Copyright (c) 1995 Association of Mizar Users
environ vocabulary PRE_TOPC, EUCLID, GOBOARD1, MCART_1, ARYTM_1, METRIC_1, PCOMPS_1, TOPS_1, SQUARE_1, FUNCT_1, FINSEQ_1, TREES_1, GOBOARD5, ARYTM_3, ABSVALUE, BOOLE, TOPREAL1, ARYTM; notation TARSKI, XBOOLE_0, ORDINAL1, XREAL_0, REAL_1, NAT_1, ABSVALUE, SQUARE_1, BINARITH, BINOP_1, FINSEQ_1, MATRIX_1, STRUCT_0, METRIC_1, PRE_TOPC, TOPS_1, PCOMPS_1, EUCLID, TOPREAL1, GOBOARD1, GOBOARD5; constructors REAL_1, ABSVALUE, SQUARE_1, BINARITH, TOPS_1, PCOMPS_1, GOBOARD1, GOBOARD5, MEMBERED, XBOOLE_0; clusters STRUCT_0, RELSET_1, EUCLID, XREAL_0, PCOMPS_1, METRIC_1, ARYTM_3, MEMBERED, ZFMISC_1, XBOOLE_0, ORDINAL2; requirements REAL, NUMERALS, SUBSET, BOOLE, ARITHM; definitions TARSKI, XBOOLE_0; theorems GOBOARD5, TOPS_1, SPPOL_2, TOPMETR, METRIC_1, PCOMPS_1, PRE_TOPC, EUCLID, GOBOARD1, RLVECT_1, REAL_1, AXIOMS, SEQ_2, TOPREAL3, REAL_2, SQUARE_1, ABSVALUE, TARSKI, SPPOL_1, TOPREAL1, NAT_1, AMI_5, XBOOLE_0, XBOOLE_1, XREAL_0, XCMPLX_0, XCMPLX_1; begin reserve i,j,n for Nat, r,s,r1,s1,r2,s2,r',s' for Real, p,q for Point of TOP-REAL 2, G for Go-board, x,y for set, v for Point of Euclid 2; Lm1: (p+q)`1 = p`1+q`1 & (p+q)`2 = p`2+q`2 proof p + q = |[ p`1 + q`1, p`2 + q`2]| by EUCLID:59; hence thesis by EUCLID:56; end; Lm2: (p-q)`1 = p`1-q`1 & (p-q)`2 = p`2-q`2 proof p - q = |[ p`1 - q`1, p`2 - q`2]| by EUCLID:65; hence thesis by EUCLID:56; end; Lm3: (r*p)`1 = r*(p`1) & (r*p)`2 = r*(p`2) proof r*p = |[ r*p`1 ,r*p`2 ]| by EUCLID:61; hence thesis by EUCLID:56; end; canceled 3; theorem Th4: for M being non empty Reflexive MetrStruct, u being Point of M, r being real number holds r > 0 implies u in Ball(u,r) proof let M be non empty Reflexive MetrStruct, u be Point of M, r be real number; A1: Ball(u,r) = {q where q is Point of M:dist(u,q)<r} by METRIC_1:18; assume A2: r > 0; dist(u,u) = 0 by METRIC_1:1; hence u in Ball(u,r) by A1,A2; end; Lm4: for M being MetrSpace, B being Subset of TopSpaceMetr(M),r being real number, u being Point of M st B = Ball(u,r) holds B is open proof let M be MetrSpace, B be Subset of TopSpaceMetr(M), r be real number, u be Point of M; A1: TopSpaceMetr M = TopStruct (#the carrier of M,Family_open_set M#) by PCOMPS_1:def 6; assume A2: B = Ball(u,r); Ball(u,r) in Family_open_set M by PCOMPS_1:33; hence B is open by A1,A2,PRE_TOPC:def 5; end; canceled; theorem Th6: for B being Subset of TOP-REAL n, u being Point of Euclid n st B = Ball(u,r) holds B is open proof TOP-REAL n = TopSpaceMetr Euclid n by EUCLID:def 8; hence thesis by Lm4; end; theorem Th7: for M being non empty MetrSpace, u being Point of M, P being Subset of TopSpaceMetr(M) holds u in Int P iff ex r being real number st r > 0 & Ball(u,r) c= P proof let M be non empty MetrSpace, u be Point of M, P be Subset of TopSpaceMetr(M); A1:Int P is open by TOPS_1:51; hereby assume u in Int P; then consider r be real number such that A2: r > 0 and A3: Ball(u,r) c= Int