Copyright (c) 1996 Association of Mizar Users
environ vocabulary ARYTM_1, FINSEQ_1, FUNCT_1, RELAT_1, FINSEQ_5, RFINSEQ, BOOLE, EUCLID, TOPREAL1, TARSKI, PRE_TOPC, MCART_1, SPPOL_2, GROUP_2, SQUARE_1, ARYTM_3, JORDAN3, FINSEQ_4, ORDINAL2, ARYTM; notation TARSKI, XBOOLE_0, SUBSET_1, ORDINAL1, ORDINAL2, NUMBERS, XREAL_0, XCMPLX_0, REAL_1, NAT_1, RFINSEQ, BINARITH, RELAT_1, FUNCT_1, FINSEQ_1, FINSEQ_4, FINSEQ_5, CQC_SIM1, STRUCT_0, TOPREAL1, PRE_TOPC, EUCLID, SPPOL_2; constructors GOBOARD9, BINARITH, RFINSEQ, REAL_1, REALSET1, FINSEQ_4, CQC_SIM1, MEMBERED; clusters SUBSET_1, STRUCT_0, RELSET_1, FUNCT_1, EUCLID, SPPOL_2, FINSEQ_5, XREAL_0, ARYTM_3, MEMBERED, ORDINAL2, NAT_1; requirements REAL, NUMERALS, BOOLE, SUBSET, ARITHM; definitions TARSKI; theorems TARSKI, AXIOMS, TOPREAL1, FINSEQ_1, FINSEQ_4, RFINSEQ, SPPOL_1, FUNCT_1, NAT_1, REAL_1, REAL_2, GOBOARD9, BINARITH, SQUARE_1, TOPREAL3, SPPOL_2, FINSEQ_5, EUCLID, FINSEQ_6, RLVECT_1, ZFMISC_1, SCMFSA_7, FINSEQ_3, RELAT_1, CQC_SIM1, PARTFUN2, AMI_5, XBOOLE_0, XBOOLE_1, FINSEQ_2, XCMPLX_0, XCMPLX_1; begin ::-------------------------------------------: :: Preliminaries : ::-------------------------------------------: reserve i,i1,i2,n for natural number; theorem Th1: i-'i1>=1 or i-i1>=1 implies i-'i1=i-i1 proof assume A1: i-'i1>=1 or i-i1>=1; per cases by A1; suppose A2:i-'i1>=1; now assume not i-i1>=0; then i-'i1=0 by BINARITH:def 3; hence contradiction by A2; end; hence thesis by BINARITH:def 3; suppose i-i1>=1; then 0<=i-i1 by AXIOMS:22; hence thesis by BINARITH:def 3; end; theorem Th2:n-'0=n proof n>=0 by NAT_1:18; then n-'0=n-0 by BINARITH:def 3 .=n; hence thesis; end; theorem i1-i2<=i1-'i2 proof i1-i2>=0 or i1-i2<0; hence thesis by BINARITH:def 3; end; theorem Th4: i1<=i2 implies n-'i2<=n-'i1 proof assume A1:i1<=i2; per cases; suppose A2:i2<=n; then i1<=n by A1,AXIOMS:22; then A3:n-'i1=n-i1 by SCMFSA_7:3; n-'i2=n-i2 by A2,SCMFSA_7:3; hence n-'i2<=n-'i1 by A1,A3,REAL_2:106; suppose i2>n; then n-i2<0 by REAL_2:105; then n-'i2=0 by BINARITH:def 3; hence n-'i2<=n-'i1 by NAT_1:18; end; theorem Th5: i1<=i2 implies i1-'n<=i2-'n proof assume A1:i1<=i2; per cases; suppose A2:i1-n>=0; then A3:i1-'n=i1-n by BINARITH:def 3; i1-n<=i2-n by A1,REAL_1:49; hence thesis by A2,A3,BINARITH:def 3; suppose i1-n<0; then i1-'n=0 by BINARITH:def 3; hence thesis by NAT_1:18; end; theorem Th6:i-'i1>=1 or i-i1>=1 implies i-'i1+i1=i proof assume i-'i1>=1 or i-i1>=1; then i-'i1+i1=i-i1+i1 by Th1 .=i by XCMPLX_1:27; hence thesis; end; theorem Th7:i1<=i2 implies i1-'1<=i2 proof assume A1:i1<=i2; per cases; suppose i1-1>=0; then i1-'1=i1-1 by BINARITH:def 3; then i1-'1<=i1-1+1 by NAT_1:37; then i1-'1<=i1 by XCMPLX_1:27; hence i1-'1<=i2 by A1,AXIOMS:22; suppose i1-1<0; then i1-'1=0 by BINARITH:def 3; hence i1-'1<=i2 by NAT_1:18; end; theorem Th8:i-'2=i-'1-'1 proof per cases; suppose A1:i>=2; then A2: i-2>=0 by SQUARE_1:12; 1<=i by A1,AXIOMS:22; then i-1>=0 by SQUARE_1:12; then A3:i-'1=i-1 by BINARITH:def 3; i-1>=1+1-1 by A1,REAL_1:49; then i-1-1>=1-1 by REAL_1:49; then i-'1-'1 = i-1-1 by A3,BINARITH:def 3 .=i-(1+1) by XCMPLX_1:36 .=i-2; hence thesis by A2,BINARITH:def 3; suppose A4:i<2; then i-2<2-2 by REAL_1:54; then A5:i-'2=0 by BINARITH:def 3; i+1<=2 by A4,NAT_1:38; then i+1-1<=1+1-1 by REAL_1:49; then A6:i<=1 by XCMPLX_1:26; now per cases; case 1<=i; then i=1 by A6,AXIOMS:21; then A7:i-'1-'1=0-'1 by GOBOARD9:1; 0<=0-'1 by NAT_1:18; hence thesis by A5,A7,GOBOARD9:2; case i<1; then i-1<1-1 by REAL_1:54; then A8:i-'1-'1=0-'1 by BINARITH:def 3; 0<=0-'1 by NAT_1:18; hence thesis by A5,A8,GOBOARD9:2; end; hence thesis; end; theorem Th9: i1+1<=i2 implies i1-'1<i2 & i1-'2<i2 & i1<=i2 proof assume A1: i1+1<=i2; then i1+1<i2+1 by NAT_1:38; then i1+1-1<i2+1-1 by REAL_1:54; then A2: i1<i2+1-1 by XCMPLX_1:26; A3: i1<i2 by A1,NAT_1:38; i1-'1<=i1 by GOBOARD9:2; hence A4:i1-'1<i2 by A3,AXIOMS:22; A5:i1-'1-'1=i1-'2 by Th8; i1-'1-'1<=i1-'1 by GOBOARD9:2; hence i1-'2<i2 by A4,A5,AXIOMS:22; thus thesis by A2,XCMPLX_1:26; end; theorem Th10:i1+2<=i2 or i1+1+1<=i2 implies i1+1<i2 & i1+1-'1<i2 & i1+1-'2<i2 & i1+1<=i2 & i1-'1+1<i2 & i1-'1+1-'1<i2 & i1<i2 & i1-'1<i2 & i1-'2<i2 & i1<=i2 proof assume A1: i1+2<=i2 or i1+1+1<=i2; i1+2<=i2 implies i1+(1+1)<=i2; then i1+1+1<=i2 by A1,XCMPLX_1:1; hence A2:i1+1<i2 & i1+1-'1<i2 & i1+1-'2<i2 & i1+1<=i2 by Th9,NAT_1:38; i1-'1<=i1 by GOBOARD9:2; then i1-'1+1<=i1+1 by AXIOMS:24; then A3:i1-'1+1<i2 by A2,AXIOMS:22; i1-'1+1-'1<=i1-'1+1 by GOBOARD9:2; hence i1-'1+1<i2 & i1-'1+1-'1<i2 by A3,AXIOMS:22; thus i1<i2 & i1-'1<i2 & i1-'2<i2 & i1<=i2 by A2,Th9,NAT_1:38; end; theorem Th11:i1<=i2 or i1<=i2-'1 implies i1<i2+1 & i1<=i2+1 & i1<i2+1+1 & i1<=i2+1+1 & i1<i2+2 & i1<=i2+2 proof assume A1:i1<=i2 or i1<=i2-'1; A2:now assume i1<=i2; then A3:i1<i2+1 by NAT_1:38; i2+1+1=i2+(1+1) by XCMPLX_1:1; hence i1<i2+1 & i1<=i2+1 & i1<i2+1+1 & i1<=i2+1+1 & i1<i2+2 & i1<=i2+2 by A3,NAT_1:38; end; now assume A4:i1<=i2-'1; i2-'1<=i2 by GOBOARD9:2; hence i1<i2+1 & i1<=i2+1 & i1<i2+1+1 & i1<=i2+1+1 & i1<i2+2 & i1<=i2+2 by A2,A4,AXIOMS:22; end; hence thesis by A1,A2; end; theorem Th12:i1<i2 or i1+1<=i2 implies i1<=i2-'1 proof assume A1:i1<i2 or i1+1<=i2; per cases by A1; suppose A2:i1<i2; then i1+1<=i2 by NAT_1:38; then i1+1-1<=i2-1 by REAL_1:49; then A3:i1<=i2-1 by XCMPLX_1:26; 0<=i1 by NAT_1:18; then 0+1<=i2 by A2,NAT_1:38; hence i1<=i2-'1 by A3,SCMFSA_7:3; suppose A4:i1+1<=i2; then i1+1-1<=i2-1 by REAL_1:49; then A5:i1<=i2-1 by XCMPLX_1:26; 0<=i1 by NAT_1:18; then 0<i2 by A4,NAT_1:38; then 0+1<=i2 by NAT_1:38; hence i1<=i2-'1 by A5,SCMFSA_7:3; end; theorem Th13:i>=i1 implies i>=i1-'i2 proof assume A1:i>=i1; i1>=i1-'i2 by GOBOARD9:2; hence thesis by A1,AXIOMS:22; end; theorem 1<=i & 1<=i1-'i implies i1-'i<i1 proof assume A1:1<=i & 1<=i1-'i; then A2:i1-i=(i1-'i)+i-i by Th6 .=i1-'i by XCMPLX_1:26; A3:i>0 by A1,AXIOMS:22; i1-(i1-'i) = i by A2,XCMPLX_1:18; hence thesis by A3,REAL_2:106; end; reserve r,r1,r2 for Real; reserve n,i,i1,i2,j,j1,j2 for Nat; reserve D for non empty set; theorem Th15:for p,q being FinSequence st len p<i & (i<=len p +len q or i<=len (p^q)) holds (p^q).i=q.(i-len p) proof let p,q be FinSequence;assume A1:len p<i & (i<=len p +len q or i<=len (p^q)); then len p +1<=i by NAT_1:38; then len p +1-len p<=i-len p by REAL_1:49; then A2:1<=i-len p by XCMPLX_1:26; then A3:0<=i-len p by AXIOMS:22; then A4:i-len p=i-'len p by BINARITH:def 3; A5:len p+(i-'len p)=len p+(i-len p) by A3,BINARITH:def 3 .=i by XCMPLX_1:27; i<=len p + len q by A1,FINSEQ_1:35; then i-len p<=len p+len q -len p by REAL_1:49; then i-len p<=len q by XCMPLX_1:26; then i-'len p in dom q by A2,A4,FINSEQ_3:27; then (p^q).(len p+(i-'len p))=q.(i-'len p) by FINSEQ_1:def 7; hence thesis by A3,A5,BINARITH:def 3; end; theorem Th16: for x being set,f being FinSequence holds (f^<*x*>).(len f +1)=x & (<*x*>^f).1=x proof let x be set,f be FinSequence; 1<=len <*x*> by FINSEQ_1:56; then A1:1 in dom <*x*> by FINSEQ_3:27; then A2:(f^<*x*>).(len f +1)=<*x*>.1 by FINSEQ_1:def 7 .=x by FINSEQ_1:def 8; (<*x*>^f).1=<*x*>.1 by A1,FINSEQ_1:def 7.=x by FINSEQ_1:def 8; hence thesis by A2; end; theorem Th17:for x being set,f being FinSequence of D st 1<=len f holds (f^<*x*>).1=f.1 & (f^<*x*>).1=f/.1 & (<*x*>^f).(len f +1)=f.len f & (<*x*>^f).(len f +1)=f/.len f proof let x be set,f be FinSequence of D;assume A1:1<=len f; then 1 in dom f by FINSEQ_3:27; then A2:(f^<*x*>).1=f.1 by FINSEQ_1:def 7; A3:len f in dom f by A1,FINSEQ_3:27; (<*x*>^f).(len f +1) =(<*x*>^f).(len <*x*>+len f) by FINSEQ_1:56 .=f.len f by A3,FINSEQ_1:def 7; hence thesis by A1,A2,FINSEQ_4:24; end; theorem Th18:for f being FinSequence st len f=1 holds Rev f=f proof let f be FinSequence; assume len f=1; then f=<*f.1*> by FINSEQ_1:57; hence Rev f=f by FINSEQ_5:63; end; theorem Th19:for f being FinSequence of D,k being Nat holds len (f/^k)=len f-'k proof let f be FinSequence of D,k be Nat; per cases; suppose A1:k<=len f; then len f-'k=len f-k by SCMFSA_7:3; hence len (f/^k)=len f-'k by A1,RFINSEQ:def 2; suppose A2:k>len f; then (f/^k)=<*>D by RFINSEQ:def 2; then A3:len (f/^k)=0 by FINSEQ_1:32; len f-k<0 by A2,REAL_2:105; hence len (f/^k)=len f-'k by A3,BINARITH:def 3; end; theorem Th20: for D being set for f being FinSequence of D,k being Nat st k<=n holds (f|n).k=f.k proof let D be set; let f be FinSequence of D,k be Nat; assume A1: k<=n; per cases by RLVECT_1:99; suppose A2: k = 0; then A3: not k in dom f by FINSEQ_3:27; not k in dom(f|n) by A2,FINSEQ_3:27; hence (f|n).k = {} by FUNCT_1:def 4 .= f.k by A3,FUNCT_1:def 4; suppose 1 <= k; then k in Seg n by A1,FINSEQ_1:3; then (f|Seg n).k=f.k by FUNCT_1:72; hence (f|n).k=f.k by TOPREAL1:def 1; end; theorem Th21:for f being FinSequence of D,l1,l2 being Nat holds (f/^l1)|(l2-'l1)=(f|l2)/^l1 proof let f be FinSequence of D,l1,l2 be Nat; A1:now assume A2:l1<=l2; now per cases; case A3:l2<=len f; then A4:l1<=len f by A2,AXIOMS:22; then A5:len (f/^l1)=len f-l1 by RFINSEQ:def 2; A6:l1<=len (f|l2) by A2,A3,TOPREAL1:3; l2-l1<=len f-l1 by A3,REAL_1:49; then A7:l2-'l1<=len (f/^l1) by A2,A5,SCMFSA_7:3; then A8:len ((f/^l1)|(l2-'l1)) = l2-'l1 by TOPREAL1:3; A9:len ((f|l2)/^l1)=len (f|l2)-l1 by A6,RFINSEQ:def 2 .=l2-l1 by A3,TOPREAL1:3 .=l2-'l1 by A2,SCMFSA_7:3; for k being Nat st 1<=k & k<=len ((f|l2)/^l1) holds ((f/^l1)|(l2-'l1)).k=((f|l2)/^l1).k proof let k be Nat such that A10: 1<=k and A11: k<=len ((f|l2)/^l1); A12:k<=len (f/^l1) by A7,A9,A11,AXIOMS:22; A13:k in Seg (l2-'l1) by A9,A10,A11,FINSEQ_1:3; A14:k in dom (f/^l1) by A10,A12,FINSEQ_3:27; k<=l2-l1 by A2,A9,A11,SCMFSA_7:3; then k+l1<=l2-l1+l1 by AXIOMS:24; then A15:k+l1<=l2 by XCMPLX_1:27; A16:k in dom ((f|l2)/^l1) by A10,A11,FINSEQ_3:27; ((f/^l1)|(l2-'l1)).k =((f/^l1)|Seg (l2-'l1)).k by TOPREAL1:def 1 .=(f/^l1).k by A13,FUNCT_1:72 .=f.(k+l1) by A4,A14,RFINSEQ:def 2 .=(f|l2).(k+l1) by A15,Th20 .=((f|l2)/^l1).k by A6,A16,RFINSEQ:def 2; hence ((f/^l1)|(l2-'l1)).k=((f|l2)/^l1).k; end; hence (f/^l1)|(l2-'l1)=(f|l2)/^l1 by A8,A9,FINSEQ_1:18; case A17:l2>len f; then A18:f|l2=f by TOPREAL1:2; len (f/^l1)=len f-'l1 by Th19; then len (f/^l1)<=l2-'l1 by A17,Th5; hence (f/^l1)|(l2-'l1)=(f|l2)/^l1 by A18,TOPREAL1:2; end; hence (f/^l1)|(l2-'l1)=(f|l2)/^l1; end; now assume A19:l1>l2; then l1-l1>l2-l1 by REAL_1:54; then 0>l2-l1 by XCMPLX_1:14; then l2-'l1=0 by BINARITH:def 3; then (f/^l1)|(l2-'l1) =(f/^l1)|({} NAT) by FINSEQ_1:4,TOPREAL1:def 1; then dom ((f/^l1)|(l2-'l1)) =dom (f/^l1) /\ ({} NAT) by FUNCT_1:68 .=({} NAT); then A20:(f/^l1)|(l2-'l1)=<*>(D) by FINSEQ_1:26; now per cases; case l1<=len f; then l2<len f by A19,AXIOMS:22; then l1>len (f|l2) by A19,TOPREAL1:3; hence (f/^l1)|(l2-'l1)=(f|l2)/^l1 by A20,FINSEQ_5:35; case A21:l1>len f; len (f|l2)<=len f by FINSEQ_5:18; then l1>len (f|l2) by A21,AXIOMS:22; hence (f/^l1)|(l2-'l1)=(f|l2)/^l1 by A20,FINSEQ_5:35; end; hence (f/^l1)|(l2-'l1)=(f|l2)/^l1; end; hence (f/^l1)|(l2-'l1)=(f|l2)/^l1 by A1; end; begin ::-------------------------------------------: :: Middle Function for Finite Sequences : ::-------------------------------------------: definition let D; let f be FinSequence of D,k1,k2 be Nat; func mid(f,k1,k2) -> FinSequence of D equals :Def1:(f/^(k1-'1))|(k2-'k1+1) if k1<=k2 otherwise Rev ((f/^(k2-'1))|(k1-'k2+1)); correctness; end; theorem Th22:for f being FinSequence of D,k1,k2 being Nat st 1<=k1 & k1<=len f & 1<=k2 & k2<=len f holds Rev mid(f,k1,k2)=mid(Rev f,len f-'k2+1,len f-'k1+1) proof let f be FinSequence of D,k1,k2 be Nat; assume A1: 1<=k1 & k1<=len f & 1<=k2 & k2<=len f; per cases; suppose A2:k1<=k2; A3:len f-'k1=len f-k1 by A1,SCMFSA_7:3; A4:len f-'k2=len f-k2 by A1,SCMFSA_7:3; A5:k1-'1<=len f by A1,Th13; then A6:(len f-'(k1-'1))+(k1-'1) =(len f-(k1-'1))+(k1-'1)by SCMFSA_7:3 .=len f by XCMPLX_1:27; A7:len f-'(k1-'1)=len f-(k1-'1) by A5,SCMFSA_7:3 .=len f-(k1-1) by A1,SCMFSA_7:3 .=len f-k1+1 by XCMPLX_1:37 .=len f-'k1+1 by A1,SCMFSA_7:3; len f-'k1>=len f-'k2 by A2,Th4; then A8:len f-'k1+1>=len f-'k2+1 by AXIOMS:24; k2-k1<=len f-k1 by A1,REAL_1:49; then k2-'k1<=len f-k1 by A2,SCMFSA_7:3; then k2-'k1<=len f-'k1 by A1,SCMFSA_7:3; then k2-'k1+1<=len f-'k1+1 by AXIOMS:24; then A9:(len f-'(k1-'1)-'(k2-'k1+1)) =(len f-'k1+1)-(k2-'k1+1) by A7,SCMFSA_7:3 .=(len f-k1+1)-(k2-k1+1) by A2,A3,SCMFSA_7:3 .=(len f-k1+1)-(k2-k1)-1 by XCMPLX_1:36 .=len f-k1+1-k2+k1-1 by XCMPLX_1:37 .=len f-k1+1+k1-k2-1 by XCMPLX_1:29 .=len f-k1+k1+1-k2-1 by XCMPLX_1:1 .=len f+1-k2-1 by XCMPLX_1:27 .=len f+1-1-k2 by XCMPLX_1:21 .=len f-k2 by XCMPLX_1:26 .=len f-'k2 by A1,SCMFSA_7:3; A10:len f-'k1>=len f-'k2 by A2,Th4; len f-'k1<=len f-'k1+1 by NAT_1:29; then len f-'k2<=len f-'k1+1 by A10,AXIOMS:22; then A11:len f-'(k1-'1)-'(len f-'k2) =len f-'k1+1-(len f-'k2) by A7,SCMFSA_7:3 .=len f-k1+1-(len f-k2) by A1,A3,SCMFSA_7:3 .=len f-k1+1-len f+k2 by XCMPLX_1:37 .=len f-(k1-1)-len f+k2 by XCMPLX_1:37 .=len f+-(k1-1)-len f+k2 by XCMPLX_0:def 8 .=k2+-(k1-1) by XCMPLX_1:26 .=k2-(k1-1) by XCMPLX_0:def 8 .=k2-k1+1 by XCMPLX_1:37 .=k2-'k1+1 by A2,SCMFSA_7:3; A12:k1-'1<=len f by A1,Th13; A13:(len (f/^(k1-'1))-'(k2-'k1+1))+(k2-'k1+1) =len f-'k2+(k2-'k1+1) by A9,Th19 .=len f-k2+(k2-k1+1) by A2,A4,SCMFSA_7:3 .=len f-k2+(k2-k1)+1 by XCMPLX_1:1 .=len f-k2+k2-k1+1 by XCMPLX_1:29 .=len f-k1+1 by XCMPLX_1:27 .=len f-(k1-1) by XCMPLX_1:37 .=len f-(k1-'1) by A1,SCMFSA_7:3 .=len f-'(k1-'1) by A12,SCMFSA_7:3 .=len (f/^(k1-'1)) by Th19; A14:(len f-'k1+1)-'(len f-'k2+1)+1 =(len f-'k1+1)-(len f-'k2+1)+1 by A8,SCMFSA_7:3 .=(len f-k1+1)-(len f-k2+1)+1 by A1,A3,SCMFSA_7:3 .=(len f-k1+1)-(len f+1-k2)+1 by XCMPLX_1:29 .=(len f+1-k1)-(len f+1-k2)+1 by XCMPLX_1:29 .=-k1+(len f+1)-(len f+1-k2)+1 by XCMPLX_0:def 8 .=-k1+(len f+1)-(len f+1)+k2+1 by XCMPLX_1:37 .=k2+-k1+1 by XCMPLX_1:26 .=k2-k1+1 by XCMPLX_0:def 8 .=k2-'k1+1 by A2,SCMFSA_7:3; len f-'k1>=len f-'k2 by A2,Th4; then len f-'k1+1>=len f-'k2+1 by AXIOMS:24; then mid(Rev f,len f-'k2+1,len f-'k1+1) =(((Rev f)/^((len f-'k2+1)-'1))|(k2-'k1+1)) by A14,Def1 .=(Rev f/^(len f-'k2))|(len f-'(k1-'1)-'(len f-'k2)) by A11,BINARITH:39 .=(Rev f|(len f-'(k1-'1)))/^(len f-'k2) by Th21 .=(Rev f|(len f-'(k1-'1)))/^(len (f/^(k1-'1))-'(k2-'k1+1)) by A9,Th19 .=(Rev (f/^(k1-'1)))/^(len (f/^(k1-'1))-'(k2-'k1+1)) by A6,FINSEQ_6:90 .=Rev (((f/^(k1-'1))|(k2-'k1+1))) by A13,FINSEQ_6:91 .=Rev mid(f,k1,k2) by A2,Def1; hence Rev mid(f,k1,k2)=mid(Rev f,len f-'k2+1,len f-'k1+1); suppose A15:k1>k2; A16:len f-'k2=len f-k2 by A1,SCMFSA_7:3; A17:len f-'k1=len f-k1 by A1,SCMFSA_7:3; A18:k2-'1<=len f by A1,Th13; then A19:(len f-'(k2-'1))+(k2-'1) =(len f-(k2-'1))+(k2-'1)by SCMFSA_7:3 .=len f by XCMPLX_1:27; A20:len f-'(k2-'1)=len f-(k2-'1) by A18,SCMFSA_7:3 .=len f-(k2-1) by A1,SCMFSA_7:3 .=len f-k2+1 by XCMPLX_1:37 .=len f-'k2+1 by A1,SCMFSA_7:3; len f-'k2>=len f-'k1 by A15,Th4; then A21:len f-'k2+1>=len f-'k1+1 by AXIOMS:24; k1-k2<=len f-k2 by A1,REAL_1:49; then k1-'k2<=len f-k2 by A15,SCMFSA_7:3; then k1-'k2<=len f-'k2 by A1,SCMFSA_7:3; then k1-'k2+1<=len f-'k2+1 by AXIOMS:24; then A22:(len f-'(k2-'1)-'(k1-'k2+1)) =(len f-'k2+1)-(k1-'k2+1) by A20,SCMFSA_7:3 .=(len f-k2+1)-(k1-k2+1) by A15,A16,SCMFSA_7:3 .=(len f-k2+1)-(k1-k2)-1 by XCMPLX_1:36 .=len f-k2+1-k1+k2-1 by XCMPLX_1:37 .=len f-k2+1+k2-k1-1 by XCMPLX_1:29 .=len f-k2+k2+1-k1-1 by XCMPLX_1:1 .=len f+1-k1-1 by XCMPLX_1:27 .=len f+1-1-k1 by XCMPLX_1:21 .=len f-k1 by XCMPLX_1:26 .=len f-'k1 by A1,SCMFSA_7:3; A23:len f-'k2>=len f-'k1 by A15,Th4; len f-'k2<=len f-'k2+1 by NAT_1:29; then len f-'k1<=len f-'k2+1 by A23,AXIOMS:22; then A24:len f-'(k2-'1)-'(len f-'k1) =len f-'k2+1-(len f-'k1) by A20,SCMFSA_7:3 .=len f-k2+1-(len f-k1) by A1,A16,SCMFSA_7:3 .=len f-k2+1-len f+k1 by XCMPLX_1:37 .=len f-(k2-1)-len f+k1 by XCMPLX_1:37 .=len f+-(k2-1)-len f+k1 by XCMPLX_0:def 8 .=-(k2-1)+k1 by XCMPLX_1:26 .=k1-(k2-1) by XCMPLX_0:def 8 .=k1-k2+1 by XCMPLX_1:37 .=k1-'k2+1 by A15,SCMFSA_7:3; A25:k2-'1<=len f by A1,Th13; A26:(len (f/^(k2-'1))-'(k1-'k2+1))+(k1-'k2+1) =len f-'k1+(k1-'k2+1) by A22,Th19 .=len f-k1+(k1-k2+1) by A15,A17,SCMFSA_7:3 .=len f-k1+(k1-k2)+1 by XCMPLX_1:1 .=len f-k1+k1-k2+1 by XCMPLX_1:29 .=len f-k2+1 by XCMPLX_1:27 .=len f-(k2-1) by XCMPLX_1:37 .=len f-(k2-'1) by A1,SCMFSA_7:3 .=len f-'(k2-'1) by A25,SCMFSA_7:3 .=len (f/^(k2-'1)) by Th19; A27:(len f-'k2+1)-'(len f-'k1+1)+1 =(len f-'k2+1)-(len f-'k1+1)+1 by A21,SCMFSA_7:3 .=(len f-k2+1)-(len f-k1+1)+1 by A1,A16,SCMFSA_7:3 .=(len f-k2+1)-(len f+1-k1)+1 by XCMPLX_1:29 .=(len f+1-k2)-(len f+1-k1)+1 by XCMPLX_1:29 .=-k2+(1+len f)-(len f+1-k1)+1 by XCMPLX_0:def 8 .=-k2+(len f+1)-(len f+1)+k1+1 by XCMPLX_1:37 .=-k2+k1+1 by XCMPLX_1:26 .=k1-k2+1 by XCMPLX_0:def 8 .=k1-'k2+1 by A15,SCMFSA_7:3; len f-k2>len f-k1 by A15,REAL_2:105; then len f-'k2+1>len f-'k1+1 by A16,A17,REAL_1:53; then mid(Rev f,len f-'k2+1,len f-'k1+1) =Rev((((Rev f)/^((len f-'k1+1)-'1))|(k1-'k2+1))) by A27,Def1 .=Rev((Rev f/^(len f-'k1))|(len f-'(k2-'1)-'(len f-'k1))) by A24,BINARITH:39 .=Rev((Rev f|(len f-'(k2-'1)))/^(len f-'k1)) by Th21 .=Rev((Rev f|(len f-'(k2-'1)))/^(len (f/^(k2-'1))-'(k1-'k2+1))) by A22,Th19 .=Rev((Rev (f/^(k2-'1)))/^(len (f/^(k2-'1))-'(k1-'k2+1))) by A19,FINSEQ_6:90 .=Rev(Rev (((f/^(k2-'1))|(k1-'k2+1)))) by A26,FINSEQ_6:91 .= Rev mid(f,k1,k2) by A15,Def1; hence Rev mid(f,k1,k2)=mid(Rev f,len f-'k2+1,len f-'k1+1); end; theorem Th23: for n,m being Nat,f being FinSequence of D st 1<= m &m+n<=len f holds (f/^n).m=f.(m+n) proof let n,m be Nat,f be FinSequence of D; assume A1: 1<= m & m+n<=len f; n<=n+m by NAT_1:29; then A2:n<=len f by A1,AXIOMS:22; then A3:len (f/^n) = len f -n by RFINSEQ:def 2; m+n-n<=len f -n by A1,REAL_1:49; then m<=len (f/^n) by A3,XCMPLX_1:26; then m in dom (f/^n) by A1,FINSEQ_3:27; hence (f/^n).m=f.(m+n) by A2,RFINSEQ:def 2; end; theorem Th24: for i being Nat,f being FinSequence of D st 1<=i & i<=len f holds (Rev f).i=f.(len f -i+1) proof let i be Nat,f be FinSequence of D; assume 1<=i & i<=len f; then i in dom (f) by FINSEQ_3:27; hence (Rev f).i=f.(len f -i+1) by FINSEQ_5:61; end; theorem for f being FinSequence of D,k being Nat st 1<=k holds mid(f,1,k)=f|k proof let f be FinSequence of D,k be Nat; assume A1:1<=k; then A2:mid(f,1,k)=(f/^(1-'1))|(k-'1+1) by Def1; 1-'1=0 by GOBOARD9:1; then f/^(1-'1)=f by FINSEQ_5:31; hence mid(f,1,k)=f|k by A1,A2,AMI_5:4; end; theorem Th26:for f being FinSequence of D,k being Nat st k<=len f holds mid(f,k,len f)=f/^(k-'1) proof let f be FinSequence of D,k be Nat; assume A1:k<=len f; then A2:mid(f,k,len f)=(f/^(k-'1))|(len f-'k+1) by Def1; k-'1<=len f by A1,Th7; then A3:len (f/^(k-'1))=len f-(k-'1) by RFINSEQ:def 2; A4:len f-'k+1=len f-k+1 by A1,SCMFSA_7:3 .=len f -(k-1) by XCMPLX_1:37; now per cases; case A5:k=0; then len f-'k+1=len f +1 by Th2; then len f <= len f-'k+1 by NAT_1:29; then A6:Seg len f c= Seg (len f -'k+1) by FINSEQ_1:7; 0-1<0; then k-'1=0 by A5,BINARITH:def 3; then f/^(k-'1)=f by FINSEQ_5:31; then dom (f/^(k-'1)) c= Seg (len f -'k+1) by A6,FINSEQ_1:def 3; then (f/^(k-'1))|Seg (len f -'k+1)= f/^(k-'1) by RELAT_1:97; hence mid(f,k,len f)=f/^(k-'1) by A2,TOPREAL1:def 1; case k<>0; then k>0 by NAT_1:19; then 0+1<=k by NAT_1:38; then len (f/^(k-'1))=len f-'k+1 by A3,A4,SCMFSA_7:3; hence mid(f,k,len f)=(f/^(k-'1))|Seg len (f/^(k-'1)) by A2,TOPREAL1:def 1 .=(f/^(k-'1))|dom (f/^(k-'1)) by FINSEQ_1:def 3 .=(f/^(k-'1)) by RELAT_1:97; end; hence mid(f,k,len f)=f/^(k-'1); end; theorem Th27:for f being FinSequence of D,k1,k2 being Nat st 1<=k1 & k1<=len f & 1<=k2 & k2<=len f holds mid(f,k1,k2).1=f.k1 & (k1<=k2 implies len mid(f,k1,k2) = k2 -' k1 +1 & for i being Nat st 1<=i & i<=len mid(f,k1,k2) holds mid(f,k1,k2).i=f.(i+k1-'1)) & (k1>k2 implies len mid(f,k1,k2) = k1 -' k2 +1 & for i being Nat st 1<=i & i<=len mid(f,k1,k2) holds mid(f,k1,k2).i=f.(k1-'i+1)) proof let f be FinSequence of D,k11,k21 be Nat; assume A1: 1<=k11 & k11<=len f & 1<=k21 & k21<=len f; A2:now let k1,k2 be Nat; now assume A3:k1<=k2 & 1<=k1 & k1<=len f; then A4:mid(f,k1,k2).1=((f/^(k1-'1))|(k2-'k1+1)).1 by Def1 .=((f/^(k1-'1))|(Seg (k2-'k1+1))).1 by TOPREAL1:def 1; k1-1>=0 by A3,SQUARE_1:12; then A5:1+(k1-'1)=1+(k1-1) by BINARITH:def 3 .=k1 by XCMPLX_1:27; then 1+(k1-'1)<=len f -(k1-'1)+(k1-'1) by A3,XCMPLX_1:27; then A6:1<=len f - (k1-'1) by REAL_1:53; A7:k1-'1<=len f by A3,Th7; then A8:len (f/^(k1-'1))=len f -(k1-'1) by RFINSEQ:def 2; k1-k1<=k2-k1 by A3,REAL_1:49; then A9:0<=k2-k1 by XCMPLX_1:14; then k2-'k1=k2-k1 by BINARITH:def 3; then 0+1<=k2-'k1+1 by A9,AXIOMS:24; then 1 in Seg (k2-'k1+1) & 1 in Seg(len (f/^(k1-'1))) by A6,A8,FINSEQ_1:3 ; then A10:1 in dom (f/^(k1-'1)) & 1 in Seg(k2-'k1+1) by FINSEQ_1:def 3; then 1 in dom (f/^(k1-'1)) /\ Seg(k2-'k1+1) by XBOOLE_0:def 3; then 1 in dom ((f/^(k1-'1))|(Seg (k2-'k1+1))) by RELAT_1:90; then mid(f,k1,k2).1=(f/^(k1-'1)).1 by A4,FUNCT_1:70; hence mid(f,k1,k2).1=f.k1 by A5,A7,A10,RFINSEQ:def 2; end; hence k1<=k2 & 1<=k1 & k1<=len f implies mid(f,k1,k2).1=f.k1; end; thus mid(f,k11,k21).1=f.k11 proof per cases; suppose k11<=k21; hence mid(f,k11,k21).1=f.k11 by A1,A2; suppose A11:k11>k21; A12:1<=(k11-'k21+1) by NAT_1:29; k21-'1<=len f by A1,Th7; then A13:len (f/^(k21-'1))=len f -(k21-'1) by RFINSEQ:def 2; A14: k21-1>=0 by A1,SQUARE_1:12; A15: k11-k21>=0 by A11,SQUARE_1:12; then A16:k11-'k21=k11-k21 by BINARITH:def 3; k11-'k21+1=k11-k21+1 by A15,BINARITH:def 3 .