1,1) & LE p1,p2,K & p1 in LSeg(|[-1,-1]|,|[-1,1]|); then p2 in LSeg(|[-1,-1]|,|[-1,1]|) & p1`2<=p2`2 or p2 in LSeg(|[-1,1]|,|[1,1]|) or p2 in LSeg(|[1,1]|,|[1,-1]|) or p2 in LSeg(|[1,-1]|,|[-1,-1]|) & p2<>W-min(K) by Th69; hence p2 in LSeg(|[-1,-1]|,|[-1,1]|)& p2`2>=p1`2 or p2 in LSeg(|[-1,1]|,|[1,1]|) or p2 in LSeg(|[1,1]|,|[1,-1]|) or p2 in LSeg(|[1,-1]|,|[-1,-1]|)& p2<>|[-1,-1]| by A1,Th56; end; theorem Th75: for p1,p2 being Point of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ & p1 in LSeg(|[-1,-1]|,|[-1,1]|)& p1`2>=0 & LE p1,p2,K holds LE f.p1,f.p2,P proof let p1,p2 be Point of TOP-REAL 2, P,K be non empty compact Subset of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ & p1 in LSeg(|[-1,-1]|,|[-1,1]|)& p1`2>=0 & LE p1,p2,K; then A2: K is_simple_closed_curve by Th60; A3: P={p: |.p.|=1} by A1,Th33; A4: p1`1=-1 & -1<=p1`2 & p1`2<=1 by A1,Th9; A5: p1 in K by A1,A2,JORDAN7:5; A6: p2 in K by A1,A2,JORDAN7:5; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A7: f.:K=P by A1,A3,Th45,JGRAPH_3:33; A8: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A9: f.p1 in P by A5,A7,FUNCT_1:def 12; A10: f.p2 in P by A6,A7,A8,FUNCT_1:def 12; A11: p1`1=-1 & -1<=p1`2 & p1`2 <=1 by A1,Th9; A12: (p1`2)^2 >=0 by SQUARE_1:72; 1+(p1`2)^2 >(p1`2)^2 by REAL_1:69; then A13: sqrt(1+(p1`2)^2)>0 by A12,SQUARE_1:93; A14: p1`2<=-p1`1 by A4; p1<>0.REAL 2 by A4,EUCLID:56,58; then A15: f.p1= |[p1`1/sqrt(1+(p1`2/p1`1)^2),p1`2/sqrt(1+(p1`2/p1`1)^2)]| by A1,A11,A14,JGRAPH_3:def 1; then A16: (f.p1)`1= p1`1/sqrt(1+(p1`2/(-1))^2) by A11,EUCLID:56 .=(p1`1)/sqrt(1+(-(p1`2/1))^2) by XCMPLX_1:189 .=(p1`1)/sqrt(1+(p1`2)^2) by SQUARE_1:61; A17: (f.p1)`2= p1`2/sqrt(1+(p1`2/(-1))^2) by A11,A15,EUCLID:56 .=(p1`2)/sqrt(1+(-(p1`2/1))^2) by XCMPLX_1:189 .=(p1`2)/sqrt(1+(p1`2)^2) by SQUARE_1:61; A18: (f.p1)`1<0 by A11,A13,A16,REAL_2:128; A19: (f.p1)`2>=0 by A1,A13,A17,REAL_2:125; then f.p1 in {p9 where p9 is Point of TOP-REAL 2:p9 in P & p9`2>=0} by A9; then A20: f.p1 in Upper_Arc(P) by A3,JGRAPH_5:37; now per cases by A1,Th74; case A21: p2 in LSeg(|[-1,-1]|,|[-1,1]|)& p2`2>=p1`2; A22: (p2`2)^2 >=0 by SQUARE_1:72; 1+(p2`2)^2 >(p2`2)^2 by REAL_1:69; then A23: sqrt(1+(p2`2)^2)>0 by A22,SQUARE_1:93; A24: p2`1=-1 & -1<=p2`2 & p2`2 <=1 by A21,Th9; then A25: p2`2<=-p2`1; p2<>0.REAL 2 by A24,EUCLID:56,58; then A26: f.p2= |[p2`1/sqrt(1+(p2`2/p2`1)^2),p2`2/sqrt(1+(p2`2/p2`1)^2)]| by A1,A24,A25,JGRAPH_3:def 1; then A27: (f.p2)`1= p2`1/sqrt(1+(p2`2/(-1))^2) by A24,EUCLID:56 .=(p2`1)/sqrt(1+(-(p2`2/1))^2) by XCMPLX_1:189 .=(p2`1)/sqrt(1+(p2`2)^2) by SQUARE_1:61; A28: (f.p2)`2= p2`2/sqrt(1+(p2`2/(-1))^2) by A24,A26,EUCLID:56 .=(p2`2)/sqrt(1+(-(p2`2/1))^2) by XCMPLX_1:189 .=(p2`2)/sqrt(1+(p2`2)^2) by SQUARE_1:61; A29: (f.p2)`1<0 by A23,A24,A27,REAL_2:128; (p1`2)*sqrt(1+(p2`2)^2)<= (p2`2)*sqrt(1+(p1`2)^2) by A1,A21,Lm4; then (p1`2)*sqrt(1+(p2`2)^2)/sqrt(1+(p2`2)^2) <= (p2`2)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`2)^2) by A23,REAL_1:73; then (p1`2) <= (p2`2)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`2)^2) by A23,XCMPLX_1:90 ; then (p1`2)/sqrt(1+(p1`2)^2) <= (p2`2)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`2)^2)/sqrt(1+(p1`2)^2) by A13,REAL_1:73; then (p1`2)/sqrt(1+(p1`2)^2) <= (p2`2)*sqrt(1+(p1`2)^2)/sqrt(1+(p1`2)^2)/sqrt(1+(p2`2)^2) by XCMPLX_1:48; then (f.p1)`2<=(f.p2)`2 by A13,A17,A28,XCMPLX_1:90; hence LE f.p1,f.p2,P by A3,A9,A10,A18,A19,A29,JGRAPH_5:56; case p2 in LSeg(|[-1,1]|,|[1,1]|); then A30: p2`2=1 & -1<=p2`1 & p2`1<=1 by Th11; A31: (p2`1)^2 >=0 by SQUARE_1:72; 1+(p2`1)^2 >(p2`1)^2 by REAL_1:69; then A32: sqrt(1+(p2`1)^2)>0 by A31,SQUARE_1:93; p2<>0.REAL 2 by A30,EUCLID:56,58; then A33: f.p2= |[p2`1/sqrt(1+(p2`1/p2`2)^2),p2`2/sqrt(1+(p2`1/p2`2)^2)]| by A1,A30,JGRAPH_3:14; then A34: (f.p2)`1=(p2`1)/sqrt(1+(p2`1)^2) by A30,EUCLID:56; (f.p2)`2=(p2`2)/sqrt(1+(p2`1)^2) by A30,A33,EUCLID:56; then A35: (f.p2)`2>=0 by A30,A32,REAL_2:125; -sqrt(1+(p2`1)^2)<= (p2`1)*sqrt(1+(p1`2)^2) by A4,A30,Th6; then (p1`1)*sqrt(1+(p2`1)^2)<= (p2`1)*sqrt(1+(p1`2)^2) by A4,XCMPLX_1:180 ; then (p1`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p2`1)^2) <= (p2`1)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`1)^2) by A32,REAL_1:73; then (p1`1) <= (p2`1)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`1)^2) by A32,XCMPLX_1:90 ; then (p1`1)/sqrt(1+(p1`2)^2) <= (p2`1)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`1)^2)/sqrt(1+(p1`2)^2) by A13,REAL_1:73; then (p1`1)/sqrt(1+(p1`2)^2) <= (p2`1)*sqrt(1+(p1`2)^2)/sqrt(1+(p1`2)^2)/sqrt(1+(p2`1)^2) by XCMPLX_1:48; then (f.p1)`1<=(f.p2)`1 by A13,A16,A34,XCMPLX_1:90; hence LE f.p1,f.p2,P by A3,A9,A10,A19,A35,JGRAPH_5:57; case p2 in LSeg(|[1,1]|,|[1,-1]|); then A36: p2`1=1 & -1<=p2`2 & p2`2<=1 by Th9; A37: (p2`2)^2 >=0 by SQUARE_1:72; 1+(p2`2)^2 >(p2`2)^2 by REAL_1:69; then A38: sqrt(1+(p2`2)^2)>0 by A37,SQUARE_1:93; p2<>0.REAL 2 by A36,EUCLID:56,58; then f.p2= |[p2`1/sqrt(1+(p2`2/p2`1)^2),p2`2/sqrt(1+(p2`2/p2`1)^2)]| by A1,A36,JGRAPH_3:def 1; then A39: (f.p2)`1=(p2`1)/sqrt(1+(p2`2)^2) by A36,EUCLID:56; (p1`1)*sqrt(1+(p2`2)^2)<=0 by A4,A38,SQUARE_1:23; then (p1`1)*sqrt(1+(p2`2)^2)/sqrt(1+(p2`2)^2) <= (p2`1)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`2)^2) by A13,A36,A38,REAL_1:73; then (p1`1) <= (p2`1)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`2)^2) by A38,XCMPLX_1:90 ; then (p1`1)/sqrt(1+(p1`2)^2) <= (p2`1)*sqrt(1+(p1`2)^2)/sqrt(1+(p2`2)^2)/sqrt(1+(p1`2)^2) by A13,REAL_1:73; then (p1`1)/sqrt(1+(p1`2)^2) <= (p2`1)*sqrt(1+(p1`2)^2)/sqrt(1+(p1`2)^2)/sqrt(1+(p2`2)^2) by XCMPLX_1:48; then A40: (f.p1)`1<=(f.p2)`1 by A13,A16,A39,XCMPLX_1:90; now per cases; case (f.p2)`2>=0; hence LE f.p1,f.p2,P by A3,A9,A10,A19,A40,JGRAPH_5:57; case A41: (f.p2)`2<0; then f.p2 in {p9 where p9 is Point of TOP-REAL 2:p9 in P & p9`2<=0} by A10; then A42: f.p2 in Lower_Arc(P) by A3,JGRAPH_5:38; W-min(P)=|[-1,0]| by A3,JGRAPH_5:32; then f.p2 <> W-min(P) by A41,EUCLID:56; hence LE f.p1,f.p2,P by A20,A42,JORDAN6:def 10; end; hence LE f.p1,f.p2,P; case p2 in LSeg(|[1,-1]|,|[-1,-1]|)& p2<>|[-1,-1]|; then A43: p2`2=-1 & -1<=p2`1 & p2`1<=1 by Th11; A44: (p2`1)^2 >=0 by SQUARE_1:72; 1+(p2`1)^2 >(p2`1)^2 by REAL_1:69; then A45: sqrt(1+(p2`1)^2)>0 by A44,SQUARE_1:93; A46: p2`1<=-p2`2 by A43; p2<>0.REAL 2 by A43,EUCLID:56,58; then f.p2= |[p2`1/sqrt(1+(p2`1/p2`2)^2),p2`2/sqrt(1+(p2`1/p2`2)^2)]| by A1,A43,A46,JGRAPH_3:14; then (f.p2)`2= p2`2/sqrt(1+(p2`1/(-1))^2) by A43,EUCLID:56 .=(p2`2)/sqrt(1+(-(p2`1/1))^2) by XCMPLX_1:189 .=(p2`2)/sqrt(1+(p2`1)^2) by SQUARE_1:61; then A47: (f.p2)`2<0 by A43,A45,REAL_2:128; then f.p2 in {p9 where p9 is Point of TOP-REAL 2:p9 in P & p9`2<=0} by A10; then A48: f.p2 in Lower_Arc(P) by A3,JGRAPH_5:38; W-min(P)=|[-1,0]| by A3,JGRAPH_5:32; then f.p2 <> W-min(P) by A47,EUCLID:56; hence LE f.p1,f.p2,P by A20,A48,JORDAN6:def 10; end; hence LE f.p1,f.p2,P; end; theorem Th76: for p1,p2,p3 being Point of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ & p1 in LSeg(|[-1,-1]|,|[-1,1]|)& p1`2>=0 & LE p1,p2,K & LE p2,p3,K holds LE f.p2,f.p3,P proof let p1,p2,p3 be Point of TOP-REAL 2, P,K be non empty compact Subset of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ & p1 in LSeg(|[-1,-1]|,|[-1,1]|)& p1`2>=0 & LE p1,p2,K & LE p2,p3,K; then A2: K is_simple_closed_curve by Th60; A3: P={p: |.p.|=1} by A1,Th33; A4: p3 in K by A1,A2,JORDAN7:5; A5: p2 in K by A1,A2,JORDAN7:5; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A6: f.:K=P by A1,A3,Th45,JGRAPH_3:33; A7: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A8: f.p2 in P by A5,A6,FUNCT_1:def 12; A9: f.p3 in P by A4,A6,A7,FUNCT_1:def 12; now per cases by A1,Th74; case p2 in LSeg(|[-1,-1]|,|[-1,1]|)& p2`2>=p1`2; hence LE f.p2,f.p3,P by A1,Th75; case A10: p2 in LSeg(|[-1,1]|,|[1,1]|); then A11: p2`2=1 & -1<=p2`1 & p2`1<=1 by Th11; A12: (p2`1)^2 >=0 by SQUARE_1:72; 1+(p2`1)^2 >(p2`1)^2 by REAL_1:69; then A13: sqrt(1+(p2`1)^2)>0 by A12,SQUARE_1:93; p2<>0.REAL 2 by A11,EUCLID:56,58; then A14: f.p2= |[p2`1/sqrt(1+(p2`1/p2`2)^2),p2`2/sqrt(1+(p2`1/p2`2)^2)]| by A1,A11,JGRAPH_3:14; then A15: (f.p2)`1=(p2`1)/sqrt(1+(p2`1)^2) by A11,EUCLID:56; (f.p2)`2=(p2`2)/sqrt(1+(p2`1)^2) by A11,A14,EUCLID:56; then A16: (f.p2)`2>=0 by A11,A13,REAL_2:125; then f.p2 in {p9 where p9 is Point of TOP-REAL 2:p9 in P & p9`2>=0} by A8; then A17: f.p2 in Upper_Arc(P) by A3,JGRAPH_5:37; now per cases by A1,A10,Th70; case A18: p3 in LSeg(|[-1,1]|,|[1,1]|) & p2`1<=p3`1; then A19: p3`2=1 & -1<=p3`1 & p3`1<=1 by Th11; A20: (p3`1)^2 >=0 by SQUARE_1:72; 1+(p3`1)^2 >(p3`1)^2 by REAL_1:69; then A21: sqrt(1+(p3`1)^2)>0 by A20,SQUARE_1:93; p3<>0.REAL 2 by A19,EUCLID:56,58; then A22: f.p3= |[p3`1/sqrt(1+(p3`1/p3`2)^2),p3`2/sqrt(1+(p3`1/p3`2)^2) ]| by A1,A19,JGRAPH_3:14; then A23: (f.p3)`1=(p3`1)/sqrt(1+(p3`1)^2) by A19,EUCLID:56; (f.p3)`2=(p3`2)/sqrt(1+(p3`1)^2) by A19,A22,EUCLID:56; then A24: (f.p3)`2>=0 by A19,A21,REAL_2:125; (p2`1)*sqrt(1+(p3`1)^2)<= (p3`1)*sqrt(1+(p2`1)^2) by A18,Th8; then (p2`1)*sqrt(1+(p3`1)^2)/sqrt(1+(p3`1)^2) <= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`1)^2) by A21,REAL_1:73; then (p2`1) <= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`1)^2) by A21,XCMPLX_1:90 ; then (p2`1)/sqrt(1+(p2`1)^2) <= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`1)^2)/sqrt(1+(p2`1)^2) by A13,REAL_1:73; then (p2`1)/sqrt(1+(p2`1)^2) <= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p2`1)^2)/sqrt(1+(p3`1)^2) by XCMPLX_1:48; then (f.p2)`1<=(f.p3)`1 by A13,A15,A23,XCMPLX_1:90; hence LE f.p2,f.p3,P by A3,A8,A9,A16,A24,JGRAPH_5:57; case p3 in LSeg(|[1,1]|,|[1,-1]|); then A25: p3`1=1 & -1<=p3`2 & p3`2<=1 by Th9; A26: (p3`2)^2 >=0 by SQUARE_1:72; 1+(p3`2)^2 >(p3`2)^2 by REAL_1:69; then A27: sqrt(1+(p3`2)^2)>0 by A26,SQUARE_1:93; p3<>0.REAL 2 by A25,EUCLID:56,58; then f.p3= |[p3`1/sqrt(1+(p3`2/p3`1)^2),p3`2/sqrt(1+(p3`2/p3`1)^2)]| by A1,A25,JGRAPH_3:def 1; then A28: (f.p3)`1=(p3`1)/sqrt(1+(p3`2)^2) by A25,EUCLID:56; A29: -1<=-p2`1 by A11,REAL_1:50; A30: --1>=-p2`1 by A11,REAL_1:50; (p2`1)^2 = (-p2`1)^2 by SQUARE_1:61; then (--p2`1)*sqrt(1+(p3`2)^2)<= sqrt(1+(p2`1)^2) by A25,A29,A30,Th6; then (p2`1)*sqrt(1+(p3`2)^2)/sqrt(1+(p3`2)^2) <= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`2)^2) by A25,A27,REAL_1:73; then (p2`1) <= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`2)^2) by A27,XCMPLX_1:90 ; then (p2`1)/sqrt(1+(p2`1)^2) <= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`2)^2)/sqrt(1+(p2`1)^2) by A13,REAL_1:73; then (p2`1)/sqrt(1+(p2`1)^2) <= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p2`1)^2)/sqrt(1+(p3`2)^2) by XCMPLX_1:48; then A31: (f.p2)`1<=(f.p3)`1 by A13,A15,A28,XCMPLX_1:90; now per cases; case (f.p3)`2>=0; hence LE f.p2,f.p3,P by A3,A8,A9,A16,A31,JGRAPH_5:57; case A32: (f.p3)`2<0; then f.p3 in {p9 where p9 is Point of TOP-REAL 2:p9 in P & p9`2<=0} by A9; then A33: f.p3 in Lower_Arc(P) by A3,JGRAPH_5:38; W-min(P)=|[-1,0]| by A3,JGRAPH_5:32; then f.p3 <> W-min(P) by A32,EUCLID:56; hence LE f.p2,f.p3,P by A17,A33,JORDAN6:def 10; end; hence LE f.p2,f.p3,P; case p3 in LSeg(|[1,-1]|,|[-1,-1]|) & p3<>W-min(K); then A34: p3`2=-1 & -1<=p3`1 & p3`1<=1 by Th11; A35: (p3`1)^2 >=0 by SQUARE_1:72; 1+(p3`1)^2 >(p3`1)^2 by REAL_1:69; then A36: sqrt(1+(p3`1)^2)>0 by A35,SQUARE_1:93; A37: -p3`2>=p3`1 by A34; p3<>0.REAL 2 by A34,EUCLID:56,58; then f.p3= |[p3`1/sqrt(1+(p3`1/p3`2)^2),p3`2/sqrt(1+(p3`1/p3`2)^2)]| by A1,A34,A37,JGRAPH_3:14; then (f.p3)`2= p3`2/sqrt(1+(p3`1/(-1))^2) by A34,EUCLID:56 .