P by A1,TOPMETR:22; take r; thus r > 0 by A2; Int P c= P by TOPS_1:44; hence Ball(u,r) c= P by A3,XBOOLE_1:1; end; given r being real number such that A4: r > 0 and A5: Ball(u,r) c= P; A6: u in Ball(u,r) by A4,Th4; TopSpaceMetr M = TopStruct (#the carrier of M,Family_open_set M#) by PCOMPS_1:def 6; then reconsider B = Ball(u,r) as Subset of TopSpaceMetr(M); B is open by Lm4; hence u in Int P by A5,A6,TOPS_1:54; end; theorem Th8: for u being Point of Euclid n, P being Subset of TOP-REAL n holds u in Int P iff ex r being real number st r > 0 & Ball(u,r) c= P proof TOP-REAL n = TopSpaceMetr Euclid n by EUCLID:def 8; hence thesis by Th7; end; theorem Th9: :: TOPREAL3:12 for u,v being Point of Euclid 2 st u = |[r1,s1]| & v = |[r2,s2]| holds dist(u,v) =sqrt ((r1 - r2)^2 + (s1 - s2)^2) proof let u,v be Point of Euclid 2 such that A1: u = |[r1,s1]| and A2: v = |[r2,s2]|; A3: |[r1,s1]|`1 = r1 & |[r1,s1]|`2 = s1 & |[r2,s2]|`1 = r2 & |[r2,s2]|`2 = s2 by EUCLID:56; Euclid 2 = MetrStruct(#REAL 2,Pitag_dist 2#) by EUCLID:def 7; hence dist(u,v) = (Pitag_dist 2).(u,v) by METRIC_1:def 1 .= sqrt ((r1 - r2)^2 + (s1 - s2)^2) by A1,A2,A3,TOPREAL3:12; end; theorem Th10: for u being Point of Euclid 2 st u = |[r,s]| holds 0 <= r2 & r2 < r1 implies |[r+r2,s]| in Ball(u,r1) proof let u be Point of Euclid 2 such that A1: u = |[r,s]| and A2: 0 <= r2 and A3: r2 < r1; reconsider v = |[r+r2,s]| as Point of Euclid 2 by TOPREAL3:13; dist(u,v) = sqrt ((r - (r+r2))^2 + (s - s)^2) by A1,Th9 .= sqrt ((r - (r+r2))^2 + 0^2) by XCMPLX_1:14 .= sqrt ((-(r - (r+r2)))^2) by SQUARE_1:60,61 .= sqrt ((r+r2-r)^2) by XCMPLX_1:143 .= sqrt (r2^2) by XCMPLX_1:26 .= r2 by A2,SQUARE_1:89; hence |[r+r2,s]| in Ball(u,r1) by A3,METRIC_1:12; end; theorem Th11: for u being Point of Euclid 2 st u = |[r,s]| holds 0 <= s2 & s2 < s1 implies |[r,s+s2]| in Ball(u,s1) proof let u be Point of Euclid 2 such that A1: u = |[r,s]| and A2: 0 <= s2 and A3: s2 < s1; reconsider v = |[r,s+s2]| as Point of Euclid 2 by TOPREAL3:13; dist(u,v) = sqrt ((r - r)^2 + (s - (s+s2))^2) by A1,Th9 .= sqrt ((s - (s+s2))^2 + 0^2) by XCMPLX_1:14 .= sqrt ((-(s - (s+s2)))^2) by SQUARE_1:60,61 .= sqrt ((s+s2-s)^2) by XCMPLX_1:143 .= sqrt (s2^2) by XCMPLX_1:26 .= s2 by A2,SQUARE_1:89; hence |[r,s+s2]| in Ball(u,s1) by A3,METRIC_1:12; end; theorem Th12: for u being Point of Euclid 2 st u = |[r,s]| holds 0 <= r2 & r2 < r1 implies |[r-r2,s]| in Ball(u,r1) proof let u be Point of Euclid 2 such that A1: u = |[r,s]| and A2: 0 <= r2 and A3: r2 < r1; reconsider v = |[r-r2,s]| as Point of Euclid 2 by TOPREAL3:13; dist(u,v) = sqrt ((r - (r-r2))^2 + (s - s)^2) by A1,Th9 .= sqrt ((r - (r-r2))^2 + 0^2) by XCMPLX_1:14 .= sqrt (r2^2) by SQUARE_1:60,XCMPLX_1:18 .= r2 by A2,SQUARE_1:89; hence |[r-r2,s]| in Ball(u,r1) by A3,METRIC_1:12; end; theorem Th13: for u being Point of Euclid 2 st u = |[r,s]| holds 0 <= s2 & s2 < s1 implies |[r,s-s2]| in Ball(u,s1) proof let u be Point of Euclid 2 such that A1: u = |[r,s]| and A2: 0 <= s2 and A3: s2 < s1; reconsider v = |[r,s-s2]| as Point of Euclid 2 by TOPREAL3:13; dist(u,v) = sqrt ((s - (s-s2))^2 + (r - r)^2) by A1,Th9 .