=k11-(k21-1) by XCMPLX_1:37 .=k11-(k21-'1) by A14,BINARITH:def 3; then A17:k11-'k21+1 <=len (f/^(k21-'1)) by A1,A13,REAL_1:49; then A18:len ((f/^(k21-'1))|(k11-'k21+1))=(k11-'k21+1) by TOPREAL1:3; then A19:k11-'k21+1 in dom ((f/^(k21-'1))|(k11-'k21+1)) by A12,FINSEQ_3:27; A20:k11-'k21+1 in dom (f/^(k21-'1)) by A12,A17,FINSEQ_3:27; A21:k21-'1 +(k11-'k21+1)=k21-1+(k11-k21+1) by A14,A16,BINARITH:def 3 .= k21-1+(k11-(k21-1)) by XCMPLX_1:37 .=k11 by XCMPLX_1:27; A22:((f/^(k21-'1))|(k11-'k21+1)).len ((f/^(k21-'1))|(k11-'k21+1)) =((f/^(k21-'1))|(k11-'k21+1))/.(k11-'k21+1) by A12,A18,FINSEQ_4:24 .=(f/^(k21-'1))/.(k11-'k21+1) by A19,TOPREAL1:1 .=f/.((k21-'1 +(k11-'k21+1))) by A20,FINSEQ_5:30 .=f.k11 by A1,A21,FINSEQ_4:24; 1 in dom ((f/^(k21-'1))|(k11-'k21+1)) by A12,A18,FINSEQ_3:27; then (Rev ((f/^(k21-'1))|(k11-'k21+1))).1 = ((f/^(k21-'1))|(k11-'k21+1)) .(len ((f/^(k21-'1))|(k11-'k21+1)) - 1 + 1) by FINSEQ_5:61 .= f.k11 by A22,XCMPLX_1:27; hence mid(f,k11,k21).1=f.k11 by A11,Def1; end; thus k11<=k21 implies len mid(f,k11,k21) = k21 -' k11 +1 & for i being Nat st 1<=i & i<=len mid(f,k11,k21) holds mid(f,k11,k21).i=f.(i+k11-'1) proof assume A23:k11<=k21; then A24:mid(f,k11,k21)=(f/^(k11-'1))|(k21-'k11+1) by Def1; k11-'1<=len f by A1,Th7; then A25:len (f/^(k11-'1))=len f -(k11-'1) by RFINSEQ:def 2; A26: k11-1>=0 by A1,SQUARE_1:12; then A27:k11-'1=k11-1 by BINARITH:def 3; A28: k21-k11>=0 by A23,SQUARE_1:12; then A29:k21-'k11=k21-k11 by BINARITH:def 3; k21-'k11+1=k21-k11+1 by A28,BINARITH:def 3 .=k21-(k11-1) by XCMPLX_1:37 .=k21-(k11-'1) by A26,BINARITH:def 3; then A30:k21-'k11+1 <=len (f/^(k11-'1)) by A1,A25,REAL_1:49; then A31: len ((f/^(k11-'1))|(k21-'k11+1))=(k21-'k11+1) by TOPREAL1:3; for i being Nat st 1<=i & i<=len mid(f,k11,k21) holds mid(f,k11,k21).i=f.(i+k11-'1) proof let i be Nat;assume A32:1<=i & i<=len mid(f,k11,k21); then i<=k21-(k11-1) by A24,A29,A31,XCMPLX_1:37; then i+(k11-1)<=k21-(k11-1)+(k11-1) by AXIOMS:24; then A33:i+(k11-'1)<=k21 by A27,XCMPLX_1:27; A34:i<= (k21-'k11+1) & (k21-'k11+1)<=len (f/^(k11-'1)) by A24,A30,A32,TOPREAL1:3; A35:1<=i & i+(k11-'1)<=len f by A1,A32,A33,AXIOMS:22; k11<=k11+i by NAT_1:29; then A36:i+k11>=1 by A1,AXIOMS:22; A37:i+(k11-'1)=i+(k11-1) by A26,BINARITH:def 3 .=i+k11-1 by XCMPLX_1:29 .=i+k11-'1 by A36,SCMFSA_7:3; mid(f,k11,k21).i=(f/^(k11-'1))|(k21-'k11+1).i by A23,Def1 .=(f/^(k11-'1)).i by A34,Th20 .=f.(i+(k11-'1)) by A35,Th23; hence mid(f,k11,k21).i=f.(i+k11-'1) by A37; end; hence len mid(f,k11,k21) = k21 -' k11 +1 & for i being Nat st 1<=i & i<=len mid(f,k11,k21) holds mid(f,k11,k21).i=f.(i+k11-'1) by A24,A30,TOPREAL1:3; end; assume A38:k11>k21; then A39:mid(f,k11,k21)=Rev ((f/^(k21-'1))|(k11-'k21+1)) by Def1; then A40:len mid(f,k11,k21)=len ((f/^(k21-'1))|(k11-'k21+1)) by FINSEQ_5: def 3; k21-'1<=len f by A1,Th7; then A41:len (f/^(k21-'1))=len f -(k21-'1) by RFINSEQ:def 2; A42: k21-1>=0 by A1,SQUARE_1:12; then A43:k21-'1=k21-1 by BINARITH:def 3; A44: k11-k21>=0 by A38,SQUARE_1:12; then A45:k11-'k21=k11-k21 by BINARITH:def 3; k11-'k21+1=k11-k21+1 by A44,BINARITH:def 3 .=k11-(k21-1) by XCMPLX_1:37 .=k11-(k21-'1) by A42,BINARITH:def 3; then A46:k11-'k21+1 <=len (f/^(k21-'1)) by A1,A41,REAL_1:49; then A47:len ((f/^(k21-'1))|(k11-'k21+1))=(k11-'k21+1) by TOPREAL1:3; thus A48:len mid(f,k11,k21) = k11 -' k21 +1 by A40,A46,TOPREAL1:3; thus for i being Nat st 1<=i & i<=len mid(f,k11,k21) holds mid(f,k11,k21).i=f.(k11-'i+1) proof let i be Nat;assume A49:1<=i & i<=len mid(f,k11,k21); then A50:i<=k11-'k21+1 by A40,A46,TOPREAL1:3; i<=k11-(k21-1) by A45,A48,A49,XCMPLX_1:37; then i+(k21-1)<=k11-(k21-1)+(k21-1) by AXIOMS:24; then A51:i+(k21-'1)<=k11 by A43,XCMPLX_1:27; i<=i+(k21-'1) by NAT_1:29; then A52:i<=k11 by A51,AXIOMS:22; A53:k11-'k21+1-'i+1+(k21-'1) =k11-'k21+1-i+1+(k21-'1) by A48,A49,SCMFSA_7:3 .= k11-k21+1-i+1+(k21-1) by A42,A45,BINARITH:def 3 .= k11-(k21-1)-i+1+(k21-1) by XCMPLX_1:37 .= k11-(k21-1)-(i-1)+(k21-1) by XCMPLX_1:37 .= k11-(k21-1)+(k21-1)-(i-1) by XCMPLX_1:29 .=k11-(i-1) by XCMPLX_1:27 .=k11-i+1 by XCMPLX_1:37 .=k11-'i+1 by A52,SCMFSA_7:3; k11-'k21+1<= k11-'k21+1+(i-'1) by NAT_1:29; then k11-'k21+1<= k11-'k21+1+(i-1) by A49,SCMFSA_7:3; then k11-'k21+1-(i-1)<= k11-'k21+1+(i-1)-(i-1) by REAL_1:49; then k11-'k21+1-(i-1)<= k11-'k21+1 by XCMPLX_1:26; then k11-'k21+1-i+1<= k11-'k21+1 by XCMPLX_1:37; then A54: (k11-'k21+1-'i+1)<=(k11-'k21+1) by A50,SCMFSA_7:3; A55:1+k11<=i+k11 by A49,AXIOMS:24; i+k11<=i+len f by A1,AXIOMS:24; then 1+k11<=i+len f by A55,AXIOMS:22; then 1+k11-i<=i+len f -i by REAL_1:49; then 1+k11-i<=len f by XCMPLX_1:26; then k11-i+1<=len f by XCMPLX_1:29; then A56:1<=k11-'k21+1-'i+1 & k11-'k21+1-'i+1+(k21-'1)<= len f by A52,A53,NAT_1:29,SCMFSA_7:3; mid(f,k11,k21).i=((f/^(k21-'1))|(k11-'k21+1)) .(len ((f/^(k21-'1))|(k11-'k21+1)) -i+1) by A39,A40,A49,Th24 .=((f/^(k21-'1))|(k11-'k21+1)) .(len ((f/^(k21-'1))|(k11-'k21+1)) -'i+1) by A40,A49,SCMFSA_7:3 .=(f/^(k21-'1)).(k11-'k21+1-'i+1) by A47,A54,Th20 .=f.(k11-'i+1) by A53,A56,Th23; hence mid(f,k11,k21).i=f.(k11-'i+1); end; end; theorem Th28: for f being FinSequence of D,k1,k2 being Nat holds rng mid(f,k1,k2) c= rng f proof let f be FinSequence of D,k1,k2 be Nat; per cases; suppose k1<=k2; then mid(f,k1,k2) = (f/^(k1-'1))|(k2-'k1+1) by Def1; then A1:rng mid(f,k1,k2) c= rng (f/^(k1-'1)) by FINSEQ_5:21; rng (f/^(k1-'1)) c= rng f by FINSEQ_5:36; hence rng mid(f,k1,k2) c= rng f by A1,XBOOLE_1:1; suppose k1>k2; then mid(f,k1,k2) = Rev ((f/^(k2-'1))|(k1-'k2+1)) by Def1; then rng mid(f,k1,k2) = rng ((f/^(k2-'1))|(k1-'k2+1)) by FINSEQ_5:60; then A2:rng mid(f,k1,k2) c= rng (f/^(k2-'1)) by FINSEQ_5:21; rng (f/^(k2-'1)) c= rng f by FINSEQ_5:36; hence rng mid(f,k1,k2) c= rng f by A2,XBOOLE_1:1; end; theorem for f being FinSequence of D st 1<=len f holds mid(f,1,len f)=f proof let f be FinSequence of D; assume A1:1<=len f; then mid(f,1,len f)=(f/^(1-'1))|(len f-'1+1) by Def1 .=(f/^0)|(len f-'1+1) by GOBOARD9:1 .=f|(len f-'1+1) by FINSEQ_5:31 .=f|len f by A1,AMI_5:4 .=f by TOPREAL1:2; hence mid(f,1,len f)=f; end; theorem for f being FinSequence of D st 1<=len f holds mid(f,len f,1)=Rev f proof let f be FinSequence of D; assume A1:1<=len f; A2:1-'1=0 by GOBOARD9:1; per cases; suppose len f<>1; then 1<len f by A1,REAL_1:def 5; then mid(f,len f,1)=Rev ((f/^(1-'1))|(len f-'1+1)) by Def1 .=Rev ((f/^0)|len f) by A1,A2,AMI_5:4 .=Rev (f|len f) by FINSEQ_5:31 .=Rev f by TOPREAL1:2; hence mid(f,len f,1)=Rev f; suppose A3:len f=1; then A4:mid(f,len f,1)=(f/^(1-'1))|(1-'1+1) by Def1 .=f|1 by A2,FINSEQ_5:31; A5:f|1=f by A3,TOPREAL1:2; len (f|1)=1 by A1,TOPREAL1:3; hence mid(f,len f,1)=Rev f by A4,A5,Th18; end; theorem Th31:for f being FinSequence of D, k1,k2,i being Nat st 1<=k1 & k1<=k2 & k2<=len f & 1<=i & (i<=k2-'k1+1 or i<=k2-k1+1 or i<=k2+1-k1) holds mid(f,k1,k2).i=f.(i+k1-'1) & mid(f,k1,k2).i=f.(i-'1+k1) & mid(f,k1,k2).i=f.(i+k1-1) & mid(f,k1,k2).i=f.(i-1+k1) proof let f be FinSequence of D, k1,k2,i be Nat; assume A1:1<=k1 & k1<=k2 & k2<=len f & 1<=i & (i<=k2-'k1+1 or i<=k2-k1+1 or i<=k2+1-k1); then A2:1<=k2 by AXIOMS:22; A3:k1<=len f by A1,AXIOMS:22; A4: i-1>=1-1 by A1,REAL_1:49; i+k1>=1+k1 by A1,AXIOMS:24; then i+k1-1>=1+k1-1 by REAL_1:49; then A5:i+k1-1>=k1 by XCMPLX_1:26; A6: 0<=k1 by NAT_1:18; A7:len mid(f,k1,k2)=k2-'k1+1 by A1,A2,A3,Th27; A8:i<=k2-k1+1 implies i<=k2-'k1+1 by A1,SCMFSA_7:3; i-'1+k1=i-1+k1 by A4,BINARITH:def 3 .=i+k1-1 by XCMPLX_1:29 .=i+k1-'1 by A5,A6,BINARITH:def 3; hence A9:mid(f,k1,k2).i=f.(i+k1-'1) & mid(f,k1,k2).i=f.(i-'1+k1) by A1,A2,A3,A7,A8,Th27,XCMPLX_1:29; hence mid(f,k1,k2).i=f.(i+k1-1) by A5,A6,BINARITH:def 3; thus mid(f,k1,k2).i=f.(i-1+k1) by A1,A9,SCMFSA_7:3; end; theorem Th32:for f being FinSequence of D,k,i being Nat st 1<=i & i<=k & k<=len f holds mid(f,1,k).i=f.i proof let f be FinSequence of D,k,i be Nat; assume A1: 1<=i & i<=k & k<=len f; then A2:1<=k & k<=len f & 1<=i & i<=k by AXIOMS:22; i<=k-1+1 by A1,XCMPLX_1:27; then mid(f,1,k).i=f.(i+1-'1) by A2,Th31; hence thesis by BINARITH:39; end; theorem for f being FinSequence of D, k1,k2 being Nat st 1<=k1 & k1<=k2 & k2<=len f holds len mid(f,k1,k2)<=len f proof let f be FinSequence of D, k1,k2 be Nat; assume A1:1<=k1 & k1<=k2 & k2<=len f; then A2:1<=k2 by AXIOMS:22; k1<=len f by A1,AXIOMS:22; then A3:len mid(f,k1,k2)=k2-'k1+1 by A1,A2,Th27; k2-k1>=0 by A1,SQUARE_1:12; then A4:k2-'k1+1=k2-k1+1 by BINARITH:def 3 .=k2-(k1-1) by XCMPLX_1:37; k1-1>=0 by A1,SQUARE_1:12; then A5:k1-1=k1-'1 by BINARITH:def 3; k2<=k2+(k1-'1) by NAT_1:29; then k2-(k1-'1)<=k2+(k1-'1)-(k1-'1) by REAL_1:49; then k2-(k1-'1)<=k2 by XCMPLX_1:26; hence len mid(f,k1,k2)<=len f by A1,A3,A4,A5,AXIOMS:22; end; theorem for f being FinSequence of TOP-REAL n st 2<=len f holds f.1 in L~f & f/.1 in L~f & f.len f in L~f & f/.len f in L~f proof let f be FinSequence of TOP-REAL n; assume A1:2<=len f; then A2: 1+1<=len f; f/.1 in LSeg(f/.1,f/.(1+1)) by TOPREAL1:6; then A3:f/.1 in LSeg(f,1) by A1,TOPREAL1:def 5; LSeg(f,1) in {LSeg(f,i):1<=i & i+1<=len f} by A2; then f/.1 in union{LSeg(f,i):1<=i & i+1<=len f} by A3,TARSKI:def 4; then A4:f/.1 in L~f by TOPREAL1:def 6; A5:1<=len f by A2,Th9; A6:1<=len f-'1 by A2,Th12; A7:len f-'1+1=len f by A5,AMI_5:4; then f/.len f in LSeg(f/.(len f-'1),f/.(len f-'1+1)) by TOPREAL1:6; then A8:f/.len f in LSeg(f,len f-'1) by A6,A7,TOPREAL1:def 5; LSeg(f,len f-'1) in {LSeg(f,i):1<=i & i+1<=len f} by A6,A7; then f/.len f in union{LSeg(f,i):1<=i & i+1<=len f} by A8,TARSKI:def 4; then f/.len f in L~f by TOPREAL1:def 6; hence f.1 in L~f & f/.1 in L~f & f.len f in L~f & f/.len f in L~f by A4,A5,FINSEQ_4:24; end; theorem Th35:for p1,p2,q1,q2 being Point of TOP-REAL 2 st (p1`1 = p2`1 or p1`2 = p2`2)& q1 in LSeg(p1,p2) & q2 in LSeg(p1,p2) holds q1`1 = q2`1 or q1`2 = q2`2 proof let p1,p2,q1,q2 be Point of TOP-REAL 2; assume A1:(p1`1 = p2`1 or p1`2 = p2`2)& q1 in LSeg(p1,p2) & q2 in LSeg(p1,p2); then q1 in { (1-r)*p1 + r*p2 : 0 <= r & r <= 1 } by TOPREAL1:def 4; then consider r1 such that A2:q1= (1-r1)*p1 + r1*p2 & 0 <= r1 & r1 <= 1; q2 in { (1-r)*p1 + r*p2 : 0 <= r & r <= 1 } by A1,TOPREAL1:def 4; then consider r2 such that A3:q2= (1-r2)*p1 + r2*p2 & 0 <= r2 & r2 <= 1; q1`1=((1-r1)*p1)`1+(r1*p2)`1 by A2,TOPREAL3:7; then q1`1=(1-r1)*(p1`1)+(r1*p2)`1 by TOPREAL3:9; then A4:q1`1=(1-r1)*(p1`1)+r1*(p2`1) by TOPREAL3:9; q1`2=((1-r1)*p1)`2+(r1*p2)`2 by A2,TOPREAL3:7; then q1`2=(1-r1)*(p1`2)+(r1*p2)`2 by TOPREAL3:9; then A5:q1`2=(1-r1)*(p1`2)+r1*(p2`2) by TOPREAL3:9; q2`1=((1-r2)*p1)`1+(r2*p2)`1 by A3,TOPREAL3:7; then q2`1=(1-r2)*(p1`1)+(r2*p2)`1 by TOPREAL3:9; then A6:q2`1=(1-r2)*(p1`1)+r2*(p2`1) by TOPREAL3:9; q2`2=((1-r2)*p1)`2+(r2*p2)`2 by A3,TOPREAL3:7; then q2`2=(1-r2)*(p1`2)+(r2*p2)`2 by TOPREAL3:9; then A7:q2`2=(1-r2)*(p1`2)+r2*(p2`2) by TOPREAL3:9; per cases by A1; suppose A8:p1`1 = p2`1; then A9:q1`1=((1-r1)+r1)*(p1`1) by A4,XCMPLX_1:8 .=1*(p1`1) by XCMPLX_1:27 .=p1`1; q2`1=((1-r2)+r2)*(p1`1) by A6,A8,XCMPLX_1:8 .=1*(p1`1) by XCMPLX_1:27 .=p1`1; hence thesis by A9; suppose A10:p1`2 = p2`2; then A11:q1`2=((1-r1)+r1)*(p1`2) by A5,XCMPLX_1:8 .=1*(p1`2) by XCMPLX_1:27 .=p1`2; q2`2=((1-r2)+r2)*(p1`2) by A7,A10,XCMPLX_1:8 .=1*(p1`2) by XCMPLX_1:27 .=p1`2; hence thesis by A11; end; theorem Th36:for p1,p2,q1,q2 being Point of TOP-REAL 2 st (p1`1 = p2`1 or p1`2 = p2`2)& LSeg(q1,q2) c= LSeg(p1,p2) holds q1`1 = q2`1 or q1`2 = q2`2 proof let p1,p2,q1,q2 be Point of TOP-REAL 2; q1 in LSeg(q1,q2) & q2 in LSeg(q1,q2) by TOPREAL1:6; hence thesis by Th35; end; theorem Th37: for f being FinSequence of TOP-REAL 2,n being Nat st 2<=n & f is_S-Seq holds f|n is_S-Seq proof let f be FinSequence of TOP-REAL 2,n be Nat; assume A1:2<=n & f is_S-Seq; then A2:f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by TOPREAL1:def 10; reconsider f'=f as s.n.c. special unfolded one-to-one FinSequence of TOP-REAL 2 by A1,TOPREAL1:def 10; now per cases; case n<=len f; hence len (f|n) >= 2 by A1,TOPREAL1:3; case n>len f; hence len (f|n) >= 2 by A2,TOPREAL1:2; end; then f'|n is one-to-one & len (f|n) >= 2 & f'|n is unfolded s.n.c. special; hence f|n is_S-Seq by TOPREAL1:def 10; end; theorem Th38: for f being FinSequence of TOP-REAL 2,n being Nat st n<=len f & 2<=len f-'n & f is_S-Seq holds f/^n is_S-Seq proof let f be FinSequence of TOP-REAL 2,n be Nat; assume A1:n<=len f & 2<=len f-'n & f is_S-Seq; then reconsider f' = f as one-to-one special s.n.c. unfolded FinSequence of TOP-REAL 2 by TOPREAL1:def 10; len (f/^n)=len f-n by A1,RFINSEQ:def 2; then f'/^n is one-to-one & len (f'/^n) >= 2 & f'/^n is unfolded s.n.c. special by A1,SCMFSA_7:3; hence f/^n is_S-Seq by TOPREAL1:def 10; end; theorem for f being FinSequence of TOP-REAL 2,k1,k2 being Nat st f is_S-Seq & 1<=k1 & k1<=len f & 1<=k2 & k2<=len f & k1<>k2 holds mid(f,k1,k2) is_S-Seq proof let f be FinSequence of TOP-REAL 2,k1,k2 be Nat; assume A1: f is_S-Seq & 1<=k1 & k1<=len f & 1<=k2 & k2<=len f & k1<>k2; per cases; suppose A2:k1<=k2; then A3:mid(f,k1,k2)=(f/^(k1-'1))|(k2-'k1+1) by Def1; k1<k2 by A1,A2,REAL_1:def 5; then A4:k1+1<=k2 by NAT_1:38; then A5:k1+1<=len f by A1,AXIOMS:22; A6:k1-'1<=len f by A1,Th13; then A7:len f-'(k1-'1)= len f-(k1-'1) by SCMFSA_7:3 .=len f-(k1-1) by A1,SCMFSA_7:3 .=len f-k1+1 by XCMPLX_1:37; k1+1-k1<=len f-k1 by A5,REAL_1:49; then 1<=len f-k1 by XCMPLX_1:26 ; then 1+1<=len f-k1+1 by AXIOMS:24; then A8:f/^(k1-'1) is_S-Seq by A1,A6,A7,Th38; k1+1-k1<=k2-k1 by A4,REAL_1:49; then 1<=k2-k1 by XCMPLX_1:26; then 1<=k2-'k1 by Th1; then 1+1<=k2-'k1+1 by AXIOMS:24; hence mid(f,k1,k2) is_S-Seq by A3,A8,Th37; suppose A9:k1>k2; then A10:mid(f,k1,k2)= Rev ((f/^(k2-'1))|(k1-'k2+1)) by Def1; A11:k2+1<=k1 by A9,NAT_1:38; then A12:k2+1<=len f by A1,AXIOMS:22; A13:k2-'1<=len f by A1,Th13; then A14:len f-'(k2-'1)= len f-(k2-'1) by SCMFSA_7:3 .=len f-(k2-1) by A1,SCMFSA_7:3 .=len f-k2+1 by XCMPLX_1:37; k2+1-k2<=len f-k2 by A12,REAL_1:49; then 1<=len f-k2 by XCMPLX_1:26 ; then 1+1<=len f-k2+1 by AXIOMS:24; then A15:f/^(k2-'1) is_S-Seq by A1,A13,A14,Th38; k2+1-k2<=k1-k2 by A11,REAL_1:49; then 1<=k1-k2 by XCMPLX_1:26; then 1<=k1-'k2 by Th1; then 1+1<=k1-'k2+1 by AXIOMS:24; then (f/^(k2-'1))|(k1-'k2+1) is S-Sequence_in_R2 by A15,Th37; hence mid(f,k1,k2) is_S-Seq by A10,SPPOL_2:47; end; begin ::---------------------------------------------------------: :: A Concept of Index for Finite Sequences in TOP-REAL 2 : ::---------------------------------------------------------: definition let f be FinSequence of TOP-REAL 2,p be Point of TOP-REAL 2; assume A1: p in L~f; func Index(p,f) -> Nat means :Def2: ex S being non empty Subset of NAT st it = min S & S = { i: p in LSeg(f,i) }; existence proof set S = { i: p in LSeg(f,i) }; consider i2 being Nat such that 1<=i2 & i2+1<=len f and A2: p in LSeg(f,i2) by A1,SPPOL_2:13; A3: i2 in S by A2; S c= NAT proof let x be set; assume x in S; then ex i st x = i & p in LSeg(f,i); hence thesis; end; then reconsider S as non empty Subset of NAT by A3; take min S, S; thus thesis; end; uniqueness; end; theorem Th40: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2, i being Nat st p in LSeg(f,i) holds Index(p,f) <= i proof let f being FinSequence of TOP-REAL 2; let p being Point of TOP-REAL 2, i0 be Nat; A1: LSeg(f,i0) c= L~f by TOPREAL3:26; assume A2: p in LSeg(f,i0); then consider S being non empty Subset of NAT such that A3: Index(p,f) = min S and A4: S = { i: p in LSeg(f,i) } by A1,Def2; i0 in S by A2,A4; hence Index(p,f) <= i0 by A3,CQC_SIM1:def 8; end; theorem Th41: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f holds 1<=Index(p,f) & Index(p,f) < len f proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume p in L~f; then consider S being non empty Subset of NAT such that A1: Index(p,f) = min S and A2: S = { i: p in LSeg(f,i) } by Def2; Index(p,f) in S by A1,CQC_SIM1:def 8; then A3: ex i st i = Index(p,f) & p in LSeg(f,i) by A2; hence 1 <= Index(p,f) by TOPREAL1:def 5; Index(p,f) + 1 <= len f by A3,TOPREAL1:def 5; hence thesis by NAT_1:38; end; theorem Th42: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f holds p in LSeg(f,Index(p,f)) proof let f be FinSequence of TOP-REAL 2; let p be Point of TOP-REAL 2; assume p in L~f; then consider S being non empty Subset of NAT such that A1: Index(p,f) = min S and A2: S = { i: p in LSeg(f,i) } by Def2; Index(p,f) in S by A1,CQC_SIM1:def 8; then ex i st i = Index(p,f) & p in LSeg(f,i) by A2; hence p in LSeg(f,Index(p,f)); end; theorem Th43: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in LSeg(f,1) holds Index(p,f) = 1 proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume A1: p in LSeg(f,1); then A2: Index(p,f) <= 1 by Th40; LSeg(f,1) c= L~f by TOPREAL3:26; then Index(p,f) >= 1 by A1,Th41; hence Index(p,f) = 1 by A2,AXIOMS:21; end; theorem Th44: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st len f >= 2 holds Index(f/.1,f) = 1 proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume len f >= 2; then 1+1 <= len f; then f/.1 in LSeg(f,1) by TOPREAL1:27; hence thesis by Th43; end; theorem Th45: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2,i1 st f is_S-Seq & 1<i1 & i1<=len f & p=f.i1 holds Index(p,f) + 1 = i1 proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2,i1; assume A1: f is_S-Seq; assume A2: 1<i1 & i1<=len f; then A3: i1 in dom f by FINSEQ_3:27; 0 < i1 by A2,AXIOMS:22; then consider j being Nat such that A4: i1 = j+1 by NAT_1:22; A5: 1 + 0 <= j by A2,A4,NAT_1:38; assume p=f.i1; then A6: p = f/.i1 by A3,FINSEQ_4:def 4; then A7: p in LSeg(f,j) by A2,A4,A5,TOPREAL1:27; then A8: Index(p,f) <= j by Th40; assume Index(p,f) + 1 <> i1; then Index(p,f) < j by A4,A8,AXIOMS:21; then A9: Index(p,f) + 1 <= j by NAT_1:38; A10: LSeg(f,j) c= L~f by TOPREAL3:26; then A11: p in LSeg(f,Index(p,f)) by A7,Th42; per cases by A9,AXIOMS:21; suppose A12: Index(p,f) + 1 = j; A13: f is unfolded by A1,TOPREAL1:def 10; 1 <= Index(p,f) & Index(p,f) + (1+1) <= len f by A2,A4,A7,A10,A12,Th41, XCMPLX_1:1; then LSeg(f,Index(p,f)) /\ LSeg(f,j) = {f/.j} by A12,A13,TOPREAL1:def 8; then p in {f/.j} by A7,A11,XBOOLE_0:def 3; then A14: p = f/.j by TARSKI:def 1; A15: j < i1 by A4,NAT_1:38; j < len f by A2,A4,NAT_1:38; then A16: j in dom f by A5,FINSEQ_3:27; f is one-to-one by A1,TOPREAL1:def 10; hence contradiction by A3,A6,A14,A15,A16,PARTFUN2:17; suppose A17: Index(p,f) + 1 < j; p in LSeg(f,Index(p,f)) /\ LSeg(f,j) by A7,A11,XBOOLE_0:def 3; then A18: LSeg(f,Index(p,f)) meets LSeg(f,j) by XBOOLE_0:4; f is s.n.c. by A1,TOPREAL1:def 10; hence contradiction by A17,A18,TOPREAL1:def 9; end; theorem Th46: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2,i1 st f is_S-Seq & p in LSeg(f,i1) holds i1=Index(p,f) or i1=Index(p,f)+1 proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2,i1; assume that A1:f is_S-Seq and A2: p in LSeg(f,i1); A3: p in L~f by A2,SPPOL_2:17; A4: Index(p,f) <= i1 by A2,Th40; assume A5: not thesis; then Index(p,f) < i1 by A4,AXIOMS:21; then Index(p,f)+1 <= i1 by NAT_1:38; then A6: Index(p,f)+1 < i1 by A5,AXIOMS:21; p in LSeg(f,Index(p,f)) by A3,Th42; then p in LSeg(f,Index(p,f)) /\ LSeg(f,i1) by A2,XBOOLE_0:def 3; then A7: LSeg(f,Index(p,f)) meets LSeg(f,i1) by XBOOLE_0:4; f is s.n.c. by A1,TOPREAL1:def 10; hence contradiction by A6,A7,TOPREAL1:def 9; end; theorem Th47: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2,i1 st f is_S-Seq & i1+1<=len f & p in LSeg(f,i1) & p <> f.i1 holds i1=Index(p,f) proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2,i1; assume that A1:f is_S-Seq and A2: i1+1<=len f and A3: p in LSeg(f,i1); assume A4: p <> f.i1; A5: p in L~f by A3,SPPOL_2:17; A6: Index(p,f) <= i1 by A3,Th40; p in LSeg(f,Index(p,f)) by A5,Th42; then A7: p in LSeg(f,Index(p,f)) /\ LSeg(f,i1) by A3,XBOOLE_0:def 3; A8: f is unfolded by A1,TOPREAL1:def 10; A9: 1 <= Index(p,f) by A5,Th41; A10: 1 <= Index(p,f)+1 by NAT_1:29; i1 < len f by A2,NAT_1:38; then Index(p,f) < len f by A6,AXIOMS:22; then Index(p,f)+1 <= len f by NAT_1:38; then A11: Index(p,f) + 1 in dom f by A10,FINSEQ_3:27; now assume A12: i1 = Index(p,f)+1; then Index(p,f) + (1+1) <= len f by A2,XCMPLX_1:1; then p in {f/.(Index(p,f)+1)} by A7,A8,A9,A12,TOPREAL1:def 8; then p = f/.(Index(p,f)+1) by TARSKI:def 1; hence contradiction by A4,A11,A12,FINSEQ_4:def 4; end; hence thesis by A1,A3,Th46; end; definition let g be FinSequence of TOP-REAL 2, p1,p2 be Point of TOP-REAL 2; pred g is_S-Seq_joining p1,p2 means :Def3: g is_S-Seq & g.1 = p1 & g.len g = p2; end; theorem Th48: for g being FinSequence of TOP-REAL 2, p1,p2 being Point of TOP-REAL 2 st g is_S-Seq_joining p1,p2 holds Rev g is_S-Seq_joining p2,p1 proof let g be FinSequence of TOP-REAL 2, p1,p2 be Point of TOP-REAL 2; assume that A1: g is_S-Seq and A2: g.1=p1 and A3: g.len g=p2; thus Rev g is_S-Seq by A1,SPPOL_2:47; thus (Rev g).1 = p2 by A3,FINSEQ_5:65; dom g = dom Rev g by FINSEQ_5:60; hence (Rev g).len Rev g = (Rev g).len g by FINSEQ_3:31 .