=(p3`2)/sqrt(1+(-(p3`1/1))^2) by XCMPLX_1:189 .=(p3`2)/sqrt(1+(p3`1)^2) by SQUARE_1:61; then A38: (f.p3)`2<0 by A34,A36,REAL_2:128; then f.p3 in {p9 where p9 is Point of TOP-REAL 2:p9 in P & p9`2<=0} by A9; then A39: f.p3 in Lower_Arc(P) by A3,JGRAPH_5:38; W-min(P)=|[-1,0]| by A3,JGRAPH_5:32; then f.p3 <> W-min(P) by A38,EUCLID:56; hence LE f.p2,f.p3,P by A17,A39,JORDAN6:def 10; end; hence LE f.p2,f.p3,P; case A40: p2 in LSeg(|[1,1]|,|[1,-1]|); then A41: p2`1=1 & -1<=p2`2 & p2`2<=1 by Th9; A42: (p2`2)^2 >=0 by SQUARE_1:72; 1+(p2`2)^2 >(p2`2)^2 by REAL_1:69; then A43: sqrt(1+(p2`2)^2)>0 by A42,SQUARE_1:93; p2<>0.REAL 2 by A41,EUCLID:56,58; then A44: f.p2= |[p2`1/sqrt(1+(p2`2/p2`1)^2),p2`2/sqrt(1+(p2`2/p2`1)^2)]| by A1,A41,JGRAPH_3:def 1; then A45: (f.p2)`1=(p2`1)/sqrt(1+(p2`2)^2) by A41,EUCLID:56; A46: (f.p2)`2=(p2`2)/sqrt(1+(p2`2)^2) by A41,A44,EUCLID:56; A47: (f.p2)`1>=0 by A41,A43,A45,REAL_2:125; now per cases by A1,A40,Th71; case A48: p3 in LSeg(|[1,1]|,|[1,-1]|) & p2`2>=p3`2; then A49: p3`1=1 & -1<=p3`2 & p3`2<=1 by Th9; A50: (p3`2)^2 >=0 by SQUARE_1:72; 1+(p3`2)^2 >(p3`2)^2 by REAL_1:69; then A51: sqrt(1+(p3`2)^2)>0 by A50,SQUARE_1:93; p3<>0.REAL 2 by A49,EUCLID:56,58; then A52: f.p3= |[p3`1/sqrt(1+(p3`2/p3`1)^2),p3`2/sqrt(1+(p3`2/p3`1)^2) ]| by A1,A49,JGRAPH_3:def 1; then A53: (f.p3)`1=(p3`1)/sqrt(1+(p3`2)^2) by A49,EUCLID:56; A54: (f.p3)`2=(p3`2)/sqrt(1+(p3`2)^2) by A49,A52,EUCLID:56; A55: (f.p3)`1>=0 by A49,A51,A53,REAL_2:125; (p2`2)*sqrt(1+(p3`2)^2)>= (p3`2)*sqrt(1+(p2`2)^2) by A48,Th8; then (p2`2)*sqrt(1+(p3`2)^2)/sqrt(1+(p3`2)^2) >= (p3`2)*sqrt(1+(p2`2)^2)/sqrt(1+(p3`2)^2) by A51,REAL_1:73; then (p2`2) >= (p3`2)*sqrt(1+(p2`2)^2)/sqrt(1+(p3`2)^2) by A51,XCMPLX_1:90 ; then (p2`2)/sqrt(1+(p2`2)^2) >= (p3`2)*sqrt(1+(p2`2)^2)/sqrt(1+(p3`2)^2)/sqrt(1+(p2`2)^2) by A43,REAL_1:73; then (p2`2)/sqrt(1+(p2`2)^2) >= (p3`2)*sqrt(1+(p2`2)^2)/sqrt(1+(p2`2)^2)/sqrt(1+(p3`2)^2) by XCMPLX_1:48; then (p2`2)/sqrt(1+(p2`2)^2) >= (p3`2)/sqrt(1+(p3`2)^2) by A43,XCMPLX_1:90; hence LE f.p2,f.p3,P by A3,A8,A9,A46,A47,A54,A55,JGRAPH_5:58; case p3 in LSeg(|[1,-1]|,|[-1,-1]|) & p3<>W-min(K); then A56: p3`2=-1 & -1<=p3`1 & p3`1<=1 by Th11; A57: (p3`1)^2 >=0 by SQUARE_1:72; 1+(p3`1)^2 >(p3`1)^2 by REAL_1:69; then A58: sqrt(1+(p3`1)^2)>0 by A57,SQUARE_1:93; A59: -p3`2>=p3`1 by A56; p3<>0.REAL 2 by A56,EUCLID:56,58; then A60: f.p3= |[p3`1/sqrt(1+(p3`1/p3`2)^2),p3`2/sqrt(1+(p3`1/p3`2)^2) ]| by A1,A56,A59,JGRAPH_3:14; then A61: (f.p3)`1= p3`1/sqrt(1+(p3`1/(-1))^2) by A56,EUCLID:56 .=(p3`1)/sqrt(1+(-(p3`1/1))^2) by XCMPLX_1:189 .=(p3`1)/sqrt(1+(p3`1)^2) by SQUARE_1:61; (f.p3)`2= p3`2/sqrt(1+(p3`1/(-1))^2) by A56,A60,EUCLID:56 .=(p3`2)/sqrt(1+(-(p3`1/1))^2) by XCMPLX_1:189 .=(p3`2)/sqrt(1+(p3`1)^2) by SQUARE_1:61; then A62: (f.p3)`2<0 by A56,A58,REAL_2:128; then f.p3 in {p9 where p9 is Point of TOP-REAL 2:p9 in P & p9`2<=0} by A9; then A63: f.p3 in Lower_Arc(P) by A3,JGRAPH_5:38; W-min(P)=|[-1,0]| by A3,JGRAPH_5:32; then A64: f.p3 <> W-min(P) by A62,EUCLID:56; now per cases; case (f.p2)`2>=0; then f.p2 in {p9 where p9 is Point of TOP-REAL 2:p9 in P & p9`2>=0} by A8; then f.p2 in Upper_Arc(P) by A3,JGRAPH_5:37; hence LE f.p2,f.p3,P by A63,A64,JORDAN6:def 10; case A65: (f.p2)`2<0; sqrt(1+(p3`1)^2)>= (p3`1)*sqrt(1+(p2`2)^2) by A41,A56,Th7; then (p2`1)*sqrt(1+(p3`1)^2)/sqrt(1+(p3`1)^2) >= (p3`1)*sqrt(1+(p2`2)^2)/sqrt(1+(p3`1)^2) by A41,A58,REAL_1:73; then (p2`1) >= (p3`1)*sqrt(1+(p2`2)^2)/sqrt(1+(p3`1)^2) by A58,XCMPLX_1:90 ; then (p2`1)/sqrt(1+(p2`2)^2) >= (p3`1)*sqrt(1+(p2`2)^2)/sqrt(1+(p3`1)^2)/sqrt(1+(p2`2)^2) by A43,REAL_1:73; then (p2`1)/sqrt(1+(p2`2)^2) >= (p3`1)*sqrt(1+(p2`2)^2)/sqrt(1+(p2`2)^2)/sqrt(1+(p3`1)^2) by XCMPLX_1:48; then (p2`1)/sqrt(1+(p2`2)^2) >= (p3`1)/sqrt(1+(p3`1)^2) by A43,XCMPLX_1:90; hence LE f.p2,f.p3,P by A3,A8,A9,A45,A61,A62,A64,A65,JGRAPH_5:59; end; hence LE f.p2,f.p3,P; end; hence LE f.p2,f.p3,P; case A66: p2 in LSeg(|[1,-1]|,|[-1,-1]|)& p2<>|[-1,-1]|; then A67: p2`2=-1 & -1<=p2`1 & p2`1<=1 by Th11; A68: (p2`1)^2 >=0 by SQUARE_1:72; 1+(p2`1)^2 >(p2`1)^2 by REAL_1:69; then A69: sqrt(1+(p2`1)^2)>0 by A68,SQUARE_1:93; A70: -p2`2>=p2`1 by A67; p2<>0.REAL 2 by A67,EUCLID:56,58; then A71: f.p2= |[p2`1/sqrt(1+(p2`1/p2`2)^2),p2`2/sqrt(1+(p2`1/p2`2)^2)]| by A1,A67,A70,JGRAPH_3:14; then A72: (f.p2)`1= p2`1/sqrt(1+(p2`1/(-1))^2) by A67,EUCLID:56 .=(p2`1)/sqrt(1+(-(p2`1/1))^2) by XCMPLX_1:189 .=(p2`1)/sqrt(1+(p2`1)^2) by SQUARE_1:61; (f.p2)`2= p2`2/sqrt(1+(p2`1/(-1))^2) by A67,A71,EUCLID:56 .=(p2`2)/sqrt(1+(-(p2`1/1))^2) by XCMPLX_1:189 .=(p2`2)/sqrt(1+(p2`1)^2) by SQUARE_1:61; then A73: (f.p2)`2<0 by A67,A69,REAL_2:128; W-min(K)=|[-1,-1]| by A1,Th56; then A74: p3 in LSeg(|[1,-1]|,|[-1,-1]|) & p2`1>=p3`1 & p3<>W-min(K) by A1,A66,Th72; then A75: p3`2=-1 & -1<=p3`1 & p3`1<=1 by Th11; A76: (p3`1)^2 >=0 by SQUARE_1:72; 1+(p3`1)^2 >(p3`1)^2 by REAL_1:69; then A77: sqrt(1+(p3`1)^2)>0 by A76,SQUARE_1:93; A78: -p3`2>=p3`1 by A75; p3<>0.REAL 2 by A75,EUCLID:56,58; then A79: f.p3= |[p3`1/sqrt(1+(p3`1/p3`2)^2),p3`2/sqrt(1+(p3`1/p3`2)^2) ]| by A1,A75,A78,JGRAPH_3:14; then A80: (f.p3)`1= p3`1/sqrt(1+(p3`1/(-1))^2) by A75,EUCLID:56 .=(p3`1)/sqrt(1+(-(p3`1/1))^2) by XCMPLX_1:189 .=(p3`1)/sqrt(1+(p3`1)^2) by SQUARE_1:61; (f.p3)`2= p3`2/sqrt(1+(p3`1/(-1))^2) by A75,A79,EUCLID:56 .=(p3`2)/sqrt(1+(-(p3`1/1))^2) by XCMPLX_1:189 .=(p3`2)/sqrt(1+(p3`1)^2) by SQUARE_1:61; then A81: (f.p3)`2<0 by A75,A77,REAL_2:128; W-min(P)=|[-1,0]| by A3,JGRAPH_5:32; then A82: f.p3 <> W-min(P) by A81,EUCLID:56; (p2`1)*sqrt(1+(p3`1)^2)>= (p3`1)*sqrt(1+(p2`1)^2) by A74,Th8; then (p2`1)*sqrt(1+(p3`1)^2)/sqrt(1+(p3`1)^2) >= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`1)^2) by A77,REAL_1:73; then (p2`1) >= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`1)^2) by A77,XCMPLX_1:90 ; then (p2`1)/sqrt(1+(p2`1)^2) >= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p3`1)^2)/sqrt(1+(p2`1)^2) by A69,REAL_1:73; then (p2`1)/sqrt(1+(p2`1)^2) >= (p3`1)*sqrt(1+(p2`1)^2)/sqrt(1+(p2`1)^2)/sqrt(1+(p3`1)^2) by XCMPLX_1:48; then (p2`1)/sqrt(1+(p2`1)^2) >= (p3`1)/sqrt(1+(p3`1)^2) by A69,XCMPLX_1:90; hence LE f.p2,f.p3,P by A3,A8,A9,A72,A73,A80,A81,A82,JGRAPH_5:59; end; hence LE f.p2,f.p3,P; end; theorem Th77: for p being Point of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st f=Sq_Circ & p`1=-1 & p`2<0 holds (f.p)`1<0 & (f.p)`2<0 proof let p be Point of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: f=Sq_Circ & p`1=-1 & p`2<0; now per cases; case p=0.REAL 2; hence contradiction by A1,EUCLID:56,58; case A2: p<> 0.REAL 2; now per cases; case (p`2<=p`1 & -p`1<=p`2 or p`2>=p`1 & p`2<=-p`1); then f.p=|[p`1/sqrt(1+(p`2/p`1)^2),p`2/sqrt(1+(p`2/p`1)^2)]| by A1,A2,JGRAPH_3:def 1; then A3: (f.p)`1= p`1/sqrt(1+(p`2/p`1)^2) & (f.p)`2= p`2/sqrt(1+(p`2/p`1)^2) by EUCLID:56; A4: (p`2/p`1)^2 >=0 by SQUARE_1:72; 1+(p`2/p`1)^2 >(p`2/p`1)^2 by REAL_1:69; then sqrt(1+(p`2/p`1)^2)>0 by A4,SQUARE_1:93; hence (f.p)`1<0 & (f.p)`2<0 by A1,A3,REAL_2:128; case not (p`2<=p`1 & -p`1<=p`2 or p`2>=p`1 & p`2<=-p`1); then f.p=|[p`1/sqrt(1+(p`1/p`2)^2),p`2/sqrt(1+(p`1/p`2)^2)]| by A1,A2,JGRAPH_3:def 1; then A5: (f.p)`1= p`1/sqrt(1+(p`1/p`2)^2) & (f.p)`2= p`2/sqrt(1+(p`1/p`2)^2) by EUCLID:56; A6: (p`1/p`2)^2 >=0 by SQUARE_1:72; 1+(p`1/p`2)^2 >(p`1/p`2)^2 by REAL_1:69; then sqrt(1+(p`1/p`2)^2)>0 by A6,SQUARE_1:93; hence (f.p)`1<0 & (f.p)`2<0 by A1,A5,REAL_2:128; end; hence (f.p)`1<0 & (f.p)`2<0; end; hence (f.p)`1<0 & (f.p)`2<0; end; theorem Th78: for p being Point of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ holds (f.p)`1>=0 iff p`1>=0 proof let p be Point of TOP-REAL 2, P,K be non empty compact Subset of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ; thus (f.p)`1>=0 implies p`1>=0 proof assume A2: (f.p)`1>=0; reconsider g=(Sq_Circ") as map of TOP-REAL 2,TOP-REAL 2 by JGRAPH_3:39; A3: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; set q=(f.p); now per cases; case q=0.REAL 2; hence (g.q)`1>=0 by A2,JGRAPH_3:38; case A4: q<> 0.REAL 2; now per cases; case (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then g.q=|[q`1*sqrt(1+(q`2/q`1)^2),q`2*sqrt(1+(q`2/q`1)^2)]| by A4,JGRAPH_3:38; then A5: (g.q)`1= q`1*sqrt(1+(q`2/q`1)^2) by EUCLID:56; A6: (q`2/q`1)^2 >=0 by SQUARE_1:72; 1+(q`2/q`1)^2 >(q`2/q`1)^2 by REAL_1:69; then sqrt(1+(q`2/q`1)^2)>0 by A6,SQUARE_1:93; hence (g.q)`1>=0 by A2,A5,SQUARE_1:19; case not (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then g.q=|[q`1*sqrt(1+(q`1/q`2)^2),q`2*sqrt(1+(q`1/q`2)^2)]| by A4,JGRAPH_3:38; then A7: (g.q)`1= q`1*sqrt(1+(q`1/q`2)^2) by EUCLID:56; A8: (q`1/q`2)^2 >=0 by