= sqrt ((s - (s-s2))^2 + 0^2) by XCMPLX_1:14 .= sqrt (s2^2) by SQUARE_1:60,XCMPLX_1:18 .= s2 by A2,SQUARE_1:89; hence |[r,s-s2]| in Ball(u,s1) by A3,METRIC_1:12; end; theorem Th14: 1 <= i & i < len G & 1 <= j & j < width G implies G*(i,j)+G*(i+1,j+1) = G*(i,j+1)+G*(i+1,j) proof assume that A1: 1 <= i & i < len G and A2: 1 <= j & j < width G; A3: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; A4: 1 <= j+1 & j+1 <= width G by A2,NAT_1:38; A5: G*(i,j)`1 = G*(i,1)`1 by A1,A2,GOBOARD5:3 .= G*(i,j+1)`1 by A1,A4,GOBOARD5:3; A6: G*(i+1,j+1)`1 = G*(i+1,1)`1 by A3,A4,GOBOARD5:3 .= G*(i+1,j)`1 by A2,A3,GOBOARD5:3; A7: (G*(i,j)+G*(i+1,j+1))`1 = G*(i,j)`1+G*(i+1,j+1)`1 by Lm1 .= (G*(i,j+1)+G*(i+1,j))`1 by A5,A6,Lm1; A8: G*(i,j)`2 = G*(1,j)`2 by A1,A2,GOBOARD5:2 .= G*(i+1,j)`2 by A2,A3,GOBOARD5:2; A9: G*(i+1,j+1)`2 = G*(1,j+1)`2 by A3,A4,GOBOARD5:2 .= G*(i,j+1)`2 by A1,A4,GOBOARD5:2; (G*(i,j)+G*(i+1,j+1))`2 = G*(i,j)`2+G*(i+1,j+1)`2 by Lm1 .= (G*(i,j+1)+G*(i+1,j))`2 by A8,A9,Lm1; hence G*(i,j)+G*(i+1,j+1) = |[(G*(i,j+1)+G*(i+1,j))`1,(G*(i,j+1)+G*(i+1,j))`2]| by A7,EUCLID:57 .= G*(i,j+1)+G*(i+1,j) by EUCLID:57; end; Lm5: TOP-REAL 2 = TopSpaceMetr Euclid 2 by EUCLID:def 8 .= TopStruct (#the carrier of Euclid 2,Family_open_set Euclid 2#) by PCOMPS_1:def 6; theorem Th15: Int v_strip(G,0) = { |[r,s]| : r < G*(1,1)`1 } proof 0 <> width G by GOBOARD1:def 5; then 1 <= width G by RLVECT_1:99; then A1: v_strip(G,0) = { |[r,s]| : r <= G*(1,1)`1 } by GOBOARD5:11; thus Int v_strip(G,0) c= { |[r,s]| : r < G*(1,1)`1 } proof let x; assume A2: x in Int v_strip(G,0); then reconsider u = x as Point of Euclid 2 by Lm5; consider r1 being real number such that A3: r1 > 0 and A4: Ball(u,r1) c= v_strip(G,0) by A2,Th8; reconsider r1 as Real by XREAL_0:def 1; reconsider p = u as Point of TOP-REAL 2 by Lm5; set q = |[p`1+r1/2,p`2+0]|; A5: p = |[p`1,p`2]| by EUCLID:57; A6: r1/2 > 0 & r1/2 < r1 by A3,SEQ_2:3,4; then q in Ball(u,r1) by A5,Th10; then q in v_strip(G,0) by A4; then ex r2,s2 st q = |[r2,s2]| & r2 <= G*(1,1)`1 by A1; then A7: p`1+r1/2 <= G*(1,1)`1 by SPPOL_2:1; p`1 < p`1 + r1/2 by A6,REAL_1:69; then p`1 < G*(1,1)`1 by A7,AXIOMS:22; hence x in {|[r,s]| : r < G*(1,1)`1} by A5; end; let x; assume x in { |[r,s]| : r < G*(1,1)`1 }; then consider r,s such that A8: x = |[r,s]| and A9: r < G*(1,1)`1; reconsider u = |[r,s]| as Point of Euclid 2 by TOPREAL3:13; G*(1,1)`1-r > 0 by A9,SQUARE_1:11; then A10: u in Ball(u,G*(1,1)`1-r) by Th4; A11: Ball(u,G*(1,1)`1-r) c= v_strip(G,0) proof let y; A12: Ball(u,G*(1,1)`1-r) = { v : dist(u,v)<G*(1,1)`1-r} by METRIC_1:18; assume y in Ball(u,G*(1,1)`1-r); then consider v such that A13: v = y and A14: dist(u,v)<G*(1,1)`1-r by A12; reconsider q = v as Point of TOP-REAL 2 by