= p1 by A2,FINSEQ_5:65; end; theorem Th49: for f,g being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2,j st p in L~f & g=<*p*>^mid(f,Index(p,f)+1,len f) & 1<=j & j+1<=len g holds LSeg(g,j) c= LSeg(f,Index(p,f)+j-'1) proof let f,g be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2,j; assume that A1: p in L~f and A2: g=<*p*>^mid(f,Index(p,f)+1,len f) and A3: 1<=j and A4: j+1<=len g; consider i such that A5:1<=i & i+1<=len f & p in LSeg(f,i) by A1,SPPOL_2:13; 1<=i+1 by NAT_1:37; then A6:1<=len f by A5,AXIOMS:22; A7:len g=(len <*p*>)+ len(mid(f,Index(p,f)+1,len f)) by A2,FINSEQ_1:35 .=1+ len(mid(f,Index(p,f)+1,len f)) by FINSEQ_1:56; then A8: 1<=len g by NAT_1:29; A9: Index(p,f)<len f by A1,Th41; then Index(p,f)+1<=len f by NAT_1:38; then Index(p,f)+1-Index(p,f)<=len f - Index(p,f) by REAL_1:49; then 1<=len f - Index(p,f) by XCMPLX_1:26; then 1-1<=len f - Index(p,f)-1 by REAL_1:49; then A10:0<=len f - (Index(p,f)+1) by XCMPLX_1:36; A11:Index(p,f)+1<=len f by A9,NAT_1:38; 0<=Index(p,f) by NAT_1:18; then 0< Index(p,f)+1 by NAT_1:38; then A12: 0+1<=Index(p,f)+1 by NAT_1:38; then A13:len(mid(f,Index(p,f)+1,len f))=len f -' (Index(p,f)+1)+1 by A6,A11,Th27; A14:1<=Index(p,f)+1 & Index(p,f)+1<=len f & 1<=len f & len f<=len f by A11,A12,AXIOMS:22; A15:len g=1+(len f -(Index(p,f)+1)+1) by A7,A10,A13,BINARITH:def 3 .=1+((len f - Index(p,f))-1+1) by XCMPLX_1:36 .=1+(len f - Index(p,f)) by XCMPLX_1:27; A16: len f -'(Index(p,f)+1)=len f -(Index(p,f)+1) by A10,BINARITH:def 3 .=len f - Index(p,f) -1 by XCMPLX_1:36; len g=len <*p*> + len mid(f,Index(p,f)+1,len f) by A2,FINSEQ_1:35; then A17:len g=1+len mid(f,Index(p,f)+1,len f) by FINSEQ_1:56; A18:len mid(f,Index(p,f)+1,len f)=len f -Index(p,f) by A13,A16,XCMPLX_1:27; A19:j<=len g by A4,NAT_1:38; A20:1<=j+1 by A3,NAT_1:38; A21:j-'1=j-1 by A3,SCMFSA_7:3; A22:j+1-'1=j+1-1 by A20,SCMFSA_7:3; A23:j=1+j-1 by XCMPLX_1:26 .=1+(j-1) by XCMPLX_1:29 .=len <*p*> +(j-'1) by A21,FINSEQ_1:56; A24:j+1=1+(j+1-1) by XCMPLX_1:26 .=len <*p*> +(j+1-1) by FINSEQ_1:56 .=len <*p*> +(j+1-'1) by A20,SCMFSA_7:3; A25:1<=Index(p,f)+j by A3,NAT_1:37; then A26: 1-1<=Index(p,f)+j-1 by REAL_1:49; j+1-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A4,A17,REAL_1:49; then j+1-1<= len f -Index(p,f) by A18,XCMPLX_1:26; then j<=len f -Index(p,f) by XCMPLX_1:26; then j+Index(p,f)<= len f -Index(p,f)+Index(p,f) by AXIOMS:24; then Index(p,f)+j <= len f by XCMPLX_1:27; then Index(p,f)+(j-1+1) <= len f by XCMPLX_1:27; then Index(p,f)+(j-1)+1 <= len f by XCMPLX_1:1; then Index(p,f)+j-1+1 <= len f by XCMPLX_1:29; then A27:Index(p,f)+j-'1+1 <= len f by A26,BINARITH:def 3; A28: j+1-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A4,A17,REAL_1:49; then A29: j+1-1<=len mid(f,Index(p,f)+1,len f) by XCMPLX_1:26; A30:1<=j+1-'1 & j+1-'1<=len mid(f,Index(p,f)+1,len f) by A3,A22,A28,XCMPLX_1:26; then A31:j+1-'1 in dom mid(f,Index(p,f)+1,len f) by FINSEQ_3:27; A32:j<=len mid(f,Index(p,f)+1,len f) by A29,XCMPLX_1:26; j-'1<=j by GOBOARD9:2; then A33:j-'1<=len mid(f,Index(p,f)+1,len f) by A32,AXIOMS:22; A34:g.(j+1) =mid(f,Index(p,f)+1,len f).(j+1-'1) by A2,A24,A31,FINSEQ_1:def 7 .=f.(j+1-'1+(Index(p,f)+1)-'1) by A14,A30,Th27 .=f.(j+1-'1+1+Index(p,f)-'1) by XCMPLX_1:1 .=f.(j+1+Index(p,f)-'1) by A20,AMI_5:4 .=f.(Index(p,f)+j+1-'1) by XCMPLX_1:1 .=f.(Index(p,f)+j) by BINARITH:39 .=f.(Index(p,f)+j-'1+1) by A25,AMI_5:4; j<=len f - Index(p,f) by A4,A15,REAL_1:53; then j+Index(p,f)<=len f - Index(p,f)+Index(p,f) by AXIOMS:24; then A35:Index(p,f)+j<=len f by XCMPLX_1:27; then A36:Index(p,f)+j-'1+1<=len f by A25,AMI_5:4; A37:Index(p,f)+j-'1<=len f by A35,Th13; A38:1<=Index(p,f)+j-'1+1 by NAT_1:29; g/.(j+1)=g.(j+1) by A4,A20,FINSEQ_4:24; then A39:f/.(Index(p,f)+j-'1+1)=g/.(j+1) by A34,A36,A38,FINSEQ_4:24; 1 <= Index(p,f) by A1,Th41; then 1+1 <= Index(p,f)+j by A3,REAL_1:55; then 1<=Index(p,f)+j-1 by REAL_1:84; then A40:1<=Index(p,f)+j-'1 by Th1; then A41:LSeg(f,Index(p,f)+j-'1) =LSeg(f/.(Index(p,f)+j-'1),f/.(Index(p,f)+j-'1+1)) by A27,TOPREAL1:def 5; now per cases by A3,REAL_1:def 5; case A42:1<j; then A43:j-'1=j-1 by SCMFSA_7:3; then A44:1<=j-'1 by A42,SPPOL_1:6; j-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A17,A19,REAL_1:49; then j-'1<=len mid(f,Index(p,f)+1,len f) by A43,XCMPLX_1:26; then j-'1 in dom mid(f,Index(p,f)+1,len f) by A44,FINSEQ_3:27; then A45:g.j =mid(f,Index(p,f)+1,len f).(j-'1) by A2,A23,FINSEQ_1:def 7 .=f.(j-'1+(Index(p,f)+1)-'1) by A14,A33,A44,Th27 .=f.(j-'1+1+Index(p,f)-'1) by XCMPLX_1:1 .=f.(Index(p,f)+j-'1) by A3,AMI_5:4; g/.j=g.j by A3,A19,FINSEQ_4:24; then LSeg(f,Index(p,f)+j-'1) =LSeg(g/.j,g/.(j+1)) by A37,A39,A40,A41,A45,FINSEQ_4:24 .=LSeg(g,j) by A3,A4,TOPREAL1:def 5; hence thesis; case A46:1=j; then 1<=j & j<=len <*p*> by FINSEQ_1:56; then j in dom <*p*> by FINSEQ_3:27; then A47:g.j =<*p*>.j by A2,FINSEQ_1:def 7 .=p by A46,FINSEQ_1:57; A48:g/.j=g.j by A8,A46,FINSEQ_4:24; A49:f/.(Index(p,f)+j-'1+1) in LSeg(f/.(Index(p,f)+j-'1),f/.(Index(p,f)+j-'1+1)) by TOPREAL1:6; A50: Index(p,f)+j-'1 = Index(p,f) by A46,BINARITH:39; p in LSeg(f,Index(p,f)) by A1,Th42; then LSeg(p,g/.(j+1)) c= LSeg(f,Index(p,f)+j-'1) by A39,A41,A49,A50,TOPREAL1:12; hence thesis by A3,A4,A47,A48,TOPREAL1:def 5; end; hence LSeg(g,j) c= LSeg(f,Index(p,f)+j-'1); end; theorem for f,g being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p<>f.(Index(p,f)+1) & g=<*p*>^mid(f,Index(p,f)+1,len f) holds g is_S-Seq_joining p,f/.len f proof let f,g be FinSequence of TOP-REAL 2,p be Point of TOP-REAL 2; assume that A1: f is_S-Seq and A2: p in L~f and A3: p<>f.(Index(p,f)+1) and A4: g=<*p*>^mid(f,Index(p,f)+1,len f); consider i such that A5:1<=i & i+1<=len f & p in LSeg(f,i) by A2,SPPOL_2:13; 1<=1+i by NAT_1:37; then A6:1<=len f by A5,AXIOMS:22; A7:len g=(len <*p*>)+ len(mid(f,Index(p,f)+1,len f)) by A4,FINSEQ_1:35 .=1+ len(mid(f,Index(p,f)+1,len f)) by FINSEQ_1:56; A8: f is unfolded by A1,TOPREAL1:def 10; A9: Index(p,f)<len f by A2,Th41; then Index(p,f)+1<=len f by NAT_1:38; then Index(p,f)+1-Index(p,f)<=len f - Index(p,f) by REAL_1:49; then A10:1<=len f - Index(p,f) by XCMPLX_1:26; then 1-1<=len f - Index(p,f)-1 by REAL_1:49; then A11:0<=len f - (Index(p,f)+1) by XCMPLX_1:36; A12:Index(p,f)<len f by A2,Th41; A13:Index(p,f)+1<=len f by A9,NAT_1:38; A14: len f - Index(p,f)>=0 by A12,SQUARE_1:11; A15: 0+1<=Index(p,f)+1 by NAT_1:29; then A16:len(mid(f,Index(p,f)+1,len f))=len f -' (Index(p,f)+1)+1 by A6,A13,Th27; then len g=1+(len f -(Index(p,f)+1)+1) by A7,A11,BINARITH:def 3 .=1+((len f - Index(p,f))-1+1) by XCMPLX_1:36 .=1+(len f - Index(p,f)) by XCMPLX_1:27; then A17:len g -1 =len f -Index(p,f) by XCMPLX_1:26; then 0<len g -1 by A10,AXIOMS:22; then A18:len g -'1=len g -1 by BINARITH:def 3; len f -'(Index(p,f)+1)=len f -(Index(p,f)+1) by A11,BINARITH:def 3 .=len f - Index(p,f) -1 by XCMPLX_1:36; then A19:len f -'(Index(p,f)+1)+1=len f -Index(p,f) by XCMPLX_1:27; then A20:len g -'1 in dom (mid(f,Index(p,f)+1,len f)) by A10,A16,A17,A18,FINSEQ_3:27; 1<=1+ len(mid(f,Index(p,f)+1,len f)) by NAT_1:29; then len g -1>=0 by A7,SQUARE_1:12; then 1+(len g -'1)=1+(len g -1) by BINARITH:def 3 .=len g by XCMPLX_1:27; then A21:g.len g =g.(len <*p*> + (len g -'1)) by FINSEQ_1:56 .=mid(f,Index(p,f)+1,len f).(len g -'1) by A4,A20,FINSEQ_1:def 7; A22:len f -Index(p,f)=len f -' Index(p,f) by A14,BINARITH:def 3; A23:len g -'1= len f -' Index(p,f) by A14,A17,A18,BINARITH:def 3; A24:mid(f,Index(p,f)+1,len f).(len f -' Index(p,f)) =f.(len f -' Index(p,f)+(Index(p,f)+1)-'1) by A6,A10,A13,A15,A16,A19,A22,Th27; len f -' Index(p,f)+(Index(p,f)+1) =len f - Index(p,f)+(Index(p,f)+1) by A14,BINARITH:def 3 .=len f - Index(p,f)+Index(p,f)+1 by XCMPLX_1:1 .= len f +1 by XCMPLX_1:27; then A25: g.len g=f.len f by A21,A23,A24,BINARITH:39; len g=len <*p*> + len mid(f,Index(p,f)+1,len f) by A4,FINSEQ_1:35; then A26:len g=1+len mid(f,Index(p,f)+1,len f) by FINSEQ_1:56; A27:f is one-to-one by A1,TOPREAL1:def 10; A28: for x1,x2 being set st x1 in dom g & x2 in dom g & g.x1=g.x2 holds x1=x2 proof let x1,x2 be set;assume A29:x1 in dom g & x2 in dom g & g.x1=g.x2; then reconsider n1=x1,n2=x2 as Nat; A30:1<=n1 & n1<=len g & 1<=n2 & n2<=len g by A29,FINSEQ_3:27; now per cases by A30,REAL_1:def 5; case n1=1 & n2=1; hence x1=x2; case that A31: n1=1 and A32: n2>1; 1 <= Index(p,f) by A2,Th41; then 1 + 1 < n2+Index(p,f) by A32,REAL_1:67; then A33: 1< n2+Index(p,f)-1 by REAL_1:86; then 0<=n2+Index(p,f)-1 by AXIOMS:22; then A34: n2+Index(p,f)-'1 = n2+Index(p,f)-1 by BINARITH:def 3; 1<=n1 & n1<=len <*p*> by A31,FINSEQ_1:56; then n1 in dom <*p*> by FINSEQ_3:27; then A35: g.n1=<*p*>.n1 by A4,FINSEQ_1:def 7; n2-1>0 by A32,SQUARE_1:11; then A36:n2-'1=n2-1 by BINARITH:def 3; then A37: 0+1<=n2-'1 by A32,SPPOL_1:6; n2-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A26,A30,REAL_1:49; then A38:1<=n2-'1 & n2-'1<=len mid(f,Index(p,f)+1,len f) by A32,A36,SPPOL_1:6,XCMPLX_1:26; then A39:n2-'1 in dom mid(f,Index(p,f)+1,len f) by FINSEQ_3:27; len <*p*>+(n2-'1)=1+(n2-1) by A36,FINSEQ_1:56 .=n2 by XCMPLX_1:27; then g.n2 =mid(f,Index(p,f)+1,len f).(n2-'1) by A4,A39,FINSEQ_1:def 7 .=f.(n2-'1+(Index(p,f)+1)-'1) by A6,A13,A15,A38,Th27 .=f.(n2-'1+1+Index(p,f)-'1) by XCMPLX_1:1 .=f.(n2+Index(p,f)-'1) by A37,Th6; then A40:f.(n2+Index(p,f)-'1)=p by A29,A31,A35,FINSEQ_1:57; n2 -' 1 <= len f - Index(p,f) by A17,A18,A30,Th5; then n2-1 <= len f - Index(p,f) by A32,SCMFSA_7:3; then n2-1+Index(p,f) <= len f - Index(p,f)+ Index(p,f) by AXIOMS:24 ; then n2-1+Index(p,f) <= len f by XCMPLX_1:27; then n2+Index(p,f)-'1 <= len f by A34,XCMPLX_1:29; hence contradiction by A1,A3,A33,A34,A40,Th45; case that A41: n1>1 and A42: n2=1; 1 <= Index(p,f) by A2,Th41; then 1 + 1 < n1+Index(p,f) by A41,REAL_1:67; then A43: 1< n1+Index(p,f)-1 by REAL_1:86; then 0<=n1+Index(p,f)-1 by AXIOMS:22; then A44: n1+Index(p,f)-'1 = n1+Index(p,f)-1 by BINARITH:def 3; 1<=n2 & n2<=len <*p*> by A42,FINSEQ_1:56; then n2 in dom <*p*> by FINSEQ_3:27; then A45: g.n2=<*p*>.n2 by A4,FINSEQ_1:def 7; n1-1>0 by A41,SQUARE_1:11; then A46:n1-'1=n1-1 by BINARITH:def 3; then A47: 0+1<=n1-'1 by A41,SPPOL_1:6; n1-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A26,A30,REAL_1:49; then A48:1<=n1-'1 & n1-'1<=len mid(f,Index(p,f)+1,len f) by A41,A46,SPPOL_1:6,XCMPLX_1:26; then A49:n1-'1 in dom mid(f,Index(p,f)+1,len f) by FINSEQ_3:27; len <*p*>+(n1-'1)=1+(n1-1) by A46,FINSEQ_1:56 .=n1 by XCMPLX_1:27; then g.n1 =mid(f,Index(p,f)+1,len f).(n1-'1) by A4,A49,FINSEQ_1:def 7 .=f.(n1-'1+(Index(p,f)+1)-'1) by A6,A13,A15,A48,Th27 .=f.(n1-'1+1+Index(p,f)-'1) by XCMPLX_1:1 .=f.(n1+Index(p,f)-'1) by A47,Th6; then A50:f.(n1+Index(p,f)-'1)=p by A29,A42,A45,FINSEQ_1:57; n1 -' 1 <= len f - Index(p,f) by A17,A18,A30,Th5; then n1-1 <= len f - Index(p,f) by A41,SCMFSA_7:3; then n1-1+Index(p,f) <= len f - Index(p,f)+ Index(p,f) by AXIOMS:24 ; then n1-1+Index(p,f) <= len f by XCMPLX_1:27; then n1+Index(p,f)-'1 <= len f by A44,XCMPLX_1:29; hence contradiction by A1,A3,A43,A44,A50,Th45; case that A51: n1>1 and A52: n2>1; A53:n2-1>0 by A52,SQUARE_1:11; then A54:n2-'1=n2-1 by BINARITH:def 3; then A55: 0+1<=n2-'1 by A53,NAT_1:38; n2-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A26,A30,REAL_1:49; then A56:1<=n2-'1 & n2-'1<=len mid(f,Index(p,f)+1,len f) by A54,A55,XCMPLX_1:26; then A57:n2-'1 in dom mid(f,Index(p,f)+1,len f) by FINSEQ_3:27; len <*p*>+(n2-'1)=1+(n2-1) by A54,FINSEQ_1:56 .=n2 by XCMPLX_1:27; then A58:g.n2 =mid(f,Index(p,f)+1,len f).(n2-'1) by A4,A57,FINSEQ_1:def 7 .=f.(n2-'1+(Index(p,f)+1)-'1) by A6,A13,A15,A56,Th27 .=f.(n2-'1+1+Index(p,f)-'1) by XCMPLX_1:1 .=f.(n2+Index(p,f)-'1) by A55,Th6; A59: 1<=n2-'1 + Index(p,f) by A55,NAT_1:37; then 1<=n2+Index(p,f)-1 by A54,XCMPLX_1:29; then 0<=n2+Index(p,f)-1 by AXIOMS:22; then A60:n2+Index(p,f)-'1 = n2+Index(p,f)-1 by BINARITH:def 3; n2-'1 <= len f -' Index(p,f) by A23,A30,Th5; then n2-'1+Index(p,f)<=len f - Index(p,f)+ Index(p,f) by A22,AXIOMS:24; then n2-1+Index(p,f)<=len f by A54,XCMPLX_1:27; then 1<=n2+Index(p,f)-'1 & n2+Index(p,f)-'1<=len f by A54,A59,A60,XCMPLX_1:29; then A61:n2+Index(p,f)-'1 in dom f by FINSEQ_3:27; A62:n1-1>0 by A51,SQUARE_1:11; then A63:n1-'1=n1-1 by BINARITH:def 3; then A64: 0+1<=n1-'1 by A62,NAT_1:38; n1-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A26,A30,REAL_1:49; then A65:1<=n1-'1 & n1-'1<=len mid(f,Index(p,f)+1,len f) by A63,A64,XCMPLX_1:26; then A66:n1-'1 in dom mid(f,Index(p,f)+1,len f) by FINSEQ_3:27; len <*p*>+(n1-'1)=1+(n1-1) by A63,FINSEQ_1:56 .=n1 by XCMPLX_1:27; then A67:g.n1 =mid(f,Index(p,f)+1,len f).(n1-'1) by A4,A66,FINSEQ_1:def 7 .=f.(n1-'1+(Index(p,f)+1)-'1) by A6,A13,A15,A65,Th27 .=f.(n1-'1+1+Index(p,f)-'1) by XCMPLX_1:1 .=f.(n1+Index(p,f)-'1) by A64,Th6; 1<=n1-1+Index(p,f) by A63,A64,NAT_1:37; then A68:1<=n1+Index(p,f)-1 by XCMPLX_1:29; then 0<=n1+Index(p,f)-1 by AXIOMS:22; then A69:n1+Index(p,f)-'1 = n1+Index(p,f)-1 by BINARITH:def 3; n1-'1 <= len f -' Index(p,f) by A23,A30,Th5; then n1-'1+Index(p,f)<=len f - Index(p,f)+ Index(p,f) by A22,AXIOMS:24; then n1-'1+Index(p,f)<=len f by XCMPLX_1:27; then n1+Index(p,f)-'1<=len f by A63,A69,XCMPLX_1:29; then n1+Index(p,f)-'1 in dom f by A68,A69,FINSEQ_3:27; then n1+Index(p,f)-'1=n2+Index(p,f)-'1 by A27,A29,A58,A61,A67,FUNCT_1:def 8; then n1+Index(p,f)=n2+Index(p,f)-1+1 by A60,A69,XCMPLX_1:27; then n1+Index(p,f)=n2+Index(p,f) by XCMPLX_1:27; hence x1=x2 by XCMPLX_1:2; end; hence x1=x2; end; A70: len g -1+1>=1+1 by A10,A17,AXIOMS:24; A71: for j st 1 <= j & j + 2 <= len g holds LSeg(g,j) /\ LSeg(g,j+1) = {g/.(j+1)} proof let j;assume A72:1 <= j & j + 2 <= len g; A73:j+2=j+(1+1) .=j+1+1 by XCMPLX_1:1; then A74:j+1<=len g by A72,NAT_1:38; A75:1<j+1 by A72,NAT_1:38; A76:1<=(j+1) by A72,NAT_1:38; A77: 1+1-1<=(j+1)-1 by A75,SPPOL_1:6; A78:LSeg(g,j) c= LSeg(f,Index(p,f)+j-'1) by A2,A4,A72,A74,Th49; LSeg(g,(j+1)) c= LSeg(f,Index(p,f)+(j+1)-'1) by A2,A4,A72,A73,A76,Th49; then A79:LSeg(g,j)/\ LSeg(g,(j+1)) c= LSeg(f,Index(p,f)+j-'1)/\ LSeg(f,Index(p,f)+(j+1)-'1) by A78,XBOOLE_1:27; 1<=Index(p,f) by A2,Th41; then A80:1<=Index(p,f)+j by NAT_1:37; then A81: 1-1<=Index(p,f)+j-1 by REAL_1:49; A82:1<=Index(p,f)+j-'1+1 by NAT_1:29; A83:j+1=j+1-1+1 by XCMPLX_1:26 .=j+1-'1+1 by A75,SCMFSA_7:3; then A84:j+1=len <*p*>+(j+1-'1) by FINSEQ_1:56; A85:1<=j+1-'1 & j+1-'1<=len mid(f,Index(p,f)+1,len f) by A26,A74,A77,A83,Th1,REAL_1:53; then j+1-'1 in dom mid(f,Index(p,f)+1,len f) by FINSEQ_3:27; then A86:g.(j+1) = mid(f,Index(p,f)+1,len f).(j+1-'1) by A4,A84,FINSEQ_1:def 7 .=f.(j+1-'1+(Index(p,f)+1)-'1) by A6,A13,A15,A85,Th27 .=f.(j+1-'1+1+Index(p,f)-'1) by XCMPLX_1:1 .=f.(j+1+Index(p,f)-'1) by A75,AMI_5:4 .=f.(Index(p,f)+j+1-'1) by XCMPLX_1:1 .=f.(Index(p,f)+j) by BINARITH:39 .=f.(Index(p,f)+j-'1+1) by A80,AMI_5:4; 1 <= Index(p,f) by A2,Th41; then 1+1 <= Index(p,f)+j by A72,REAL_1:55; then 1<=Index(p,f)+j-1 by REAL_1:84; then A87:1<=Index(p,f)+j-'1 by Th1; A88:1<=Index(p,f)+j+1 by NAT_1:29; A89:Index(p,f)+(j+1)-'1 =Index(p,f)+j+1-'1 by XCMPLX_1:1 .=Index(p,f)+j+1-1 by A88,SCMFSA_7:3 .=Index(p,f)+j-1+1 by XCMPLX_1:29 .=Index(p,f)+j-'1+1 by A80,SCMFSA_7:3; A90:g/.(j+1)=g.(j+1) by A74,A75,FINSEQ_4:24; A91:LSeg(g/.(j+1),g/.(j+1+1))=LSeg(g,j+1) by A72,A73,A75,TOPREAL1:def 5; j+1+1-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A26,A72,A73,REAL_1:49; then j+1+1-1<=len mid(f,Index(p,f)+1,len f) by XCMPLX_1:26; then j+1<=len f -Index(p,f) by A16,A19,XCMPLX_1:26; then j+1+Index(p,f)<= len f -Index(p,f)+Index(p,f) by AXIOMS:24; then j+1+Index(p,f)<= len f by XCMPLX_1:27; then A92:Index(p,f)+j+1 <= len f by XCMPLX_1:1; then Index(p,f)+(j-1+1)+1 <= len f by XCMPLX_1:27; then Index(p,f)+(j-1)+1+1 <= len f by XCMPLX_1:1; then Index(p,f)+j-1+1+1 <= len f by XCMPLX_1:29; then Index(p,f)+j-1+(1+1) <= len f by XCMPLX_1:1; then Index(p,f)+j-'1+2 <= len f by A81,BINARITH:def 3; then A93:{f/.(Index(p,f)+j-'1+1)} = LSeg(f,Index(p,f)+j-'1)/\ LSeg(f,Index(p,f)+j-'1+1) by A8,A87,TOPREAL1:def 8; Index(p,f)+j<=len f by A92,Th9; then Index(p,f)+(j-1+1) <= len f by XCMPLX_1:27; then Index(p,f)+(j-1)+1 <= len f by XCMPLX_1:1; then Index(p,f)+j-1+1 <= len f by XCMPLX_1:29; then Index(p,f)+j-'1+1 <= len f by A81,BINARITH:def 3; then A94:f/.(Index(p,f)+j-'1+1)=g/.(j+1) by A82,A86,A90,FINSEQ_4:24; A95:LSeg(g,j)=LSeg(g/.j,g/.(j+1)) by A72,A74,TOPREAL1:def 5; A96:g/.(j+1) in LSeg(g/.j,g/.(j+1)) by TOPREAL1:6; g/.(j+1) in LSeg(g/.(j+1),g/.(j+1+1)) by TOPREAL1:6; then g/.(j+1) in LSeg(g/.j,g/.(j+1)) /\ LSeg(g/.(j+1),g/.(j+1+1)) by A96,XBOOLE_0:def 3; then {g/.(j+1)} c= LSeg(g,j) /\ LSeg(g,j+1) by A91,A95,ZFMISC_1:37; hence {g/.(j+1)} = LSeg(g,j)/\ LSeg(g,j+1) by A79,A89,A93,A94,XBOOLE_0:def 10; end; A97: f is s.n.c. by A1,TOPREAL1:def 10; A98: for j1,j2 st j1+1 < j2 holds LSeg(g,j1) misses LSeg(g,j2) proof let j1,j2;assume A99:j1+1 < j2; j1>=0 by NAT_1:18; then A100: j1=0 or j1>=0+1 by NAT_1:38; now per cases by A100,REAL_1:def 5; case j1=0; then LSeg(g,j1)={} by TOPREAL1:def 5; then LSeg(g,j1) /\ LSeg(g,j2) = {}; hence LSeg(g,j1) misses LSeg(g,j2) by XBOOLE_0:def 7; case that A101:j1=1 or j1>1 and A102: j2+1<=len g; j2<len g by A102,NAT_1:38; then A103:j1+1<=len g by A99,AXIOMS:22; 1<j1+1 by A101,NAT_1:38; then A104:1<=j2 by A99,AXIOMS:22; A105:LSeg(g,j1) c= LSeg(f,Index(p,f)+j1-'1) by A2,A4,A101,A103,Th49; LSeg(g,j2) c= LSeg(f,Index(p,f)+j2-'1) by A2,A4,A102,A104,Th49; then A106:LSeg(g,j1)/\ LSeg(g,j2) c= LSeg(f,Index(p,f)+j1-'1)/\ LSeg(f,Index(p,f)+j2-'1) by A105,XBOOLE_1:27; Index(p,f)+(j1+1)<Index(p,f)+j2 by A99,REAL_1:53; then Index(p,f)+j1+1<Index(p,f)+j2 by XCMPLX_1:1; then Index(p,f)+j1+1-1<Index(p,f)+j2-1 by REAL_1:54; then A107:Index(p,f)+j1-1+1<Index(p,f)+j2-1 by XCMPLX_1:29; 1<=Index(p,f) by A2,Th41; then 1<=Index(p,f)+j1 by NAT_1:37; then 1-1<=Index(p,f)+j1-1 by REAL_1:49; then A108:Index(p,f)+j1-1=Index(p,f)+j1-'1 by BINARITH:def 3; 1<=Index(p,f) by A2,Th41; then 1<=Index(p,f)+j2 by NAT_1:37; then 1-1<=Index(p,f)+j2-1 by REAL_1:49; then Index(p,f)+j1-'1+1<Index(p,f)+j2-'1 by A107,A108,BINARITH:def 3; then LSeg(f,Index(p,f)+j1-'1) misses LSeg(f,Index(p,f)+j2-'1) by A97, TOPREAL1:def 9; then LSeg(f,Index(p,f)+j1-'1) /\ LSeg(f,Index(p,f)+j2-'1) = {} by XBOOLE_0:def 7; then LSeg(g,j1) /\ LSeg(g,j2) = {} by A106,XBOOLE_1:3; hence LSeg(g,j1) misses LSeg(g,j2) by XBOOLE_0:def 7; case j2+1>len g; then LSeg(g,j2)={} by TOPREAL1:def 5; then LSeg(g,j1) /\ LSeg(g,j2) = {}; hence thesis by XBOOLE_0:def 7; end; hence LSeg(g,j1) misses LSeg(g,j2); end; A109: f is special by A1,TOPREAL1:def 10; for j st 1 <= j & j+1 <= len g holds (g/.j)`1 = (g/.(j+1))`1 or (g/.j)`2 = (g/.(j+1))`2 proof let j;assume A110: 1 <= j & j+1 <= len g; then A111:LSeg(g,j) c= LSeg(f,Index(p,f)+j-'1) by A2,A4,Th49; A112:LSeg(g,j) = LSeg(g/.j,g/.(j+1)) by A110,TOPREAL1:def 5; 1<=Index(p,f) by A2,Th41; then A113:1<Index(p,f)+1 by NAT_1:38; Index(p,f)+1<=Index(p,f)+j by A110,AXIOMS:24; then 1<Index(p,f)+j by A113,AXIOMS:22; then A114:1<=Index(p,f)+j-1 by SPPOL_1:6; then 0<=Index(p,f)+j-1 by AXIOMS:22; then A115:Index(p,f)+j-1=Index(p,f)+j-'1 by BINARITH:def 3; j+1-1<=1+len mid(f,Index(p,f)+1,len f)-1 by A26,A110,REAL_1:49; then j+1-1<= len f -Index(p,f) by A16,A19,XCMPLX_1:26; then j<=len f -Index(p,f) by XCMPLX_1:26; then j+Index(p,f)<= len f -Index(p,f)+Index(p,f) by AXIOMS:24; then j+Index(p,f)<= len f by XCMPLX_1:27; then Index(p,f)+(j-1+1) <= len f by XCMPLX_1:27; then Index(p,f)+(j-1)+1 <= len f by XCMPLX_1:1; then A116:Index(p,f)+j-'1+1 <= len f by A115,XCMPLX_1:29; then A117:LSeg(f,Index(p,f)+j-'1) = LSeg(f/.(Index(p,f)+j-'1),f/.(Index(p,f)+j-'1+1)) by A114,A115,TOPREAL1:def 5; (f/.(Index(p,f)+j-'1))`1 = (f/.(Index(p,f)+j-'1+1))`1 or (f/.(Index(p,f)+j-'1))`2 = (f/.(Index(p,f)+j-'1+1))`2 by A109,A114,A115,A116,TOPREAL1:def 7; hence (g/.j)`1 = (g/.(j+1))`1 or (g/.j)`2 = (g/.(j+1))`2 by A111,A112,A117,Th36; end; then g is one-to-one & len g >= 2 & g is unfolded s.n.c. special by A28,A70,A71,A98,FUNCT_1:def 8,TOPREAL1: def 7,def 8,def 9,XCMPLX_1:27; then g is_S-Seq & g.1 = p & g.len g = f/.len f by A4,A6,A25,FINSEQ_1:58, FINSEQ_4:24,TOPREAL1:def 10; hence g is_S-Seq_joining p,f/.len f by Def3; end; theorem Th51: for f,g being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2,j st p in L~f & 1<=j & j+1<=len g & g=mid(f,1,Index(p,f))^<*p*> holds LSeg(g,j) c= LSeg(f,j) proof let f,g be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2,j; assume that A1: p in L~f and A2: 1<=j and A3: j+1<=len g and A4: g=mid(f,1,Index(p,f))^<*p*>; A5:1<=Index(p,f) by A1,Th41; A6:Index(p,f) < len f by A1,Th41; then A7:1<=1 & 1<=len f & 1<=Index(p,f) & Index(p,f)<=len f by A5,AXIOMS:22; j<=j+1 by NAT_1:29; then A8:j<=len g by A3,AXIOMS:22; A9:1<=j+1 by NAT_1:29; now len g=len mid(f,1,Index(p,f)) + len <*p*> by A4,FINSEQ_1:35 .=len mid(f,1,Index(p,f))+1 by FINSEQ_1:56; then len g=Index(p,f)-'1+1+1 by A7,Th27; then A10:len g=Index(p,f)+1 by A5,AMI_5:4; Index(p,f)+1<=len f +1 by A6,AXIOMS:24; then j+1<=len f +1 by A3,A10,AXIOMS:22; then j+1-1<=len f +1-1 by REAL_1:49; then j<=len f +1-1 by XCMPLX_1:26; then A11:j<=len f by XCMPLX_1:26; A12:j<=Index(p,f) by A3,A10,REAL_1:53; A13: len mid(f,1,Index(p,f))=Index(p,f)-'1+1 by A7,Th27 .=Index(p,f) by A5,AMI_5:4; then A14:j in dom mid(f,1,Index(p,f)) by A2,A12,FINSEQ_3:27; A15:g/.j=g.j by A2,A8,FINSEQ_4:24 .=mid(f,1,Index(p,f)).j by A4,A14,FINSEQ_1:def 7 .=f.(j+1-'1) by A2,A7,A12,A13,Th27 .=f.j by BINARITH:39 .