SQUARE_1:72; 1+(q`1/q`2)^2 >(q`1/q`2)^2 by REAL_1:69; then sqrt(1+(q`1/q`2)^2)>0 by A8,SQUARE_1:93; hence (g.q)`1>=0 by A2,A7,SQUARE_1:19; end; hence (g.q)`1>=0; end; hence p`1>=0 by A1,A3,FUNCT_1:56; end; thus p`1>=0 implies (f.p)`1>=0 proof assume A9: p`1>=0; now per cases; case p=0.REAL 2; hence (f.p)`1>=0 by A1,A9,JGRAPH_3:def 1; case A10: p<> 0.REAL 2; now per cases; case (p`2<=p`1 & -p`1<=p`2 or p`2>=p`1 & p`2<=-p`1); then f.p=|[p`1/sqrt(1+(p`2/p`1)^2),p`2/sqrt(1+(p`2/p`1)^2)]| by A1,A10,JGRAPH_3:def 1; then A11: (f.p)`1= p`1/sqrt(1+(p`2/p`1)^2) by EUCLID:56; A12: (p`2/p`1)^2 >=0 by SQUARE_1:72; 1+(p`2/p`1)^2 >(p`2/p`1)^2 by REAL_1:69; then sqrt(1+(p`2/p`1)^2)>0 by A12,SQUARE_1:93; hence (f.p)`1>=0 by A9,A11,REAL_2:125; case not (p`2<=p`1 & -p`1<=p`2 or p`2>=p`1 & p`2<=-p`1); then f.p=|[p`1/sqrt(1+(p`1/p`2)^2),p`2/sqrt(1+(p`1/p`2)^2)]| by A1,A10,JGRAPH_3:def 1; then A13: (f.p)`1= p`1/sqrt(1+(p`1/p`2)^2) by EUCLID:56; A14: (p`1/p`2)^2 >=0 by SQUARE_1:72; 1+(p`1/p`2)^2 >(p`1/p`2)^2 by REAL_1:69; then sqrt(1+(p`1/p`2)^2)>0 by A14,SQUARE_1:93; hence (f.p)`1>=0 by A9,A13,REAL_2:125; end; hence (f.p)`1>=0; end; hence (f.p)`1>=0; end; end; theorem Th79: for p being Point of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ holds (f.p)`2>=0 iff p`2>=0 proof let p be Point of TOP-REAL 2, P,K be non empty compact Subset of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ; thus (f.p)`2>=0 implies p`2>=0 proof assume A2: (f.p)`2>=0; reconsider g=(Sq_Circ") as map of TOP-REAL 2,TOP-REAL 2 by JGRAPH_3:39; A3: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; set q=(f.p); now per cases; case q=0.REAL 2; hence (g.q)`2>=0 by A2,JGRAPH_3:38; case A4: q<> 0.REAL 2; now per cases; case (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then g.q=|[q`1*sqrt(1+(q`2/q`1)^2),q`2*sqrt(1+(q`2/q`1)^2)]| by A4,JGRAPH_3:38; then A5: (g.q)`2= q`2*sqrt(1+(q`2/q`1)^2) by EUCLID:56; A6: (q`2/q`1)^2 >=0 by SQUARE_1:72; 1+(q`2/q`1)^2 >(q`2/q`1)^2 by REAL_1:69; then sqrt(1+(q`2/q`1)^2)>0 by A6,SQUARE_1:93; hence (g.q)`2>=0 by A2,A5,SQUARE_1:19; case not (q`2<=q`1 & -q`1<=q`2 or q`2>=q`1 & q`2<=-q`1); then g.q=|[q`1*sqrt(1+(q`1/q`2)^2),q`2*sqrt(1+(q`1/q`2)^2)]| by A4,JGRAPH_3:38; then A7: (g.q)`2= q`2*sqrt(1+(q`1/q`2)^2) by EUCLID:56; A8: (q`1/q`2)^2 >=0 by SQUARE_1:72; 1+(q`1/q`2)^2 >(q`1/q`2)^2 by REAL_1:69; then sqrt(1+(q`1/q`2)^2)>0 by A8,SQUARE_1:93; hence (g.q)`2>=0 by A2,A7,SQUARE_1:19; end; hence (g.q)`2>=0; end; hence p`2>=0 by A1,A3,FUNCT_1:56; end; thus p`2>=0 implies (f.p)`2>=0 proof assume A9: p`2>=0; now per cases; case p=0.REAL 2; hence (f.p)`2>=0 by A1,A9,JGRAPH_3:def 1; case A10: p<> 0.REAL 2; now per cases; case (p`2<=p`1 & -p`1<=p`2 or p`2>=p`1 & p`2<=-p`1); then f.p=|[p`1/sqrt(1+(p`2/p`1)^2),p`2/sqrt(1+(p`2/p`1)^2)]| by A1,A10,JGRAPH_3:def 1; then A11: (f.p)`2= p`2/sqrt(1+(p`2/p`1)^2) by EUCLID:56; A12: (p`2/p`1)^2 >=0 by SQUARE_1:72; 1+(p`2/p`1)^2 >(p`2/p`1)^2 by REAL_1:69; then sqrt(1+(p`2/p`1)^2)>0 by A12,SQUARE_1:93; hence (f.p)`2>=0 by A9,A11,REAL_2:125; case not (p`2<=p`1 & -p`1<=p`2 or p`2>=p`1 & p`2<=-p`1); then f.p=|[p`1/sqrt(1+(p`1/p`2)^2),p`2/sqrt(1+(p`1/p`2)^2)]| by A1,A10,JGRAPH_3:def 1; then A13: (f.p)`2= p`2/sqrt(1+(p`1/p`2)^2) by EUCLID:56; A14: (p`1/p`2)^2 >=0 by SQUARE_1:72; 1+(p`1/p`2)^2 >(p`1/p`2)^2 by REAL_1:69; then sqrt(1+(p`1/p`2)^2)>0 by A14,SQUARE_1:93; hence (f.p)`2>=0 by A9,A13,REAL_2:125; end; hence (f.p)`2>=0; end; hence (f.p)`2>=0; end; end; theorem Th80: for p,q being Point of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st f=Sq_Circ & p in LSeg(|[-1,-1]|,|[-1,1]|) & q in LSeg(|[1,-1]|,|[-1,-1]|) holds (f.p)`1<=(f.q)`1 proof let p,q be Point of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: f=Sq_Circ & p in LSeg(|[-1,-1]|,|[-1,1]|) & q in LSeg(|[1,-1]|,|[-1,-1]|); then A2: p`1=-1 & -1<=p`2 & p`2<=1 by Th9; A3: q`2=-1 & -1<=q`1 & q`1<=1 by A1,Th11; A4: p<>0.REAL 2 by A2,EUCLID:56,58; A5: q<>0.REAL 2 by A3,EUCLID:56,58; p`2<=-p`1 by A2; then f.p= |[p`1/sqrt(1+(p`2/p`1)^2),p`2/sqrt(1+(p`2/p`1)^2)]| by A1,A2,A4,JGRAPH_3:def 1; then A6: (f.p)`1=(-1)/sqrt(1+(p`2/(-1))^2) by A2,EUCLID:56 .=(-1)/sqrt(1+(-(p`2/1))^2) by XCMPLX_1:189 .=(-1)/sqrt(1+(p`2)^2) by SQUARE_1:61; A7: (p`2)^2 >=0 by SQUARE_1:72; 1+(p`2)^2 >(p`2)^2 by REAL_1:69; then A8: sqrt(1+(p`2)^2)>0 by A7,SQUARE_1:93; A9: (q`1)^2 >=0 by SQUARE_1:72; 1+(q`1)^2 >(q`1)^2 by REAL_1:69; then A10: sqrt(1+(q`1)^2)>0 by A9,SQUARE_1:93; q`1<=-q`2 by A3; then f.q= |[q`1/sqrt(1+(q`1/q`2)^2),q`2/sqrt(1+(q`1/q`2)^2)]| by A1,A3,A5,JGRAPH_3:14; then A11: (f.q)`1=q`1/sqrt(1+(q`1/(-1))^2) by A3,EUCLID:56 .=q`1/sqrt(1+(-(q`1/1))^2) by XCMPLX_1:189 .=q`1/sqrt(1+(q`1)^2) by SQUARE_1:61; -sqrt(1+(q`1)^2)<= q`1*sqrt(1+(p`2)^2) by A2,A3,Th6; then (-1)*sqrt(1+(q`1)^2)<= q`1*sqrt(1+(p`2)^2) by XCMPLX_1:180; then (-1)*sqrt(1+(q`1)^2)/sqrt(1+(q`1)^2) <= q`1*sqrt(1+(p`2)^2)/sqrt(1+(q`1)^2) by A10,REAL_1:73; then (-1) <= q`1*sqrt(1+(p`2)^2)/sqrt(1+(q`1)^2) by A10,XCMPLX_1:90; then -1<= q`1/sqrt(1+(q`1)^2)*sqrt(1+(p`2)^2) by XCMPLX_1:75; then (-1)/sqrt(1+(p`2)^2) <= q`1/sqrt(1+(q`1)^2)*sqrt(1+(p`2)^2)/sqrt(1+(p`2)^2) by A8,REAL_1:73; hence (f.p)`1<=(f.q)`1 by A6,A8,A11,XCMPLX_1:90; end; theorem Th81: for p,q being Point of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st f=Sq_Circ & p in LSeg(|[-1,-1]|,|[-1,1]|) & q in LSeg(|[-1,-1]|,|[-1,1]|) & p`2>=q`2 & p`2<0 holds (f.p)`2>=(f.q)`2 proof let p,q be Point of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: f=Sq_Circ & p in LSeg(|[-1,-1]|,|[-1,1]|) & q in LSeg(|[-1,-1]|,|[-1,1]|) & p`2>=q`2 & p`2<0; then A2: p`1=-1 & -1<=p`2 & p`2 <=1 by Th9; A3: q`2<0 by A1; A4: (p`2)^2 >=0 by SQUARE_1:72; 1+(p`2)^2 >(p`2)^2 by REAL_1:69; then A5: sqrt(1+(p`2)^2)>0 by A4,SQUARE_1:93; A6: (q`2)^2 >=0 by SQUARE_1:72; 1+(q`2)^2 >(q`2)^2 by REAL_1:69; then A7: sqrt(1+(q`2)^2)>0 by A6,SQUARE_1:93; A8: p`2<=-p`1 by A2; p<>0.REAL 2 by A1,EUCLID:56,58; then f.p= |[p`1/sqrt(1+(p`2/p`1)^2),p`2/sqrt(1+(p`2/p`1)^2)]| by A1,A2,A8,JGRAPH_3:def 1; then A9: (f.p)`2= p`2/sqrt(1+(p`2/(-1))^2) by A2,EUCLID:56 .=(p`2)/sqrt(1+(-(p`2/1))^2) by XCMPLX_1:189 .=(p`2)/sqrt(1+(p`2)^2) by SQUARE_1:61; A10: q`1=-1 & -1<=q`2 & q`2 <=1 by A1,Th9; then A11: q`2<=-q`1; q<>0.REAL 2 by A1,EUCLID:56,58; then f.q= |[q`1/sqrt(1+(q`2/q`1)^2),q`2/sqrt(1+(q`2/q`1)^2)]| by A1,A10,A11,JGRAPH_3:def 1; then A12: (f.q)`2= q`2/sqrt(1+(q`2/(-1))^2) by A10,EUCLID:56 .=(q`2)/sqrt(1+(-(q`2/1))^2) by XCMPLX_1:189 .=(q`2)/sqrt(1+(q`2)^2) by SQUARE_1:61; (p`2)*sqrt(1+(q`2)^2)>= (q`2)*sqrt(1+(p`2)^2) by A1,A3,Lm3; then (p`2)*sqrt(1+(q`2)^2)/sqrt(1+(q`2)^2) >= (q`2)*sqrt(1+(p`2)^2)/sqrt(1+(q`2)^2) by A7,REAL_1:73; then (p`2) >= (q`2)*sqrt(1+(p`2)^2)/sqrt(1+(q`2)^2) by A7,XCMPLX_1:90; then (p`2)/sqrt(1+(p`2)^2) >= (q`2)*sqrt(1+(p`2)^2)/sqrt(1+(q`2)^2)/sqrt(1+(p`2)^2) by A5,REAL_1:73; then (p`2)/sqrt(1+(p`2)^2) >= (q`2)*sqrt(1+(p`2)^2)/sqrt(1+(p`2)^2)/sqrt(1+(q`2)^2) by XCMPLX_1:48; hence (f.p)`2>=(f.q)`2 by A5,A9,A12,XCMPLX_1:90; end; theorem Th82: for p1,p2,p3,p4 being Point of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ holds LE p1,p2,K & LE p2,p3,K & LE p3,p4,K implies f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P proof let p1,p2,p3,p4 be Point of TOP-REAL 2, P,K be non empty compact Subset of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ; then A2: K is_simple_closed_curve by Th60; A3: K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; A4: P={p: |.p.|=1} by A1,Th33; thus LE p1,p2,K & LE p2,p3,K & LE p3,p4,K implies f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P proof assume A5: LE p1,p2,K & LE p2,p3,K & LE p3,p4,K; then A6: p1 in K & p2 in K by A2,JORDAN7:5; A7: p3 in K & p4 in K by A2,A5,JORDAN7:5; then consider q8 being Point of TOP-REAL 2 such that A8: q8=p4 & (q8`1=-1 & -1 <=q8`2 & q8`2<=1 or q8`2=1 & -1<=q8`1 & q8`1<=1 or q8`1=1 & -1 <=q8`2 & q8`2<=1 or q8`2=-1 & -1<=q8`1 & q8`1<=1) by A3; A9: LE p1,p3,K by A2,A5,JORDAN6:73; A10: LE p2,p4,K by A2,A5,JORDAN6:73; A11: W-min(K)=|[-1,-1]| by A1,Th56; A12: (|[-1,0]|)`1=-1 & (|[-1,0]|)`2=0 by EUCLID:56; 1/2*(|[-1,-1]|+|[-1,1]|)=1/2*(|[-1,-1]|)+1/2*(|[-1,1]|) by EUCLID:36 .= (|[1/2*(-1),1/2*(-1)]|)+1/2*(|[-1,1]|) by EUCLID:62 .= (|[1/2*(-1),1/2*(-1)]|)+(|[1/2*(-1),1/2*1]|) by EUCLID:62 .= (|[1/2*(-1)+1/2*(-1),1/2*(-1)+1/2*1]|) by EUCLID:60 .= (|[(-1),0]|); then A13: |[-1,0]| in LSeg(|[-1,-1]|,|[-1,1]|) by GOBOARD7:7; now per cases by A1,A6,A11,Th73,TOPREAL1:6; case A14: p1 in LSeg(|[-1,-1]|,|[-1,1]|); then A15: p1`1=-1 & -1<=p1`2 & p1`2<=1 by Th9; then A16: (f.p1)`1<0 by A1,Th78; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A17: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A18: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A19: f.p1 in P by A6,A17,FUNCT_1:def 12; now per cases; case A20: p1`2>=0; then A21: LE f.p1,f.p2,P by A1,A5,A14,Th75; A22: LE f.p2,f.p3,P by A1,A5,A14,A20,Th76; LE f.p3,f.p4,P by A1,A5,A9,A14,A20,Th76; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A21,A22,JORDAN17:def 1; case A23: p1`2<0; then A24: (f.p1)`2<0 by A1,Th79; now per cases; case A25: p2`2<0 & p2 in LSeg(|[-1,-1]|,|[-1,1]|); then A26: p2`1=-1 & -1<=p2`2 & p2`2<=1 by Th9; A27: f.p2 in P by A6,A17,A18,FUNCT_1:def 12; A28: p1`2<=p2`2 by A1,A5,A14,A25,Th65; now per cases; case A29: p3`2<0 & p3 in LSeg(|[-1,-1]|,|[-1,1]|); then A30: p3`1=-1 & -1<=p3`2 & p3`2<=1 by Th9; A31: f.p3 in P by A7,A17,A18,FUNCT_1:def 12; A32: p2`2<=p3`2 by A1,A5,A25,A29,Th65; now per cases; case A33: p4`2<0 & p4 in LSeg(|[-1,-1]|,|[-1,1]|); then A34: p4`1=-1 & -1<=p4`2 & p4`2<=1 by Th9; A35: (f.p2)`1<0 & (f.p2)`2<0 by A1,A25,A26,Th77; A36: (f.p3)`1<0 & (f.p3)`2<0 by A1,A29,A30,Th77; A37: (f.p4)`1<0 & (f.p4)`2<0 by A1,A33,A34,Th77; (f.p1)`2<=(f.p2)`2 by A1,A14,A25,A28,Th81; then A38: LE f.p1,f.p2,P by A4,A16,A19,A24,A27,A35,JGRAPH_5:54; (f.p2)`2<=(f.p3)`2 by A1,A25,A29,A32,Th81; then A39: LE f.p2,f.p3,P by A4,A27,A31,A35,A36,JGRAPH_5:54; A40: f.p4 in P by A7,A17,A18,FUNCT_1:def 12; p3`2<=p4`2 by A1,A5,A29,A33,Th65; then (f.p3)`2<=(f.p4)`2 by