TOPREAL3:13; A15: q = |[q`1,q`2]| by EUCLID:57; then A16: sqrt ((r - q`1)^2 + (s - q`2)^2) < G*(1,1)`1-r by A14,Th9; A17: (r - q`1)^2 >= 0 by SQUARE_1:72; 0 <= (s - q`2)^2 by SQUARE_1:72; then (r - q`1)^2 + 0 <= (r - q`1)^2 + (s - q`2)^2 by AXIOMS:24; then sqrt (r - q`1)^2 <= sqrt ((r - q`1)^2 + (s - q`2)^2) by A17,SQUARE_1:94; then sqrt (r - q`1)^2 <= G*(1,1)`1-r by A16,AXIOMS:22; then A18: abs(r-q`1) <= G*(1,1)`1-r by SQUARE_1:91; per cases; suppose r <= q`1; then A19: q`1-r >= 0 by SQUARE_1:12; abs(r-q`1) = abs(-(r-q`1)) by ABSVALUE:17 .= abs(q`1 - r) by XCMPLX_1:143 .= q`1 - r by A19,ABSVALUE:def 1; then q`1 <= G*(1,1)`1 by A18,REAL_1:54; hence y in v_strip(G,0) by A1,A13,A15; suppose r >= q`1; then q`1 <= G*(1,1)`1 by A9,AXIOMS:22; hence y in v_strip(G,0) by A1,A13,A15; end; Ball(u,G*(1,1)`1-r) is Subset of TOP-REAL2 by TOPREAL3:13; then reconsider B = Ball(u,G*(1,1)`1-r) as Subset of TOP-REAL2; B is open by Th6; hence x in Int v_strip(G,0) by A8,A10,A11,TOPS_1:54; end; theorem Th16: Int v_strip(G,len G) = { |[r,s]| : G*(len G,1)`1 < r } proof 0 <> width G by GOBOARD1:def 5; then 1 <= width G by RLVECT_1:99; then A1: v_strip(G,len G) = { |[r,s]| : G*(len G,1)`1 <= r } by GOBOARD5:10; thus Int v_strip(G,len G) c= { |[r,s]| : G*(len G,1)`1 < r } proof let x; assume A2: x in Int v_strip(G,len G); then reconsider u = x as Point of Euclid 2 by Lm5; consider r1 being real number such that A3: r1 > 0 and A4: Ball(u,r1) c= v_strip(G,len G) by A2,Th8; reconsider r1 as Real by XREAL_0:def 1; reconsider p = u as Point of TOP-REAL 2 by Lm5; set q = |[p`1-r1/2,p`2+0]|; A5: p = |[p`1,p`2]| by EUCLID:57; A6: r1/2 > 0 & r1/2 < r1 by A3,SEQ_2:3,4; then q in Ball(u,r1) by A5,Th12; then q in v_strip(G,len G) by A4; then ex r2,s2 st q = |[r2,s2]| & G*(len G,1)`1 <= r2 by A1; then G*(len G,1)`1 <= p`1-r1/2 by SPPOL_2:1; then A7: G*(len G,1)`1+r1/2 <= p`1 by REAL_1:84; G*(len G,1)`1 < G*(len G,1)`1 + r1/2 by A6,REAL_1:69; then G*(len G,1)`1 < p`1 by A7,AXIOMS:22; hence x in {|[r,s]| : G*(len G,1)`1 < r } by A5; end; let x; assume x in { |[r,s]| : G*(len G,1)`1 < r }; then consider r,s such that A8: x = |[r,s]| and A9: G*(len G,1)`1 < r; reconsider u = |[r,s]| as Point of Euclid 2 by TOPREAL3:13; r - G*(len G,1)`1 > 0 by A9,SQUARE_1:11; then A10: u in Ball(u,r-G*(len G,1)`1) by Th4; A11: Ball(u,r-G*(len G,1)`1) c= v_strip(G,len G) proof let y; A12: Ball(u,r-G*(len G,1)`1) = { v : dist(u,v)<r-G*(len G,1)`1} by METRIC_1:18; assume y in Ball(u,r-G*(len G,1)`1); then consider v such that A13: v = y and A14: dist(u,v)<r-G*(len G,1)`1 by A12; reconsider q = v as Point of TOP-REAL 2 by TOPREAL3:13; A15: q = |[q`1,q`2]| by EUCLID:57; then A16: sqrt ((r - q`1)^2 + (s - q`2)^2) < r-G*(len G,1)`1 by A14, Th9; A17: (r - q`1)^2 >= 0 by SQUARE_1:72; 0 <= (s - q`2)^2 by SQUARE_1:72; then (r - q`1)^2 + 0 <= (r - q`1)^2 + (s - q`2)^2 by AXIOMS:24; then sqrt (r - q`1)^2 <= sqrt ((r - q`1)^2 + (s - q`2)^2) by