=f/.j by A2,A11,FINSEQ_4:24; now per cases; case A16:j+1<=Index(p,f); then A17:j+1<=len f by A6,AXIOMS:22; A18: len mid(f,1,Index(p,f))=Index(p,f)-'1+1 by A7,Th27 .=Index(p,f) by A5,AMI_5:4; then A19:j+1 in dom mid(f,1,Index(p,f)) by A9,A16,FINSEQ_3:27; A20:g/.(j+1)=g.(j+1) by A3,A9,FINSEQ_4:24 .= mid(f,1,Index(p,f)).(j+1) by A4,A19,FINSEQ_1:def 7 .=f.(j+1+1-'1) by A7,A9,A16,A18,Th27 .=f.(j+1) by BINARITH:39 .=f/.(j+1) by A9,A17,FINSEQ_4:24; LSeg(g,j)=LSeg(g/.j,g/.(j+1)) by A2,A3,TOPREAL1:def 5; hence LSeg(g,j) c= LSeg(f,j) by A2,A15,A17,A20,TOPREAL1:def 5; case j+1>Index(p,f); then j>=Index(p,f) by NAT_1:38; then A21:j=Index(p,f) by A12,AXIOMS:21; 1<=1 & 1<=len <*p*> by FINSEQ_1:57; then A22:1 in dom <*p*> by FINSEQ_3:27; A23:len mid(f,1,Index(p,f))=Index(p,f)-'1+1 by A7,Th27 .=Index(p,f) by A5,AMI_5:4; A24:g/.(j+1)=g.(j+1) by A3,A9,FINSEQ_4:24 .=<*p*>.1 by A4,A21,A22,A23,FINSEQ_1:def 7 .=p by FINSEQ_1:def 8; A25:f/.j in LSeg(f/.j,f/.(j+1)) by TOPREAL1:6; A26:p in LSeg(f,j) by A1,A21,Th42; now assume j+1>len f; then j>=len f by NAT_1:38; hence contradiction by A1,A21,Th41; end; then A27:LSeg(f,j)=LSeg(f/.j,f/.(j+1)) by A2,TOPREAL1:def 5; then LSeg(g/.j,g/.(j+1)) c= LSeg(f/.j,f/.(j+1)) by A15,A24,A25,A26,TOPREAL1:12; hence LSeg(g,j) c= LSeg(f,j) by A2,A3,A27,TOPREAL1:def 5; end; hence LSeg(g,j) c= LSeg(f,j); end; hence LSeg(g,j) c= LSeg(f,j); end; theorem Th52: for f,g being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p<>f.1 & g=mid(f,1,Index(p,f))^<*p*> holds g is_S-Seq_joining f/.1,p proof let f,g be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume that A1:f is_S-Seq and A2: p in L~f and A3: p<>f.1 and A4: g=mid(f,1,Index(p,f))^<*p*>; consider i such that A5:1<=i & i+1<=len f & p in LSeg(f,i) by A2,SPPOL_2:13; A6:1<=Index(p,f) by A2,Th41; A7:Index(p,f)<=len f by A2,Th41; 1<=1+i by NAT_1:37; then A8:1<=len f by A5,AXIOMS:22; then A9: len mid(f,1,Index(p,f))=Index(p,f)-'1+1 by A6,A7,Th27; then A10:len mid(f,1,Index(p,f))=Index(p,f) by A6,AMI_5:4; 1<=len <*p*> by FINSEQ_1:56; then A11: 1 in dom <*p*> by FINSEQ_3:27; g.1=mid(f,1,Index(p,f)).1 by A4,A6,A10,Th17; then g.1=f.1 by A6,A7,A8,Th27; then A12: g.1=f/.1 by A8,FINSEQ_4:24; A13: len g = len mid(f,1,Index(p,f))+ len<*p*> by A4,FINSEQ_1:35 .= len mid(f,1,Index(p,f))+ 1 by FINSEQ_1:56; then A14: g.len g = p by A4,Th16; A15: 1+1<=len g by A6,A10,A13,AXIOMS:24; A16: f is one-to-one by A1,TOPREAL1:def 10; A17:for n1,n2 being Nat st 1<=n1 & n1<=len f & 1<=n2 & n2<=len f & f.n1=f.n2 holds n1=n2 proof let n1,n2 be Nat;assume A18:1<=n1 & n1<=len f & 1<=n2 & n2<=len f & f.n1=f.n2; then n1 in dom f & n2 in dom f by FINSEQ_3:27; hence n1=n2 by A16,A18,FUNCT_1:def 8; end; A19: for x1,x2 being set st x1 in dom g & x2 in dom g & g.x1=g.x2 holds x1=x2 proof let x1,x2 be set;assume A20:x1 in dom g & x2 in dom g & g.x1=g.x2; then reconsider n1=x1,n2=x2 as Nat; A21:1<=n1 & n1<=len g & 1<=n2 & n2<=len g by A20,FINSEQ_3:27; now A22:g.len g =<*p*>.1 by A4,A11,A13,FINSEQ_1:def 7 .=p by FINSEQ_1:def 8; now per cases; case A23:n1=len g; now assume A24: n2<>len g; then n2<len g by A21,REAL_1:def 5; then A25:n2<=len mid(f,1,Index(p,f)) by A13,NAT_1:38; then g.n2=mid(f,1,Index(p,f)).n2 by A4,A21,SCMFSA_7:9; then g.n2=f.(n2+1-'1) by A6,A7,A8,A21,A25,Th27; then A26:p=f.n2 by A20,A22,A23,BINARITH:39; A27: n2 <= len f by A7,A10,A25,AXIOMS:22; 1 < n2 by A3,A21,A26,AXIOMS:21; then Index(p,f)+1 = n2 by A1,A26,A27,Th45; hence contradiction by A6,A9,A13,A24,AMI_5:4; end; hence x1=x2 by A23; case A28:n2=len g; now assume A29: n1<>len g; then n1<len g by A21,REAL_1:def 5; then A30:n1<=len mid(f,1,Index(p,f)) by A13,NAT_1:38; then g.n1=mid(f,1,Index(p,f)).n1 by A4,A21,SCMFSA_7:9; then g.n1=f.(n1+1-'1) by A6,A7,A8,A21,A30,Th27; then A31:p=f.n1 by A20,A22,A28,BINARITH:39; A32: n1 <= len f by A7,A10,A30,AXIOMS:22; 1 < n1 by A3,A21,A31,AXIOMS:21; then Index(p,f)+1 = n1 by A1,A31,A32,Th45; hence contradiction by A6,A9,A13,A29,AMI_5:4; end; hence x1=x2 by A28; case that A33: n1<>len g and A34: n2 <> len g; n1<len g by A21,A33,REAL_1:def 5; then A35:n1<=len mid(f,1,Index(p,f)) by A13,NAT_1:38; then A36:n1<=len f by A7,A10,AXIOMS:22; A37:g.n1=mid(f,1,Index(p,f)).n1 by A4,A21,A35,SCMFSA_7:9 .=f.n1 by A7,A10,A21,A35,Th32; n2 < len g by A21,A34,AXIOMS:21; then A38:n2<=len mid(f,1,Index(p,f)) by A13,NAT_1:38; then A39:n2<=len f by A7,A10,AXIOMS:22; g.n2=mid(f,1,Index(p,f)).n2 by A4,A21,A38,SCMFSA_7:9 .=f.n2 by A7,A10,A21,A38,Th32; hence x1=x2 by A17,A20,A21,A36,A37,A39; end; hence x1=x2; end; hence x1=x2; end; A40: f is unfolded by A1,TOPREAL1:def 10; A41: for j st 1 <= j & j + 2 <= len g holds LSeg(g,j) /\ LSeg(g,j+1) = {g/.(j+1)} proof let j;assume A42: 1 <= j & j + 2 <= len g; then j+1<=len g by Th10; then A43:LSeg(g,j) c= LSeg(f,j) by A2,A4,A42,Th51; j+(1+1)<=len g by A42; then A44:j+1+1<=len g by XCMPLX_1:1; A45:1<=j+1 by A42,Th11; then LSeg(g,j+1) c= LSeg(f,j+1) by A2,A4,A44,Th51; then A46:LSeg(g,j)/\ LSeg(g,j+1) c= LSeg(f,j)/\ LSeg(f,j+1) by A43,XBOOLE_1: 27; A47:j+1<=len g by A42,Th10; then LSeg(g,j)=LSeg(g/.j,g/.(j+1)) by A42,TOPREAL1:def 5; then A48:g/.(j+1) in LSeg(g,j) by TOPREAL1:6; A49:g/.(j+1)=g.(j+1) by A45,A47,FINSEQ_4:24; A50:Index(p,f)<=len f by A2,Th41; j+(1+1)<=len g by A42; then j+1+1<=len g by XCMPLX_1:1; then LSeg(g,j+1)=LSeg(g/.(j+1),g/.(j+1+1)) by A45,TOPREAL1:def 5; then g/.(j+1) in LSeg(g,j+1) by TOPREAL1:6; then g/.(j+1) in LSeg(g,j) /\ LSeg(g,j+1) by A48,XBOOLE_0:def 3; then A51:{g/.(j+1)} c= LSeg(g,j) /\ LSeg(g,j+1) by ZFMISC_1:37; now A52:len g=len mid(f,1,Index(p,f))+1 by A4,FINSEQ_2:19; Index(p,f)<=len f by A2,Th41; then A53: len g<=len f +1 by A10,A52,AXIOMS:24; now per cases by A53,REAL_1:def 5; case len g=len f +1; then len f =Index(p,f) by A10,A52,XCMPLX_1:2; hence contradiction by A2,Th41; case len g<len f+1; then len g<=len f by NAT_1:38; then A54:j+2<=len f by A42,AXIOMS:22; A55:j+1<=Index(p,f) by A10,A44,A52,REAL_1:53; then A56:j+1<=len f by A50,AXIOMS:22; A57:LSeg(g,j)/\ LSeg(g,j+1) c= {f/.(j+1)} by A40,A42,A46,A54,TOPREAL1:def 8; A58:f.(j+1)=f/.(j+1) by A45,A56,FINSEQ_4:24; g.(j+1)=mid(f,1,Index(p,f)).(j+1) by A4,A10,A45,A55,SCMFSA_7:9 .=f.(j+1) by A7,A45,A55,Th32; hence LSeg(g,j)/\ LSeg(g,j+1) = {g/.(j+1)} by A49,A51,A57,A58,XBOOLE_0:def 10; end; hence LSeg(g,j) /\ LSeg(g,j+1) = {g/.(j+1)}; end; hence LSeg(g,j) /\ LSeg(g,j+1) = {g/.(j+1)}; end; A59: f is s.n.c. by A1,TOPREAL1:def 10; A60: for j1,j2 st j1+1 < j2 holds LSeg(g,j1) misses LSeg(g,j2) proof let j1,j2;assume A61:j1+1 < j2; j1>=0 by NAT_1:18; then A62: j1=0 or j1>=0+1 by NAT_1:38; now per cases by A62,REAL_1:def 5; case j1=0; then LSeg(g,j1)={} by TOPREAL1:def 5; then LSeg(g,j1) /\ LSeg(g,j2) = {}; hence LSeg(g,j1) misses LSeg(g,j2) by XBOOLE_0:def 7; case that A63: j1=1 or j1>1 and A64: j2+1<=len g; j2<len g by A64,NAT_1:38; then j1+1<len g by A61,AXIOMS:22; then A65:LSeg(g,j1) c= LSeg(f,j1) by A2,A4,A63,Th51; 1+1<=j1+1 by A63,AXIOMS:24; then 2<=j2 by A61,AXIOMS:22; then 1<=j2 by AXIOMS:22; then LSeg(g,j2) c= LSeg(f,j2) by A2,A4,A64,Th51; then A66:LSeg(g,j1)/\ LSeg(g,j2) c= LSeg(f,j1)/\ LSeg(f,j2) by A65,XBOOLE_1:27; LSeg(f,j1) misses LSeg(f,j2) by A59,A61,TOPREAL1:def 9; then LSeg(f,j1) /\ LSeg(f,j2) = {} by XBOOLE_0:def 7; then LSeg(g,j1) /\ LSeg(g,j2) = {} by A66,XBOOLE_1:3; hence LSeg(g,j1) misses LSeg(g,j2) by XBOOLE_0:def 7; case j2+1>len g; then LSeg(g,j2)={} by TOPREAL1:def 5; then LSeg(g,j1)/\ LSeg(g,j2)={}; hence thesis by XBOOLE_0:def 7; end; hence LSeg(g,j1) misses LSeg(g,j2); end; A67: f is special by A1,TOPREAL1:def 10; for j st 1 <= j & j+1 <= len g holds (g/.j)`1 = (g/.(j+1))`1 or (g/.j)`2 = (g/.(j+1))`2 proof let j;assume A68: 1 <= j & j+1 <= len g; A69: now j+1<=Index(p,f)+1 by A4,A10,A68,FINSEQ_2:19; then A70:j<=Index(p,f) by REAL_1:53; Index(p,f)<len f by A2,Th41; then j<len f by A70,AXIOMS:22; hence j+1<=len f by NAT_1:38; end; A71:LSeg(g,j) c= LSeg(f,j) by A2,A4,A68,Th51; A72:LSeg(g,j) = LSeg(g/.j,g/.(j+1)) by A68,TOPREAL1:def 5; A73:LSeg(f,j) = LSeg(f/.j,f/.(j+1)) by A68,A69,TOPREAL1:def 5; (f/.j)`1 = (f/.(j+1))`1 or (f/.j)`2 = (f/.(j+1))`2 by A67,A68,A69,TOPREAL1:def 7; hence (g/.j)`1 = (g/.(j+1))`1 or (g/.j)`2 = (g/.(j+1))`2 by A71,A72,A73,Th36; end; then g is one-to-one & len g >= 2 & g is unfolded s.n.c. special by A15,A19,A41,A60,FUNCT_1:def 8,TOPREAL1:def 7,def 8,def 9; then g is_S-Seq by TOPREAL1:def 10; hence g is_S-Seq_joining f/.1,p by A12,A14,Def3; end; begin ::----------------------------------------------------------------------: :: Left and Right Cutting Functions for Finite Sequences in TOP-REAL 2 : ::----------------------------------------------------------------------: definition let f be FinSequence of TOP-REAL 2,p be Point of TOP-REAL 2; func L_Cut(f,p) -> FinSequence of TOP-REAL 2 equals :Def4: <*p*>^mid(f,Index(p,f)+1,len f) if p<>f.(Index(p,f)+1) otherwise mid(f,Index(p,f)+1,len f); correctness; func R_Cut(f,p) -> FinSequence of TOP-REAL 2 equals :Def5: mid(f,1,Index(p,f))^<*p*> if p<>f.1 otherwise <*p*>; correctness; end; theorem Th53: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p = f.(Index(p,f)+1) & p <> f.len f holds Index(p,Rev f) + Index(p,f) + 1 = len f proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2 such that A1: f is_S-Seq and A2: p in L~f and A3: p = f.(Index(p,f)+1) and A4: p <> f.len f; A5: Rev f is_S-Seq by A1,SPPOL_2:47; A6: len f = len Rev f by FINSEQ_5:def 3; len f <= len f + Index(p,f) by NAT_1:29; then A7: len f - Index(p,f) <= len Rev f by A6,REAL_1:86; Index(p,f) < len f by A2,Th41; then A8: Index(p,f)+1 <= len f by NAT_1:38; 1 <= Index(p,f)+1 by NAT_1:29; then Index(p,f)+1 in dom f by A8,FINSEQ_3:27; then A9: Index(p,f)+1 in dom Rev f by FINSEQ_5:60; Index(p,f)+1 < len f by A3,A4,A8,AXIOMS:21; then A10: 1 < len f - Index(p,f) by REAL_1:86; Index(p,f) <= len f by A2,Th41; then A11: len f - Index(p,f) = len f -' Index(p,f) by SCMFSA_7:3; p = (Rev Rev f).(Index(p,f)+1) by A3,FINSEQ_6:29 .= (Rev f).(len Rev f - (Index(p,f)+1) + 1) by A9,FINSEQ_5:61 .= (Rev f).(len Rev f - Index(p,f) - 1 + 1) by XCMPLX_1:36 .= (Rev f).(len Rev f - Index(p,f)) by XCMPLX_1:27 .= (Rev f).(len f - Index(p,f)) by FINSEQ_5:def 3; then A12: Index(p,Rev f) + 1 = len f -' Index(p,f) by A5,A7,A10,A11,Th45; thus Index(p,Rev f) + Index(p,f) + 1 = Index(p,Rev f) + 1 + Index(p,f) by XCMPLX_1:1 .= len f by A11,A12,XCMPLX_1:27; end; theorem Th54: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p <> f.(Index(p,f)+1) holds Index(p,Rev f) + Index(p,f) = len f proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2 such that A1: f is_S-Seq and A2: p in L~f and A3: p <> f.(Index(p,f)+1); A4: Rev f is_S-Seq by A1,SPPOL_2:47; A5: Index(p,f) < len f by A2,Th41; then A6: len f -' Index(p,f) + Index(p,f) = len f by AMI_5:4; A7: len f = len Rev f by FINSEQ_5:def 3; p in LSeg(f,Index(p,f)) by A2,Th42; then A8: p in LSeg(Rev f,len f -' Index(p,f)) by A6,SPPOL_2:2; A9: Index(p,f) < len f by A2,Th41; then Index(p,f) + 1 <= len f by NAT_1:38; then 1<=len f - Index(p,f) by REAL_1:84; then A10: 1<=len f -' Index(p,f) by Th1; 0+1 <= Index(p,f) by A2,Th41; then 0 < Index(p,f) by NAT_1:38; then len f + 0 < len f + Index(p,f) by REAL_1:53; then len f - Index(p,f) < len f by REAL_1:84; then A11: len f -' Index(p,f) < len f by A5,SCMFSA_7:3; then A12: len f -' Index(p,f)+1<=len Rev f by A7,NAT_1:38; len f -' Index(p,f) in dom f by A10,A11,FINSEQ_3:27; then (Rev f).(len f -' Index(p,f)) = f.(len f - (len f -' Index(p,f)) + 1) by FINSEQ_5:61 .= f.(len f - (len f - Index(p,f)) + 1) by A9,SCMFSA_7:3 .= f.(len f - len f + Index(p,f) + 1) by XCMPLX_1:37 .= f.(0 + Index(p,f) + 1) by XCMPLX_1:14; then len f -' Index(p,f)=Index(p,Rev f) by A3,A4,A8,A12,Th47; hence Index(p,Rev f) + Index(p,f) = len f by A9,AMI_5:4; end; theorem Th55: for D for f being FinSequence of D, k being Nat, p being Element of D holds (<*p*>^f)|(k+1) = <*p*>^(f|k) proof let D; let f be FinSequence of D, k be Nat, p be Element of D; A1: f|Seg k = f|k by TOPREAL1:def 1; thus (<*p*>^f)|(k+1) = (<*p*>^f)|Seg(k+1) by TOPREAL1:def 1 .= (<*p*>^f)|Seg(k+len<*p*>) by FINSEQ_1:56 .= <*p*>^(f|k) by A1,FINSEQ_6:16; end; theorem Th56: for D for f being non empty FinSequence of D, k1,k2 being Nat st k1 < k2 & k1 in dom f holds mid(f,k1,k2) = <*f.k1*>^ mid(f,k1+1,k2) proof let D; let f be non empty FinSequence of D, k1,k2 being Nat; assume A1: k1 < k2; then A2: k1+1 <= k2 by NAT_1:38; A3: 1 <= k2 -' k1 proof per cases by A2,AXIOMS:21; suppose k1 + 1 = k2; hence 1 <= k2 -' k1 by BINARITH:39; suppose A4: k1 + 1 < k2; k2-'k1 <= 1 implies k2 <= 1 + k1 proof assume k2-'k1 <= 1; then k2-'k1 +k1 <= 1 + k1 by AXIOMS:24; hence k2 <= 1 + k1 by A1,AMI_5:4; end; hence 1 <= k2 -' k1 by A4; end; assume A5: k1 in dom f; then A6: f.k1 = f/.k1 by FINSEQ_4:def 4; k2-'k1 = k2-k1 by A3,Th1; then A7: k2-'k1-'1 = k2-k1-1 by A3,SCMFSA_7:3 .= k2-(k1+1) by XCMPLX_1:36 .= k2-'(k1+1) by A2,SCMFSA_7:3; 1 <= k1 by A5,FINSEQ_3:27; then k1 -' 1 + 1 = k1 by AMI_5:4; then (f/^(k1-'1)) = <*f/.k1*>^(f/^k1) by A5,FINSEQ_5:34; hence mid(f,k1,k2) = (<*f/.k1*>^ (f/^k1))|(k2-'k1+1) by A1,Def1 .= <*f.k1*>^ ((f/^k1)|(k2-'k1)) by A6,Th55 .= <*f.k1*>^ ((f/^k1)|(k2-'(k1+1)+1)) by A3,A7,AMI_5:4 .= <*f.k1*>^ ((f/^(k1+1-'1))|(k2-'(k1+1)+1)) by BINARITH:39 .= <*f.k1*>^ mid(f,k1+1,k2) by A2,Def1; end; definition let f be non empty FinSequence; cluster Rev f -> non empty; coherence proof dom Rev f = dom f by FINSEQ_5:60; hence thesis by RELAT_1:60,64; end; end; theorem Th57: for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f holds L_Cut(Rev f,p) = Rev R_Cut(f,p) proof let f be non empty FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2 such that A1: f is_S-Seq and A2: p in L~f; A3: Rev f is_S-Seq by A1,SPPOL_2:47; A4: p in L~Rev f by A2,SPPOL_2:22; A5: Rev Rev f = f by FINSEQ_6:29; A6: len f = len Rev f by FINSEQ_5:def 3; A7: L~f = L~Rev f by SPPOL_2:22; A8: dom Rev f = dom f by FINSEQ_5:60; A9: 1 <= Index(p, Rev f)+1 by NAT_1:29; Index(p, Rev f) < len Rev f by A2,A7,Th41; then A10: Index(p, Rev f) + 1 <= len f by A6,NAT_1:38; then A11: Index(p, Rev f)+1 in dom f by A9,FINSEQ_3:27; A12: 1+1 <= len f by A1,TOPREAL1:def 10; then A13: 1 < len f by NAT_1:38; A14: 1 <= Index(p,f) by A2,Th41; A15: Index(p,f) < len f by A2,Th41; A16: 1 in dom f by A13,FINSEQ_3:27; A17: 2 in dom f by A12,FINSEQ_3:27; A18: len f in dom f by A13,FINSEQ_3:27; per cases; suppose A19: p = f.len f; then A20: p = (Rev f).1 by FINSEQ_5:65; then p = (Rev f)/.1 by A8,A16,FINSEQ_4:def 4; then A21: Index(p,Rev f) = 1 by A6,A12,Th44; f is one-to-one by A1,TOPREAL1:def 10; then A22: p<>f.1 by A13,A16,A18,A19,FUNCT_1:def 8; Rev f is one-to-one by A3,TOPREAL1:def 10; then A23: p <> (Rev f).(1+1) by A8,A16,A17,A20,FUNCT_1:def 8; then Index(p,Rev f) + Index(p,f) = len f by A3,A4,A5,A6,A21,Th54; then A24: Index(p,Rev f) = len f - Index(p,f) by XCMPLX_1:26; thus L_Cut(Rev f,p) = <*p*>^mid(Rev f,Index(p,Rev f)+1,len f) by A6,A21,A23,Def4 .= <*p*>^mid(Rev f,len f -'Index(p,f)+1,len f) by A15,A24,SCMFSA_7:3 .= <*p*>^mid(Rev f,len f -'Index(p,f)+1,len f -' 1 + 1) by A13,AMI_5: 4 .= <*p*>^Rev mid(f,1,Index(p,f)) by A13,A14,A15,Th22 .= Rev(mid(f,1,Index(p,f))^<*p*>) by FINSEQ_5:66 .= Rev R_Cut(f,p) by A22,Def5; suppose A25: p = f.1; then A26: p = (Rev f).len f by FINSEQ_5:65; A27:len (Rev f/^(len Rev f-'1))=len Rev f-'(len Rev f-'1) by Th19; A28: len Rev f-'1+1=len Rev f by A6,A13,AMI_5:4; then A29:(Rev f/^(len Rev f-'1)).1=Rev f.len Rev f by Th23; 1<=len Rev f-(len Rev f-'1) by A28,XCMPLX_1:26; then A30: 1<=len (Rev f/^(len Rev f-'1)) by A27,Th1; then 0<len (Rev f/^(len Rev f-'1)) by AXIOMS:22; then A31:Rev f/^(len Rev f-'1) is non empty by FINSEQ_1:25; len Rev f-'len Rev f+1=len Rev f-len Rev f+1 by SCMFSA_7:3 .=1 by XCMPLX_1:25; then A32: mid(Rev f,len Rev f,len Rev f)=(Rev f/^(len Rev f-'1))|1 by Def1 .=<*(Rev f/^(len Rev f-'1))/.1 *> by A31,FINSEQ_5:23 .=<*Rev f.len Rev f*> by A29,A30,FINSEQ_4:24; Index(p,Rev f) + 1 = len f by A3,A6,A13,A26,Th45; hence L_Cut(Rev f,p) = <*p*> by A6,A26,A32,Def4 .= Rev <*p*> by FINSEQ_5:63 .= Rev R_Cut(f,p) by A25,Def5; suppose that A33: p <> f.1 and A34: p <> f.len f and A35: p = f.(Index(p,f)+1); A36: p <> (Rev f).len f by A33,FINSEQ_5:65; len f = Index(p,Rev f) + Index(p,f) + 1 by A1,A2,A34,A35,Th53 .= Index(p,Rev f) + (Index(p,f) + 1) by XCMPLX_1:1; then Index(p,f) + 1 = len f - Index(p,Rev f) by XCMPLX_1:26; then A37: p = f.(len f - Index(p, Rev f) - 1 + 1) by A35,XCMPLX_1:27 .= f.(len f - (Index(p, Rev f)+1) + 1) by XCMPLX_1:36 .= (Rev f).(Index(p, Rev f)+1) by A11,FINSEQ_5:61; A38: len f = Index(p,Rev f) + Index(p,f) + 1 by A1,A2,A34,A35,Th53 .= Index(p,f) + (Index(p,Rev f) + 1) by XCMPLX_1:1; A39: len f -' Index(p,f) = len f - Index(p,f) by A15,SCMFSA_7:3 .= Index(p,Rev f)+1 by A38,XCMPLX_1:26; A40: Index(p, Rev f)+1 < len f by A10,A36,A37,AXIOMS:21; thus L_Cut(Rev f,p) = mid(Rev f,Index(p,Rev f)+1,len f) by A6,A37,Def4 .= <*p*>^mid(Rev f,len f -' Index(p,f)+1, len f) by A8,A11,A37,A39,A40,Th56 .= <*p*>^mid(Rev f,len f -' Index(p,f)+1, len f-'1+1) by A13,AMI_5:4 .= <*p*>^Rev mid(f,1,Index(p,f)) by A13,A14,A15,Th22 .= Rev (mid(f,1,Index(p,f))^<*p*>) by FINSEQ_5:66 .= Rev R_Cut(f,p) by A33,Def5; suppose that A41: p <> f.1 and A42: p <> f.(Index(p,f)+1); A43: p <> (Rev f).len f by A41,FINSEQ_5:65; A44: now assume A45: p = (Rev f).(Index(p, Rev f)+1); then len Rev f = Index(p,Rev Rev f) + Index(p,Rev f) + 1 by A3,A4,A6,A43,Th53 .= Index(p,f) + 1 + Index(p,Rev f) by A5,XCMPLX_1:1; then A46: Index(p,f) + 1 = len f - Index(p,Rev f) by A6,XCMPLX_1:26; p = f.(len f - (Index(p, Rev f)+1) + 1) by A11,A45,FINSEQ_5:61 .= f.(len f - Index(p, Rev f) - 1 + 1) by XCMPLX_1:36 .= f.(Index(p,f)+1) by A46,XCMPLX_1:27; hence contradiction by A42; end; A47: len f = Index(p,Rev f) + Index(p,f) by A1,A2,A42,Th54; A48: Index(p, f) < len f by A2,Th41; Index(p,Rev f) = len f - Index(p,f) by A47,XCMPLX_1:26 .= len f -' Index(p,f) by A48,SCMFSA_7:3; hence L_Cut(Rev f,p) = <*p*>^mid(Rev f,len f -' Index(p,f)+1, len f) by A6,A44,Def4 .= <*p*>^mid(Rev f,len f -' Index(p,f)+1, len f-'1+1) by A13,AMI_5:4 .= <*p*>^Rev mid(f,1,Index(p,f)) by A13,A14,A15,Th22 .= Rev (mid(f,1,Index(p,f))^<*p*>) by FINSEQ_5:66 .= Rev R_Cut(f,p) by A41,Def5; end; theorem Th58: for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f holds (L_Cut(f,p)).1=p & for i st 1<i & i<=len L_Cut(f,p) holds (p = f.(Index(p,f)+1) implies (L_Cut(f,p)).i=f.(Index(p,f)+i)) & (p <> f.(Index(p,f)+1) implies (L_Cut(f,p)).i=f.(Index(p,f)+i-1)) proof let f be non empty FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2 such that A1: p in L~f; now per cases; suppose A2: p = f.(Index(p,f)+1); then A3: L_Cut(f,p)=mid(f,Index(p,f)+1,len f) by Def4; A4: 1 <= Index(p,f)+1 by NAT_1:29; Index(p,f) < len f by A1,Th41; then A5: Index(p,f)+1 <= len f by NAT_1:38; 1 in dom f by FINSEQ_5:6; then 1 <= len f by FINSEQ_3:27; hence (L_Cut(f,p)).1 = p by A2,A3,A4,A5,Th27; suppose p<> f.(Index(p,f)+1); then L_Cut(f,p)=<*p*>^mid(f,Index(p,f)+1,len f) by Def4; hence (L_Cut(f,p)).1=p by Th16; end; hence (L_Cut(f,p)).1=p; let i;assume A6: 1<i & i<=len L_Cut(f,p); Index(p,f) < len f by A1,Th41; then A7:1<=Index(p,f)+1 & Index(p,f)+1<=len f by NAT_1:29,38; then A8:1<=len f by AXIOMS:22; A9:len <*p*><=i by A6,FINSEQ_1:57; A10:len <*p*><i by A6,FINSEQ_1:56; A11: 1<=i-1 by A6,SPPOL_1:6; A12:(i-'1)+1=i-1+1 by A6,SCMFSA_7:3 .=i by XCMPLX_1:27; hereby assume p = f.(Index(p,f)+1); then L_Cut(f,p)=mid(f,Index(p,f)+1,len f) by Def4; hence (L_Cut(f,p)).i = f.(i+(Index(p,f)+1)-'1) by A6,A7,A8,Th27 .= f.(i+Index(p,f)+1-'1) by XCMPLX_1:1 .= f.(Index(p,f)+i) by BINARITH:39; end; assume p <> f.(Index(p,f)+1); then A13: L_Cut(f,p)=<*p*>^mid(f,Index(p,f)+1,len f) by Def4; then A14: i<=len <*p*>+len mid(f,Index(p,f)+1,len f) by A6,FINSEQ_1:35; len mid(f,Index(p,f)+1,len f)=len f -'(Index(p,f)+1)+1 by A7,A8,Th27; then len <*p*>+len mid(f,Index(p,f)+1,len f) =1+(len f -'(Index(p,f)+1)+1) by FINSEQ_1:57 .=1+(len f -(Index(p,f)+1)+1) by A7,SCMFSA_7:3 .=1+(len f -Index(p,f)-1+1) by XCMPLX_1:36 .=(len f -Index(p,f))+1 by XCMPLX_1:27; then i-1<=len f -Index(p,f)+1-1 by A14,REAL_1:49; then i-1<=len f -Index(p,f)-1+1 by XCMPLX_1:29; then i-1<=len f -(Index(p,f)+1)+1 by XCMPLX_1:36; then A15:1<=i-'1 & i-'1<=len f -(Index(p,f)+1)+1 by A11,Th1; A16: (L_Cut(f,p)).i =mid(f,Index(p,f)+1,len f).(i-len <*p*>) by A6,A10,A13,Th15 .=mid(f,Index(p,f)+1,len f).(i-'len <*p*>) by A9,SCMFSA_7:3 .=mid(f,Index(p,f)+1,len f).(i-'1) by FINSEQ_1:56 .=f.((i-'1)+(Index(p,f)+1)-'1) by A7,A15,Th31 .=f.(Index(p,f)+i-'1) by A12,XCMPLX_1:1; i <=i+Index(p,f) by NAT_1:29; then 1<=i+Index(p,f) by A6,AXIOMS:22; hence (L_Cut(f,p)).i=f.(Index(p,f)+i-1) by A16,SCMFSA_7:3; end; theorem Th59: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f holds (R_Cut(f,p)).(len R_Cut(f,p))=p & for i st 1<=i & i<=Index(p,f) holds R_Cut(f,p).i=f.i proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume that A1: f is_S-Seq and A2: p in L~f; f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by A1,TOPREAL1:def 10; then A3:1<=len f by AXIOMS:22; A4:1<=Index(p,f) & Index(p,f)<=len f by A2,Th41; then A5:len mid(f,1,Index(p,f))=Index(p,f)-'1+1 by A3,Th27 .