A1,A29,A33,Th81; then LE f.p3,f.p4,P by A4,A31,A36,A37,A40,JGRAPH_5:54; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A38,A39,JORDAN17:def 1; case A41: not(p4`2<0 & p4 in LSeg(|[-1,-1]|,|[-1,1]|)); A42: now per cases by A1,A7,Th73; case p4 in LSeg(|[-1,-1]|,|[-1,1]|); hence p4 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p4`2 or p4 in LSeg(|[-1,1]|,|[1,1]|) or p4 in LSeg(|[1,1]|,|[1,-1]|) or p4 in LSeg(|[1,-1]|,|[-1,-1]|) & p4<>W-min(K) by A41,EUCLID:56; case p4 in LSeg(|[-1,1]|,|[1,1]|); hence p4 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p4`2 or p4 in LSeg(|[-1,1]|,|[1,1]|) or p4 in LSeg(|[1,1]|,|[1,-1]|) or p4 in LSeg(|[1,-1]|,|[-1,-1]|) & p4<>W-min(K); case p4 in LSeg(|[1,1]|,|[1,-1]|); hence p4 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p4`2 or p4 in LSeg(|[-1,1]|,|[1,1]|) or p4 in LSeg(|[1,1]|,|[1,-1]|) or p4 in LSeg(|[1,-1]|,|[-1,-1]|) & p4<>W-min(K); case A43: p4 in LSeg(|[1,-1]|,|[-1,-1]|); A44: W-min(K)=|[-1,-1]| by A1,Th56; now assume A45: p4= W-min(K); then p4`2=-1 by A44,EUCLID:56; hence contradiction by A41,A44,A45,TOPREAL1:6; end; hence p4 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p4`2 or p4 in LSeg(|[-1,1]|,|[1,1]|) or p4 in LSeg(|[1,1]|,|[1,-1]|) or p4 in LSeg(|[1,-1]|,|[-1,-1]|) & p4<>W-min(K) by A43; end; A46: (f.p2)`1<0 & (f.p2)`2<0 by A1,A25,A26,Th77; A47: (f.p3)`1<0 & (f.p3)`2<0 by A1,A29,A30,Th77; (f.p1)`2<=(f.p2)`2 by A1,A14,A25,A28,Th81; then A48: LE f.p1,f.p2,P by A4,A16,A19,A24,A27,A46,JGRAPH_5:54; (f.p2)`2<=(f.p3)`2 by A1,A25,A29,A32,Th81; then A49: LE f.p2,f.p3,P by A4,A27,A31,A46,A47,JGRAPH_5:54; A50: now per cases; case A51: p4`1=-1 & p4`2<0 & p1`2<=p4`2; now per cases by A42; case p4 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p4`2; hence contradiction by A51,EUCLID:56; case p4 in LSeg(|[-1,1]|,|[1,1]|); then p4`2=1 by Th11; hence contradiction by A51; case p4 in LSeg(|[1,1]|,|[1,-1]|); hence contradiction by A51,Th9; case A52: p4 in LSeg(|[1,-1]|,|[-1,-1]|) & p4<>W-min(K); then A53: p4`2= -1 by Th11; W-min(K)= |[-1,-1]| by A1,Th56; then (W-min(K))`1=-1 & (W-min(K))`2=-1 by EUCLID:56; hence contradiction by A51,A52,A53,TOPREAL3:11; end; hence contradiction; case A54: not (p4`1=-1 & p4`2<0 & p1`2<=p4`2); A55: p4 in LSeg(|[-1,-1]|,|[-1,1]|) or p4 in LSeg(|[-1,1]|,|[1,1]|) or p4 in LSeg(|[1,1]|,|[1,-1]|) or p4 in LSeg(|[1,-1]|,|[-1,-1]|) by A1,A7,Th73; now per cases by A54; case A56: p4`1<>-1; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A57: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A58: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; A59: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A60: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A61: f.p1 in P by A6,A57,A58,FUNCT_1:def 12; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then A62: f.p1 in Lower_Arc(P) by A59,A61; A63: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A64: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A58,A63,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; now per cases by A55,A56,Th9; case p4 in LSeg(|[-1,1]|,|[1,1]|); then A65: p4`2=1 by Th11; A66: f.p4 in P by A7,A57,A58,FUNCT_1:def 12; (f.p4)`2>=0 by A1,A65,Th79; then f.p4 in Upper_Arc(P) by A60,A66; hence LE f.p4,f.p1,P by A62,A64,JORDAN6:def 10; case p4 in LSeg(|[1,1]|,|[1,-1]|); then A67: p4`1=1 by Th9; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A68: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A69: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A70: f.p4 in P by A7,A68,FUNCT_1:def 12; A71: f.p1 in P by A6,A68,A69,FUNCT_1:def 12; A72: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A73: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A74: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A69,A73,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A75: (f.p4)`1>=0 by A1,A67,Th78; now per cases; case A76: (f.p4)`2>=0; A77: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A78: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A79: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A80: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A69,A79,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A81: f.p4 in Upper_Arc(P) by A70,A76,A78; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then f.p1 in Lower_Arc(P) by A71,A77; hence LE f.p4,f.p1,P by A80,A81,JORDAN6:def 10; case A82: (f.p4)`2<0; (f.p1)`1<=0 & (f.p4)`1>=(f.p1)`1 by A72,A75,AXIOMS:22; hence LE f.p4,f.p1,P by A4,A70,A71,A72,A74,A82,JGRAPH_5:59; end; hence LE f.p4,f.p1,P; case A83: p4 in LSeg(|[1,-1]|,|[-1,-1]|); then p4`2=-1 & -1 <=p4`1 & p4`1<=1 by Th11; then A84: (f.p4)`2<0 by A1,Th79; A85: f.p4 in P by A7,A57,A58,FUNCT_1:def 12; A86: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; (f.p4)`1>=(f.p1)`1 by A1,A14,A83,Th80; hence LE f.p4,f.p1,P by A4,A61,A64,A84,A85,A86,JGRAPH_5:59; end; hence LE f.p4,f.p1,P; case A87: p4`1=-1 & p4`2>=0; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A88: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A89: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A90: f.p4 in P by A7,A88,FUNCT_1:def 12; A91: f.p1 in P by A6,A88,A89,FUNCT_1:def 12; A92: (f.p4)`2>=0 by A1,A87,Th79; A93: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A94: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A95: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A96: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A89,A95,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A97: f.p4 in Upper_Arc(P) by A90,A92,A94; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then f.p1 in Lower_Arc(P) by A91,A93; hence LE f.p4,f.p1,P by A96,A97,JORDAN6:def 10; case A98: p4`1=-1 & p4`2<0 & p1`2>p4`2; then A99: p4 in LSeg(|[-1,-1]|,|[-1,1]|) by A8,Th10; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A100: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A101: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A102: f.p4 in P by A7,A100,FUNCT_1:def 12; A103: f.p1 in P by A6,A100,A101,FUNCT_1:def 12; A104: (f.p1)`1<0 & (f.p1)`2<0 by A1,A15,A23,Th77; A105: (f.p4)`2<=(f.p1)`2 by A1,A14,A23,A98,A99,Th81; A106: (f.p4)`1<0 by A1,A98,Th78; (f.p4)`2<0 by A1,A98,Th79; hence LE f.p4,f.p1,P by A4,A102,A103,A104,A105,A106,JGRAPH_5:54; end; hence LE f.p4,f.p1,P; end; A107: K={p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; thus K={p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} proof thus K c= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} proof let x be set;assume x in K; then consider p such that A108: p=x & (p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1) by A107; thus x in {q: q`1=-1 & -1 <=q`2 & q`2<=1 or q`1=1 & -1 <=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1} by A108; end; thus {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} c= K proof let x be set;assume x in {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1}; then consider p such that A109: p=x & (p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1); thus x in K by A107,A109; end; end; thus f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A48,A49,A50,JORDAN17:def 1; end; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P; case A110: not(p3`2<0 & p3 in LSeg(|[-1,-1]|,|[-1,1]|)); A111: now per cases by A1,A7,Th73; case p3 in LSeg(|[-1,-1]|,|[-1,1]|); hence p3 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p3`2 or p3 in LSeg(|[-1,1]|,|[1,1]|) or p3 in LSeg(|[1,1]|,|[1,-1]|) or p3 in LSeg(|[1,-1]|,|[-1,-1]|) & p3<>W-min(K) by A110,EUCLID:56; case p3 in LSeg(|[-1,1]|,|[1,1]|); hence p3 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p3`2 or p3 in LSeg(|[-1,1]|,|[1,1]|) or p3 in LSeg(|[1,1]|,|[1,-1]|) or p3 in LSeg(|[1,-1]|,|[-1,-1]|) & p3<>W-min(K); case p3 in LSeg(|[1,1]|,|[1,-1]|); hence p3 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p3`2 or p3 in LSeg(|[-1,1]|,|[1,1]|) or p3 in LSeg(|[1,1]|,|[1,-1]|) or p3 in LSeg(|[1,-1]|,|[-1,-1]|) & p3<>W-min(K); case A112: p3 in LSeg(|[1,-1]|,|[-1,-1]|); A113: W-min(K)=|[-1,-1]| by A1,Th56; now assume A114: p3= W-min(K); then p3`2=-1 by A113,EUCLID:56; hence contradiction by A110,A113,A114,TOPREAL1:6; end; hence p3 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p3`2 or p3 in LSeg(|[-1,1]|,|[1,1]|) or p3 in LSeg(|[1,1]|,|[1,-1]|) or p3 in LSeg(|[1,-1]|,|[-1,-1]|) & p3<>W-min(K) by A112; end; then A115: LE |[-1,0]|,p3,K by A1,A13,Th69; A116: (f.p2)`1<0 & (f.p2)`2<0 by A1,A25,A26,Th77; (f.p1)`2<=(f.p2)`2 by A1,A14,A25,A28,Th81; then A117: LE f.p1,f.p2,P by A4,A16,A19,A24,A27,A116,JGRAPH_5:54; A118: LE f.p3,f.p4,P by A1,A5,A12,A13,A115,Th76; A119: now per cases; case A120: p4`1=-1 & p4`2<0 & p1`2<=p4`2; A121: (|[-1,-1]|)`1=-1 by EUCLID:56; A122: (|[-1,-1]|)`2=-1 by EUCLID:56; A123: (|[-1,1]|)`1=-1 by EUCLID:56; A124: (|[-1,1]|)`2=1 by EUCLID:56; -1<=p4`2 & p4`2<=1 by A1,A7,Th28; then A125: p4 in LSeg(|[-1,-1]|,|[-1,1]|) by A120,A121,A122,A123,A124, GOBOARD7:8; now per cases by A111; case A126: p3 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p3`2; then 0<=p3`2 by EUCLID:56; hence contradiction by A1,A5,A120,A125,A126,Th65; case A127: p3 in LSeg(|[-1,1]|,|[1,1]|); then LE p4,p3,K by A1,A125,Th69; then A128: p3=p4 by A2,A5,JORDAN6:72; p3`2=1 by A127,Th11; hence contradiction by A120,A128; case A129: p3 in LSeg(|[1,1]|,|[1,-1]|); then LE p4,p3,K by A1,A125,Th69; then p3=p4 by A2,A5,JORDAN6:72; hence contradiction by A120,A129,Th9; case A130: p3 in LSeg(|[1,-1]|,|[-1,-1]|) & p3<>W-min(K); then LE p4,p3,K by A1,A125,Th69; then A131: p3=p4 by A2,A5,JORDAN6:72; A132: p3`2= -1 by A130,Th11; W-min(K)= |[-1,-1]| by A1,Th56; then (W-min(K))`1=-1 & (W-min(K))`2=-1 by EUCLID:56; hence contradiction by A120,A130,A131,A132,TOPREAL3:11; end; hence contradiction; case A133: not (p4`1=-1 & p4`2<0 & p1`2<=p4`2); A134: p4 in LSeg(|[-1,-1]|,|[-1,1]|) or p4 in LSeg(|[-1,1]|,|[1,1]|) or p4 in LSeg(|[1,1]|,|[1,-1]|) or p4 in LSeg(|[1,-1]|,|[-1,-1]|) by A1,A7,Th73; now per cases by A133; case A135: p4`1<>-1; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A136: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A137: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; A138: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A139: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A140: f.p1 in P by A6,A136,A137,FUNCT_1:def 12; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then A141: f.p1 in Lower_Arc(P) by A138,A140; A142: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A143: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A137,A142,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; now per cases by A134,A135,Th9; case p4 in LSeg(|[-1,1]|,|[1,1]|); then A144: p4`2=1 by Th11; A145: f.p4 in P by A7,A136,A137,FUNCT_1:def 12; (f.p4)`2>=0 by A1,A144,Th79; then f.p4 in Upper_Arc(P) by A139,A145; hence LE f.p4,f.p1,P by A141,A143,JORDAN6:def 10; case p4 in LSeg(|[1,1]|,|[1,-1]|); then A146: p4`1=1 by Th9; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A147: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A148: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A149: f.p4 in P by A7,A147,FUNCT_1:def 12; A150: f.p1 in P by A6,A147,A148,FUNCT_1:def 12; A151: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A152: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A153: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A148,A152,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A154: (f.p4)`1>=0 by A1,A146,Th78; now per cases; case A155: (f.p4)`2>=0; A156: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A157: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A158: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A159: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A148,A158,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A160: f.p4 in Upper_Arc(P) by A149,A155,A157; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then f.p1 in Lower_Arc(P) by A150,A156; hence LE f.p4,f.p1,P by A159,A160,JORDAN6:def 10; case A161: (f.p4)`2<0; (f.p1)`1<=0 & (f.p4)`1>=(f.p1)`1 by A151,A154,AXIOMS:22; hence LE f.p4,f.p1,P by A4,A149,A150,A151,A153,A161,JGRAPH_5:59; end; hence LE f.p4,f.p1,P; case A162: p4 in LSeg(|[1,-1]|,|[-1,-1]|); then p4`2=-1 & -1 <=p4`1 & p4`1<=1 by Th11; then A163: (f.p4)`2<0 by A1,Th79; A164: f.p4 in P by A7,A136,A137,FUNCT_1:def 12; A165: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; (f.p4)`1>=(f.p1)`1 by A1,A14,A162,Th80; hence LE f.p4,f.p1,P by A4,A140,A143,A163,A164,A165,JGRAPH_5:59; end; hence LE f.p4,f.p1,P; case A166: p4`1=-1 & p4`2>=0; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A167: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A168: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A169: f.p4 in P by A7,A167,FUNCT_1:def 12; A170: f.p1 in P by A6,A167,A168,FUNCT_1:def 12; A171: (f.p4)`2>=0 by A1,A166,Th79; A172: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A173: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A174: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A175: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A168,A174,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A176: f.p4 in Upper_Arc(P) by A169,A171,A173; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then f.p1 in Lower_Arc(P) by A170,A172; hence LE f.p4,f.p1,P by A175,A176,JORDAN6:def 10; case A177: p4`1=-1 & p4`2<0 & p1`2>p4`2; then A178: p4 in LSeg(|[-1,-1]|,|[-1,1]|) by A8,Th10; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A179: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A180: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A181: f.p4 in P by A7,A179,FUNCT_1:def 12; A182: f.p1 in P by A6,A179,A180,FUNCT_1:def 12; A183: (f.p1)`1<0 & (f.p1)`2<0 by A1,A15,A23,Th77; A184: (f.p4)`2<=(f.p1)`2 by A1,A14,A23,A177,A178,Th81; A185: (f.p4)`1<0 by A1,A177,Th78; (f.p4)`2<0 by A1,A177,Th79; hence LE f.p4,f.p1,P by A4,A181,A182,A183,A184,A185,JGRAPH_5:54; end; hence LE f.p4,f.p1,P; end; A186: K={p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; thus K={p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} proof thus K c= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} proof let x be set;assume x in K; then consider p such that A187: p=x & (p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1) by A186; thus x in {q: q`1=-1 & -1 <=q`2 & q`2<=1 or q`1=1 & -1 <=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1} by A187; end; thus {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} c= K proof let x be set;assume x in {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1}; then consider p such that A188: p=x & (p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1); thus x in K by A186,A188; end; end; thus f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A117,A118,A119,JORDAN17:def 1; end; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P; case A189: not(p2`2<0 & p2 in LSeg(|[-1,-1]|,|[-1,1]|)); A190: now per cases by A1,A6,Th73; case p2 in LSeg(|[-1,-1]|,|[-1,1]|); hence p2 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p2`2 or p2 in LSeg(|[-1,1]|,|[1,1]|) or p2 in LSeg(|[1,1]|,|[1,-1]|) or p2 in LSeg(|[1,-1]|,|[-1,-1]|) & p2<>W-min(K) by A189,EUCLID:56; case p2 in LSeg(|[-1,1]|,|[1,1]|); hence p2 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p2`2 or p2 in LSeg(|[-1,1]|,|[1,1]|) or p2 in LSeg(|[1,1]|,|[1,-1]|) or p2 in LSeg(|[1,-1]|,|[-1,-1]|) & p2<>W-min(K); case p2 in LSeg(|[1,1]|,|[1,-1]|); hence p2 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p2`2 or p2 in LSeg(|[-1,1]|,|[1,1]|) or p2 in LSeg(|[1,1]|,|[1,-1]|) or p2 in LSeg(|[1,-1]|,|[-1,-1]|) & p2<>W-min(K); case A191: p2 in LSeg(|[1,-1]|,|[-1,-1]|); A192: W-min(K)=|[-1,-1]| by A1,Th56; now assume A193: p2= W-min(K); then p2`2=-1 by A192,EUCLID:56; hence contradiction by A189,A192,A193,TOPREAL1:6; end; hence p2 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p2`2 or p2 in LSeg(|[-1,1]|,|[1,1]|) or p2 in LSeg(|[1,1]|,|[1,-1]|) or p2 in LSeg(|[1,-1]|,|[-1,-1]|) & p2<>W-min(K) by A191; end; then A194: LE |[-1,0]|,p2,K by A1,A13,Th69; then A195: LE f.p2,f.p3,P by A1,A5,A12,A13,Th76; LE |[-1,0]|,p3,K by A2,A5,A194,JORDAN6:73; then A196: LE f.p3,f.p4,P by A1,A5,A12,A13,Th76; A197: now per cases; case A198: p4`1=-1 & p4`2<0 & p1`2<=p4`2; A199: (|[-1,-1]|)`1=-1 by EUCLID:56; A200: (|[-1,-1]|)`2=-1 by EUCLID:56; A201: (|[-1,1]|)`1=-1 by EUCLID:56; A202: (|[-1,1]|)`2=1 by EUCLID:56; -1<=p4`2 & p4`2<=1 by A1,A7,Th28; then A203: p4 in LSeg(|[-1,-1]|,|[-1,1]|) by A198,A199,A200,A201,A202, GOBOARD7:8; now per cases by A190; case A204: p2 in LSeg(|[-1,-1]|,|[-1,1]|) & (|[-1,0]|)`2<=p2`2; then 0<=p2`2 by EUCLID:56; hence contradiction by A1,A10,A198,A203,A204,Th65; case A205: p2 in LSeg(|[-1,1]|,|[1,1]|); then LE p4,p2,K by A1,A203,Th69; then A206: p2=p4 by A2,A10,JORDAN6:72; p2`2=1 by A205,Th11; hence contradiction by A198,A206; case A207: p2 in LSeg(|[1,1]|,|[1,-1]|); then LE p4,p2,K by A1,A203,Th69; then p2=p4 by A2,A10,JORDAN6:72; hence contradiction by A198,A207,Th9; case A208: p2 in LSeg(|[1,-1]|,|[-1,-1]|) & p2<>W-min(K); then LE p4,p2,K by A1,A203,Th69; then A209: p2=p4 by A2,A10,JORDAN6:72; A210: p2`2= -1 by A208,Th11; W-min(K)= |[-1,-1]| by A1,Th56; then (W-min(K))`1=-1 & (W-min(K))`2=-1 by EUCLID:56; hence contradiction by A198,A208,A209,A210,TOPREAL3:11; end; hence contradiction; case A211: not (p4`1=-1 & p4`2<0 & p1`2<=p4`2); A212: p4 in LSeg(|[-1,-1]|,|[-1,1]|) or p4 in LSeg(|[-1,1]|,|[1,1]|) or p4 in LSeg(|[1,1]|,|[1,-1]|) or p4 in LSeg(|[1,-1]|,|[-1,-1]|) by A1,A7,Th73; now per cases by A211; case A213: p4`1<>-1; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A214: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A215: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; A216: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A217: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A218: f.p1 in P by A6,A214,A215,FUNCT_1:def 12; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then A219: f.p1 in Lower_Arc(P) by A216,A218; A220: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A221: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A215,A220,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; now per cases by A212,A213,Th9; case p4 in LSeg(|[-1,1]|,|[1,1]|); then A222: p4`2=1 by Th11; A223: f.p4 in P by A7,A214,A215,FUNCT_1:def 12; (f.p4)`2>=0 by A1,A222,Th79; then f.p4 in Upper_Arc(P) by A217,A223; hence LE f.p4,f.p1,P by A219,A221,JORDAN6:def 10; case p4 in LSeg(|[1,1]|,|[1,-1]|); then A224: p4`1=1 by Th9; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A225: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A226: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A227: f.p4 in P by A7,A225,FUNCT_1:def 12; A228: f.p1 in P by A6,A225,A226,FUNCT_1:def 12; A229: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A230: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A231: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A226,A230,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A232: (f.p4)`1>=0 by A1,A224,Th78; now per cases; case A233: (f.p4)`2>=0; A234: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A235: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A236: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A237: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A226,A236,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A238: f.p4 in Upper_Arc(P) by A227,A233,A235; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then f.p1 in Lower_Arc(P) by A228,A234; hence LE f.p4,f.p1,P by A237,A238,JORDAN6:def 10; case A239: (f.p4)`2<0; (f.p1)`1<=0 & (f.p4)`1>=(f.p1)`1 by A229,A232,AXIOMS:22; hence LE f.p4,f.p1,P by A4,A227,A228,A229,A231,A239,JGRAPH_5:59; end; hence LE f.p4,f.p1,P; case A240: p4 in LSeg(|[1,-1]|,|[-1,-1]|); then p4`2=-1 & -1 <=p4`1 & p4`1<=1 by Th11; then A241: (f.p4)`2<0 by A1,Th79; A242: f.p4 in P by A7,A214,A215,FUNCT_1:def 12; A243: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; (f.p4)`1>=(f.p1)`1 by A1,A14,A240,Th80; hence LE f.p4,f.p1,P by A4,A218,A221,A241,A242,A243,JGRAPH_5:59; end; hence LE f.p4,f.p1,P; case A244: p4`1=-1 & p4`2>=0; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A245: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A246: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A247: f.p4 in P by A7,A245,FUNCT_1:def 12; A248: f.p1 in P by A6,A245,A246,FUNCT_1:def 12; A249: (f.p4)`2>=0 by A1,A244,Th79; A250: (f.p1)`1<0 & (f.p1)`2<=0 by A1,A15,A23,Th77; A251: Upper_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2>=0} by A4,JGRAPH_5:37; A252: f.