A17,SQUARE_1:94; then sqrt (r - q`1)^2 <= r-G*(len G,1)`1 by A16,AXIOMS:22; then A18: abs(r-q`1) <= r-G*(len G,1)`1 by SQUARE_1:91; per cases; suppose r >= q`1; then r-q`1 >= 0 by SQUARE_1:12; then abs(r-q`1) = r - q`1 by ABSVALUE:def 1; then G*(len G,1)`1 <= q`1 by A18,REAL_2:105; hence y in v_strip(G,len G) by A1,A13,A15; suppose r <= q`1; then G*(len G,1)`1 <= q`1 by A9,AXIOMS:22; hence y in v_strip(G,len G) by A1,A13,A15; end; Ball(u,r-G*(len G,1)`1) is Subset of TOP-REAL2 by TOPREAL3:13; then reconsider B = Ball(u,r-G*(len G,1)`1) as Subset of TOP-REAL2 ; B is open by Th6; hence x in Int v_strip(G,len G) by A8,A10,A11,TOPS_1:54; end; theorem Th17: 1 <= i & i < len G implies Int v_strip(G,i) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 } proof assume A1: 1 <= i & i < len G; 0 <> width G by GOBOARD1:def 5; then 1 <= width G by RLVECT_1:99; then A2: v_strip(G,i) = { |[r,s]| : G*(i,1)`1 <= r & r <= G*(i+1,1)`1 } by A1,GOBOARD5:9; thus Int v_strip(G,i) c= { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 } proof let x; assume A3: x in Int v_strip(G,i); then reconsider u = x as Point of Euclid 2 by Lm5; consider r1 being real number such that A4: r1 > 0 and A5: Ball(u,r1) c= v_strip(G,i) by A3,Th8; reconsider r1 as Real by XREAL_0:def 1; reconsider p = u as Point of TOP-REAL 2 by Lm5; set q1 = |[p`1+r1/2,p`2+0]|; A6: p = |[p`1,p`2]| by EUCLID:57; A7: r1/2 > 0 & r1/2 < r1 by A4,SEQ_2:3,4; then q1 in Ball(u,r1) by A6,Th10; then q1 in v_strip(G,i) by A5; then ex r2,s2 st q1 = |[r2,s2]| & G*(i,1)`1 <= r2 & r2 <= G*(i+1,1)`1 by A2; then A8: p`1+r1/2 <= G*(i+1,1)`1 by SPPOL_2:1; p`1 < p`1 + r1/2 by A7,REAL_1:69; then A9: p`1 < G*(i+1,1)`1 by A8,AXIOMS:22; set q2 = |[p`1-r1/2,p`2+0]|; q2 in Ball(u,r1) by A6,A7,Th12; then q2 in v_strip(G,i) by A5; then ex r2,s2 st q2 = |[r2,s2]| & G*(i,1)`1 <= r2 & r2 <= G*(i+1,1)`1 by A2; then G*(i,1)`1 <= p`1-r1/2 by SPPOL_2:1; then A10: G*(i,1)`1+r1/2 <= p`1 by REAL_1:84; G*(i,1)`1 < G*(i,1)`1 + r1/2 by A7,REAL_1:69; then G*(i,1)`1 < p`1 by A10,AXIOMS:22; hence x in {|[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1} by A6,A9; end; let x; assume x in { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 }; then consider r,s such that A11: x = |[r,s]| and A12: G*(i,1)`1 < r and A13: r < G*(i+1,1)`1; reconsider u = |[r,s]| as Point of Euclid 2 by TOPREAL3:13; A14:G*(i+1,1)`1-r > 0 by A13,SQUARE_1:11; r - G*(i,1)`1 > 0 by A12,SQUARE_1:11; then min(r-G*(i,1)`1,G*(i+1,1)`1-r) > 0 by A14,SQUARE_1:38; then A15: u in Ball(u,min(r-G*(i,1)`1,G*(i+1,1)`1-r)) by Th4; A16: Ball(u,min(r-G*(i,1)`1,G*(i+1,1)`1-r)) c= v_strip(G,i) proof let y; A17: Ball(u,min(r-G*(i,1)`1,G*(i+1,1)`1-r)) = { v : dist(u,v)<min(r-G*(i,1)`1,G*(i+1,1)`1-r)} by METRIC_1:18; assume y in Ball(u,min(r-G*(i,1)`1,G*(i+1,1)`1-r)); then consider v such that A18: v = y and A19: dist(u,v)<min(r-G*(i,1)`1,G*(i+1,1)`1-r) by A17; reconsider q = v as Point of TOP-REAL 2 by