=Index(p,f) by A4,AMI_5:4; now per cases; case p<>f.1; then A6:R_Cut(f,p)= mid(f,1,Index(p,f))^<*p*> by Def5; len (mid(f,1,Index(p,f))^<*p*>)= len mid(f,1,Index(p,f))+len <*p*> by FINSEQ_1:35 .= len mid(f,1,Index(p,f))+1 by FINSEQ_1:56; hence (R_Cut(f,p)).(len R_Cut(f,p))=p by A6,FINSEQ_1:59; case p=f.1; then A7:R_Cut(f,p)=<*p*> by Def5; then len R_Cut(f,p) = 1 by FINSEQ_1:57; hence (R_Cut(f,p)).(len R_Cut(f,p))=p by A7,FINSEQ_1:57; end; hence (R_Cut(f,p)).(len R_Cut(f,p))=p; thus for i st 1<=i & i<=Index(p,f) holds R_Cut(f,p).i=f.i proof let i;assume A8: 1<=i & i<=Index(p,f); now per cases; case p<>f.1; then (R_Cut(f,p)).i=(mid(f,1,Index(p,f))^<*p*>).i by Def5 .=mid(f,1,Index(p,f)).i by A5,A8,SCMFSA_7:9 .=f.i by A4,A8,Th32; hence R_Cut(f,p).i=f.i; case A9: p=f.1; then A10: (R_Cut(f,p)) = <*p*> by Def5; A11: 1+1 <= len f by A1,TOPREAL1:def 10; then 1 < len f by NAT_1:38; then 1 in dom f by FINSEQ_3:27; then p = f/.1 by A9,FINSEQ_4:def 4; then Index(p,f) = 1 by A11,Th44; then i = 1 by A8,AXIOMS:21; hence R_Cut(f,p).i = f.i by A9,A10,FINSEQ_1:57; end; hence (R_Cut(f,p)).i=f.i; end; end; theorem Th60: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f holds (p<>f.1 implies len R_Cut(f,p)=Index(p,f)+1)& (p=f.1 implies len R_Cut(f,p)=Index(p,f)) proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume that A1: f is_S-Seq and A2: p in L~f; consider i such that A3: 1 <= i & i+1 <= len f & p in LSeg(f,i) by A2,SPPOL_2:13; i<=len f by A3,Th9; then A4:1<=len f by A3,AXIOMS:22; A5:1<=Index(p,f) & Index(p,f)<=len f by A2,Th41; now per cases; case p<>f.1; then R_Cut(f,p)=mid(f,1,Index(p,f))^<*p*> by Def5; hence len R_Cut(f,p) = len mid(f,1,Index(p,f))+len <*p*> by FINSEQ_1:35 .= len mid(f,1,Index(p,f))+1 by FINSEQ_1:56 .= Index(p,f)-'1+1+1 by A4,A5,Th27 .=Index(p,f)+1 by A5,AMI_5:4; case A6:p=f.1; then A7:R_Cut(f,p)=<*p*> by Def5; A8: len f >= 1+1 by A1,TOPREAL1:def 10; len f <> 0 by A1,TOPREAL1:def 10; then f <> {} by FINSEQ_1:25; then 1 in dom f by FINSEQ_5:6; then A9: p = f/.1 by A6,FINSEQ_4:def 4; thus len R_Cut(f,p)= 1 by A7,FINSEQ_1:56 .= Index(p,f) by A8,A9,Th44; end; hence (p<>f.1 implies len R_Cut(f,p)=Index(p,f)+1)& (p=f.1 implies len R_Cut(f,p)=Index(p,f)); end; theorem Th61:for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p<>f.len f holds ( p = f.(Index(p,f)+1) implies len L_Cut(f,p)=len f -Index(p,f)) & ( p <> f.(Index(p,f)+1) implies len L_Cut(f,p)=len f -Index(p,f)+1) proof let f be non empty FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume that A1: f is_S-Seq and A2: p in L~f and A3: p<>f.len f; A4: Rev f is_S-Seq & p in L~Rev f by A1,A2,SPPOL_2:22,47; A5: p <> (Rev f).1 by A3,FINSEQ_5:65; L_Cut(f,p) = L_Cut(Rev Rev f,p) by FINSEQ_6:29 .= Rev R_Cut(Rev f,p) by A4,Th57; then A6: len L_Cut(f,p) = len R_Cut(Rev f,p) by FINSEQ_5:def 3 .= Index(p,Rev f)+1 by A4,A5,Th60; now per cases; case A7: p = f.(Index(p,f)+1); Index(p,Rev f) + (Index(p,f) + 1) = Index(p,Rev f) + Index(p,f) + 1 by XCMPLX_1:1 .= len f by A1,A2,A3,A7,Th53; then Index(p,Rev f) = len f - (Index(p,f) + 1) by XCMPLX_1:26 .= len f - Index(p,f) - 1 by XCMPLX_1:36; hence len L_Cut(f,p) = len f - Index(p,f) by A6,XCMPLX_1:27; case p <> f.(Index(p,f)+1); then Index(p,Rev f) + Index(p,f) = len f by A1,A2,Th54; hence len L_Cut(f,p) = len f - Index(p,f) + 1 by A6,XCMPLX_1:26; end; hence thesis; end; definition let p1,p2,q1,q2 be Point of TOP-REAL 2; pred LE q1,q2,p1,p2 means :Def6:q1 in LSeg(p1,p2) & q2 in LSeg(p1,p2) & for r1,r2 being Real st 0<=r1 & r1<=1 & q1=(1-r1)*p1+r1*p2 & 0<=r2 & r2<=1 & q2=(1-r2)*p1+r2*p2 holds r1<=r2; end; definition let p1,p2,q1,q2 be Point of TOP-REAL 2; pred LT q1,q2,p1,p2 means :Def7:LE q1,q2,p1,p2 & q1<>q2; end; theorem for p1,p2,q1,q2 being Point of TOP-REAL 2 st LE q1,q2,p1,p2 & LE q2,q1,p1,p2 holds q1=q2 proof let p1,p2,q1,q2 be Point of TOP-REAL 2; assume A1:LE q1,q2,p1,p2 & LE q2,q1,p1,p2; then A2:q1 in LSeg(p1,p2) & q2 in LSeg(p1,p2) & for r1,r2 being Real st 0<=r1 & r1<=1 & q1=(1-r1)*p1+r1*p2 & 0<=r2 & r2<=1 & q2=(1-r2)*p1+r2*p2 holds r1<=r2 by Def6; then consider r1 such that A3: 0<=r1 & r1<=1 & q1 = (1-r1)*p1+r1*p2 by SPPOL_1 :21; consider r2 such that A4: 0<=r2 & r2<=1 & q2 = (1-r2)*p1+r2*p2 by A2,SPPOL_1: 21; A5:r1<=r2 by A1,A3,A4,Def6; r2<=r1 by A1,A3,A4,Def6; then r1=r2 by A5,AXIOMS:21; hence q1=q2 by A3,A4; end; theorem Th63:for p1,p2,q1,q2 being Point of TOP-REAL 2 st q1 in LSeg(p1,p2) & q2 in LSeg(p1,p2) & p1<>p2 holds (LE q1,q2,p1,p2 or LT q2,q1,p1,p2) & not(LE q1,q2,p1,p2 & LT q2,q1,p1,p2) proof let p1,p2,q1,q2 be Point of TOP-REAL 2; assume A1: q1 in LSeg(p1,p2) & q2 in LSeg(p1,p2)& p1<>p2; then consider r1 such that A2: 0 <= r1 & r1 <= 1 & q1= (1-r1)*p1 + r1*p2 by SPPOL_1:21; consider r2 such that A3: 0 <= r2 & r2 <= 1& q2= (1-r2)*p1 + r2*p2 by A1,SPPOL_1:21; A4:now per cases; case A5:r1<=r2; for s1,s2 being Real st 0<=s1 & s1<=1 & q1=(1-s1)*p1+s1*p2 & 0<=s2 & s2<=1 & q2=(1-s2)*p1+s2*p2 holds s1<=s2 proof let s1,s2 be Real; assume A6: 0<=s1 & s1<=1 & q1=(1-s1)*p1+s1*p2 & 0<=s2 & s2<=1 & q2=(1-s2)*p1+s2*p2; then (1-s1)*p1+(s1*p2-s1*p2)=(1-r1)*p1+r1*p2-s1*p2 by A2,EUCLID:49; then (1-s1)*p1+(s1*p2-s1*p2)=(1-r1)*p1+(r1*p2-s1*p2) by EUCLID:49; then (1-s1)*p1+(0.REAL 2)=(1-r1)*p1+(r1*p2-s1*p2) by EUCLID:46; then (1-s1)*p1=(1-r1)*p1+(r1*p2-s1*p2) by EUCLID:31; then (1-s1)*p1=(1-r1)*p1+(r1-s1)*p2 by EUCLID:54; then (1-s1)*p1-(1-r1)*p1=(r1-s1)*p2+((1-r1)*p1-(1-r1)*p1) by EUCLID:49; then (1-s1)*p1-(1-r1)*p1=(r1-s1)*p2+(0.REAL 2) by EUCLID:46; then (1-s1)*p1-(1-r1)*p1=(r1-s1)*p2 by EUCLID:31; then ((1-s1)-(1-r1))*p1=(r1-s1)*p2 by EUCLID:54; then ((1-s1)-1+r1)*p1=(r1-s1)*p2 by XCMPLX_1:37; then ((1+-s1)-1+r1)*p1=(r1-s1)*p2 by XCMPLX_0:def 8; then (-s1+r1)*p1=(r1-s1)*p2 by XCMPLX_1:26; then (r1-s1)*p1=(r1-s1)*p2 by XCMPLX_0:def 8; then (r1-s1)=0 or p1=p2 by EUCLID:38; then A7:r1=s1 by A1,XCMPLX_1:15; (1-s2)*p1+(s2*p2-s2*p2)=(1-r2)*p1+r2*p2-s2*p2 by A3,A6,EUCLID:49; then (1-s2)*p1+(s2*p2-s2*p2)=(1-r2)*p1+(r2*p2-s2*p2) by EUCLID:49; then (1-s2)*p1+(0.REAL 2)=(1-r2)*p1+(r2*p2-s2*p2) by EUCLID:46; then (1-s2)*p1=(1-r2)*p1+(r2*p2-s2*p2) by EUCLID:31; then (1-s2)*p1=(1-r2)*p1+(r2-s2)*p2 by EUCLID:54; then (1-s2)*p1-(1-r2)*p1=(r2-s2)*p2+((1-r2)*p1-(1-r2)*p1) by EUCLID:49; then (1-s2)*p1-(1-r2)*p1=(r2-s2)*p2+(0.REAL 2) by EUCLID:46; then (1-s2)*p1-(1-r2)*p1=(r2-s2)*p2 by EUCLID:31; then ((1-s2)-(1-r2))*p1=(r2-s2)*p2 by EUCLID:54; then ((1-s2)-1+r2)*p1=(r2-s2)*p2 by XCMPLX_1:37; then ((1+-s2)-1+r2)*p1=(r2-s2)*p2 by XCMPLX_0:def 8; then (-s2+r2)*p1=(r2-s2)*p2 by XCMPLX_1:26; then (r2-s2)*p1=(r2-s2)*p2 by XCMPLX_0:def 8; then (r2-s2)=0 or p1=p2 by EUCLID:38; hence s1<=s2 by A1,A5,A7,XCMPLX_1:15; end; hence (LE q1,q2,p1,p2 or LT q2,q1,p1,p2) by A1,Def6; case A8:r1>r2; for s2,s1 being Real st 0<=s2 & s2<=1 & q2=(1-s2)*p1+s2*p2 & 0<=s1 & s1<=1 & q1=(1-s1)*p1+s1*p2 holds s1>=s2 proof let s2,s1 be Real; assume A9:0<=s2 & s2<=1 & q2=(1-s2)*p1+s2*p2 & 0<=s1 & s1<=1 & q1=(1-s1)*p1+s1*p2; then (1-s1)*p1+(s1*p2-s1*p2)=(1-r1)*p1+r1*p2-s1*p2 by A2,EUCLID:49; then (1-s1)*p1+(s1*p2-s1*p2)=(1-r1)*p1+(r1*p2-s1*p2) by EUCLID:49; then (1-s1)*p1+(0.REAL 2)=(1-r1)*p1+(r1*p2-s1*p2) by EUCLID:46; then (1-s1)*p1=(1-r1)*p1+(r1*p2-s1*p2) by EUCLID:31; then (1-s1)*p1=(1-r1)*p1+(r1-s1)*p2 by EUCLID:54; then (1-s1)*p1-(1-r1)*p1=(r1-s1)*p2+((1-r1)*p1-(1-r1)*p1) by EUCLID:49; then (1-s1)*p1-(1-r1)*p1=(r1-s1)*p2+(0.REAL 2) by EUCLID:46; then (1-s1)*p1-(1-r1)*p1=(r1-s1)*p2 by EUCLID:31; then ((1-s1)-(1-r1))*p1=(r1-s1)*p2 by EUCLID:54; then ((1-s1)-1+r1)*p1=(r1-s1)*p2 by XCMPLX_1:37; then ((1+-s1)-1+r1)*p1=(r1-s1)*p2 by XCMPLX_0:def 8; then (-s1+r1)*p1=(r1-s1)*p2 by XCMPLX_1:26; then (r1-s1)*p1=(r1-s1)*p2 by XCMPLX_0:def 8; then (r1-s1)=0 or p1=p2 by EUCLID:38; then A10:r1=s1 by A1,XCMPLX_1:15; (1-s2)*p1+(s2*p2-s2*p2)=(1-r2)*p1+r2*p2-s2*p2 by A3,A9,EUCLID:49; then (1-s2)*p1+(s2*p2-s2*p2)=(1-r2)*p1+(r2*p2-s2*p2) by EUCLID:49; then (1-s2)*p1+(0.REAL 2)=(1-r2)*p1+(r2*p2-s2*p2) by EUCLID:46; then (1-s2)*p1=(1-r2)*p1+(r2*p2-s2*p2) by EUCLID:31 .=(r2-s2)*p2+(1-r2)*p1 by EUCLID:54; then (1-s2)*p1-(1-r2)*p1=(r2-s2)*p2+((1-r2)*p1-(1-r2)*p1) by EUCLID:49; then (1-s2)*p1-(1-r2)*p1=(r2-s2)*p2+(0.REAL 2) by EUCLID:46; then (1-s2)*p1-(1-r2)*p1=(r2-s2)*p2 by EUCLID:31; then ((1-s2)-(1-r2))*p1=(r2-s2)*p2 by EUCLID:54; then ((1-s2)-1+r2)*p1=(r2-s2)*p2 by XCMPLX_1:37; then ((1+-s2)-1+r2)*p1=(r2-s2)*p2 by XCMPLX_0:def 8; then (-s2+r2)*p1=(r2-s2)*p2 by XCMPLX_1:26; then (r2-s2)*p1=(r2-s2)*p2 by XCMPLX_0:def 8; then (r2-s2)=0 or p1=p2 by EUCLID:38; hence s1>=s2 by A1,A8,A10,XCMPLX_1:15; end; then LE q2,q1,p1,p2 & q1<>q2 by A1,A2,A3,A8,Def6; hence (LE q1,q2,p1,p2 or LT q2,q1,p1,p2) by Def7; end; now assume A11: LE q1,q2,p1,p2 & LT q2,q1,p1,p2; then A12:r1<=r2 by A2,A3,Def6; LE q2,q1,p1,p2 & q1<>q2 by A11,Def7; then r2<=r1 by A2,A3,Def6; then r1=r2 by A12,AXIOMS:21; hence contradiction by A2,A3,A11,Def7; end; hence (LE q1,q2,p1,p2 or LT q2,q1,p1,p2) & not(LE q1,q2,p1,p2 & LT q2,q1,p1,p2) by A4; end; theorem Th64: for f being non empty FinSequence of TOP-REAL 2, p,q,p1,p2 being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & q in L~f & Index(p,f)<Index(q,f) holds q in L~L_Cut(f,p) proof let f be non empty FinSequence of TOP-REAL 2,p,q,p1,p2 be Point of TOP-REAL 2; assume that A1: f is_S-Seq and A2: p in L~f and A3: q in L~f and A4: Index(p,f)<Index(q,f); set i1=Index(q,f)-'Index(p,f)+1; A5:1<=Index(q,f) & Index(q,f)<len f by A3,Th41; A6:Index(p,f)+1<=Index(q,f) by A4,NAT_1:38; then Index(p,f)+1-Index(p,f)<=Index(q,f)-Index(p,f) by REAL_1:49; then A7:1<=Index(q,f)-Index(p,f) by XCMPLX_1:26; then A8:0<=Index(q,f)-Index(p,f) by AXIOMS:22; then A9:1<=Index(q,f)-'Index(p,f) by A7,BINARITH:def 3; then A10:1<=Index(q,f)-'Index(p,f)+1 by Th11; 1+1<=Index(q,f)-'Index(p,f)+1 by A9,AXIOMS:24; then A11: 1<Index(q,f)-'Index(p,f)+1 by AXIOMS:22; then A12:len <*p*><Index(q,f)-'Index(p,f)+1 by FINSEQ_1:57; then A13:len <*p*><Index(q,f)-'Index(p,f)+1+1 by NAT_1:38; A14:1<=Index(q,f)-'Index(p,f)+1 by NAT_1:29; A15:1<=Index(p,f)+1 & Index(p,f)+1<=len f by A5,A6,AXIOMS:22,NAT_1:29; A16: 1<len f by A5,AXIOMS:22; then len mid(f,Index(p,f)+1,len f)=len f -'(Index(p,f)+1)+1 by A15,Th27; then A17:len <*p*>+len mid(f,Index(p,f)+1,len f)=1+(len f -'(Index(p,f)+1)+1) by FINSEQ_1:57 .=1+(len f -(Index(p,f)+1)+1) by A15,SCMFSA_7:3 .=1+(len f -Index(p,f)-1+1) by XCMPLX_1:36 .=(len f -Index(p,f))+1 by XCMPLX_1:27; A18:Index(q,f)-Index(p,f)<=len f -Index(p,f) by A5,REAL_1:49; then A19: Index(q,f)-Index(p,f)+1<=len f -Index(p,f)+1 by AXIOMS:24; then A20:Index(q,f)-'Index(p,f)+1<=len <*p*>+len mid(f,Index(p,f)+1,len f) by A4,A17,SCMFSA_7:3; Index(q,f)-Index(p,f)<=len f -Index(p,f)-1+1 by A18,XCMPLX_1:27; then Index(q,f)-Index(p,f)<=len f -(Index(p,f)+1)+1 by XCMPLX_1:36; then A21:Index(q,f)-'Index(p,f)<=len f - (Index(p,f)+1)+1 by A4,SCMFSA_7:3; A22:1<=Index(q,f)-'Index(p,f)+1+1 by NAT_1:29; A23: now assume p=f.len f; then len f <= Index(q,f) by A1,A6,A16,Th45; hence contradiction by A3,Th41; end; per cases; suppose A24: p = f.(Index(p,f)+1); then A25:len L_Cut(f,p)=len f -Index(p,f) by A1,A2,A23,Th61; then len L_Cut(f,p)>=Index(q,f)-'Index(p,f) by A4,A18,SCMFSA_7:3; then (L_Cut(f,p))/.(Index(q,f)-'Index(p,f)) =L_Cut(f,p).(Index(q,f)-'Index(p,f)) by A9,FINSEQ_4:24 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)) by A24,Def4 .=f.(Index(p,f)+1+(Index(q,f)-'Index(p,f))-1) by A9,A15,A21,Th31 .=f.(Index(p,f)+1+(Index(q,f)-Index(p,f))-1) by A4,SCMFSA_7:3 .=f.(1+(Index(p,f)+(Index(q,f)-Index(p,f)))-1) by XCMPLX_1:1 .=f.(1+(Index(p,f)+Index(q,f)-Index(p,f))-1) by XCMPLX_1:29 .=f.(1+(Index(q,f))-1) by XCMPLX_1:26 .=f.Index(q,f) by XCMPLX_1:26; then A26:(L_Cut(f,p))/.(Index(q,f)-'Index(p,f))=f/.Index(q,f) by A5,FINSEQ_4:24; A27:Index(q,f)<len f by A3,Th41; then A28:Index(q,f)+1<=len f by NAT_1:38; then Index(q,f)+1-Index(p,f)<=len f -Index(p,f) by REAL_1:49; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by XCMPLX_1:29; then A29:i1<=len L_Cut(f,p) by A8,A25,BINARITH:def 3; A30:1<=Index(q,f) & Index(q,f)+1<=len f & q in LSeg(f,Index(q,f)) by A3,A27,Th41,Th42,NAT_1:38; A31:Index(q,f)+1-Index(p,f)<=len f -Index(p,f) by A28,REAL_1:49; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by XCMPLX_1:29; then A32:len L_Cut(f,p)>=Index(q,f)-'Index(p,f)+1 by A4,A25,SCMFSA_7:3; Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by A31,XCMPLX_1:29; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f)-1+1 by XCMPLX_1:27; then Index(q,f)-Index(p,f)+1<=len f -(Index(p,f)+1)+1 by XCMPLX_1:36; then A33:Index(q,f)-'Index(p,f)+1<=len f - (Index(p,f)+1)+1 by A4,SCMFSA_7: 3; A34:1<=Index(q,f)+1 & Index(q,f)+1<=len f by A30,Th11; A35:(L_Cut(f,p))/.(Index(q,f)-'Index(p,f)+1) =L_Cut(f,p).(Index(q,f)-'Index(p,f)+1) by A11,A32,FINSEQ_4:24 .=(mid(f,Index(p,f)+1,len f)).(Index(q,f)-'Index(p,f)+1) by A24,Def4 .=f.(Index(p,f)+1+(Index(q,f)-'Index(p,f)+1)-1) by A10,A15,A33,Th31 .=f.(Index(p,f)+1+(Index(q,f)-Index(p,f)+1)-1) by A4,SCMFSA_7:3 .=f.(1+(Index(p,f)+(Index(q,f)-Index(p,f)+1))-1) by XCMPLX_1:1 .=f.(1+(Index(p,f)+(Index(q,f)-Index(p,f))+1)-1) by XCMPLX_1:1 .=f.(1+(Index(p,f)+Index(q,f)-Index(p,f)+1)-1) by XCMPLX_1:29 .=f.((Index(q,f)+1)+1-1) by XCMPLX_1:26 .=f.(Index(q,f)+1) by XCMPLX_1:26 .=f/.(Index(q,f)+1) by A34,FINSEQ_4:24; q in LSeg(f,Index(q,f)) by A3,Th42; then q in LSeg((L_Cut(f,p))/.((Index(q,f)-'Index(p,f))), (L_Cut(f,p))/.((Index(q,f)-'Index(p,f)+1))) by A5,A26,A28,A35,TOPREAL1:def 5; hence q in L~(L_Cut(f,p)) by A9,A29,SPPOL_2:15; suppose that A36: p <> f.(Index(p,f)+1); A37:len L_Cut(f,p)=len f -Index(p,f)+1 by A1,A2,A23,A36,Th61; then len L_Cut(f,p)>=Index(q,f)-'Index(p,f)+1 by A4,A19,SCMFSA_7:3; then (L_Cut(f,p))/.(Index(q,f)-'Index(p,f)+1) =L_Cut(f,p).(Index(q,f)-'Index(p,f)+1) by A14,FINSEQ_4:24 .=(<*p*>^mid(f,Index(p,f)+1,len f)).(Index(q,f)-'Index(p,f)+1) by A36,Def4 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)+1-len <*p*>) by A12,A20,Th15 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)+1-1) by FINSEQ_1:57 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)) by XCMPLX_1:26 .=f.(Index(p,f)+1+(Index(q,f)-'Index(p,f))-1) by A9,A15,A21,Th31 .=f.(Index(p,f)+1+(Index(q,f)-Index(p,f))-1) by A4,SCMFSA_7:3 .=f.(1+(Index(p,f)+(Index(q,f)-Index(p,f)))-1) by XCMPLX_1:1 .=f.(1+(Index(p,f)+Index(q,f)-Index(p,f))-1) by XCMPLX_1:29 .=f.(1+(Index(q,f))-1) by XCMPLX_1:26 .=f.Index(q,f) by XCMPLX_1:26; then A38:(L_Cut(f,p))/.(Index(q,f)-'Index(p,f)+1)=f/.Index(q,f) by A5,FINSEQ_4: 24; A39:Index(q,f)<len f by A3,Th41; then A40:Index(q,f)+1<=len f by NAT_1:38; then Index(q,f)+1-Index(p,f)<=len f -Index(p,f) by REAL_1:49; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by XCMPLX_1:29; then i1<=len f -Index(p,f) by A8,BINARITH:def 3; then A41:i1+1<=len L_Cut(f,p) by A37,AXIOMS:24; A42:1<=Index(q,f) & Index(q,f)+1<=len f & q in LSeg(f,Index(q,f)) by A3,A39,Th41,Th42,NAT_1:38; A43:Index(q,f)+1-Index(p,f)<=len f -Index(p,f) by A40,REAL_1:49; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by XCMPLX_1:29; then A44: Index(q,f)-Index(p,f)+1+1<=len f -Index(p,f)+1 by AXIOMS:24; then A45:len L_Cut(f,p)>=Index(q,f)-'Index(p,f)+1+1 by A4,A37,SCMFSA_7:3; A46:Index(q,f)-'Index(p,f)+1+1<=len <*p*>+len mid(f,Index(p,f)+1,len f) by A4,A17,A44,SCMFSA_7:3; Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by A43,XCMPLX_1:29; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f)-1+1 by XCMPLX_1:27; then Index(q,f)-Index(p,f)+1<=len f -(Index(p,f)+1)+1 by XCMPLX_1:36; then A47:Index(q,f)-'Index(p,f)+1<=len f - (Index(p,f)+1)+1 by A4,SCMFSA_7: 3; A48:1<=Index(q,f)+1 & Index(q,f)+1<=len f by A42,Th11; A49:(L_Cut(f,p))/.(Index(q,f)-'Index(p,f)+1+1) =L_Cut(f,p).(Index(q,f)-'Index(p,f)+1+1) by A22,A45,FINSEQ_4:24 .=(<*p*>^mid(f,Index(p,f)+1,len f)).(Index(q,f)-'Index(p,f)+1+1) by A36,Def4 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)+1+1-len <*p*>) by A13,A46,Th15 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)+1+1-1) by FINSEQ_1:57 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)+1) by XCMPLX_1:26 .=f.(Index(p,f)+1+(Index(q,f)-'Index(p,f)+1)-1) by A10,A15,A47,Th31 .=f.(Index(p,f)+1+(Index(q,f)-Index(p,f)+1)-1) by A4,SCMFSA_7:3 .=f.(1+(Index(p,f)+(Index(q,f)-Index(p,f)+1))-1) by XCMPLX_1:1 .=f.(1+(Index(p,f)+(Index(q,f)-Index(p,f))+1)-1) by XCMPLX_1:1 .=f.(1+(Index(p,f)+Index(q,f)-Index(p,f)+1)-1) by XCMPLX_1:29 .=f.((Index(q,f)+1)+1-1) by XCMPLX_1:26 .=f.(Index(q,f)+1) by XCMPLX_1:26 .=f/.(Index(q,f)+1) by A48,FINSEQ_4:24; q in LSeg(f,Index(q,f)) by A3,Th42; then q in LSeg((L_Cut(f,p))/.((Index(q,f)-'Index(p,f)+1)), (L_Cut(f,p))/.((Index(q,f)-'Index(p,f)+1+1))) by A5,A38,A40,A49,TOPREAL1:def 5; hence q in L~(L_Cut(f,p)) by A14,A41,SPPOL_2:15; end; theorem Th65: for p,q,p1,p2 being Point of TOP-REAL 2 st LE p,q,p1,p2 holds q in LSeg(p,p2) & p in LSeg(p1,q) proof let p,q,p1,p2 be Point of TOP-REAL 2; assume A1: LE p,q,p1,p2; then A2:p in LSeg(p1,p2) & q in LSeg(p1,p2) & for r1,r2 being Real st 0<=r1 & r1<=1 & p=(1-r1)*p1+r1*p2 & 0<=r2 & r2<=1 & q=(1-r2)*p1+r2*p2 holds r1<=r2 by Def6; then consider s1 being Real such that A3:0<=s1 & s1<=1 & p=(1-s1)*p1+s1*p2 by SPPOL_1:21; consider s2 being Real such that A4:0<=s2 & s2<=1 & q=(1-s2)*p1+s2*p2 by A2,SPPOL_1:21; A5:s1<=s2 by A1,A3,A4,Def6; A6: 1-s1>=0 by A3,SQUARE_1:12; A7:now per cases; case A8:1-s1<>0; A9:s2-s1>=0 by A5,SQUARE_1:12; set s=(s2-s1)/(1-s1); A10:s>=0 by A6,A9,REAL_2:125; A11:(1-s1)+s1-s2=1-s2 by XCMPLX_1:27; A12:(s2-s1)+s1-s2*s1=s2-s2*s1 by XCMPLX_1:27; A13:(1-s1)*(((1-s2)/(1-s1)))=1-s2 by A8,XCMPLX_1:88; A14:(1-s1)*(((s2-s1)/(1-s1)))=s2-s1 by A8,XCMPLX_1:88; A15:(1-(s2-s1)/(1-s1))=(1*(1-s1)-(s2-s1))/(1-s1) by A8,XCMPLX_1:128 .=((1-s1)-s2+s1)/(1-s1) by XCMPLX_1:37 .=((1-s1)+s1-s2)/(1-s1) by XCMPLX_1:29; 1-s1>=s2-s1 by A4,REAL_1:49; then (1-s1)/(1-s1)>=(s2-s1)/(1-s1) by A6,A8,REAL_1:73; then A16:1>=s by A8,XCMPLX_1:60; (1-s1)*((1-s)*p+s*p2) =(1-s1)*(((1-s2)/(1-s1))*((1-s1)*p1+s1*p2)) +(1-s1)*(((s2-s1)/(1-s1))*p2) by A3,A11,A15,EUCLID:36 .=(1-s1)*(((1-s2)/(1-s1)))*((1-s1)*p1+s1*p2) +(1-s1)*(((s2-s1)/(1-s1))*p2) by EUCLID:34 .=(1-s2)*((1-s1)*p1+s1*p2) +(1-s1)*(((s2-s1)/(1-s1)))*p2 by A13,EUCLID:34 .=(1-s2)*((1-s1)*p1)+(1-s2)*(s1*p2) +(s2-s1)*p2 by A14,EUCLID:36 .=(1-s2)*(1-s1)*p1+(1-s2)*(s1*p2) +(s2-s1)*p2 by EUCLID:34 .=(1-s2)*(1-s1)*p1+(1-s2)*s1*p2 +(s2-s1)*p2 by EUCLID:34 .=(1-s2)*(1-s1)*p1+((1-s2)*s1*p2 +(s2-s1)*p2) by EUCLID:30 .=(1-s2)*(1-s1)*p1+((1-s2)*s1+(s2-s1))*p2 by EUCLID:37 .=(1-s2)*(1-s1)*p1+(1*s1-s2*s1+(s2-s1))*p2 by XCMPLX_1:40 .=(1-s2)*(1-s1)*p1+(1*s2-s1*s2)*p2 by A12,XCMPLX_1:29 .=(1-s2)*(1-s1)*p1+(1-s1)*s2*p2 by XCMPLX_1:40 .=(1-s1)*((1-s2)*p1)+(1-s1)*s2*p2 by EUCLID:34 .=(1-s1)*((1-s2)*p1)+(1-s1)*(s2*p2) by EUCLID:34 .=(1-s1)*q by A4,EUCLID:36; then q=(1-s)*p+s*p2 by A8,EUCLID:38; hence q in LSeg(p,p2) by A10,A16,SPPOL_1:22; case 1-s1=0; then 1=0+s1 by XCMPLX_1:27 .=s1; then s2=1 by A4,A5,AXIOMS:21; then q =0.REAL 2 + 1*p2 by A4,EUCLID:33 .=0.REAL 2 + p2 by EUCLID:33 .=p2 by EUCLID:31; hence q in LSeg(p,p2) by TOPREAL1:6; end; now per cases; case A17:s2<>0; set s=s1/s2; A18:s>=0 by A3,A4,REAL_2:125; A19:s2*(((s2-s1)/s2))=s2-s1 by A17,XCMPLX_1:88; A20: s2*((s1)/s2)=s1 by A17,XCMPLX_1:88; A21:(s2-s1)+s1*(1-s2)=(s2-s1)+(s1*1-s1*s2) by XCMPLX_1:40 .=(s2-s1)+s1-s1*s2 by XCMPLX_1:29 .=1*s2-s1*s2 by XCMPLX_1:27 .=s2*(1-s1) by XCMPLX_1:40; s2/s2>=s1/s2 by A4,A5,A17,REAL_1:73; then A22:1>=s by A17,XCMPLX_1:60; s2*((1-s)*p1+s*q) =s2*(((1*s2-s1)/s2)*p1 +(s1/s2)*((1-s2)*p1+s2*p2)) by A4,A17,XCMPLX_1:128 .=s2*(((s2-s1)/s2)*p1) +s2*((s1/s2)*((1-s2)*p1+s2*p2)) by EUCLID:36 .=s2*(((s2-s1)/s2))*p1 +s2*((s1/s2)*((1-s2)*p1+s2*p2)) by EUCLID:34 .=(s2-s1)*p1 +s2*(s1/s2)*((1-s2)*p1+s2*p2) by A19,EUCLID:34 .=(s2-s1)*p1 +(s1*((1-s2)*p1)+s1*(s2*p2)) by A20,EUCLID:36 .=(s2-s1)*p1 +(s1*(1-s2)*p1+s1*(s2*p2)) by EUCLID:34 .=(s2-s1)*p1 +(s1*(1-s2)*p1+s1*s2*p2) by EUCLID:34 .=(s2-s1)*p1 +s1*(1-s2)*p1+s1*s2*p2 by EUCLID:30 .=((s2-s1)+s1*(1-s2))*p1+s1*s2*p2 by EUCLID:37 .=s2*((1-s1)*p1)+s2*s1*p2 by A21,EUCLID:34 .=s2*((1-s1)*p1)+s2*(s1*p2) by EUCLID:34 .=s2*p by A3,EUCLID:36; then p=(1-s)*p1+s*q by A17,EUCLID:38; hence p in LSeg(p1,q) by A18,A22,SPPOL_1:22; case s2=0; then s1=0 by A1,A3,A4,Def6; then p =1*p1+(0.REAL 2) by A3,EUCLID:33 .=p1+(0.REAL 2) by EUCLID:33 .=p1 by EUCLID:31; hence p in LSeg(p1,q) by TOPREAL1:6; end; hence q in LSeg(p,p2) & p in LSeg(p1,q) by A7; end; theorem Th66: for f being non empty FinSequence of TOP-REAL 2,p,q,p1,p2 being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & q in L~f & p<>q & Index(p,f)=Index(q,f) & LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1) holds q in L~(L_Cut(f,p)) proof let f be non empty FinSequence of TOP-REAL 2,p,q,p1,p2 be Point of TOP-REAL 2; assume that A1:f is_S-Seq and A2: p in L~f and A3: q in L~f and A4: p<>q and A5: Index(p,f)=Index(q,f) and A6: LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1); set i1=Index(q,f)-'Index(p,f)+1; A7:1<=Index(q,f) & Index(q,f)<len f by A3,Th41; Index(q,f)<len f by A3,Th41; then A8:Index(q,f)+1<=len f by NAT_1:38; A9:Index(q,f)-'Index(p,f)=Index(q,f)-Index(p,f) by A5,SCMFSA_7:3 .