(|[-1,0]|)=W-min(P) by A1,A4,Th18,JGRAPH_5:32; A253: now assume f.p1=W-min(P); then p1=|[-1,0]| by A1,A246,A252,FUNCT_1:def 8; hence contradiction by A23,EUCLID:56; end; A254: f.p4 in Upper_Arc(P) by A247,A249,A251; Lower_Arc(P) ={p where p is Point of TOP-REAL 2:p in P & p`2<=0} by A4,JGRAPH_5:38; then f.p1 in Lower_Arc(P) by A248,A250; hence LE f.p4,f.p1,P by A253,A254,JORDAN6:def 10; case A255: p4`1=-1 & p4`2<0 & p1`2>p4`2; then A256: p4 in LSeg(|[-1,-1]|,|[-1,1]|) by A8,Th10; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A257: f.:K=P by A1,A4,Th45,JGRAPH_3:33; A258: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; then A259: f.p4 in P by A7,A257,FUNCT_1:def 12; A260: f.p1 in P by A6,A257,A258,FUNCT_1:def 12; A261: (f.p1)`1<0 & (f.p1)`2<0 by A1,A15,A23,Th77; A262: (f.p4)`2<=(f.p1)`2 by A1,A14,A23,A255,A256,Th81; A263: (f.p4)`1<0 by A1,A255,Th78; (f.p4)`2<0 by A1,A255,Th79; hence LE f.p4,f.p1,P by A4,A259,A260,A261,A262,A263,JGRAPH_5:54; end; hence LE f.p4,f.p1,P; end; A264: K={p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; thus K={p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} proof thus K c= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} proof let x be set;assume x in K; then consider p such that A265: p=x & (p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1) by A264; thus x in {q: q`1=-1 & -1 <=q`2 & q`2<=1 or q`1=1 & -1 <=q`2 & q`2<=1 or -1=q`2 & -1<=q`1 & q`1<=1 or 1=q`2 & -1<=q`1 & q`1<=1} by A265; end; thus {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1} c= K proof let x be set;assume x in {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1}; then consider p such that A266: p=x & (p`1=-1 & -1 <=p`2 & p`2<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or -1=p`2 & -1<=p`1 & p`1<=1 or 1=p`2 & -1<=p`1 & p`1<=1); thus x in K by A264,A266; end; end; thus f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A195,A196,A197,JORDAN17:def 1; end; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P; end; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P; case A267: p1 in LSeg(|[-1,1]|,|[1,1]|); A268: |[-1,1]| in LSeg(|[-1,1]|,|[1,1]|) by TOPREAL1:6; A269: |[-1,1]| in LSeg(|[-1,-1]|,|[-1,1]|) by TOPREAL1:6; A270: (|[-1,1]|)`1=-1 & (|[-1,1]|)`2=1 by EUCLID:56; p1`2=1 & -1 <=p1`1 & p1`1<=1 by A267,Th11; then A271: LE |[-1,1]|,p1,K by A1,A267,A268,A270,Th70; then A272: LE f.p1,f.p2,P by A1,A5,A269,A270,Th76; A273: LE |[-1,1]|,p2,K by A2,A5,A271,JORDAN6:73; then A274: LE f.p2,f.p3,P by A1,A5,A269,A270,Th76; LE |[-1,1]|,p3,K by A2,A5,A273,JORDAN6:73; then LE f.p3,f.p4,P by A1,A5,A269,A270,Th76; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A272,A274,JORDAN17:def 1; case A275: p1 in LSeg(|[1,1]|,|[1,-1]|); A276: |[-1,1]| in LSeg(|[-1,1]|,|[1,1]|) by TOPREAL1:6; A277: |[-1,1]| in LSeg(|[-1,-1]|,|[-1,1]|) by TOPREAL1:6; A278: (|[-1,1]|)`1=-1 & (|[-1,1]|)`2=1 by EUCLID:56; A279: |[1,1]| in LSeg(|[1,1]|,|[1,-1]|) by TOPREAL1:6; A280: |[1,1]| in LSeg(|[-1,1]|,|[1,1]|) by TOPREAL1:6; A281: (|[1,1]|)`1=1 & (|[1,1]|)`2=1 by EUCLID:56; then A282: LE |[-1,1]|,|[1,1]|,K by A1,A276,A278,A280,Th70; p1`1=1 & -1 <=p1`2 & p1`2<=1 by A275,Th9; then LE |[1,1]|,p1,K by A1,A275,A279,A281,Th71; then A283: LE |[-1,1]|,p1,K by A2,A282,JORDAN6:73; then A284: LE f.p1,f.p2,P by A1,A5,A277,A278,Th76; A285: LE |[-1,1]|,p2,K by A2,A5,A283,JORDAN6:73; then A286: LE f.p2,f.p3,P by A1,A5,A277,A278,Th76; LE |[-1,1]|,p3,K by A2,A5,A285,JORDAN6:73; then LE f.p3,f.p4,P by A1,A5,A277,A278,Th76; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A284,A286,JORDAN17:def 1; case A287: p1 in LSeg(|[1,-1]|,|[-1,-1]|) & p1 <> W-min(K); A288: |[-1,1]| in LSeg(|[-1,1]|,|[1,1]|) by TOPREAL1:6; A289: |[-1,1]| in LSeg(|[-1,-1]|,|[-1,1]|) by TOPREAL1:6; A290: (|[-1,1]|)`1=-1 & (|[-1,1]|)`2=1 by EUCLID:56; A291: |[1,1]| in LSeg(|[-1,1]|,|[1,1]|) by TOPREAL1:6; (|[1,1]|)`1=1 & (|[1,1]|)`2=1 by EUCLID:56; then A292: LE |[-1,1]|,|[1,1]|,K by A1,A288,A290,A291,Th70; A293: |[1,-1]| in LSeg(|[1,1]|,|[1,-1]|) by TOPREAL1:6; A294: |[1,-1]| in LSeg(|[1,-1]|,|[-1,-1]|) by TOPREAL1:6; A295: (|[1,-1]|)`1=1 & (|[1,-1]|)`2= -1 by EUCLID:56; LE |[1,1]|,|[1,-1]|,K by A1,A291,A293,Th70; then A296: LE |[-1,1]|,|[1,-1]|,K by A2,A292,JORDAN6:73; W-min(K)=|[-1,-1]| by A1,Th56; then (W-min(K))`1=-1 & (W-min(K))`2=-1 by EUCLID:56; then A297: |[1,-1]| <> W-min(K) by EUCLID:56; p1`2=-1 & -1 <=p1`1 & p1`1<=1 by A287,Th11; then LE |[1,-1]|,p1,K by A1,A287,A294,A295,A297,Th72; then A298: LE |[-1,1]|,p1,K by A2,A296,JORDAN6:73; then A299: LE f.p1,f.p2,P by A1,A5,A289,A290,Th76; A300: LE |[-1,1]|,p2,K by A2,A5,A298,JORDAN6:73; then A301: LE f.p2,f.p3,P by A1,A5,A289,A290,Th76; LE |[-1,1]|,p3,K by A2,A5,A300,JORDAN6:73; then LE f.p3,f.p4,P by A1,A5,A289,A290,Th76; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A299,A301,JORDAN17:def 1; end; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P; end; end; theorem Th83: for p1,p2 being Point of TOP-REAL 2, P being non empty compact Subset of TOP-REAL 2 st P is_simple_closed_curve & p1 in P & p2 in P & not LE p1,p2,P holds LE p2,p1,P proof let p1,p2 be Point of TOP-REAL 2, P be non empty compact Subset of TOP-REAL 2; assume A1: P is_simple_closed_curve & p1 in P & p2 in P & not LE p1,p2,P; then A2: P=Upper_Arc(P) \/ Lower_Arc(P) by JORDAN6:def 9; A3: not p1=W-min(P) by A1,JORDAN7:3; per cases by A1,A2,XBOOLE_0:def 2; suppose A4: p1 in Upper_Arc(P) & p2 in Upper_Arc(P); A5: Upper_Arc(P) is_an_arc_of W-min(P),E-max(P) by A1,JORDAN6:def 8; set q1=W-min(P),q2=E-max(P); set Q= Upper_Arc(P); now per cases; case A6: p1<>p2; now per cases by A4,A5,A6,JORDAN5C:14; case LE p1,p2,Q,q1,q2 & not LE p2,p1,Q,q1,q2; hence contradiction by A1,A4,JORDAN6:def 10; case LE p2,p1,Q,q1,q2 & not LE p1,p2,Q,q1,q2; hence LE p2,p1,P by A4,JORDAN6:def 10; end; hence LE p2,p1,P; case p1=p2; hence LE p2,p1,P by A1,JORDAN6:71; end; hence LE p2,p1,P; suppose A7: p1 in Upper_Arc(P) & p2 in Lower_Arc(P); now per cases; case p2=W-min(P); hence LE p2,p1,P by A1,JORDAN7:3; case p2<>W-min(P); hence contradiction by A1,A7,JORDAN6:def 10; end; hence LE p2,p1,P; suppose p1 in Lower_Arc(P) & p2 in Upper_Arc(P); hence LE p2,p1,P by A3,JORDAN6:def 10; suppose A8: p1 in Lower_Arc(P) & p2 in Lower_Arc(P); A9: Lower_Arc(P) is_an_arc_of E-max(P),W-min(P) by A1,JORDAN6:65; set q2=W-min(P),q1=E-max(P); set Q= Lower_Arc(P); now per cases; case A10: p1<>p2; now per cases by A8,A9,A10,JORDAN5C:14; case A11: LE p1,p2,Q,q1,q2 & not LE p2,p1,Q,q1,q2; now per cases; case p2=W-min(P); hence LE p2,p1,P by A1,JORDAN7:3; case p2<>W-min(P); hence contradiction by A1,A8,A11,JORDAN6:def 10; end; hence LE p2,p1,P; case LE p2,p1,Q,q1,q2 & not LE p1,p2,Q,q1,q2; hence LE p2,p1,P by A3,A8,JORDAN6:def 10; end; hence LE p2,p1,P; case p1=p2; hence LE p2,p1,P by A1,JORDAN6:71; end; hence LE p2,p1,P; end; theorem for p1,p2,p3 being Point of TOP-REAL 2, P being non empty compact Subset of TOP-REAL 2 st P is_simple_closed_curve & p1 in P & p2 in P & p3 in P holds LE p1,p2,P & LE p2,p3,P or LE p1,p3,P & LE p3,p2,P or LE p2,p1,P & LE p1,p3,P or LE p2,p3,P & LE p3,p1,P or LE p3,p1,P & LE p1,p2,P or LE p3,p2,P & LE p2,p1,P by Th83; theorem for p1,p2,p3 being Point of TOP-REAL 2, P being non empty compact Subset of TOP-REAL 2 st P is_simple_closed_curve & p1 in P & p2 in P & p3 in P & LE p2,p3,P holds LE p1,p2,P or LE p2,p1,P & LE p1,p3,P or LE p3,p1,P by Th83; theorem for p1,p2,p3,p4 being Point of TOP-REAL 2, P being non empty compact Subset of TOP-REAL 2 st P is_simple_closed_curve & p1 in P & p2 in P & p3 in P & p4 in P & LE p2,p3,P & LE p3,p4,P holds LE p1,p2,P or LE p2,p1,P & LE p1,p3,P or LE p3,p1,P & LE p1,p4,P or LE p4,p1,P by Th83; theorem Th87: for p1,p2,p3,p4 being Point of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ & LE f.p1,f.p2,P & LE f.p2,f.p3,P & LE f.p3,f.p4,P holds p1,p2,p3,p4 are_in_this_order_on K proof let p1,p2,p3,p4 be Point of TOP-REAL 2, P,K be non empty compact Subset of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ & LE f.p1,f.p2,P & LE f.p2,f.p3,P & LE f.p3,f.p4,P; then A2: K is_simple_closed_curve by Th60; A3: P={p: |.p.|=1} by A1,Th33; then A4: P is_simple_closed_curve by JGRAPH_3:36; then A5: LE f.p1,f.p3,P by A1,JORDAN6:73; A6: LE f.p2,f.p4,P by A1,A4,JORDAN6:73; K= {p: p`1=-1 & -1 <=p`2 & p`2<=1 or p`2=1 & -1<=p`1 & p`1<=1 or p`1=1 & -1 <=p`2 & p`2<=1 or p`2=-1 & -1<=p`1 & p`1<=1} by A1,Def1; then A7: f.:K=P by A1,A3,Th45,JGRAPH_3:33; A8: dom f = the carrier of TOP-REAL 2 by FUNCT_2:def 1; P={p: |.p.