TOPREAL3:13; A20: q = |[q`1,q`2]| by EUCLID:57; then A21: sqrt ((r - q`1)^2 + (s - q`2)^2) < min(r-G*(i,1)`1,G*(i+1,1 )`1-r) by A19,Th9; A22: (r - q`1)^2 >= 0 by SQUARE_1:72; 0 <= (s - q`2)^2 by SQUARE_1:72; then (r - q`1)^2 + 0 <= (r - q`1)^2 + (s - q`2)^2 by AXIOMS:24; then sqrt (r - q`1)^2 <= sqrt ((r - q`1)^2 + (s - q`2)^2) by A22,SQUARE_1:94; then sqrt (r - q`1)^2 <= min(r-G*(i,1)`1,G* (i+1,1)`1-r) by A21,AXIOMS:22; then abs(r-q`1) <= min(r-G*(i,1)`1,G*(i+1,1)`1-r) by SQUARE_1:91; then A23: abs(r-q`1) <= r-G*(i,1)`1 & abs(r-q`1) <= G* (i+1,1)`1-r by SQUARE_1:39; per cases; suppose A24: r <= q`1; then A25: q`1-r >= 0 by SQUARE_1:12; abs(r-q`1) = abs(-(r-q`1)) by ABSVALUE:17 .= abs(q`1 - r) by XCMPLX_1:143 .= q`1 - r by A25,ABSVALUE:def 1; then A26: q`1 <= G*(i+1,1)`1 by A23,REAL_1:54; G*(i,1)`1 <= q`1 by A12,A24,AXIOMS:22; hence y in v_strip(G,i) by A2,A18,A20,A26; suppose A27: r >= q`1; then r-q`1 >= 0 by SQUARE_1:12; then abs(r-q`1) = r - q`1 by ABSVALUE:def 1; then A28: G*(i,1)`1 <= q`1 by A23,REAL_2:105; q`1 <= G*(i+1,1)`1 by A13,A27,AXIOMS:22; hence y in v_strip(G,i) by A2,A18,A20,A28; end; Ball(u,min(r-G*(i,1)`1,G*(i+1,1)`1-r)) is Subset of TOP-REAL2 by TOPREAL3:13; then reconsider B = Ball(u,min(r-G*(i,1)`1,G*(i+1,1)`1-r)) as Subset of TOP-REAL2; B is open by Th6; hence x in Int v_strip(G,i) by A11,A15,A16,TOPS_1:54; end; theorem Th18: Int h_strip(G,0) = { |[r,s]| : s < G*(1,1)`2 } proof 0 <> len G by GOBOARD1:def 5; then 1 <= len G by RLVECT_1:99; then A1: h_strip(G,0) = { |[r,s]| : s <= G*(1,1)`2 } by GOBOARD5:8; thus Int h_strip(G,0) c= { |[r,s]| : s < G*(1,1)`2 } proof let x; assume A2: x in Int h_strip(G,0); then reconsider u = x as Point of Euclid 2 by Lm5; consider s1 being real number such that A3: s1 > 0 and A4: Ball(u,s1) c= h_strip(G,0) by A2,Th8; reconsider s1 as Real by XREAL_0:def 1; reconsider p = u as Point of TOP-REAL 2 by Lm5; set q = |[p`1+0,p`2+s1/2]|; A5: p = |[p`1,p`2]| by EUCLID:57; A6: s1/2 > 0 & s1/2 < s1 by A3,SEQ_2:3,4; then q in Ball(u,s1) by A5,Th11; then q in h_strip(G,0) by A4; then ex r2,s2 st q = |[r2,s2]| & s2 <= G*(1,1)`2 by A1; then A7: p`2+s1/2 <= G*(1,1)`2 by SPPOL_2:1; p`2 < p`2 + s1/2 by A6,REAL_1:69; then p`2 < G*(1,1)`2 by A7,AXIOMS:22; hence x in {|[r,s]| : s < G*(1,1)`2} by A5; end; let x; assume x in { |[r,s]| : s < G*(1,1)`2 }; then consider r,s such that A8: x = |[r,s]| and A9: s < G*(1,1)`2; reconsider u = |[r,s]| as Point of Euclid 2 by TOPREAL3:13; G*(1,1)`2-s > 0 by A9,SQUARE_1:11; then A10: u in Ball(u,G*(1,1)`2-s) by Th4; A11: Ball(u,G*(1,1)`2-s) c= h_strip(G,0) proof let y; A12: Ball(u,G*(1,1)`2-s) = { v : dist(u,v)<G*(1,1)`2-s} by METRIC_1:18; assume y in Ball(u,G*(1,1)`2-s); then consider v such that A13: v = y and A14: dist(u,v)<G*(1,1)`2-s by A12; reconsider q = v as Point of TOP-REAL 2 by TOPREAL3:13; A15: q = |[q`1,q`2]| by EUCLID:57; then A16: sqrt ((r - q`1)^2 + (s - q`2)^2) < G*(1,1)`2-s by A14,Th9; A17: (s - q`2)^2 >= 0 by SQUARE_1:72; 0 <= (r - q`1)^2 by SQUARE_1:72; then (s - q`2)^2 + 0 <= (r - q`1)^2 + (s - q`2)^2 by AXIOMS:24; then sqrt (s - q`2)^2 <= sqrt ((r - q`1)^2 + (s - q`2)^2) by A17,SQUARE_1:94; then sqrt (s - q`2)^2 <= G*(1,1)`2-s by A16,AXIOMS:22; then A18: abs(s-q`2) <= G*(1,1)`2-s by SQUARE_1:91; per cases; suppose s <= q`2; then A19: q`2-s >= 0 by SQUARE_1:12; abs(s-q`2) = abs(-(s-q`2)) by ABSVALUE:17 .