=0 by A5,XCMPLX_1:14; A10:0<=Index(q,f)-Index(p,f) by A5,XCMPLX_1:14; 1<0+1+1; then A11:len <*p*><Index(q,f)-'Index(p,f)+1+1 by A9,FINSEQ_1:57; A12:1<=Index(p,f)+1 by NAT_1:29; A13: 1<len f by A7,AXIOMS:22; then len mid(f,Index(p,f)+1,len f)=len f -'(Index(p,f)+1)+1 by A5,A8,A12,Th27; then A14:len <*p*>+len mid(f,Index(p,f)+1,len f)=1+(len f -'(Index(p,f)+1)+1) by FINSEQ_1:57 .=1+(len f -(Index(p,f)+1)+1) by A5,A8,SCMFSA_7:3 .=1+(len f -Index(p,f)-1+1) by XCMPLX_1:36 .=(len f -Index(p,f))+1 by XCMPLX_1:27; Index(q,f)-Index(p,f)<=len f -Index(p,f) by A7,REAL_1:49; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f)+1 by AXIOMS:24; then A15:Index(q,f)-'Index(p,f)+1<=len f -Index(p,f)+1 by A5,SCMFSA_7:3; A16: now assume A17: p = f.(Index(p,f)+1); then A18: p = f/.(Index(p,f)+1) by A5,A8,A12,FINSEQ_4:24; q in LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) by A6,Def6; then consider r being Real such that A19: 0 <= r & r <= 1 and A20: q = (1-r)*f/.(Index(p,f))+r*f/.(Index(p,f)+1) by SPPOL_1:21; A21: p = 1*p by EUCLID:33 .= 0.REAL 2 + 1*p by EUCLID:31 .= (1-1)*f/.(Index(p,f))+1*p by EUCLID:33; then 1<=r by A6,A18,A19,A20,Def6; then r = 1 by A19,AXIOMS:21; hence contradiction by A4,A5,A8,A12,A17,A20,A21,FINSEQ_4:24; end; then p <> f.len f by A1,A13,Th45; then A22:len L_Cut(f,p)=len f -Index(p,f)+1 by A1,A2,A16,Th61; then A23: (L_Cut(f,p))/.(Index(q,f)-'Index(p,f)+1) =L_Cut(f,p).(Index(q,f)-'Index(p,f)+1) by A9,A15,FINSEQ_4:24 .=(<*p*>^mid(f,Index(p,f)+1,len f)).(Index(q,f)-'Index(p,f)+1) by A16,Def4 .=p by A9,Th16; A24:Index(q,f)<len f by A3,Th41; then A25:Index(q,f)+1<=len f by NAT_1:38; then Index(q,f)+1-Index(p,f)<=len f -Index(p,f) by REAL_1:49; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by XCMPLX_1:29; then i1<=len f -Index(p,f) by A10,BINARITH:def 3; then A26:i1+1<=len L_Cut(f,p) by A22,AXIOMS:24; A27:1<=Index(q,f) & Index(q,f)+1<=len f & q in LSeg(f,Index(q,f)) by A3,A24,Th41,Th42,NAT_1:38; A28:Index(q,f)+1-Index(p,f)<=len f -Index(p,f) by A25,REAL_1:49; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by XCMPLX_1:29; then A29: Index(q,f)-Index(p,f)+1+1<=len f -Index(p,f)+1 by AXIOMS:24; then A30:len L_Cut(f,p)>=Index(q,f)-'Index(p,f)+1+1 by A5,A22,SCMFSA_7:3; A31:Index(q,f)-'Index(p,f)+1+1<=len <*p*>+len mid(f,Index(p,f)+1,len f) by A5,A14,A29,SCMFSA_7:3; Index(q,f)-Index(p,f)+1<=len f -Index(p,f) by A28,XCMPLX_1:29; then Index(q,f)-Index(p,f)+1<=len f -Index(p,f)-1+1 by XCMPLX_1:27; then Index(q,f)-Index(p,f)+1<=len f -(Index(p,f)+1)+1 by XCMPLX_1:36; then A32:Index(q,f)-'Index(p,f)+1<=len f - (Index(p,f)+1)+1 by A5,SCMFSA_7:3; A33:1<=Index(q,f)+1 & Index(q,f)+1<=len f by A27,Th11; (L_Cut(f,p))/.(Index(q,f)-'Index(p,f)+1+1) =L_Cut(f,p).(Index(q,f)-'Index(p,f)+1+1) by A9,A30,FINSEQ_4:24 .=(<*p*>^mid(f,Index(p,f)+1,len f)).(Index(q,f)-'Index(p,f)+1+1) by A16,Def4 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)+1+1-len <*p*>) by A11,A31,Th15 .=mid(f,Index(p,f)+1,len f).(Index(q,f)-'Index(p,f)+1+1-1) by FINSEQ_1:57 .=f.(Index(p,f)+1+(Index(q,f)-'Index(p,f)+1)-1) by A5,A8,A9,A12,A32,Th31 .=f.(Index(p,f)+1+(Index(q,f)-Index(p,f)+1)-1) by A5,SCMFSA_7:3 .=f.(1+(Index(p,f)+(Index(q,f)-Index(p,f)+1))-1) by XCMPLX_1:1 .=f.(1+(Index(p,f)+(Index(q,f)-Index(p,f))+1)-1) by XCMPLX_1:1 .=f.(1+(Index(p,f)+Index(q,f)-Index(p,f)+1)-1) by XCMPLX_1:29 .=f.(1+(Index(q,f)+1)-1) by XCMPLX_1:26 .=f.(Index(q,f)+1) by XCMPLX_1:26 .=f/.(Index(q,f)+1) by A33,FINSEQ_4:24; then q in LSeg((L_Cut(f,p))/.((Index(q,f)-'Index(p,f)+1)), (L_Cut(f,p))/.((Index(q,f)-'Index(p,f)+1+1))) by A5,A6,A23,Th65; hence q in L~(L_Cut(f,p)) by A9,A26,SPPOL_2:15; end; begin ::--------------------------------------------------------: :: Cutting Both Sides of a Finite Sequence and : :: a Discussion of Speciality of Sequences in TOP-REAL 2 : ::--------------------------------------------------------: definition let f be FinSequence of TOP-REAL 2,p,q be Point of TOP-REAL 2; func B_Cut(f,p,q) -> FinSequence of TOP-REAL 2 equals :Def8: R_Cut(L_Cut(f,p),q) if p in L~f & q in L~f & Index(p,f)<Index(q,f) or Index(p,f)=Index(q,f) & LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1) otherwise Rev (R_Cut(L_Cut(f,q),p)); correctness; end; theorem Th67:for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p<>f.1 holds R_Cut(f,p) is_S-Seq_joining f/.1,p proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume that A1: f is_S-Seq and A2: p in L~f and A3: p<>f.1; R_Cut(f,p)=mid(f,1,Index(p,f))^<*p*> by A3,Def5; hence thesis by A1,A2,A3,Th52; end; theorem Th68: for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p<>f.len f holds L_Cut(f,p) is_S-Seq_joining p,f/.len f proof let f be non empty FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume that A1: f is_S-Seq & p in L~f and A2: p<>f.len f; A3: Rev f is_S-Seq & p in L~Rev f by A1,SPPOL_2:22,47; A4: L_Cut(f,p) = L_Cut(Rev Rev f,p) by FINSEQ_6:29 .= Rev R_Cut(Rev f,p) by A3,Th57; p <> (Rev f).1 by A2,FINSEQ_5:65; then R_Cut(Rev f,p) is_S-Seq_joining (Rev f)/.1,p by A3,Th67; then L_Cut(f,p) is_S-Seq_joining p,(Rev f)/.1 by A4,Th48; hence thesis by FINSEQ_5:68; end; theorem Th69:for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p<>f.len f holds L_Cut(f,p) is_S-Seq proof let f be non empty FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume f is_S-Seq & p in L~f & p<>f.len f; then L_Cut(f,p) is_S-Seq_joining p,f/.len f by Th68; hence L_Cut(f,p) is_S-Seq by Def3; end; theorem Th70:for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & p<>f.1 holds R_Cut(f,p) is_S-Seq proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume f is_S-Seq & p in L~f & p<>f.1; then R_Cut(f,p) is_S-Seq_joining f/.1,p by Th67; hence R_Cut(f,p) is_S-Seq by Def3; end; Lm1: for f being non empty FinSequence of TOP-REAL 2, p,q being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & q in L~f & p<>q & (Index(p,f)<Index(q,f) or Index(p,f)=Index(q,f) & LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1)) holds B_Cut(f,p,q) is_S-Seq_joining p,q proof let f be non empty FinSequence of TOP-REAL 2, p,q be Point of TOP-REAL 2; assume A1: f is_S-Seq & p in L~f & q in L~f & p<>q; assume A2: Index(p,f)<Index(q,f) or Index(p,f)=Index(q,f) & LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1); then A3:B_Cut(f,p,q)=R_Cut(L_Cut(f,p),q) by A1,Def8; A4:1<=Index(q,f) & Index(q,f)<len f by A1,Th41; Index(p,f) < len f by A1,Th41; then A5: Index(p,f)+1 <= len f by NAT_1:38; A6:1<=Index(p,f)+1 by NAT_1:29; A7: 1<len f by A4,AXIOMS:22; A8: now per cases by A2; case Index(p,f)<Index(q,f); then A9:Index(p,f)+1<=Index(q,f) by NAT_1:38; assume p=f.len f; then len f <= Index(q,f) by A1,A7,A9,Th45; hence contradiction by A1,Th41; case A10: Index(p,f)=Index(q,f) & LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1); A11: now assume A12: p = f.(Index(p,f)+1); then A13: p = f/.(Index(p,f)+1) by A5,A6,FINSEQ_4:24; q in LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) by A10,Def6; then consider r being Real such that A14: 0 <= r & r <= 1 and A15: q = (1-r)*f/.(Index(p,f))+r*f/.(Index(p,f)+1) by SPPOL_1:21; A16: p = 1*p by EUCLID:33 .= 0.REAL 2 + 1*p by EUCLID:31 .= (1-1)*f/.(Index(p,f))+1*p by EUCLID:33; then 1<=r by A10,A13,A14,A15,Def6; then r = 1 by A14,AXIOMS:21; hence contradiction by A1,A5,A6,A12,A15,A16,FINSEQ_4:24; end; assume p=f.len f; hence contradiction by A1,A7,A11,Th45; end; then A17:L_Cut(f,p) is_S-Seq_joining p,f/.len f by A1,Th68; A18:L_Cut(f,p) is_S-Seq by A1,A8,Th69; now per cases by A2; case Index(p,f)<Index(q,f); then q in L~(L_Cut(f,p)) by A1,Th64; hence ex i1 being Nat st 1<=i1 & i1+1<=len L_Cut(f,p) & q in LSeg(L_Cut(f,p),i1) by SPPOL_2:13; case Index(p,f)=Index(q,f) & LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1); then q in L~(L_Cut(f,p)) by A1,Th66; hence ex i1 being Nat st 1<=i1 & i1+1<=len L_Cut(f,p) & q in LSeg(L_Cut(f,p),i1) by SPPOL_2:13; end; then A19: q in L~L_Cut(f,p) by SPPOL_2:17; then 1<=Index(q,L_Cut(f,p)) & Index(q,L_Cut(f,p))<len L_Cut(f,p) by Th41 ; then A20: 1<=len L_Cut(f,p) by AXIOMS:22; A21:(L_Cut(f,p)).1=p by A17,Def3; then p=(L_Cut(f,p))/.(1) by A20,FINSEQ_4:24; hence B_Cut(f,p,q) is_S-Seq_joining p,q by A1,A3,A18,A19,A21,Th67; end; theorem Th71: for f being non empty FinSequence of TOP-REAL 2, p,q being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & q in L~f & p<>q holds B_Cut(f,p,q) is_S-Seq_joining p,q proof let f be non empty FinSequence of TOP-REAL 2, p,q be Point of TOP-REAL 2; assume A1: f is_S-Seq & p in L~f & q in L~f & p<>q; per cases; suppose Index(p,f)<Index(q,f) or Index(p,f)=Index(q,f) & LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1); hence thesis by A1,Lm1; suppose A2:not(Index(p,f)<Index(q,f) or Index(p,f)=Index(q,f) & LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1)); then A3:B_Cut(f,p,q)=Rev R_Cut(L_Cut(f,q),p) by Def8; A4: Index(q,f) < Index(p,f) or Index(p,f)=Index(q,f) & not LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1) by A2,AXIOMS:21; A5: now assume that A6: Index(p,f)=Index(q,f) and A7: not LE p,q,f/.(Index(p,f)),f/.(Index(p,f)+1); A8: 1 <= Index(p,f) by A1,Th41; A9: Index(p,f) < len f by A1,Th41; then A10: Index(p,f)+1 <= len f by NAT_1:38; then A11: LSeg(f,Index(p,f)) = LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) by A8,TOPREAL1:def 5; then A12: p in LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) by A1,Th42; A13: q in LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) by A1,A6,A11,Th42; A14: Index(p,f) in dom f by A8,A9,FINSEQ_3:27; 1 <= Index(p,f)+1 by NAT_1:29; then A15: Index(p,f)+1 in dom f by A10,FINSEQ_3:27; A16: Index(p,f)+0 <> Index(p,f)+1 by XCMPLX_1:2; f is one-to-one by A1,TOPREAL1:def 10; then f/.(Index(p,f))<>f/.(Index(p,f)+1) by A14,A15,A16,PARTFUN2:17; then LT q,p,f/.(Index(p,f)),f/.(Index(p,f)+1) by A7,A12,A13,Th63; hence LE q,p,f/.Index(q,f),f/.(Index(q,f)+1) by A6,Def7; end; then A17: B_Cut(f,q,p) is_S-Seq_joining q,p by A1,A4,Lm1; Rev B_Cut(f,q,p) = B_Cut(f,p,q) by A1,A3,A4,A5,Def8; hence thesis by A17,Th48; end; theorem for f being non empty FinSequence of TOP-REAL 2, p,q being Point of TOP-REAL 2 st f is_S-Seq & p in L~f & q in L~f & p<>q holds B_Cut(f,p,q) is_S-Seq proof let f be non empty FinSequence of TOP-REAL 2, p,q be Point of TOP-REAL 2; assume f is_S-Seq & p in L~f & q in L~f & p<>q; then B_Cut(f,p,q) is_S-Seq_joining p,q by Th71; hence B_Cut(f,p,q) is_S-Seq by Def3; end; theorem Th73:for f,g being FinSequence of TOP-REAL 2 st f.len f=g.1 & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} holds f^mid(g,2,len g) is_S-Seq proof let f,g be FinSequence of TOP-REAL 2; assume A1: f.len f=g.1 & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1}; then A2:f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by TOPREAL1:def 10; A3:g is one-to-one & len g >= 2 & g is unfolded s.n.c. special by A1,TOPREAL1:def 10; A4:1<=len f by A2,AXIOMS:22; A5:1<=len g by A3,AXIOMS:22; A6:len (f^mid(g,2,len g))=len f + len mid(g,2,len g) by FINSEQ_1:35; then A7: len f<=len f + len mid(g,2,len g) & len f<=len (f^mid(g,2,len g)) by NAT_1:29; A8:len mid(g,2,len g)=len g -'2+1 by A3,A5,Th27 .=len g -2+1 by A3,SCMFSA_7:3 .=len g -(2-1) by XCMPLX_1:37 .=len g -1; A9: for x1,x2 being set st x1 in dom (f^mid(g,2,len g)) & x2 in dom (f^mid(g,2,len g)) & (f^mid(g,2,len g)).x1=(f^mid(g,2,len g)).x2 holds x1=x2 proof let x1,x2 be set; assume A10: x1 in dom (f^mid(g,2,len g)) & x2 in dom (f^mid(g,2,len g)) & (f^mid(g,2,len g)).x1=(f^mid(g,2,len g)).x2; then A11: x1 in Seg len (f^mid(g,2,len g)) & x2 in Seg len (f^mid(g,2,len g)) by FINSEQ_1:def 3; reconsider n1=x1,n2=x2 as Nat by A10; A12:1<=n1 & n1<=len (f^mid(g,2,len g)) & 1<=n2 & n2<=len (f^mid(g,2,len g)) by A11,FINSEQ_1:3; then n1-len f <=len f + len mid(g,2,len g)-len f by A6,REAL_1:49; then A13:n1-len f <=len mid(g,2,len g) by XCMPLX_1:26; n2-len f <=len f + len mid(g,2,len g)-len f by A6,A12,REAL_1:49; then A14:n2-len f <=len mid(g,2,len g) by XCMPLX_1:26; A15:rng (f^mid(g,2,len g)) c= the carrier of TOP-REAL 2 by FINSEQ_1:def 4; (f^mid(g,2,len g)).x1 in rng (f^mid(g,2,len g)) by A10,FUNCT_1:def 5; then reconsider q=(f^mid(g,2,len g)).x1 as Point of TOP-REAL 2 by A15; A16:rng f c= L~f by A2,SPPOL_2:18; A17:rng mid(g,2,len g) c= rng g by Th28; A18:rng g c=L~g by A3,SPPOL_2:18; A19:now assume A20:q in rng f & q in rng mid(g,2,len g); then q in rng g by A17; then A21: q in L~f /\ L~g by A16,A18,A20,XBOOLE_0:def 3; now assume A22:g.1 in rng mid(g,2,len g); 2-'1=2-1 by SCMFSA_7:3; then A23:g.1 in rng (g/^1) by A3,A22,Th26; A24:g|1=g|Seg 1 by TOPREAL1:def 1; 1 in Seg 1 by FINSEQ_1:5; then A25:(g|1).1=g.1 by A24,FUNCT_1:72; len (g|1)=1 by A5,TOPREAL1:3; then 1 in dom (g|1) by FINSEQ_3:27; then A26:g.1 in rng (g|1) by A25,FUNCT_1:def 5; rng(g|1) misses rng (g/^1) by A3,FINSEQ_5:37; hence contradiction by A23,A26,XBOOLE_0:3; end; hence contradiction by A1,A20,A21,TARSKI:def 1; end; now per cases; case n1<=len f; then A27:n1 in dom f by A12,FINSEQ_3:27; then A28:(f^mid(g,2,len g)).x1 =f.n1 by FINSEQ_1:def 7; now per cases; case n2<=len f; then A29:n2 in dom f by A12,FINSEQ_3:27; then (f^mid(g,2,len g)).x2 =f.n2 by FINSEQ_1:def 7; hence x1=x2 by A2,A10,A27,A28,A29,FUNCT_1:def 8; case A30:n2>len f; then len f +1<=n2 by NAT_1:38; then len f +1 -len f <=n2 - len f by REAL_1:49; then 1<=n2-len f by XCMPLX_1:26; then 1<=(n2-'len f) & (n2-'len f)<=len mid(g,2,len g) by A14,Th1; then A31:(n2-'len f) in dom mid(g,2,len g) by FINSEQ_3:27; then A32:(f^mid(g,2,len g)).(len f +(n2-'len f)) =mid(g,2,len g).(n2-'len f) by FINSEQ_1:def 7; len f + (n2-'len f)=len f+(n2-len f) by A30,SCMFSA_7:3 .=n2 by XCMPLX_1:27; hence contradiction by A10,A19,A27,A28,A31,A32,FUNCT_1:def 5; end; hence x1=x2; case A33:n1>len f; then len f +1<=n1 by NAT_1:38; then len f +1 -len f <=n1 - len f by REAL_1:49; then A34: 1<=n1-len f by XCMPLX_1:26; then A35:1<=n1-'len f by Th1; A36:n1-'len f<=len mid(g,2,len g) by A13,A34,Th1; then A37:n1-'len f in dom mid(g,2,len g) by A35,FINSEQ_3:27; then A38:(f^mid(g,2,len g)).(len f +(n1-'len f)) =mid(g,2,len g).(n1-'len f) by FINSEQ_1:def 7; n1-'len f<=n1-'len f +2 by NAT_1:29; then 1<=n1-'len f +2 by A35,AXIOMS:22; then A39:n1-'len f +2-'1=n1-'len f +2-1 by SCMFSA_7:3 .=n1-'len f +((1+1)-1) by XCMPLX_1:29; A40:1<=n1-'len f+1 by A35,Th11; n1-'len f+1<=len g -1+1 by A8,A36,AXIOMS:24; then n1-'len f+1<=len g by XCMPLX_1:27; then A41:n1-'len f+1 in dom g by A40,FINSEQ_3:27; len f + (n1-'len f)=len f+(n1-len f) by A33,SCMFSA_7:3 .=n1 by XCMPLX_1:27; then A42:(f^mid(g,2,len g)).n1 =g.(n1-'len f+1) by A3,A5,A35,A36,A38,A39,Th27; A43: len f + (n1-'len f)=len f+(n1-len f) by A33,SCMFSA_7:3 .=n1 by XCMPLX_1:27; now per cases; case n2<=len f; then A44:n2 in dom f by A12,FINSEQ_3:27; then (f^mid(g,2,len g)).x2 =f.n2 by FINSEQ_1:def 7; hence contradiction by A10,A19,A37,A38,A43,A44,FUNCT_1:def 5; case A45:n2>len f; then len f +1<=n2 by NAT_1:38; then len f +1 -len f <=n2 - len f by REAL_1:49; then A46: 1<=n2-len f by XCMPLX_1:26; then A47:1<=n2-'len f by Th1; A48:1<=(n2-'len f) & (n2-'len f)<=len mid(g,2,len g) by A14,A46,Th1; then (n2-'len f) in dom mid(g,2,len g) by FINSEQ_3:27; then A49:(f^mid(g,2,len g)).(len f +(n2-'len f)) =mid(g,2,len g).(n2-'len f) by FINSEQ_1:def 7; n2-'len f<=n2-'len f +2 by NAT_1:29; then 1<=n2-'len f +2 by A47,AXIOMS:22; then A50:n2-'len f +2-'1=n2-'len f +2-1 by SCMFSA_7:3 .=n2-'len f +((1+1)-1) by XCMPLX_1:29 .=n2-'len f+1; A51:1<=n2-'len f+1 by A47,Th11; n2-'len f+1<=len g -1+1 by A8,A48,AXIOMS:24; then n2-'len f+1<=len g by XCMPLX_1:27; then A52:n2-'len f+1 in dom g by A51,FINSEQ_3:27; len f + (n2-'len f)=len f+(n2-len f) by A45,SCMFSA_7:3 .=n2 by XCMPLX_1:27; then (f^mid(g,2,len g)).n2 =g.(n2-'len f+1) by A3,A5,A48,A49,A50,Th27; then n1-'len f+1=n2-'len f+1 by A3,A10,A41,A42,A52,FUNCT_1:def 8; then n1-'len f=n2-'len f+1-1 by XCMPLX_1:26; then n1-'len f=n2-'len f by XCMPLX_1:26; then n1-len f=n2-'len f by A33,SCMFSA_7:3; then n1-len f=n2-len f by A45,SCMFSA_7:3; hence x1=x2 by XCMPLX_1:19; end; hence x1=x2; end; hence x1=x2; end; A53: for i st 1 <= i & i + 2 <= len (f^mid(g,2,len g)) holds LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),i+1) = {(f^mid(g,2,len g))/.(i+1)} proof let i be Nat; assume A54:1 <= i & i + 2 <= len (f^mid(g,2,len g)); then A55:1<=i+1 by Th11; A56:1<=i+1+1 by A54,Th11; A57:i+1<=len (f^mid(g,2,len g)) by A54,Th10; A58:i<=len (f^mid(g,2,len g)) by A54,Th10; i+(1+1)<= len (f^mid(g,2,len g)) by A54; then A59:i+1+1<= len (f^mid(g,2,len g)) by XCMPLX_1:1; then i+1+1<=len f + len mid(g,2,len g) by FINSEQ_1:35; then i+1+1<=len f + (len g -'2+1) by A3,A5,Th27; then i+1+1<=len f + (len g -(1+1)+1) by A3,SCMFSA_7:3; then i+1+1-len f<=len f + (len g -(1+1)+1)-len f by REAL_1:49; then i+1+1-len f<=(len g -(1+1)+1) by XCMPLX_1:26; then i+1+1-len f<=len g -1-1+1 by XCMPLX_1:36; then i+1+1-len f<=len g -1 by XCMPLX_1:27; then i+1-len f+1<=len g -1 by XCMPLX_1:29; then i+1-len f+1+1<=len g -1+1 by AXIOMS:24; then A60: i+1-len f+1+1<=len g by XCMPLX_1:27; then A61:i-len f+1+1+1<=len g by XCMPLX_1:29; now per cases; case A62:i+2<=len f; then i+(1+1)<=len f; then A63:i+1+1<=len f by XCMPLX_1:1; then A64:i+1<=len f by Th9; then A65:i<=len f by Th9; A66:(f^mid(g,2,len g))/.i=(f^mid(g,2,len g)).i by A54,A58,FINSEQ_4:24; f/.i=f.i by A54,A65,FINSEQ_4:24; then A67:(f^mid(g,2,len g))/.i=f/.i by A54,A65,A66,SCMFSA_7:9; A68:(f^mid(g,2,len g))/.(i+1)=(f^mid(g,2,len g)).(i+1) by A55,A57,FINSEQ_4:24; f/.(i+1)=f.(i+1) by A55,A64,FINSEQ_4:24; then A69:(f^mid(g,2,len g))/.(i+1)=f/.(i+1) by A55,A64,A68,SCMFSA_7:9; LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) = LSeg(f^mid(g,2,len g),i) by A54,A57,TOPREAL1:def 5; then A70:LSeg(f^mid(g,2,len g),i)=LSeg(f,i) by A54,A64,A67,A69,TOPREAL1:def 5; A71:(f^mid(g,2,len g))/.(i+1+1)=(f^mid(g,2,len g)).(i+1+1) by A56,A59,FINSEQ_4:24; f/.(i+1+1)=f.(i+1+1) by A56,A63,FINSEQ_4:24; then A72:LSeg((f^mid(g,2,len g))/.(i+1),(f^mid(g,2,len g))/.(i+1+1)) =LSeg(f/.(i+1),f/.(i+1+1)) by A56,A63,A69,A71,SCMFSA_7:9; LSeg((f^mid(g,2,len g))/.(i+1),(f^mid(g,2,len g))/.(i+1+1)) = LSeg(f^mid(g,2,len g),i+1) by A55,A59,TOPREAL1:def 5; then LSeg(f^mid(g,2,len g),i+1)=LSeg(f,i+1) by A55,A63,A72,TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),i+1) = {(f^mid(g,2,len g))/.(i+1)} by A2,A54,A62,A69,A70,TOPREAL1:def 8; case i+2>len f; then A73: i+2>=len f +1 by NAT_1:38; now per cases by A73,REAL_1:def 5; case i+2>len f +1; then i+(1+1)>len f+1; then A74: i+1+1>len f+1 by XCMPLX_1:1; then i+1+1>=len f+1+1 by NAT_1:38; then i+1+1-(len f+1)>=len f+1+1-(len f+1) by REAL_1:49; then i+1+1-(len f+1)>=1 by XCMPLX_1:26; then i+1+1-1-len f>=1 by XCMPLX_1:36; then i+1-len f>=1 by XCMPLX_1:26; then A75:i-len f+1>=1 by XCMPLX_1:29; A76: i+1>=len f +1 by A74,NAT_1:38; then A77:i>=len f by REAL_1:53; A78:i+1>=len f by A76,Th11; A79:i-'len f+1+1+1<=len g by A61,A77,SCMFSA_7:3; then A80:i-'len f+1+1<=len g by Th9; then A81:i-'len f+1<=len g by Th9; i-'len f+1+1-1<=len g -1 by A80,REAL_1:49; then i-'len f+1<=len g -(2-1) by XCMPLX_1:26; then i-'len f+1<=len g -2+1 by XCMPLX_1:37; then A82:i-'len f+1<=len g -'2+1 by A3,SCMFSA_7:3; then A83:i-'len f<=len g -'2+1 by Th9; A84:i+1-'len f+1+1<=len g by A60,A78,SCMFSA_7:3; i-len f+1<=len g -'2+1 by A77,A82,SCMFSA_7:3; then i+1-len f<=len g -'2+1 by XCMPLX_1:29; then A85:i+1-'len f<=len g -'2+1 by A78,SCMFSA_7:3; i+1-len f+1+1-1<=len g-1 by A60,REAL_1:49; then A86:i+1-len f+1<=len g-1 by XCMPLX_1:26; then i+1-len f+1+1<=len g-1+1 by AXIOMS:24; then A87:i+1-len f+1+1<=len g by XCMPLX_1:27; A88:i+1+1-len f<=len g-1 by A86,XCMPLX_1:29; A89:i-'len f+1>=1 by A75,A77,SCMFSA_7:3; then A90:i-'len f+1+1>=1 by Th11; then A91: i-len f+1+1>=1 by A77,SCMFSA_7:3; then A92:i+1-len f+1>=1 by XCMPLX_1:29; then A93:i+1-'len f+1>=1 by A78,SCMFSA_7:3; then A94:i+1-'len f+1+1>=1 by Th11; i+1+1-len f>=1 by A92,XCMPLX_1:29; then A95:i+1+1-len f>=0 by AXIOMS:22; A96: i+1-len f+1>=0+1 by A91,XCMPLX_1:29; then A97:i+1-len f>=0 by REAL_1:53; then A98:i+1-'len f+1+1<=len g by A87,BINARITH:def 3; 0<i+1-len f+1 by A96,AXIOMS:22; then A99:0<i+1+1-len f by XCMPLX_1:29; then i+1+1-'len f<=len g-(2-1) by A88,BINARITH:def 3; then A100: i+1+1-'len f<=len g-2+1 by XCMPLX_1:37; i+1-len f+1=i-len f+1+1 by XCMPLX_1:29; then i+1-len f+1=i-'len f+1+1 by A77,SCMFSA_7:3; then A101:i+1-'len f+1=i-'len f+1+1 by A78,SCMFSA_7:3; i+1+1-len f+1=i+1-len f+1+1 by XCMPLX_1:29; then A102: i+1+1-len f+1=i+1-'len f+1+1 by A97,BINARITH:def 3; A103:LSeg(f^mid(g,2,len g),i) =LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) by A54,A57,TOPREAL1:def 5; A104:LSeg(g,i-'len f+1)=LSeg(g/.(i-'len f+1),g/.(i-'len f+1+1)) by A80,A89,TOPREAL1:def 5; A105:g/.(i-'len f+1)=g.(i-'len f+1) by A81,A89,FINSEQ_4:24; A106:now assume A107:1<=i-'len f; then 1<=i-len f by Th1; then 1+len f<=i-len f +len f by AXIOMS:24; then len f +1<=i by XCMPLX_1:27; then A108: len f<i by NAT_1:38; then (f^mid(g,2,len g)).i=mid(g,2,len g).(i-len f) by A58,Th15; then (f^mid(g,2,len g)).i=mid(g,2,len g).(i-'len f) by A108,SCMFSA_7:3; then (f^mid(g,2,len g)).i=g.(i-'len f+2-1) by A3,A83,A107,Th31; then (f^mid(g,2,len g)).i=g.(i-'len f+(2-1)) by XCMPLX_1:29; hence (f^mid(g,2,len g)).i=g.(i-'len f+1); end; now assume 1>i-'len f; then i-'len f+1<=0+1 by NAT_1:38; then i-'len f<=0 by REAL_1:53; then A109:i-'len f=0 by NAT_1:18; then i-len f=0 by A77,SCMFSA_7:3; then i=len f by XCMPLX_1:15; hence (f^mid(g,2,len g)).i = g.