|=1} by A1,Th33; then A9: P is_simple_closed_curve by JGRAPH_3:36; then f.p1 in P by A1,JORDAN7:5; then consider x1 being set such that A10: x1 in dom f & x1 in K & f.p1=f.x1 by A7,FUNCT_1:def 12; A11: p1 in K by A1,A8,A10,FUNCT_1:def 8; f.p2 in P by A1,A9,JORDAN7:5; then consider x2 being set such that A12: x2 in dom f & x2 in K & f.p2=f.x2 by A7,FUNCT_1:def 12; A13: p2 in K by A1,A8,A12,FUNCT_1:def 8; f.p3 in P by A1,A9,JORDAN7:5; then consider x3 being set such that A14: x3 in dom f & x3 in K & f.p3=f.x3 by A7,FUNCT_1:def 12; A15: p3 in K by A1,A8,A14,FUNCT_1:def 8; f.p4 in P by A1,A9,JORDAN7:5; then consider x4 being set such that A16: x4 in dom f & x4 in K & f.p4=f.x4 by A7,FUNCT_1:def 12; A17: p4 in K by A1,A8,A16,FUNCT_1:def 8; now assume A18: not p1,p2,p3,p4 are_in_this_order_on K; A19: now assume A20: p1,p2,p4,p3 are_in_this_order_on K; now per cases by A20,JORDAN17:def 1; case A21: LE p1,p2,K & LE p2,p4,K & LE p4,p3,K; then f.p1,f.p2,f.p4,f.p3 are_in_this_order_on P by A1,Th82; then LE f.p1,f.p2,P & LE f.p2,f.p4,P & LE f.p4,f.p3,P or LE f.p2,f.p4,P & LE f.p4,f.p3,P & LE f.p3,f.p1,P or LE f.p4,f.p3,P & LE f.p3,f.p1,P & LE f.p1,f.p2,P or LE f.p3,f.p1,P & LE f.p1,f.p2,P & LE f.p2,f.p4,P by JORDAN17:def 1; then f.p3=f.p4 or f.p3=f.p1 by A1,A5,A9,JORDAN6:72; then A22: p3=p4 or p3=p1 by A1,A8,FUNCT_1:def 8; LE p1,p4,K by A2,A21,JORDAN6:73; then p3=p1 & p1=p4 by A2,A18,A20,A21,A22,JORDAN6:72; hence contradiction by A18,A20; case A23: LE p2,p4,K & LE p4,p3,K & LE p3,p1,K; then f.p2,f.p4,f.p3,f.p1 are_in_this_order_on P by A1,Th82; then LE f.p2,f.p4,P & LE f.p4,f.p3,P & LE f.p3,f.p1,P or LE f.p4,f.p3,P & LE f.p3,f.p1,P & LE f.p1,f.p2,P or LE f.p3,f.p1,P & LE f.p1,f.p2,P & LE f.p2,f.p4,P or LE f.p1,f.p2,P & LE f.p2,f.p4,P & LE f.p4,f.p3,P by JORDAN17:def 1; then f.p3=f.p4 or LE f.p3,f.p2,P by A1,A9,JORDAN6:72,73; then f.p3=f.p4 or f.p3=f.p2 by A1,A9,JORDAN6:72; then p3=p4 or p3=p2 by A1,A8,FUNCT_1:def 8; then p3=p2 & p4=p2 by A2,A18,A20,A23,JORDAN6:72; hence contradiction by A18,A20; case A24: LE p4,p3,K & LE p3,p1,K & LE p1,p2,K; then f.p4,f.p3,f.p1,f.p2 are_in_this_order_on P by A1,Th82; then LE f.p4,f.p3,P & LE f.p3,f.p1,P & LE f.p1,f.p2,P or LE f.p3,f.p1,P & LE f.p1,f.p2,P & LE f.p2,f.p4,P or LE f.p1,f.p2,P & LE f.p2,f.p4,P & LE f.p4,f.p3,P or LE f.p2,f.p4,P & LE f.p4,f.p3,P & LE f.p3,f.p1,P by JORDAN17:def 1; then f.p3=f.p4 or LE f.p3,f.p2,P by A1,A9,JORDAN6:72,73; then f.p3=f.p4 or f.p3=f.p2 by A1,A9,JORDAN6:72; then p3=p4 or p3=p2 by A1,A8,FUNCT_1:def 8; then p3=p2 & p3=p1 by A2,A18,A20,A24,JORDAN6:72; hence contradiction by A2,A18,A20,JORDAN17:12; case A25: LE p3,p1,K & LE p1,p2,K & LE p2,p4,K; then f.p3,f.p1,f.p2,f.p4 are_in_this_order_on P by A1,Th82; then LE f.p4,f.p3,P & LE f.p3,f.p1,P & LE f.p1,f.p2,P or LE f.p3,f.p1,P & LE f.p1,f.p2,P & LE f.p2,f.p4,P or LE f.p1,f.p2,P & LE f.p2,f.p4,P & LE f.p4,f.p3,P or LE f.p2,f.p4,P & LE f.p4,f.p3,P & LE f.p3,f.p1,P by JORDAN17:def 1; then f.p3=f.p4 or LE f.p3,f.p2,P by A1,A9,JORDAN6:72,73; then f.p3=f.p4 or f.p3=f.p2 by A1,A9,JORDAN6:72; then p3=p4 or p3=p2 by A1,A8,FUNCT_1:def 8; then p3=p2 & p3=p1 by A2,A18,A20,A25,JORDAN6:72; hence contradiction by A2,A18,A20,JORDAN17:12; end; hence contradiction; end; A26: now assume A27: p1,p3,p4,p2 are_in_this_order_on K; now per cases by A27,JORDAN17:def 1; case LE p1,p3,K & LE p3,p4,K & LE p4,p2,K; then f.p1,f.p3,f.p4,f.p2 are_in_this_order_on P by A1,Th82; then LE f.p1,f.p3,P & LE f.p3,f.p4,P & LE f.p4,f.p2,P or LE f.p3,f.p4,P & LE f.p4,f.p2,P & LE f.p2,f.p1,P or LE f.p4,f.p2,P & LE f.p2,f.p1,P & LE f.p1,f.p3,P or LE f.p2,f.p1,P & LE f.p1,f.p3,P & LE f.p3,f.p4,P by JORDAN17:def 1; then f.p4=f.p2 or f.p2=f.p1 by A1,A6,A9,JORDAN6:72; then A28: p4=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then f.p3=f.p2 or f.p4=f.p1 by A1,A2,A9,A18,A27,JORDAN17:12,JORDAN6:72 ; then p3=p2 or p4=p1 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A18,A27,A28,JORDAN17:12; case LE p3,p4,K & LE p4,p2,K & LE p2,p1,K; then f.p3,f.p4,f.p2,f.p1 are_in_this_order_on P by A1,Th82; then A29: LE f.p1,f.p3,P & LE f.p3,f.p4,P & LE f.p4,f.p2,P or LE f.p3,f.p4,P & LE f.p4,f.p2,P & LE f.p2,f.p1,P or LE f.p4,f.p2,P & LE f.p2,f.p1,P & LE f.p1,f.p3,P or LE f.p2,f.p1,P & LE f.p1,f.p3,P & LE f.p3,f.p4,P by JORDAN17:def 1; then f.p4=f.p2 or f.p2=f.p1 by A1,A6,A9,JORDAN6:72; then A30: p4=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; f.p2=f.p1 or LE f.p3,f.p2,P by A1,A9,A29,JORDAN6:72,73; then f.p2=f.p1 or f.p3=f.p2 by A1,A9,JORDAN6:72; then p2=p1 or p3=p2 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A18,A27,A30,JORDAN17:12; case LE p4,p2,K & LE p2,p1,K & LE p1,p3,K; then f.p4,f.p2,f.p1,f.p3 are_in_this_order_on P by A1,Th82; then A31: LE f.p1,f.p3,P & LE f.p3,f.p4,P & LE f.p4,f.p2,P or LE f.p3,f.p4,P & LE f.p4,f.p2,P & LE f.p2,f.p1,P or LE f.p4,f.p2,P & LE f.p2,f.p1,P & LE f.p1,f.p3,P or LE f.p2,f.p1,P & LE f.p1,f.p3,P & LE f.p3,f.p4,P by JORDAN17:def 1; then f.p4=f.p2 or f.p2=f.p1 by A1,A6,A9,JORDAN6:72; then A32: p4=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; f.p2=f.p1 or LE f.p3,f.p2,P by A1,A9,A31,JORDAN6:72,73; then f.p2=f.p1 or f.p3=f.p2 by A1,A9,JORDAN6:72; then p2=p1 or p3=p2 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A18,A27,A32,JORDAN17:12; case A33: LE p2,p1,K & LE p1,p3,K & LE p3,p4,K; then f.p2,f.p1,f.p3,f.p4 are_in_this_order_on P by A1,Th82; then LE f.p1,f.p3,P & LE f.p3,f.p4,P & LE f.p4,f.p2,P or LE f.p3,f.p4,P & LE f.p4,f.p2,P & LE f.p2,f.p1,P or LE f.p4,f.p2,P & LE f.p2,f.p1,P & LE f.p1,f.p3,P or LE f.p2,f.p1,P & LE f.p1,f.p3,P & LE f.p3,f.p4,P by JORDAN17:def 1; then f.p4=f.p2 or f.p2=f.p1 by A1,A6,A9,JORDAN6:72; then A34: p4=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then LE p2,p3,K & LE p3,p2,K by A2,A18,A27,A33,JORDAN17:12,JORDAN6:73 ; then p2=p3 by A2,JORDAN6:72; hence contradiction by A2,A18,A27,A34,JORDAN17:12; end; hence contradiction; end; now per cases by A2,A11,A13,A15,A17,A18,JORDAN17:27; case p1,p2,p4,p3 are_in_this_order_on K; hence contradiction by A19; case A35: p1,p3,p2,p4 are_in_this_order_on K; now per cases by A35,JORDAN17:def 1; case A36: LE p1,p3,K & LE p3,p2,K & LE p2,p4,K; then f.p1,f.p3,f.p2,f.p4 are_in_this_order_on P by A1,Th82; then LE f.p1,f.p3,P & LE f.p3,f.p2,P & LE f.p2,f.p4,P or LE f.p3,f.p2,P & LE f.p2,f.p4,P & LE f.p4,f.p1,P or LE f.p2,f.p4,P & LE f.p4,f.p1,P & LE f.p1,f.p3,P or LE f.p4,f.p1,P & LE f.p1,f.p3,P & LE f.p3,f.p2,P by JORDAN17:def 1; then f.p3=f.p2 or LE f.p2,f.p1,P by A1,A9,JORDAN6:72,73; then f.p3=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then p3=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then p2=p1 & p3=p1 by A2,A18,A35,A36,JORDAN6:72; hence contradiction by A18,A35; case A37: LE p3,p2,K & LE p2,p4,K & LE p4,p1,K; then f.p3,f.p2,f.p4,f.p1 are_in_this_order_on P by A1,Th82; then LE f.p1,f.p3,P & LE f.p3,f.p2,P & LE f.p2,f.p4,P or LE f.p3,f.p2,P & LE f.p2,f.p4,P & LE f.p4,f.p1,P or LE f.p2,f.p4,P & LE f.p4,f.p1,P & LE f.p1,f.p3,P or LE f.p4,f.p1,P & LE f.p1,f.p3,P & LE f.p3,f.p2,P by JORDAN17:def 1; then f.p3=f.p2 or LE f.p2,f.p1,P by A1,A9,JORDAN6:72,73; then f.p3=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then p3=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then p2=p1 & p4=p1 by A2,A18,A35,A37,JORDAN6:72; hence contradiction by A2,A18,A35,JORDAN17:12; case A38: LE p2,p4,K & LE p4,p1,K & LE p1,p3,K; then f.p2,f.p4,f.p1,f.p3 are_in_this_order_on P by A1,Th82; then LE f.p1,f.p3,P & LE f.p3,f.p2,P & LE f.p2,f.p4,P or LE f.p3,f.p2,P & LE f.p2,f.p4,P & LE f.p4,f.p1,P or LE f.p2,f.p4,P & LE f.p4,f.p1,P & LE f.p1,f.p3,P or LE f.p4,f.p1,P & LE f.p1,f.p3,P & LE f.p3,f.p2,P by JORDAN17:def 1; then f.p3=f.p2 or LE f.p2,f.p1,P by A1,A9,JORDAN6:72,73; then f.p3=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then p3=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then p2=p1 & p4=p1 by A2,A18,A35,A38,JORDAN6:72; hence contradiction by A2,A18,A35,JORDAN17:12; case A39: LE p4,p1,K & LE p1,p3,K & LE p3,p2,K; then f.p4,f.p1,f.p3,f.p2 are_in_this_order_on P by A1,Th82; then LE f.p1,f.p3,P & LE f.p3,f.p2,P & LE f.p2,f.p4,P or LE f.p3,f.p2,P & LE f.p2,f.p4,P & LE f.p4,f.p1,P or LE f.p2,f.p4,P & LE f.p4,f.p1,P & LE f.p1,f.p3,P or LE f.p4,f.p1,P & LE f.p1,f.p3,P & LE f.p3,f.p2,P by JORDAN17:def 1; then f.p3=f.p2 or LE f.p2,f.p1,P by A1,A9,JORDAN6:72,73; then f.p3=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then p3=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then p2=p1 & p3=p1 by A2,A18,A35,A39,JORDAN6:72; hence contradiction by A18,A35; end; hence contradiction; case p1,p3,p4,p2 are_in_this_order_on K; hence contradiction by A26; case A40: p1,p4,p2,p3 are_in_this_order_on K; now per cases by A40,JORDAN17:def 1; case A41: LE p1,p4,K & LE p4,p2,K & LE p2,p3,K; then f.p1,f.p4,f.p2,f.p3 are_in_this_order_on P by A1,Th82; then A42: LE f.p1,f.p4,P & LE f.p4,f.p2,P & LE f.p2,f.p3,P or LE f.p4,f.p2,P & LE f.p2,f.p3,P & LE f.p3,f.p1,P or LE f.p2,f.p3,P & LE f.p3,f.p1,P & LE f.p1,f.p4,P or LE f.p3,f.p1,P & LE f.p1,f.p4,P & LE f.p4,f.p2,P by JORDAN17:def 1; then f.p4=f.p2 or LE f.p2,f.p1,P by A6,A9,JORDAN6:72,73; then f.p4=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then A43: p4=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then A44: p4=p2 by A2,A41,JORDAN6:72; f.p3=f.p1 or LE f.p4,f.p3,P by A5,A9,A42,JORDAN6:72,73; then f.p3=f.p1 or f.p4=f.p3 by A1,A9,JORDAN6:72; then A45: p3=p1 or p4=p3 by A1,A8,FUNCT_1:def 8; then p1=p2 by A2,A18,A40,A41,A43,JORDAN6:72; hence contradiction by A18,A40,A44,A45; case A46: LE p4,p2,K & LE p2,p3,K & LE p3,p1,K; then f.p4,f.p2,f.p3,f.p1 are_in_this_order_on P by A1,Th82; then A47: LE f.p1,f.p4,P & LE f.p4,f.p2,P & LE f.p2,f.p3,P or LE f.p4,f.p2,P & LE f.p2,f.p3,P & LE f.p3,f.p1,P or LE f.p2,f.p3,P & LE f.p3,f.p1,P & LE f.p1,f.p4,P or LE f.p3,f.p1,P & LE f.p1,f.p4,P & LE f.p4,f.p2,P by JORDAN17:def 1; then f.p4=f.p2 or LE f.p2,f.p1,P by A6,A9,JORDAN6:72,73; then f.p4=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then p4=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then A48: p4=p2 or p2=p1 & p3=p1 by A2,A46,JORDAN6:72; f.p3=f.p1 or LE f.p4,f.p3,P by A5,A9,A47,JORDAN6:72,73; then f.p3=f.p1 or f.p4=f.p3 by A1,A9,JORDAN6:72; then p3=p1 or p4=p3 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A26,A40,A48,JORDAN17:12; case A49: LE p2,p3,K & LE p3,p1,K & LE p1,p4,K; then f.p2,f.p3,f.p1,f.p4 are_in_this_order_on P by A1,Th82; then A50: LE f.p1,f.p4,P & LE f.p4,f.p2,P & LE f.p2,f.p3,P or LE f.p4,f.p2,P & LE f.p2,f.p3,P & LE f.p3,f.p1,P or LE f.p2,f.p3,P & LE f.p3,f.p1,P & LE f.p1,f.p4,P or LE f.p3,f.p1,P & LE f.p1,f.p4,P & LE f.p4,f.p2,P by JORDAN17:def 1; then f.p4=f.p2 or LE f.p2,f.p1,P by A6,A9,JORDAN6:72,73; then f.p4=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then p4=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then A51: p4=p2 or p2=p1 & p3=p1 by A2,A49,JORDAN6:72; f.p3=f.p1 or LE f.p4,f.p3,P by A5,A9,A50,JORDAN6:72,73; then