= abs(q`2 - s) by XCMPLX_1:143 .= q`2 - s by A19,ABSVALUE:def 1; then q`2 <= G*(1,1)`2 by A18,REAL_1:54; hence y in h_strip(G,0) by A1,A13,A15; suppose s >= q`2; then q`2 <= G*(1,1)`2 by A9,AXIOMS:22; hence y in h_strip(G,0) by A1,A13,A15; end; Ball(u,G*(1,1)`2-s) is Subset of TOP-REAL2 by TOPREAL3:13; then reconsider B = Ball(u,G*(1,1)`2-s) as Subset of TOP-REAL2 ; B is open by Th6; hence x in Int h_strip(G,0) by A8,A10,A11,TOPS_1:54; end; theorem Th19: Int h_strip(G,width G) = { |[r,s]| : G*(1,width G)`2 < s } proof 0 <> len G by GOBOARD1:def 5; then 1 <= len G by RLVECT_1:99; then A1: h_strip(G,width G) = { |[r,s]| : G*(1,width G)`2 <= s } by GOBOARD5:7; thus Int h_strip(G,width G) c= { |[r,s]| : G*(1,width G)`2 < s } proof let x; assume A2: x in Int h_strip(G,width G); then reconsider u = x as Point of Euclid 2 by Lm5; consider s1 being real number such that A3: s1 > 0 and A4: Ball(u,s1) c= h_strip(G,width G) by A2,Th8; reconsider s1 as Real by XREAL_0:def 1; reconsider p = u as Point of TOP-REAL 2 by Lm5; set q = |[p`1+0,p`2-s1/2]|; A5: p = |[p`1,p`2]| by EUCLID:57; A6: s1/2 > 0 & s1/2 < s1 by A3,SEQ_2:3,4; then q in Ball(u,s1) by A5,Th13; then q in h_strip(G,width G) by A4; then ex r2,s2 st q = |[r2,s2]| & G*(1,width G)`2 <= s2 by A1; then G*(1,width G)`2 <= p`2-s1/2 by SPPOL_2:1; then A7: G*(1,width G)`2+s1/2 <= p`2 by REAL_1:84; G*(1,width G)`2 < G*(1,width G)`2 + s1/2 by A6,REAL_1:69; then G*(1,width G)`2 < p`2 by A7,AXIOMS:22; hence x in {|[r,s]| : G*(1,width G)`2 < s } by A5; end; let x; assume x in { |[r,s]| : G*(1,width G)`2 < s }; then consider r,s such that A8: x = |[r,s]| and A9: G*(1,width G)`2 < s; reconsider u = |[r,s]| as Point of Euclid 2 by TOPREAL3:13; s - G*(1,width G)`2 > 0 by A9,SQUARE_1:11; then A10: u in Ball(u,s-G*(1,width G)`2) by Th4; A11: Ball(u,s-G*(1,width G)`2) c= h_strip(G,width G) proof let y; A12: Ball(u,s-G*(1,width G)`2) = { v : dist(u,v)<s-G*(1,width G)`2} by METRIC_1:18; assume y in Ball(u,s-G*(1,width G)`2); then consider v such that A13: v = y and A14: dist(u,v)<s-G*(1,width G)`2 by A12; reconsider q = v as Point of TOP-REAL 2 by TOPREAL3:13; A15: q = |[q`1,q`2]| by EUCLID:57; then A16: sqrt ((r - q`1)^2 + (s - q`2)^2) < s-G*(1,width G)`2 by A14 ,Th9; A17: (s - q`2)^2 >= 0 by SQUARE_1:72; 0 <= (r - q`1)^2 by SQUARE_1:72; then (s - q`2)^2 + 0 <= (r - q`1)^2 + (s - q`2)^2 by AXIOMS:24; then sqrt (s - q`2)^2 <= sqrt ((r - q`1)^2 + (s - q`2)^2) by A17,SQUARE_1:94; then sqrt (s - q`2)^2 <= s-G*(1,width