(i-'len f+1) by A1,A4,A109,SCMFSA_7:9; end; then A110:(f^mid(g,2,len g))/.i=g/.(i-'len f+1) by A54,A58,A105, A106,FINSEQ_4:24; A111:(f^mid(g,2,len g))/.(i+1)=(f^mid(g,2,len g)).(i+1) by A55,A57,FINSEQ_4:24; A112:g/.(i-'len f+1+1)=g.(i-'len f+1+1) by A80,A90,FINSEQ_4:24; A113:now assume A114:1<=(i+1)-'len f; then 1<=(i+1)-len f by Th1; then 1+len f<=(i+1)-len f +len f by AXIOMS:24; then len f +1<=(i+1) by XCMPLX_1:27; then A115: len f<(i+1) by NAT_1:38; then (f^mid(g,2,len g)).(i+1)=mid(g,2,len g).((i+1)-len f) by A57,Th15; then (f^mid(g,2,len g)).(i+1)=mid(g,2,len g).((i+1)-'len f) by A115,SCMFSA_7:3; then (f^mid(g,2,len g)).(i+1)=g.((i+1)-'len f+2-1) by A3,A85,A114,Th31; then (f^mid(g,2,len g)).(i+1)=g.((i+1)-'len f+(2-1)) by XCMPLX_1:29; hence (f^mid(g,2,len g)).(i+1)=g.((i+1)-'len f+1); end; A116: now assume 1>(i+1)-'len f; then (i+1)-'len f+1<=0+1 by NAT_1:38; then (i+1)-'len f<=0 by REAL_1:53; then A117:(i+1)-'len f=0 by NAT_1:18; then (i+1)-len f=0 by A78,SCMFSA_7:3; then (i+1)=len f by XCMPLX_1:15; hence (f^mid(g,2,len g)).(i+1) = g.((i+1)-'len f+1) by A1,A4,A117,SCMFSA_7:9; end; A118:LSeg(f^mid(g,2,len g),i+1) =LSeg((f^mid(g,2,len g))/.(i+1),(f^mid(g,2,len g))/.(i+1+1)) by A55,A59,TOPREAL1:def 5; A119:LSeg(g,i+1-'len f+1) =LSeg(g/.(i+1-'len f+1),g/.(i+1-'len f+1+1)) by A84,A93,TOPREAL1:def 5; A120:(f^mid(g,2,len g))/.(i+1+1)=(f^mid(g,2,len g)).(i+1+1) by A56,A59,FINSEQ_4:24; A121:g/.(i+1-'len f+1+1)=g.(i+1-'len f+1+1) by A94,A98,FINSEQ_4:24; A122:now assume A123:1<=(i+1+1)-'len f; then 1<=(i+1+1)-len f by Th1; then 1+len f<=(i+1+1)-len f +len f by AXIOMS:24; then len f +1<=(i+1+1) by XCMPLX_1:27; then A124: len f<(i+1+1) by NAT_1:38; then (f^mid(g,2,len g)).(i+1+1)=mid(g,2,len g).((i+1+1)-len f) by A59,Th15; then (f^mid(g,2,len g)).(i+1+1)=mid(g,2,len g).((i+1+1)-'len f) by A124,SCMFSA_7:3; then (f^mid(g,2,len g)).(i+1+1)=g.((i+1+1)-'len f+2-1) by A3,A100,A123,Th31; then (f^mid(g,2,len g)).(i+1+1)=g.((i+1+1)-'len f+(2-1)) by XCMPLX_1:29; hence (f^mid(g,2,len g)).(i+1+1)=g.((i+1+1)-'len f+1); end; now assume 1>(i+1+1)-'len f; then (i+1+1)-'len f+1<=0+1 by NAT_1:38; then A125:(i+1+1)-'len f<=0 by REAL_1:53; then A126:(i+1+1)-'len f=0 by NAT_1:18; (i+1+1)-len f=0 by A95,A125,BINARITH:def 3; then (i+1+1)=len f by XCMPLX_1:15; hence (f^mid(g,2,len g)).(i+1+1) = g.((i+1+1)-'len f+1) by A1,A4,A126,SCMFSA_7:9; end; then A127:LSeg(f^mid(g,2,len g),i+1)=LSeg(g,i+1-'len f+1) by A99,A101,A102,A111,A112,A113,A116,A118,A119,A120,A121,A122 ,BINARITH:def 3; i-'len f+1+(1+1)<=len g by A79,XCMPLX_1:1; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),i+1) = {(f^mid(g,2,len g))/.(i+1)} by A3,A89,A101,A103,A104,A110,A111,A112 ,A113,A116,A127,TOPREAL1:def 8; case i+2=len f +1; then i+(1+1)=len f+1; then A128: i+1+1=len f+1 by XCMPLX_1:1; then A129:i+1=len f by XCMPLX_1:2; then A130:i<=len f by Th9; i=len f -1 by A129,XCMPLX_1:26; then A131:i=len f-'1 by A4,SCMFSA_7:3; A132:(f^mid(g,2,len g))/.i=(f^mid(g,2,len g)).i by A54,A58,FINSEQ_4:24; f/.i=f.i by A54,A130,FINSEQ_4:24; then A133:(f^mid(g,2,len g))/.i=f/.i by A54,A130,A132,SCMFSA_7:9; A134:(f^mid(g,2,len g))/.(i+1)=(f^mid(g,2,len g)).(i+1) by A55,A57,FINSEQ_4:24; A135:f/.(i+1)=f.(i+1) by A55,A129,FINSEQ_4:24; then A136:f/.(i+1)=g/.1 by A1,A5,A129,FINSEQ_4:24; A137:(f^mid(g,2,len g))/.(i+1)=f/.(i+1) by A55,A129,A134,A135,SCMFSA_7:9; A138:LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) = LSeg(f^mid(g,2,len g),i) by A54,A57,TOPREAL1:def 5; A139:LSeg(f,i)=LSeg(f/.i,f/.(i+1)) by A54,A129,TOPREAL1:def 5; A140:LSeg(f^mid(g,2,len g),i+1) =LSeg((f^mid(g,2,len g))/.(i+1),(f^mid(g,2,len g))/.(i+1+1)) by A55,A59,TOPREAL1:def 5; A141:i+1-'len f+1 =0+1 by A129,GOBOARD9:1 .=1; then A142:LSeg(g,i+1-'len f+1) =LSeg(g/.(i+1-'len f+1),g/.(i+1-'len f+1+1)) by A3,TOPREAL1:def 5; A143:(f^mid(g,2,len g))/.(i+1+1)=(f^mid(g,2,len g)).(i+1+1) by A56,A59,FINSEQ_4:24; A144:g/.(i+1-'len f+1+1)=g.(i+1-'len f+1+1) by A3,A141,FINSEQ_4:24; len g -2>=0 by A3,SQUARE_1:12; then A145: 0+1<=len g-2+1 by AXIOMS:24; len f <=len f +1 by NAT_1:29; then A146: len f+1-'len f=len f+1-len f by SCMFSA_7:3 .=1 by XCMPLX_1:26 ; A147: len f<(i+1+1) by A128,NAT_1:38; then (f^mid(g,2,len g)).(i+1+1)=mid(g,2,len g).((i+1+1)-len f) by A59,Th15; then A148:(f^mid(g,2,len g)).(i+1+1)=mid(g,2,len g).((i+1+1)-'len f) by A147,SCMFSA_7:3 .=g.(2+1-'1) by A3,A128,A145,A146,Th31 .=g.2 by BINARITH:39; A149:LSeg(g,1)=LSeg(g/.1,g/.(1+1)) by A3,TOPREAL1:def 5; A150:g/.1=g.1 by A5,FINSEQ_4:24; then g/.1= f/.len f by A1,A4,FINSEQ_4:24; then A151:g/.1 in LSeg(f/.(len f-'1),f/.len f) by TOPREAL1:6; g/.1 in LSeg(g/.1,g/.(1+1)) by TOPREAL1:6; then g/.1 in LSeg(f,i) /\ LSeg(g,1) by A129,A131,A139,A149,A151,XBOOLE_0:def 3; then A152:{g/.1} c= LSeg(f,i) /\ LSeg(g,1) by ZFMISC_1:37; A153:LSeg(f,i)c=L~f by TOPREAL3:26; LSeg(g,1)c=L~g by TOPREAL3:26; then LSeg(f,i) /\ LSeg(g,1) c= {g/.1} by A1,A150,A153,XBOOLE_1:27; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),i+1) = {(f^mid(g,2,len g))/.(i+1)} by A133,A136,A137,A138,A139,A140,A141,A142,A143,A144,A148,A152, XBOOLE_0:def 10; end; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),i+1) = {(f^mid(g,2,len g))/.(i+1)}; end; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),i+1) = {(f^mid(g,2,len g))/.(i+1)}; end; A154: for i,j st i+1 < j holds LSeg(f^mid(g,2,len g),i) misses LSeg(f^mid(g,2,len g),j) proof let i,j;assume A155: i+1 < j; now per cases; case A156:j<len f & j+1<=len (f^mid(g,2,len g)); then A157:j<=len (f^mid(g,2,len g)) by Th9; then A158:i+1<len (f^mid(g,2,len g)) by A155,AXIOMS:22; then A159:i<=len (f^mid(g,2,len g)) by Th9; A160:i+1<len f by A155,A156,AXIOMS:22; then A161:i<len f by NAT_1:38; now per cases; case A162:1<=i; then A163:1<=i+1 by Th11; then A164:1<j by A155,AXIOMS:22; then A165:1<=j+1 by Th11; A166:(f^mid(g,2,len g))/.i=(f^mid(g,2,len g)).i by A159,A162,FINSEQ_4:24; f/.i=f.i by A161,A162,FINSEQ_4:24; then A167:(f^mid(g,2,len g))/.i=f/.i by A161,A162,A166,SCMFSA_7:9; A168:(f^mid(g,2,len g))/.(i+1)=(f^mid(g,2,len g)).(i+1) by A158,A163,FINSEQ_4:24; f/.(i+1)=f.(i+1) by A160,A163,FINSEQ_4:24; then A169:LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) =LSeg(f/.i,f/.(i+1)) by A160,A163,A167,A168,SCMFSA_7:9; LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) = LSeg(f^mid(g,2,len g),i) by A158,A162,TOPREAL1:def 5; then A170:LSeg(f^mid(g,2,len g),i)=LSeg(f,i) by A160,A162,A169,TOPREAL1:def 5; A171:j+1<=len f by A156,NAT_1:38; A172:(f^mid(g,2,len g))/.j=(f^mid(g,2,len g)).j by A157,A164,FINSEQ_4:24; f/.j=f.j by A156,A164,FINSEQ_4:24; then A173:(f^mid(g,2,len g))/.j=f/.j by A156,A164,A172,SCMFSA_7:9; A174:(f^mid(g,2,len g))/.(j+1)=(f^mid(g,2,len g)).(j+1) by A156,A165,FINSEQ_4:24; f/.(j+1)=f.(j+1) by A165,A171,FINSEQ_4:24; then A175:LSeg((f^mid(g,2,len g))/.j,(f^mid(g,2,len g))/.(j+1)) =LSeg(f/.j,f/.(j+1)) by A165,A171,A173,A174,SCMFSA_7:9; A176:LSeg((f^mid(g,2,len g))/.j,(f^mid(g,2,len g))/.(j+1)) = LSeg(f^mid(g,2,len g),j) by A156,A164,TOPREAL1:def 5; LSeg(f,j)=LSeg(f/.j,f/.(j+1)) by A164,A171,TOPREAL1:def 5; then LSeg(f^mid(g,2,len g),i) misses LSeg(f^mid(g,2,len g),j) by A2,A155,A170,A175,A176,TOPREAL1:def 9; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {} by XBOOLE_0:def 7; case i<1; then LSeg(f^mid(g,2,len g),i)={} by TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {}; end; hence LSeg(f^mid(g,2,len g),i) misses LSeg(f^mid(g,2,len g),j) by XBOOLE_0:def 7; case A177:i+1<=len f & len f<=j & j+1<=len (f^mid(g,2,len g)); now per cases by A155,A177,AXIOMS:21; case A178:i+1<len f & len f<=j; len f<=len f+len mid(g,2,len g) by NAT_1:29; then A179:i+1<len (f^mid(g,2,len g)) by A6,A178,AXIOMS:22; A180: 1+1<=j by A2,A178,AXIOMS:22; then A181:1<=j by Th9; A182:len f<=j+1 by A178,Th11; now per cases; case A183:1<=i; then A184:1<=i+1 by Th11; A185:i+1+1<=len f by A178,NAT_1:38; A186: now 1<=i & i<=len (f^mid(g,2,len g)) by A179,A183,Th9; then A187:(f^mid(g,2,len g))/.i=(f^mid(g,2,len g)).i by FINSEQ_4:24; 1<=i & i<=len f by A177,A183,Th9; then A188:f/.i=f.i by FINSEQ_4:24; 1<=i & i<=len f by A177,A183,Th9; then A189:(f^mid(g,2,len g))/.i=f/.i by A187,A188,SCMFSA_7:9; A190:(f^mid(g,2,len g))/.(i+1)=(f^mid(g,2,len g)).(i+1) by A179,A184,FINSEQ_4:24; f/.(i+1)=f.(i+1) by A177,A184,FINSEQ_4:24; then A191:LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) =LSeg(f/.i,f/.(i+1)) by A177,A184,A189,A190,SCMFSA_7:9; LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) = LSeg(f^mid(g,2,len g),i) by A179,A183,TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i)=LSeg(f,i) by A177,A183,A191,TOPREAL1:def 5; end; A192:1<=1+(j-'len f) by NAT_1:29; j+1+1<=len f+(len g-1)+1 by A6,A8,A177,AXIOMS:24; then j+1+1<=len f+(len g-1+1) by XCMPLX_1:1; then j+1+1<=len f+len g by XCMPLX_1:27; then j+1+1-len f<=len f +len g -len f by REAL_1:49; then j+1+1-len f<=len g by XCMPLX_1:26; then j+(1+1)-len f<=len g by XCMPLX_1:1; then j-len f+(1+1)<=len g by XCMPLX_1:29; then j-len f+1+1<=len g by XCMPLX_1:1; then A193:j-'len f+1+1<=len g by A178,SCMFSA_7:3; then j-'len f+1+1-1<=len g-1 by REAL_1:49; then j-'len f+1<=len g-(1+1-1) by XCMPLX_1:26; then A194: j-'len f+1<=len g-2+1 by XCMPLX_1:37; then j-'len f+1<=len g-'2+1 by A3,SCMFSA_7:3; then A195:j-'len f<=len g-'2+1 by Th9; A196:j-'len f+1=j-len f+1 by A177,SCMFSA_7:3 .=j+1-len f by XCMPLX_1:29 .=j+1-'len f by A182,SCMFSA_7:3; A197:LSeg(g,j-'len f+1)=LSeg(g/.(j-'len f+1),g/.(j-'len f+1+1)) by A192,A193,TOPREAL1:def 5; A198:1<=j & j<=len (f^mid(g,2,len g)) by A177,A180,Th9; 1<=j-'len f+1 & j-'len f+1<=len g by A193,Th9,NAT_1:29; then A199:g/.(j-'len f+1)=g.(j-'len f+1) by FINSEQ_4:24; A200:now assume A201:1<=j-'len f; then 1<=j-len f by Th1; then 1+len f<=j-len f +len f by AXIOMS:24; then len f +1<=j by XCMPLX_1:27; then A202: len f<j by NAT_1:38; then (f^mid(g,2,len g)).j=mid(g,2,len g).(j-len f) by A198,Th15; then (f^mid(g,2,len g)).j=mid(g,2,len g).(j-'len f) by A202,SCMFSA_7:3; then (f^mid(g,2,len g)).j=g.(j-'len f+2-1) by A3,A195,A201,Th31; then (f^mid(g,2,len g)).j=g.(j-'len f+(2-1)) by XCMPLX_1:29; hence (f^mid(g,2,len g)).j=g.(j-'len f+1); end; now assume 1>j-'len f; then j-'len f+1<=0+1 by NAT_1:38; then j-'len f<=0 by REAL_1:53; then A203:j-'len f=0 by NAT_1:18; then j-len f=0 by A177,SCMFSA_7:3; then j=len f by XCMPLX_1:15; hence (f^mid(g,2,len g)).j = g.(j-'len f+1) by A1,A4,A203,SCMFSA_7:9; end; then A204:(f^mid(g,2,len g))/.j=g/.(j-'len f+1) by A198,A199,A200, FINSEQ_4:24; 1<=j+1 & j+1<=len (f^mid(g,2,len g)) by A177,A181,Th11; then A205:(f^mid(g,2,len g))/.(j+1)=(f^mid(g,2,len g)).(j+1) by FINSEQ_4:24; 1<=j-'len f+1+1 by NAT_1:29; then A206:g/.(j-'len f+1+1)=g.(j-'len f+1+1) by A193,FINSEQ_4:24; A207:now assume A208:1<=(j+1)-'len f; then 1<=(j+1)-len f by Th1; then 1+len f<=(j+1)-len f +len f by AXIOMS:24; then len f +1<=(j+1) by XCMPLX_1:27; then A209: len f<(j+1) by NAT_1:38; then (f^mid(g,2,len g)).(j+1)=mid(g,2,len g).((j+1)-len f) by A177,Th15; then (f^mid(g,2,len g)).(j+1)=mid(g,2,len g).((j+1)-'len f) by A209,SCMFSA_7:3; then (f^mid(g,2,len g)).(j+1)=g.((j+1)-'len f+2-1) by A3,A194,A196,A208,Th31; then (f^mid(g,2,len g)).(j+1)=g.((j+1)-'len f+(2-1)) by XCMPLX_1:29; hence (f^mid(g,2,len g)).(j+1)=g.((j+1)-'len f+1); end; now assume 1>(j+1)-'len f; then (j+1)-'len f+1<=0+1 by NAT_1:38; then (j+1)-'len f<=0 by REAL_1:53; then A210:(j+1)-'len f=0 by NAT_1:18; then (j+1)-len f=0 by A182,SCMFSA_7:3; then (j+1)=len f by XCMPLX_1:15; hence (f^mid(g,2,len g)).(j+1) = g.((j+1)-'len f+1) by A1,A4,A210,SCMFSA_7:9; end; then A211:LSeg(f^mid(g,2,len g),j)=LSeg(g,j-'len f+1) by A177,A181,A196,A197,A204,A205,A206,A207, TOPREAL1:def 5; A212: LSeg(f^mid(g,2,len g),i) c= L~f by A186,TOPREAL3:26; LSeg(f^mid(g,2,len g),j) c=L~g by A211,TOPREAL3:26; then A213:LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) c={g. 1} by A1,A212,XBOOLE_1:27; now per cases; case A214:i+1<len f-'1; A215: 1+1-1<=len f -1 by A2,REAL_1:49; A216:1<=len f by A2,AXIOMS:22; then A217:len f-'1+1=len f-1+1 by SCMFSA_7:3 .=len f by XCMPLX_1:27; then A218:1<=len f-'1 & len f-'1+1<=len f by A215,Th1; now given x being set such that A219:x in LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j); A220:x=g.1 by A213,A219,TARSKI:def 1; A221:x in LSeg(f,i) by A186,A219,XBOOLE_0:def 3; f/.len f in LSeg(f,len f-'1) by A217,A218,TOPREAL1:27; then g.1 in LSeg(f,len f-'1) by A1,A216,FINSEQ_4:24; then x in LSeg(f,i)/\ LSeg(f,len f-'1) by A220,A221,XBOOLE_0:def 3; then LSeg(f,i) meets LSeg(f,len f-'1) by XBOOLE_0:4; hence contradiction by A2,A214,TOPREAL1:def 9; end; hence LSeg(f^mid(g,2,len g),i) misses LSeg(f^mid(g,2,len g),j) by XBOOLE_0:4; case i+1>=len f-'1; then i+1>=len f-1 by A4,SCMFSA_7:3; then i+1+1>=len f-1+1 by AXIOMS:24; then i+1+1>=len f by XCMPLX_1:27; then A222: i+1+1=len f by A185,AXIOMS:21; then i+1=len f-1 by XCMPLX_1:26; then A223:i+1=len f-1 & i+1=len f-'1 by A4,SCMFSA_7:3; A224:i+1+1=len f & i+(1+1)=len f by A222,XCMPLX_1:1; A225:i+1+1=len f & i+(1+1)=len f & 1<=i+1 & i+1<=len f by A222,NAT_1:29,XCMPLX_1:1; A226:len f-'1+1=len f-1+1 by A4,SCMFSA_7:3 .=len f by XCMPLX_1:27; then 1+1<=len f-'1+1 by A1,TOPREAL1:def 10; then A227:1<=len f-'1 & len f-'1+1<=len f by A226,REAL_1:53; now given x being set such that A228:x in LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j); A229:x=g.1 by A213,A228,TARSKI:def 1; A230:x in LSeg(f,i) by A186,A228,XBOOLE_0:def 3; f/.len f in LSeg(f,len f-'1) by A226,A227,TOPREAL1:27; then g.1 in LSeg(f,len f-'1) by A1,A4,FINSEQ_4:24; then A231:x in LSeg(f,i)/\ LSeg(f,len f-'1) by A229,A230, XBOOLE_0:def 3; LSeg(f,i)/\ LSeg(f,len f-'1)={f/.(i+1)} by A2,A183,A223,A224,TOPREAL1:def 8; then f.len f=f/.(i+1) by A1,A229,A231,TARSKI:def 1; then A232:f.len f=f.(len f-'1) by A223,A225,FINSEQ_4:24; A233:len f in dom f by A4,FINSEQ_3:27; A234:len f-'1<=len f by GOBOARD9:2; 1+1-1<=len f-1 by A2,REAL_1:49; then 1<=len f-'1 by Th1; then len f-'1 in dom f by A234,FINSEQ_3:27; then len f=len f-'1 by A2,A232,A233,FUNCT_1:def 8; then len f=len f-1 by A4,SCMFSA_7:3; then len f+1=len f by XCMPLX_1:27; hence contradiction by NAT_1:38; end; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {} by XBOOLE_0:def 1; end; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {} by XBOOLE_0:def 7; case i<1; then LSeg(f^mid(g,2,len g),i)={} by TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {}; end; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {}; case A235:i+1<=len f & len f<j; len f<len f+len mid(g,2,len g) proof 1+1-1<=len g-1 by A3,REAL_1:49; then len f+1<=len f+len mid(g,2,len g) by A8,REAL_1:55; hence thesis by NAT_1:38; end; then A236:i+1<len (f^mid(g,2,len g)) by A6,A235,AXIOMS:22; A237: 1+1<=j by A2,A235,AXIOMS:22; then A238:1<=j by Th9; A239:len f<=j+1 by A235,Th11; now per cases; case A240:1<=i; then A241:1<=i+1 by Th11; A242: now 1<=i & i<=len (f^mid(g,2,len g)) by A236,A240,Th9; then A243:(f^mid(g,2,len g))/.i=(f^mid(g,2,len g)).i by FINSEQ_4:24; 1<=i & i<=len f by A177,A240,Th9; then A244:f/.i=f.i by FINSEQ_4:24; 1<=i & i<=len f by A177,A240,Th9; then A245:(f^mid(g,2,len g))/.i=f/.i by A243,A244,SCMFSA_7:9; A246:(f^mid(g,2,len g))/.(i+1)=(f^mid(g,2,len g)).(i+1) by A236,A241,FINSEQ_4:24; f/.(i+1)=f.(i+1) by A177,A241,FINSEQ_4:24; then A247:LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) =LSeg(f/.i,f/.(i+1)) by A177,A241,A245,A246,SCMFSA_7:9; LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) = LSeg(f^mid(g,2,len g),i) by A236,A240,TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i)=LSeg(f,i) by A177,A240,A247,TOPREAL1:def 5; end; A248:1<=1+(j-'len f) by NAT_1:29; j+1+1<=len f+(len g-1)+1 by A6,A8,A177,AXIOMS:24; then j+1+1<=len f+(len g-1+1) by XCMPLX_1:1; then j+1+1<=len f+len g by XCMPLX_1:27; then j+1+1-len f<=len f +len g -len f by REAL_1:49; then j+1+1-len f<=len g by XCMPLX_1:26; then j+(1+1)-len f<=len g by XCMPLX_1:1; then j-len f+(1+1)<=len g by XCMPLX_1:29; then j-len f+1+1<=len g by XCMPLX_1:1; then A249:j-'len f+1+1<=len g by A235,SCMFSA_7:3; then j-'len f+1+1-1<=len g-1 by REAL_1:49; then j-'len f+1<=len g-(1+1-1) by XCMPLX_1:26; then A250: j-'len f+1<=len g-2+1 by XCMPLX_1:37; then j-'len f+1<=len g-'2+1 by A3,SCMFSA_7:3; then A251:j-'len f<=len g-'2+1 by Th9; A252:j-'len f+1=j-len f+1 by A177,SCMFSA_7:3 .=j+1-len f by XCMPLX_1:29 .=j+1-'len f by A239,SCMFSA_7:3; A253:LSeg(g,j-'len f+1)=LSeg(g/.(j-'len f+1),g/.(j-'len f+1+1)) by A248,A249,TOPREAL1:def 5; A254:1<=j & j<=len (f^mid(g,2,len g)) by A177,A237,Th9; 1<=j-'len f+1 & j-'len f+1<=len g by A249,Th9,NAT_1:29; then A255:g/.(j-'len f+1)=g.(j-'len f+1) by FINSEQ_4:24; A256:now assume A257:1<=j-'len f; then 1<=j-len f by Th1; then 1+len f<=j-len f +len f by AXIOMS:24; then len f +1<=j by XCMPLX_1:27; then A258: len f<j by NAT_1:38; then (f^mid(g,2,len g)).j=mid(g,2,len g).(j-len f) by A254,Th15; then (f^mid(g,2,len g)).j=mid(g,2,len g).(j-'len f) by A258,SCMFSA_7:3; then (f^mid(g,2,len g)).j=g.(j-'len f+2-1) by A3,A251,A257,Th31; then (f^mid(g,2,len g)).j=g.(j-'len f+(2-1)) by XCMPLX_1:29; hence (f^mid(g,2,len g)).j=g.(j-'len f+1); end; now assume 1>j-'len f; then j-'len f+1<=0+1 by NAT_1:38; then j-'len f<=0 by REAL_1:53; then A259:j-'len f=0 by NAT_1:18; then j-len f=0 by A177,SCMFSA_7:3; then j=len f by XCMPLX_1:15; hence (f^mid(g,2,len g)).j = g.(j-'len f+1) by A1,A4,A259,SCMFSA_7:9; end; then A260:(f^mid(g,2,len g))/.j=g/.(j-'len f+1) by A254,A255,A256, FINSEQ_4:24; 1<=j+1 & j+1<=len (f^mid(g,2,len g)) by A177,A238,Th11; then A261:(f^mid(g,2,len g))/.(j+1)=(f^mid(g,2,len g)).(j+1) by FINSEQ_4:24; 1<=j-'len f+1+1 by NAT_1:29; then A262:g/.(j-'len f+1+1)=g.(j-'len f+1+1) by A249,FINSEQ_4:24; A263:now assume A264:1<=(j+1)-'len f; then 1<=(j+1)-len f by Th1; then 1+len f<=(j+1)-len f +len f by AXIOMS:24; then len f +1<=(j+1) by XCMPLX_1:27; then A265: len f<(j+1) by NAT_1:38; then (f^mid(g,2,len g)).(j+1)=mid(g,2,len g).((j+1)-len f) by A177,Th15; then (f^mid(g,2,len g)).(j+1)=mid(g,2,len g).((j+1)-'len f) by A265,SCMFSA_7:3; then (f^mid(g,2,len g)).(j+1)=g.((j+1)-'len f+2-1) by A3,A250,A252,A264,Th31; then (f^mid(g,2,len g)).(j+1)=g.((j+1)-'len f+(2-1)) by XCMPLX_1:29; hence (f^mid(g,2,len g)).(j+1)=g.((j+1)-'len f+1); end; now assume 1>(j+1)-'len f; then (j+1)-'len f+1<=0+1 by NAT_1:38; then (j+1)-'len f<=0 by REAL_1:53; then A266:(j+1)-'len f=0 by NAT_1:18; then (j+1)-len f=0 by A239,SCMFSA_7:3; then (j+1)=len f by XCMPLX_1:15; hence (f^mid(g,2,len g)).(j+1) = g.((j+1)-'len f+1) by A1,A4,A266,SCMFSA_7:9; end; then A267:LSeg(f^mid(g,2,len g),j)=LSeg(g,j-'len f+1) by A177,A238,A252,A253,A260,A261,A262,A263,TOPREAL1:def 5; A268: LSeg(f^mid(g,2,len g),i) c= L~f by A242,TOPREAL3:26; LSeg(f^mid(g,2,len g),j) c=L~g by A267,TOPREAL3:26; then A269:LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) c={g. 1} by A1,A268,XBOOLE_1:27; now given x being set such that A270:x in LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j); A271:x=g.1 by A269,A270,TARSKI:def 1; then A272:g/.1=x by A5,FINSEQ_4:24; A273:LSeg(g,j-'len f+1)<>{} & x in LSeg(g,j-'len f+1) & 1+1<=len g by A1,A267,A270,TOPREAL1:def 10,XBOOLE_0:def 3; then x in LSeg(g,1) & x in LSeg(g,j-'len f+1) by A272,TOPREAL1:27; then A274:x in LSeg(g,1)/\ LSeg(g,j-'len f+1) by XBOOLE_0:def 3; then LSeg(g,1) meets LSeg(g,j-'len f+1) by XBOOLE_0:4; then 1+1 >= j-'len f+1 by A3,TOPREAL1:def 9; then 1>=j-'len f by REAL_1:53; then 1>=j-len f by Th1; then 1+len f>=j-len f+len f by AXIOMS:24; then len f+1>=j & j>=len f+1 by A235,NAT_1:38,XCMPLX_1:27; then j=len f +1 & j-'len f+1=j-len f+1 by A235,AXIOMS:21, SCMFSA_7:3; then A275:j-'len f+1=1+1 by XCMPLX_1:26; then 1+2<=len g by A273,TOPREAL1:def 5; then LSeg(g,1)/\ LSeg(g,j-'len f+1)={g/.(1+1)} by A3,A275, TOPREAL1:def 8; then A276: x=g/.(1+1) by A274,TARSKI:def 1 .=g.(1+1) by A3, FINSEQ_4:24; A277:1 in dom g by A5,FINSEQ_3:27; 1+1 in dom g by A3,FINSEQ_3:27; hence contradiction by A3,A271,A276,A277,FUNCT_1:def 8; end; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {} by XBOOLE_0:def 1; case i<1; then LSeg(f^mid(g,2,len g),i)={} by TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {}; end; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {}; end; hence LSeg(f^mid(g,2,len g),i) misses LSeg(f^mid(g,2,len g),j) by XBOOLE_0:def 7; case A278:len f<i+1 & j+1<=len (f^mid(g,2,len g)); then A279:len f<=i by NAT_1:38; then A280: 1+1<=i by A2,AXIOMS:22; then A281:1<=i by Th9; then A282: 1<=i+1 by Th11; then A283:1<=j by A155,AXIOMS:22; A284:len f<j by A155,A278,AXIOMS:22; j<=j+1 by NAT_1:29; then A285:len f<j+1 by A284,AXIOMS:22; A286:i-'len f=i-len f by A279,SCMFSA_7:3; A287:j-'len f=j-len f by A284,SCMFSA_7:3; i+1-len f<j-len f by A155,REAL_1:54; then i-'len f+1<j-'len f by A286,A287,XCMPLX_1:29; then A288:i-'len f +1+1<j-'len f +1 by REAL_1:53; A289:1<=(i-'len f)+1 by NAT_1:29; A290:1<=(j-'len f)+1 by NAT_1:29; now per cases; case A291:j+1<=len (f^mid(g,2,len g)); then A292:j<=len (f^mid(g,2,len g)) by Th9; A293: now A294: i+1<len (f^mid(g,2,len g)) by A155,A292,AXIOMS:22; then i+1<len f+(len g-1) by A8,FINSEQ_1:35; then i+1-len f<len f+(len g-1)-len f by REAL_1:54; then i+1-len f<len g -1 by XCMPLX_1:26; then i-len f+1<len g-1 by XCMPLX_1:29; then A295: i-len f+1+1<len g-1+1 by REAL_1:53; then A296: i-'len f+1+1<len g by A286,XCMPLX_1:27; then A297:(i-'len f+1)<=len g by Th9; (i-'len f+1)+1-1<=len g-1 by A296,REAL_1:49; then (i-'len f+1)<=len g-(2-1) by XCMPLX_1:26; then A298:(i-'len f+1)<=len g-2+1 by XCMPLX_1:37; A299:1<=i & i<=len (f^mid(g,2,len g)) by A280,A294,Th9; A300:g/.