f.p3=f.p1 or f.p4=f.p3 by A1,A9,JORDAN6:72; then p3=p1 or p4=p3 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A26,A40,A51,JORDAN17:12; case A52: LE p3,p1,K & LE p1,p4,K & LE p4,p2,K; then f.p3,f.p1,f.p4,f.p2 are_in_this_order_on P by A1,Th82; then A53: LE f.p1,f.p4,P & LE f.p4,f.p2,P & LE f.p2,f.p3,P or LE f.p4,f.p2,P & LE f.p2,f.p3,P & LE f.p3,f.p1,P or LE f.p2,f.p3,P & LE f.p3,f.p1,P & LE f.p1,f.p4,P or LE f.p3,f.p1,P & LE f.p1,f.p4,P & LE f.p4,f.p2,P by JORDAN17:def 1; then f.p4=f.p2 or LE f.p2,f.p1,P by A6,A9,JORDAN6:72,73; then f.p4=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then p4=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; then A54: p4=p2 by A2,A52,JORDAN6:72; f.p3=f.p1 or LE f.p4,f.p3,P by A5,A9,A53,JORDAN6:72,73; then f.p3=f.p1 or f.p4=f.p3 by A1,A9,JORDAN6:72; then p3=p1 or p4=p3 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A26,A40,A54,JORDAN17:12; end; hence contradiction; case A55: p1,p4,p3,p2 are_in_this_order_on K; now per cases by A55,JORDAN17:def 1; case A56: LE p1,p4,K & LE p4,p3,K & LE p3,p2,K; then f.p1,f.p4,f.p3,f.p2 are_in_this_order_on P by A1,Th82; then A57: LE f.p1,f.p4,P & LE f.p4,f.p3,P & LE f.p3,f.p2,P or LE f.p4,f.p3,P & LE f.p3,f.p2,P & LE f.p2,f.p1,P or LE f.p3,f.p2,P & LE f.p2,f.p1,P & LE f.p1,f.p4,P or LE f.p2,f.p1,P & LE f.p1,f.p4,P & LE f.p4,f.p3,P by JORDAN17:def 1; then f.p3=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then A58: p3=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; LE p1,p3,K by A2,A56,JORDAN6:73; then A59: p3=p2 by A2,A56,A58,JORDAN6:72; f.p4=f.p3 or f.p2=f.p1 by A1,A9,A57,JORDAN6:72; then p4=p3 or p2=p1 by A1,A8,FUNCT_1:def 8; then p4=p3 or p2,p3,p4,p1 are_in_this_order_on K by A2,A55,A59,JORDAN17:12; hence contradiction by A2,A18,A55,A58,JORDAN17:12; case LE p4,p3,K & LE p3,p2,K & LE p2,p1,K; then f.p4,f.p3,f.p2,f.p1 are_in_this_order_on P by A1,Th82; then A60: LE f.p1,f.p4,P & LE f.p4,f.p3,P & LE f.p3,f.p2,P or LE f.p4,f.p3,P & LE f.p3,f.p2,P & LE f.p2,f.p1,P or LE f.p3,f.p2,P & LE f.p2,f.p1,P & LE f.p1,f.p4,P or LE f.p2,f.p1,P & LE f.p1,f.p4,P & LE f.p4,f.p3,P by JORDAN17:def 1; then f.p3=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then A61: p3=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; f.p4=f.p3 or f.p2=f.p1 by A1,A9,A60,JORDAN6:72; then p4=p3 or p2=p1 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A19,A55,A61,JORDAN17:12; case LE p3,p2,K & LE p2,p1,K & LE p1,p4,K; then f.p3,f.p2,f.p1,f.p4 are_in_this_order_on P by A1,Th82; then LE f.p1,f.p4,P & LE f.p4,f.p3,P & LE f.p3,f.p2,P or LE f.p4,f.p3,P & LE f.p3,f.p2,P & LE f.p2,f.p1,P or LE f.p3,f.p2,P & LE f.p2,f.p1,P & LE f.p1,f.p4,P or LE f.p2,f.p1,P & LE f.p1,f.p4,P & LE f.p4,f.p3,P by JORDAN17:def 1; then f.p4=f.p3 or f.p2=f.p1 by A1,A9,JORDAN6:72; then p4=p3 or p2=p1 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A19,A26,A55,JORDAN17:12; case A62: LE p2,p1,K & LE p1,p4,K & LE p4,p3,K; then f.p2,f.p1,f.p4,f.p3 are_in_this_order_on P by A1,Th82; then A63: LE f.p1,f.p4,P & LE f.p4,f.p3,P & LE f.p3,f.p2,P or LE f.p4,f.p3,P & LE f.p3,f.p2,P & LE f.p2,f.p1,P or LE f.p3,f.p2,P & LE f.p2,f.p1,P & LE f.p1,f.p4,P or LE f.p2,f.p1,P & LE f.p1,f.p4,P & LE f.p4,f.p3,P by JORDAN17:def 1; then f.p3=f.p2 or f.p2=f.p1 by A1,A9,JORDAN6:72; then A64: p3=p2 or p2=p1 by A1,A8,FUNCT_1:def 8; LE p1,p3,K by A2,A62,JORDAN6:73; then A65: p1=p2 by A2,A62,A64,JORDAN6:72; f.p4=f.p3 or f.p2=f.p3 by A1,A9,A63,JORDAN6:72; then p4=p3 or p2=p3 by A1,A8,FUNCT_1:def 8; hence contradiction by A2,A26,A55,A65,JORDAN17:12; end; hence contradiction; end; hence contradiction; end; hence p1,p2,p3,p4 are_in_this_order_on K; end; theorem Th88: for p1,p2,p3,p4 being Point of TOP-REAL 2, P,K being non empty compact Subset of TOP-REAL 2, f being map of TOP-REAL 2,TOP-REAL 2 st P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ holds p1,p2,p3,p4 are_in_this_order_on K iff f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P proof let p1,p2,p3,p4 be Point of TOP-REAL 2, P,K be non empty compact Subset of TOP-REAL 2, f be map of TOP-REAL 2,TOP-REAL 2; assume A1: P= circle(0,0,1) & K=rectangle(-1,1,-1,1) & f=Sq_Circ; then A2: K is_simple_closed_curve by Th60; circle(0,0,1)={p5 where p5 is Point of TOP-REAL 2: |.p5.|=1} by Th33; then A3: P is_simple_closed_curve by A1,JGRAPH_3:36; thus p1,p2,p3,p4 are_in_this_order_on K implies f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P proof assume A4: p1,p2,p3,p4 are_in_this_order_on K; now per cases by A4,JORDAN17:def 1; case LE p1,p2,K & LE p2,p3,K & LE p3,p4,K; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A1,Th82; case LE p2,p3,K & LE p3,p4,K & LE p4,p1,K; then f.p2,f.p3,f.p4,f.p1 are_in_this_order_on P by A1,Th82; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A3,JORDAN17:12; case LE p3,p4,K & LE p4,p1,K & LE p1,p2,K; then f.p3,f.p4,f.p1,f.p2 are_in_this_order_on P by A1,Th82; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A3,JORDAN17:11; case LE p4,p1,K & LE p1,p2,K & LE p2,p3,K; then f.p4,f.p1,f.p2,f.p3 are_in_this_order_on P by A1,Th82; hence f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P by A3,JORDAN17:10; end; hence thesis; end; thus f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P implies p1,p2,p3,p4 are_in_this_order_on K proof assume A5: f.p1,f.p2,f.p3,f.p4 are_in_this_order_on P; now per cases by A5,JORDAN17:def 1; case LE f.p1,f.p2,P & LE f.p2,f.p3,P & LE f.p3,f.p4,P; hence p1,p2,p3,p4 are_in_this_order_on K by A1,Th87; case LE f.p2,f.p3,P & LE f.p3,f.p4,P & LE f.p4,f.p1,P; then p2,p3,p4,p1 are_in_this_order_on K by A1,Th87; hence p1,p2,p3,p4 are_in_this_order_on K by A2,JORDAN17:12; case LE f.p3,f.p4,P & LE f.p4,f.p1,P & LE f.p1,f.p2,P; then p3,p4,p1,p2 are_in_this_order_on K by A1,Th87; hence p1,p2,p3,p4 are_in_this_order_on K by A2,JORDAN17:11; case LE f.p4,f.p1,P & LE f.p1,f.p2,P & LE f.p2,f.p3,P; then p4,p1,p2,p3 are_in_this_order_on K by A1,Th87; hence p1,p2,p3,p4 are_in_this_order_on K by A2,JORDAN17:10; end; hence p1,p2,p3,p4 are_in_this_order_on K; end; end; theorem for p1,p2,p3,p4 being Point of TOP-REAL 2, K being compact non empty Subset of TOP-REAL 2,K0 being Subset of TOP-REAL 2 st K=rectangle(-1,1,-1,1) & p1,p2,p3,p4 are_in_this_order_on K holds (for f,g being map of I[01],TOP-REAL 2 st f is continuous one-to-one & g is continuous one-to-one & K0= closed_inside_of_rectangle(-1,1,-1,1) & f.0=p1 & f.1=p3 & g.0=p2 & g.1=p4 & rng f c= K0 & rng g c= K0 holds rng f meets rng g) proof let p1,p2,p3,p4 be Point of TOP-REAL 2, K be compact non empty Subset of TOP-REAL 2,K0 be Subset of TOP-REAL 2; assume A1: K=rectangle(-1,1,-1,1) & p1,p2,p3,p4 are_in_this_order_on K; reconsider P= circle(0,0,1) as compact non empty Subset of TOP-REAL 2; A2: P={p6 where p6 is Point of TOP-REAL 2: |.p6.|=1} by Th33; thus (for f,g being map of I[01],TOP-REAL 2 st f is continuous one-to-one & g is continuous one-to-one & K0= closed_inside_of_rectangle(-1,1,-1,1) & f.0=p1 & f.1=p3 & g.0=p2 & g.1=p4 & rng f c= K0 & rng g c= K0 holds rng f meets rng g) proof let f,g be map of I[01],TOP-REAL 2; assume A3: f is continuous one-to-one & g is continuous one-to-one & K0= closed_inside_of_rectangle(-1,1,-1,1) & f.0=p1 & f.1=p3 & g.0=p2 & g.1=p4 & rng f c= K0 & rng g c= K0; then A4: K0={p: -1 <=p`1 & p`1<= 1 & -1 <=p`2 & p`2<= 1} by Def3; reconsider s=Sq_Circ as map of TOP-REAL 2,TOP-REAL 2; A5: dom s=the carrier of TOP-REAL 2 by FUNCT_2:def 1; reconsider f1=s*f as map of I[01],TOP-REAL 2; reconsider g1=s*g as map of I[01],TOP-REAL 2; s is_homeomorphism by JGRAPH_3:54; then A6: s is continuous by TOPS_2:def 5; then A7: f1 is continuous by A3,TOPS_2:58; A8: g1 is continuous by A3,A6,TOPS_2:58; A9: f1 is one-to-one by A3,FUNCT_1:46; A10: g1 is one-to-one by A3,FUNCT_1:46; A11: dom f=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then 0 in dom f by TOPREAL5:1; then A12: f1.0=Sq_Circ.p1 by A3,FUNCT_1:23; 1 in dom f by A11,TOPREAL5:1; then A13: f1.1=Sq_Circ.p3 by A3,FUNCT_1:23; A14: dom g=[.0,1.] by BORSUK_1:83,FUNCT_2:def 1; then 0 in dom g by TOPREAL5:1; then A15: g1.0=Sq_Circ.p2 by A3,FUNCT_1:23; 1 in dom g by A14,TOPREAL5:1; then A16: g1.1=Sq_Circ.p4 by A3,FUNCT_1:23; defpred P[Point of TOP-REAL 2] means |.$1.|<=1; {p8 where p8 is Point of TOP-REAL 2: P[p8]} is Subset of TOP-REAL 2 from SubsetD; then reconsider C0={p8 where p8 is Point of TOP-REAL 2: |.p8.|<=1} as Subset of TOP-REAL 2; A17: s.:K0 = C0 by A4,Th36; A18: rng f1 c= C0 proof let y be set;assume y in rng f1; then consider x being set such that A19: x in dom f1 & y=f1.x by FUNCT_1:def 5; A20: x in dom f & f.x in dom s by A19,FUNCT_1:21; then f.x in rng f by FUNCT_1:12; then s.(f.x) in s.:K0 by A3,A20,FUNCT_1:def 12; hence y in C0 by A17,A19,FUNCT_1:22; end; A21: rng g1 c= C0 proof let y be set;assume y in rng g1; then consider x being set such that A22: x in dom g1 & y=g1.x by FUNCT_1:def 5; A23: x in dom g & g.x in dom s by A22,FUNCT_1:21; then g.x in rng g by FUNCT_1:12; then s.(g.x) in s.:K0 by A3,A23,FUNCT_1:def 12; hence y in C0 by A17,A22,FUNCT_1:22; end; reconsider q1=s.p1,q2=s.p2,q3=s.p3,q4=s.p4 as Point of TOP-REAL 2; q1,q2,q3,q4 are_in_this_order_on P by A1,Th88; then rng f1 meets rng g1 by A2,A7,A8,A9,A10,A12,A13,A15,A16,A18,A21,Th27; then consider y being set such that A24: y in rng f1 & y in rng g1 by XBOOLE_0:3; consider x1 being set such that A25: x1 in dom f1 & y=f1.x1 by A24,FUNCT_1:def 5; consider x2 being set such that A26: x2 in dom g1 & y=g1.x2 by A24,FUNCT_1:def 5; dom f1 c= dom f by RELAT_1:44; then A27: f.x1 in rng f by A25,FUNCT_1:12; dom g1 c= dom g by RELAT_1:44; then A28: g.x2 in rng g by A26,FUNCT_1:12; y=(Sq_Circ).(f.x1) by A25,FUNCT_1:22; then A29: Sq_Circ".y=f.x1 by A5,A27,FUNCT_1:54; x1 in dom f by A25,FUNCT_1:21; then A30: f.x1 in rng f by FUNCT_1:def 5; y=(Sq_Circ).(g.x2) by A26,FUNCT_1:22; then A31: Sq_Circ".y=g.x2 by A5,A28,FUNCT_1:54; x2 in dom g by A26,FUNCT_1:21; then g.x2 in rng g by FUNCT_1:def 5; hence rng f meets rng g by A29,A30,A31,XBOOLE_0:3; end; end;