(i-'len f+1)=g.(i-'len f+1) by A289,A297,FINSEQ_4:24; A301: now per cases; case i<=len f; then A302:i=len f by A279,AXIOMS:21; then (f^mid(g,2,len g)).i =g.(0+1) by A1,A281,SCMFSA_7:9 .=g.(i-'len f+1) by A302,GOBOARD9:1; hence (f^mid(g,2,len g))/.i=g/.(i-'len f+1) by A299,A300,FINSEQ_4: 24; case A303:i>len f; then len f+1<=i by NAT_1:38; then len f+1-len f<=i-len f by REAL_1:49; then A304:1<=i-'len f by A286,XCMPLX_1:26; i-'len f+1-1<=len g-1 by A297,REAL_1:49; then i-'len f<=len g -(2-1) by XCMPLX_1:26; then A305:i-'len f<=len g -2+1 by XCMPLX_1:37; (f^mid(g,2,len g)).i =mid(g,2,len g).(i-'len f) by A286,A299,A303,Th15 .=g.(i-'len f+2-1) by A3,A304,A305,Th31 .=g.(i-'len f +(2-1)) by XCMPLX_1:29 .=g.(i-'len f +1); hence (f^mid(g,2,len g))/.i=g/.(i-'len f+1) by A299,A300,FINSEQ_4: 24; end; 1<=i+1 & i+1<=len (f^mid(g,2,len g)) by A155,A292,A299,Th11,AXIOMS :22; then A306:(f^mid(g,2,len g))/.(i+1)=(f^mid(g,2,len g)).(i+1) by FINSEQ_4:24; 1<=(i-'len f+1)+1 & (i-'len f+1)+1<=len g by A286,A295,NAT_1:29, XCMPLX_1:27; then A307:g/.((i-'len f+1)+1)=g.((i-'len f+1)+1) by FINSEQ_4:24; A308:i-'len f+1+2-1 =i-'len f+1+(1+1-1) by XCMPLX_1:29 .=i-'len f+1+1; A309: (f^mid(g,2,len g)).(i+1)=mid(g,2,len g).(i+1-len f) by A278,A294,Th15 .=mid(g,2,len g).(i-len f+1) by XCMPLX_1:29 .=g.(i-'len f +1+1) by A3,A286,A289,A298,A308,Th31; LSeg((f^mid(g,2,len g))/.i,(f^mid(g,2,len g))/.(i+1)) = LSeg(f^mid(g,2,len g),i) by A281,A294,TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i)=LSeg(g,(i-'len f+1)) by A289,A296,A301,A306,A307,A309,TOPREAL1:def 5 ; end; j+1<=len f+(len g-1) by A8,A291,FINSEQ_1:35; then j+1-len f<=len f+(len g-1)-len f by REAL_1:49; then j+1-len f<=len g -1 by XCMPLX_1:26; then j-len f+1<=len g-1 by XCMPLX_1:29; then A310: j-len f+1+1<=len g-1+1 by AXIOMS:24; then A311:(j-'len f+1)+1<=len g by A287,XCMPLX_1:27; then A312:(j-'len f+1)<=len g by Th9; (j-'len f+1)+1-1<=len g-1 by A311,REAL_1:49; then (j-'len f+1)<=len g-(2-1) by XCMPLX_1:26; then A313:(j-'len f+1)<=len g-2+1 by XCMPLX_1:37; A314:1<=j & j<=len (f^mid(g,2,len g)) by A155,A282,A291,Th9,AXIOMS: 22; then A315:(f^mid(g,2,len g))/.j=(f^mid(g,2,len g)).j by FINSEQ_4:24; A316:g/.(j-'len f+1)=g.(j-'len f+1) by A290,A312,FINSEQ_4:24; len f+1<=j by A284,NAT_1:38; then len f+1-len f<=j-len f by REAL_1:49; then A317:1<=j-'len f by A287,XCMPLX_1:26; j-'len f+1-1<=len g-1 by A312,REAL_1:49; then j-'len f<=len g -(1+1-1) by XCMPLX_1:26; then A318:j-'len f<=len g -2+1 by XCMPLX_1:37; A319: (f^mid(g,2,len g)).j=mid(g,2,len g).(j-len f) by A284,A314, Th15 .=g.(j-'len f+2-1) by A3,A287,A317,A318,Th31 .=g.(j-'len f +(2-1)) by XCMPLX_1:29 .=g.(j-'len f +1); 1<=j+1 & j+1<=len (f^mid(g,2,len g)) by A291,A314,Th11; then A320:(f^mid(g,2,len g))/.(j+1)=(f^mid(g,2,len g)).(j+1) by FINSEQ_4:24; 1<=(j-'len f+1)+1 & (j-'len f+1)+1<=len g by A287,A310,NAT_1:29, XCMPLX_1:27; then A321:g/.((j-'len f+1)+1)=g.((j-'len f+1)+1) by FINSEQ_4:24; A322:j-'len f+1+2-1= j-'len f+1+(1+1-1) by XCMPLX_1:29 .=j-'len f+1+1; A323: (f^mid(g,2,len g)).(j+1)=mid(g,2,len g).(j+1-len f) by A285,A291,Th15 .=mid(g,2,len g).(j-len f+1) by XCMPLX_1:29 .=g.(j-'len f +1+1) by A3,A287,A290,A313,A322,Th31; LSeg((f^mid(g,2,len g))/.j,(f^mid(g,2,len g))/.(j+1)) = LSeg(f^mid(g,2,len g),j) by A283,A291,TOPREAL1:def 5; then LSeg(f^mid(g,2,len g),j)=LSeg(g,j-'len f+1) by A290,A311,A315,A316,A319,A320,A321,A323,TOPREAL1:def 5; then LSeg(f^mid(g,2,len g),i) misses LSeg(f^mid(g,2,len g),j) by A3,A288,A293,TOPREAL1:def 9; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {} by XBOOLE_0:def 7; case j+1>len (f^mid(g,2,len g)); then LSeg(f^mid(g,2,len g),j)={} by TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {}; end; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {}; case j+1>len (f^mid(g,2,len g)); then LSeg(f^mid(g,2,len g),j) = {} by TOPREAL1:def 5; hence LSeg(f^mid(g,2,len g),i) /\ LSeg(f^mid(g,2,len g),j) = {}; end; hence LSeg(f^mid(g,2,len g),i) misses LSeg(f^mid(g,2,len g),j) by XBOOLE_0:def 7; end; for i st 1 <= i & i+1 <= len (f^mid(g,2,len g)) holds ((f^mid(g,2,len g))/.i)`1 = ((f^mid(g,2,len g))/.(i+1))`1 or ((f^mid(g,2,len g))/.i)`2 = ((f^mid(g,2,len g))/.(i+1))`2 proof let i;assume A324: 1 <= i & i+1 <= len (f^mid(g,2,len g)); now per cases; case A325:i<len f; A326:1<=i+1 by A324,Th11; A327:i+1<=len f by A325,NAT_1:38; 1<=i & i<=len (f^mid(g,2,len g)) by A324,Th9; then A328:(f^mid(g,2,len g))/.i=(f^mid(g,2,len g)).i by FINSEQ_4:24; f/.i=f.i by A324,A325,FINSEQ_4:24; then A329:(f^mid(g,2,len g))/.i=f/.i by A324,A325,A328,SCMFSA_7:9; A330:(f^mid(g,2,len g))/.((i+1))=(f^mid(g,2,len g)).(i+1) by A324,A326,FINSEQ_4:24; A331:f/.(i+1)=f.(i+1) by A326,A327,FINSEQ_4:24; (f^mid(g,2,len g)).(i+1)=f.(i+1) by A326,A327,SCMFSA_7:9; hence ((f^mid(g,2,len g))/.i)`1 = ((f^mid(g,2,len g))/.(i+1))`1 or ((f^mid(g,2,len g))/.i)`2 = ((f^mid(g,2,len g))/.(i+1))`2 by A2,A324,A327,A329,A330,A331,TOPREAL1:def 7; case A332:i>=len f; then i-len f>=0 by SQUARE_1:12; then A333:i-'len f=i-len f by BINARITH:def 3; A334:i+1>=len f by A332,Th11; A335: i+1-len f<=len f+(len g-1)-len f by A6,A8,A324,REAL_1:49; then i+1-len f<=(len g-1) by XCMPLX_1:26; then A336:i-len f+1<=(len g-1) by XCMPLX_1:29; then A337: i-len f+1+1<=len g-1+1 by AXIOMS:24; then A338:i-'len f+1+1<=len g by A333,XCMPLX_1:27; A339: 1<=i-'len f+1 & i-'len f+1+1<=len g by A333,A337,NAT_1:29, XCMPLX_1:27; i-'len f<=i-'len f+1 by NAT_1:29; then i-'len f<=len g-(2-1) by A333,A336,AXIOMS:22; then A340:i-'len f<=len g-2+1 by XCMPLX_1:37; A341:1<=i & i<=len (f^mid(g,2,len g)) by A324,Th9; 1<=i-'len f+1 & i-'len f+1<=len g by A338,Th9,NAT_1:29; then A342:g/.(i-'len f+1)=g.(i-'len f+1) by FINSEQ_4:24; i+1-len f<=len g-(1+1-1) by A335,XCMPLX_1:26; then i+1-len f<=len g-2+1 by XCMPLX_1:37; then i+1-len f<=len g-'2+1 by A3,SCMFSA_7:3; then A343:i+1-'len f<=len g -'2+1 by A334,SCMFSA_7:3; A344:i+1-'len f+1=i+1-len f+1 by A334,SCMFSA_7:3 .=i-len f+1+1 by XCMPLX_1:29 .=i-'len f+1+1 by A332,SCMFSA_7:3; 1<=1+(i-'len f) by NAT_1:29; then 1<=1+(i-len f) by A332,SCMFSA_7:3; then A345: 1<=1+i-len f by XCMPLX_1:29; then A346:1<=i+1-'len f by Th1; A347:now assume A348:1<=i-'len f; then 1<=i-len f by Th1; then 1+len f<=i-len f +len f by AXIOMS:24; then len f +1<=i by XCMPLX_1:27; then A349: len f<i by NAT_1:38; then (f^mid(g,2,len g)).i=mid(g,2,len g).(i-len f) by A341,Th15; then (f^mid(g,2,len g)).i=mid(g,2,len g).(i-'len f) by A349,SCMFSA_7:3; then (f^mid(g,2,len g)).i=g.(i-'len f+2-1) by A3,A340,A348,Th31; then (f^mid(g,2,len g)).i=g.(i-'len f+(2-1)) by XCMPLX_1:29; hence (f^mid(g,2,len g)).i=g.(i-'len f+1); end; now assume 1>i-'len f; then i-'len f+1<=0+1 by NAT_1:38; then i-'len f<=0 by REAL_1:53; then A350:i-'len f=0 by NAT_1:18; then i=len f by A333,XCMPLX_1:15; hence (f^mid(g,2,len g)).i = g.(i-'len f+1) by A1,A4,A350,SCMFSA_7:9; end; then A351:(f^mid(g,2,len g))/.i=g/.(i-'len f+1) by A341,A342,A347, FINSEQ_4:24; 1<=i+1 & i+1<=len (f^mid(g,2,len g)) by A324,Th11; then A352:(f^mid(g,2,len g))/.(i+1)=(f^mid(g,2,len g)).(i+1) by FINSEQ_4:24; 1<=i-'len f+1+1 & i-'len f+1+1<=len g by A333,A337,NAT_1:29, XCMPLX_1:27; then A353:g/.(i-'len f+1+1)=g.(i-'len f+1+1) by FINSEQ_4:24; 1+len f<=(i+1)-len f +len f by A345,AXIOMS:24; then len f +1<=(i+1) by XCMPLX_1:27; then len f<(i+1) by NAT_1:38; then (f^mid(g,2,len g)).(i+1)=mid(g,2,len g).((i+1)-len f) by A324,Th15; then (f^mid(g,2,len g)).(i+1)=mid(g,2,len g).((i+1)-'len f) by A334,SCMFSA_7:3; then (f^mid(g,2,len g)).(i+1)=g.((i+1)-'len f+2-1) by A3,A343,A346,Th31; then (f^mid(g,2,len g)).(i+1)=g.((i+1)-'len f+(1+1-1)) by XCMPLX_1:29; hence ((f^mid(g,2,len g))/.i)`1 = ((f^mid(g,2,len g))/.(i+1))`1 or ((f^mid(g,2,len g))/.i)`2 = ((f^mid(g,2,len g))/.(i+1))`2 by A3,A339,A344,A351,A352,A353,TOPREAL1:def 7; end; hence ((f^mid(g,2,len g))/.i)`1 = ((f^mid(g,2,len g))/.(i+1))`1 or ((f^mid(g,2,len g))/.i)`2 = ((f^mid(g,2,len g))/.(i+1))`2; end; then f^mid(g,2,len g) is one-to-one & len (f^mid(g,2,len g)) >= 2 & f^mid(g,2,len g) is unfolded s.n.c. special by A2,A7,A9,A53,A154,AXIOMS:22,FUNCT_1:def 8,TOPREAL1: def 7,def 8,def 9; hence f^mid(g,2,len g) is_S-Seq by TOPREAL1:def 10; end; theorem Th74:for f,g being FinSequence of TOP-REAL 2 st f.len f=g.1 & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} holds f^mid(g,2,len g) is_S-Seq_joining f/.1,g/.len g proof let f,g be FinSequence of TOP-REAL 2; assume A1: f.len f=g.1 & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1}; then A2:f^mid(g,2,len g) is_S-Seq by Th73; A3:f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by A1,TOPREAL1:def 10; A4:g is one-to-one & len g >= 2 & g is unfolded s.n.c. special by A1,TOPREAL1:def 10; A5:1<=len f by A3,AXIOMS:22; A6:1<=len g by A4,AXIOMS:22; A7:len (f^mid(g,2,len g))=len f + len mid(g,2,len g) by FINSEQ_1:35; A8:len mid(g,2,len g)=len g -'2+1 by A4,A6,Th27; then A9:len mid(g,2,len g) =len g -2+1 by A4,SCMFSA_7:3 .=len g -(2-1) by XCMPLX_1:37 .=len g -1; A10: 1+1-1<=len g-1 by A4,REAL_1:49; A11:len (mid(g,2,len g))+2-1=len (mid(g,2,len g))+(2-1) by XCMPLX_1:29 .=len g by A9,XCMPLX_1:27; A12:(f^mid(g,2,len g)).1=f.1 by A5,SCMFSA_7:9 .=f/.1 by A5,FINSEQ_4:24; len g-1>=1+1-1 by A4,REAL_1:49; then len f+1<=len (f^mid(g,2,len g)) by A7,A9,AXIOMS:24; then len f<len (f^mid(g,2,len g)) by NAT_1:38; then (f^mid(g,2,len g)).(len (f^mid(g,2,len g))) =(mid(g,2,len g)).(len (f^mid(g,2,len g))-len f) by Th15 .=(mid(g,2,len g)).(len (mid(g,2,len g))) by A7,XCMPLX_1:26 .=g.len g by A4,A8,A9,A10,A11,Th31 .=g/.len g by A6,FINSEQ_4:24; hence f^mid(g,2,len g) is_S-Seq_joining f/.1,g/.len g by A2,A12,Def3; end; theorem for f being FinSequence of TOP-REAL 2, n being Nat holds L~(f/^n) c= L~f proof let f be FinSequence of TOP-REAL 2, n be Nat; let x be set;assume x in L~(f/^n); then x in union { LSeg(f/^n,i) : 1 <= i & i+1 <= len (f/^n) } by TOPREAL1:def 6; then consider Y being set such that A1: x in Y & Y in { LSeg(f/^n,i) : 1 <= i & i+1 <= len (f/^n) } by TARSKI:def 4; consider i such that A2:Y= LSeg(f/^n,i) &(1 <= i & i+1 <= len (f/^n)) by A1; now per cases; case n<=len f; then LSeg(f/^n,i)=LSeg(f,n+i) by A2,SPPOL_2:4; then Y c=L~f by A2,TOPREAL3:26; hence x in L~f by A1; case n>len f; then f/^n=<*>(the carrier of TOP-REAL 2) by RFINSEQ:def 2; then A3:i+1<=0 by A2,FINSEQ_1:32; 1<=1+i by NAT_1:29; hence contradiction by A3,AXIOMS:22; end; hence x in L~f; end; theorem Th76: for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f & f is_S-Seq holds L~R_Cut(f,p) c= L~f proof let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2 such that A1: p in L~f and A2: f is_S-Seq; f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by A2,TOPREAL1:def 10; then A3:1<=len f by AXIOMS:22; A4:1<=Index(p,f) & Index(p,f)<=len f by A1,Th41; per cases; suppose p = f.1; then R_Cut(f,p)=<*p*> by Def5; then len R_Cut(f,p)=1 by FINSEQ_1:56; then L~R_Cut(f,p) = {} by TOPREAL1:28; hence thesis by XBOOLE_1:2; suppose p<>f.1; then A5: R_Cut(f,p)=mid(f,1,Index(p,f))^<*p*> by Def5; Index(p,f) < len f by A1,Th41; then A6:1<=Index(p,f)+1 & Index(p,f)+1<=len f by NAT_1:29,38; A7:len (mid(f,1,Index(p,f))) =Index(p,f)-'1+1 by A3,A4,Th27 .=Index(p,f) by A4,AMI_5:4; then 0<len (mid(f,1,Index(p,f))) by A4,AXIOMS:22; then (mid(f,1,Index(p,f)))<><*>(the carrier of TOP-REAL 2) by FINSEQ_1:32; then A8:L~(mid(f,1,Index(p,f))^<*p*>) = L~mid(f,1,Index(p,f)) \/ LSeg((mid(f,1,Index(p,f))/.Index(p,f)),p) by A7,SPPOL_2:19; A9:(mid(f,1,Index(p,f)))/.Index(p,f)=mid(f,1,Index(p,f)).Index(p,f) by A4,A7,FINSEQ_4:24 .=f.(Index(p,f)) by A4,Th32 .=f/.(Index(p,f)) by A4,FINSEQ_4:24; p in LSeg(f,Index(p,f)) by A1,Th42; then A10:p in LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) by A4,A6,TOPREAL1: def 5; f/.(Index(p,f)) in LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) by TOPREAL1:6; then A11:LSeg((mid(f,1,Index(p,f))/.Index(p,f)),p) c= LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) by A9,A10,TOPREAL1:12; LSeg(f/.(Index(p,f)),f/.(Index(p,f)+1)) c= L~f by A4,A6,SPPOL_2:16; then A12:LSeg((mid(f,1,Index(p,f))/.Index(p,f)),p)c= L~f by A11,XBOOLE_1: 1; mid(f,1,Index(p,f)) =(f/^(1-'1))|(Index(p,f)-'1+1) by A4,Def1 .=(f/^(0))|(Index(p,f)-'1+1) by GOBOARD9:1 .=f|(Index(p,f)-'1+1) by FINSEQ_5:31 .=f|Index(p,f) by A4,AMI_5:4; then L~mid(f,1,Index(p,f)) c= L~f by TOPREAL3:27; hence L~(R_Cut(f,p)) c= L~f by A5,A8,A12,XBOOLE_1:8; end; theorem Th77: for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f & f is_S-Seq holds L~L_Cut(f,p) c= L~f proof let f be non empty FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2 such that A1: p in L~f and A2: f is_S-Seq; A3: p in L~Rev f & Rev f is_S-Seq by A1,A2,SPPOL_2:22,47; L_Cut(f,p) = L_Cut(Rev Rev f,p) by FINSEQ_6:29 .= Rev R_Cut(Rev f,p) by A3,Th57; then L~L_Cut(f,p) = L~R_Cut(Rev f,p) by SPPOL_2:22; then L~L_Cut(f,p) c= L~Rev f by A3,Th76; hence L~(L_Cut(f,p)) c= L~f by SPPOL_2:22; end; theorem Th78:for f,g being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f.len f=g.1 & p in L~f & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} & p<>f.len f holds L_Cut(f,p)^mid(g,2,len g) is_S-Seq_joining p,g/.len g proof let f,g be non empty FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume that A1: f.len f=g.1 and A2: p in L~f and A3: f is_S-Seq and A4: g is_S-Seq and A5: L~f /\ L~g={g.1} and A6: p<>f.len f; A7:f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by A3,TOPREAL1:def 10; A8:g is one-to-one & len g >= 2 & g is unfolded s.n.c. special by A4,TOPREAL1:def 10; A9:1<=len f by A7,AXIOMS:22; A10:1<=len g by A8,AXIOMS:22; A11:L_Cut(f,p) is_S-Seq by A2,A3,A6,Th69; then A12:1+1<=len L_Cut(f,p) by TOPREAL1:def 10; then 1+1-1<=len L_Cut(f,p)-1 by REAL_1:49; then A13:1<=len L_Cut(f,p)-'1 by Th1; L_Cut(f,p) is_S-Seq_joining p,f/.len f by A2,A3,A6,Th68; then A14:L_Cut(f,p).1=p & L_Cut(f,p).(len L_Cut(f,p))=f/.len f by Def3; then A15:L_Cut(f,p).len L_Cut(f,p)=g.1 by A1,A9,FINSEQ_4:24; A16:1<=len L_Cut(f,p) by A12,AXIOMS:22; then L_Cut(f,p).1=(L_Cut(f,p))/.1 by FINSEQ_4:24; then A17:(L_Cut(f,p))/.(1)=p by A2,Th58; g/.1 in LSeg(g/.1,g/.(1+1)) by TOPREAL1:6; then g/.1 in LSeg(g,1) by A8,TOPREAL1:def 5; then g.1 in LSeg(g,1) by A10,FINSEQ_4:24; then A18:g.1 in L~g by SPPOL_2:17; A19:len L_Cut(f,p)-'1+1=len L_Cut(f,p) by A16,AMI_5:4; then (L_Cut(f,p))/.(len L_Cut(f,p)) in LSeg((L_Cut(f,p))/.(len L_Cut(f,p) -'1), (L_Cut(f,p))/.(len L_Cut(f,p)-'1+1)) by TOPREAL1:6; then L_Cut(f,p).len L_Cut(f,p) in LSeg((L_Cut(f,p))/.(len L_Cut(f,p)-'1), (L_Cut(f,p))/.(len L_Cut(f,p)-'1+1)) by A16,FINSEQ_4:24; then L_Cut(f,p).len L_Cut(f,p) in LSeg(L_Cut(f,p),len L_Cut(f,p)-'1) by A13,A19,TOPREAL1:def 5; then f/.len f in L~(L_Cut(f,p)) by A14,SPPOL_2:17; then f.len f in L~(L_Cut(f,p)) by A9,FINSEQ_4:24; then g.1 in L~(L_Cut(f,p))/\ L~g by A1,A18,XBOOLE_0:def 3; then A20:{g.1}c= L~(L_Cut(f,p))/\ L~g by ZFMISC_1:37; L~(L_Cut(f,p)) c= L~f by A2,A3,Th77; then L~(L_Cut(f,p))/\ L~g c= L~f /\ L~g by XBOOLE_1:27; then L~(L_Cut(f,p))/\ L~g={g.1} by A5,A20,XBOOLE_0:def 10; hence L_Cut(f,p)^mid(g,2,len g) is_S-Seq_joining p,g/.len g by A4,A11,A15,A17,Th74; end; theorem for f,g being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f.len f=g.1 & p in L~f & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} & p<>f.len f holds L_Cut(f,p)^mid(g,2,len g) is_S-Seq proof let f,g be non empty FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2;assume f.len f=g.1 & p in L~f & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} & p<>f.len f; then L_Cut(f,p)^mid(g,2,len g) is_S-Seq_joining p,g/.len g by Th78; hence L_Cut(f,p)^mid(g,2,len g) is_S-Seq by Def3; end; theorem Th80:for f,g being FinSequence of TOP-REAL 2 st f.len f=g.1 & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} holds mid(f,1,len f-'1)^g is_S-Seq proof let f,g be FinSequence of TOP-REAL 2; assume A1:f.len f=g.1 & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1}; then A2:f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by TOPREAL1:def 10; then A3:1<=len f by AXIOMS:22; len f-1>=1+1-1 by A2,REAL_1:49; then A4:len f-'1>=1 by Th1; A5:Rev f is_S-Seq by A1,SPPOL_2:47; A6:Rev g is_S-Seq by A1,SPPOL_2:47; L~(Rev f)=L~f by SPPOL_2:22; then A7:L~(Rev g)/\ L~(Rev f)={g.1} by A1,SPPOL_2:22; A8:(Rev f).1=f.len f by FINSEQ_5:65; A9:(Rev g).len (Rev g)=(Rev Rev g).1 by FINSEQ_5:65 .=(Rev f).1 by A1,A8,FINSEQ_6:29; A10:len f-'1<=len f by Th13; then A11:len f-'(len f-'1)+1=len f-(len f-'1)+1 by SCMFSA_7:3 .=len f-(len f-1)+1 by A3,SCMFSA_7:3 .=1+1 by XCMPLX_1:18 .=2; A12:len (Rev f)=len f by FINSEQ_5:def 3; A13:len f-'1+1=len f-1+1 by A3,SCMFSA_7:3 .=len f by XCMPLX_1:27; (Rev g)^(mid(Rev f,2,len (Rev f))) is_S-Seq by A1,A5,A6,A7,A8,A9,Th73; then (Rev g)^(Rev mid(f,1,len f-'1)) is_S-Seq by A3,A4,A10,A11,A12,A13,Th22; then Rev (mid(f,1,len f-'1)^g) is_S-Seq by FINSEQ_5:67; then Rev Rev (mid(f,1,len f-'1)^g) is_S-Seq by SPPOL_2:47; hence mid(f,1,len f-'1)^g is_S-Seq by FINSEQ_6:29; end; theorem Th81: for f,g being FinSequence of TOP-REAL 2 st f.len f=g.1 & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} holds mid(f,1,len f-'1)^g is_S-Seq_joining f/.1,g/.len g proof let f,g be FinSequence of TOP-REAL 2; assume A1: f.len f=g.1 & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1}; then A2:mid(f,1,len f-'1)^g is_S-Seq by Th80; A3:f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by A1,TOPREAL1:def 10; A4:g is one-to-one & len g >= 2 & g is unfolded s.n.c. special by A1,TOPREAL1:def 10; A5:1<=len f by A3,AXIOMS:22; A6:1<=len g by A4,AXIOMS:22; A7:len f-'1<=len f by Th13; 1+1-1<=len f-1 by A3,REAL_1:49; then A8:1<=len f-'1 by Th1; A9:len (mid(f,1,len f-'1)^g)=len (mid(f,1,len f-'1)) + len g by FINSEQ_1:35; len mid(f,1,len f-'1)=len f-'1-'1+1 by A5,A7,A8,Th27 .=len f-'1 -1+1 by A8,SCMFSA_7:3 .=len f -'1 by XCMPLX_1:27; then A10:(mid(f,1,len f-'1)^g).1=mid(f,1,len f-'1).1 by A8,SCMFSA_7:9 .=f.1 by A7,A8,Th32.=f/.1 by A5,FINSEQ_4:24; 0<len g by A4,AXIOMS:22; then 0+len (mid(f,1,len f-'1))<len g+len (mid(f,1,len f-'1)) by REAL_1:53; then (mid(f,1,len f-'1)^g).(len (mid(f,1,len f-'1)^g)) =g.(len (mid(f,1,len f-'1)^g)-len (mid(f,1,len f-'1))) by A9,Th15 .=g.(len g) by A9,XCMPLX_1:26 .=g/.len g by A6,FINSEQ_4:24; hence mid(f,1,len f-'1)^g is_S-Seq_joining f/.1,g/.len g by A2,A10,Def3; end; theorem Th82:for f,g being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f.len f=g.1 & p in L~g & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} & p<>g.1 holds mid(f,1,len f -'1)^R_Cut(g,p) is_S-Seq_joining f/.1,p proof let f,g be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume A1:f.len f=g.1 & p in L~g & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} & p<>g.1; then A2:f is one-to-one & len f >= 2 & f is unfolded s.n.c. special by TOPREAL1:def 10; A3:g is one-to-one & len g >= 2 & g is unfolded s.n.c. special by A1,TOPREAL1:def 10; A4:1<=len f by A2,AXIOMS:22; A5:1<=len g by A3,AXIOMS:22; 1+1-1<=len f-1 by A2,REAL_1:49; then A6:1<=len f-'1 by Th1; A7:len f-'1+1=len f by A4,AMI_5:4; A8:R_Cut(g,p) is_S-Seq by A1,Th70; then A9:1+1<=len R_Cut(g,p) by TOPREAL1:def 10; R_Cut(g,p) is_S-Seq_joining g/.1,p by A1,Th67; then A10:R_Cut(g,p).1=g/.1 & R_Cut(g,p).(len R_Cut(g,p))=p by Def3; then A11:R_Cut(g,p).1=f.len f by A1,A5,FINSEQ_4:24; A12:1<=len R_Cut(g,p) by A9,AXIOMS:22; then R_Cut(g,p).len R_Cut(g,p)=(R_Cut(g,p))/.(len R_Cut(g,p)) by FINSEQ_4:24; then A13:(R_Cut(g,p))/.(len R_Cut(g,p))=p by A1,Th59; f/.len f in LSeg(f/.(len f-'1),f/.(len f-'1+1)) by A7,TOPREAL1:6; then f/.len f in LSeg(f,len f-'1) by A6,A7,TOPREAL1:def 5; then f.len f in LSeg(f,len f-'1) by A4,FINSEQ_4:24; then A14:f.len f in L~f by SPPOL_2:17; (R_Cut(g,p))/.(1) in LSeg((R_Cut(g,p))/.(1), (R_Cut(g,p))/.(1+1)) by TOPREAL1:6; then R_Cut(g,p).1 in LSeg((R_Cut(g,p))/.(1),(R_Cut(g,p))/.(1+1)) by A12,FINSEQ_4:24; then R_Cut(g,p).1 in LSeg(R_Cut(g,p),1) by A9,TOPREAL1:def 5; then g/.1 in L~(R_Cut(g,p)) by A10,SPPOL_2:17; then g.1 in L~(R_Cut(g,p)) by A5,FINSEQ_4:24; then f.len f in L~f /\ L~R_Cut(g,p) by A1,A14,XBOOLE_0:def 3; then A15:{f.len f}c= L~f /\ L~R_Cut(g,p) by ZFMISC_1:37; L~(R_Cut(g,p)) c= L~g by A1,Th76; then L~f /\ L~R_Cut(g,p) c= L~f /\ L~g by XBOOLE_1:27; then L~f /\ L~R_Cut(g,p)={R_Cut(g,p).1} by A1,A11,A15,XBOOLE_0:def 10; hence mid(f,1,len f -'1)^R_Cut(g,p) is_S-Seq_joining f/.1,p by A1,A8,A11,A13,Th81; end; theorem for f,g being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f.len f=g.1 & p in L~g & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} & p<>g.1 holds mid(f,1,len f -'1)^R_Cut(g,p) is_S-Seq proof let f,g be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2; assume f.len f=g.1 & p in L~g & f is_S-Seq & g is_S-Seq & L~f /\ L~g={g.1} & p<>g.1; then mid(f,1,len f -'1)^R_Cut(g,p) is_S-Seq_joining f/.1,p by Th82; hence mid(f,1,len f -'1)^R_Cut(g,p) is_S-Seq by Def3; end;