G)`2 by A16,AXIOMS:22; then A18: abs(s-q`2) <= s-G*(1,width G)`2 by SQUARE_1:91; per cases; suppose s >= q`2; then s-q`2 >= 0 by SQUARE_1:12; then abs(s-q`2) = s - q`2 by ABSVALUE:def 1; then G*(1,width G)`2 <= q`2 by A18,REAL_2:105; hence y in h_strip(G,width G) by A1,A13,A15; suppose s <= q`2; then G*(1,width G)`2 <= q`2 by A9,AXIOMS:22; hence y in h_strip(G,width G) by A1,A13,A15; end; Ball(u,s-G*(1,width G)`2) is Subset of TOP-REAL2 by TOPREAL3:13; then reconsider B = Ball(u,s-G*(1,width G)`2) as Subset of TOP-REAL2; B is open by Th6; hence x in Int h_strip(G,width G) by A8,A10,A11,TOPS_1:54; end; theorem Th20: 1 <= j & j < width G implies Int h_strip(G,j) = { |[r,s]| : G*(1,j)`2 < s & s < G*(1,j+1)`2 } proof assume A1: 1 <= j & j < width G; 0 <> len G by GOBOARD1:def 5; then 1 <= len G by RLVECT_1:99; then A2: h_strip(G,j) = { |[r,s]| : G*(1,j)`2 <= s & s <= G*(1,j+1)`2 } by A1,GOBOARD5:6; thus Int h_strip(G,j) c= { |[r,s]| : G*(1,j)`2 < s & s < G*(1,j+1)`2 } proof let x; assume A3: x in Int h_strip(G,j); then reconsider u = x as Point of Euclid 2 by Lm5; consider s1 being real number such that A4: s1 > 0 and A5: Ball(u,s1) c= h_strip(G,j) by A3,Th8; reconsider s1 as Real by XREAL_0:def 1; reconsider p = u as Point of TOP-REAL 2 by Lm5; set q1 = |[p`1+0,p`2+s1/2]|; A6: p = |[p`1,p`2]| by EUCLID:57; A7: s1/2 > 0 & s1/2 < s1 by A4,SEQ_2:3,4; then q1 in Ball(u,s1) by A6,Th11; then q1 in h_strip(G,j) by A5; then ex r2,s2 st q1 = |[r2,s2]| & G*(1,j)`2 <= s2 & s2 <= G*(1,j+1)`2 by A2; then A8: p`2+s1/2 <= G*(1,j+1)`2 by SPPOL_2:1; p`2 < p`2 + s1/2 by A7,REAL_1:69; then A9: p`2 < G*(1,j+1)`2 by A8,AXIOMS:22; set q2 = |[p`1+0,p`2-s1/2]|; q2 in Ball(u,s1) by A6,A7,Th13; then q2 in h_strip(G,j) by A5; then ex r2,s2 st q2 = |[r2,s2]| & G*(1,j)`2 <= s2 & s2 <= G*(1,j+1)`2 by A2; then G*(1,j)`2 <= p`2-s1/2 by SPPOL_2:1; then A10: G*(1,j)`2+s1/2 <= p`2 by REAL_1:84; G*(1,j)`2 < G*(1,j)`2 + s1/2 by A7,REAL_1:69; then G*(1,j)`2 < p`2 by A10,AXIOMS:22; hence x in {|[r,s]| : G*(1,j)`2 < s & s < G*(1,j+1)`2} by A6,A9; end; let x; assume x in { |[r,s]| : G*(1,j)`2 < s & s < G*(1,j+1)`2 }; then consider r,s such that A11: x = |[r,s]| and A12: G*(1,j)`2 < s and A13: s < G*(1,j+1)`2; reconsider u = |[r,s]| as Point of Euclid 2 by TOPREAL3:13; A14:G*(1,j+1)`2-s > 0 by A13,SQUARE_1:11; s - G*(1,j)`2 > 0 by A12,SQUARE_1:11; then min(s-G*(1,j)`2,G*(1,j+1)`2-s) > 0 by A14,SQUARE_1:38; then A15: u in Ball(u,min(s-G*(1,j)`2,G*(1,j+1)`2-s)) by Th4; A16: Ball(u,min(s-G*(1,j)`2,G*(1,j+1)`2-s)) c= h_strip(G,j) proof let y; A17: Ball(u,min(s-G*(1,j)`2,G*(1,j+1)`2-s)) = { v : dist(u,v)<min(s-G*(1,j)`2,G*(1,j+1)`2-s)} by METRIC_1:18; assume y in Ball(u,min(s-G*(1,j)`2,G*(1,j+1)`2-s)); then consider v such that A18: v = y and A19: dist(u,v)<min(s-G*(1,j)`2,G*(1,j+1)`2-s) by A17; reconsider q = v as Point of TOP-REAL 2 by TOPREAL3:13; A20: q = |[q`1,q`2]| by EUCLID:57; then A21: sqrt ((r - q`1)^2 + (s - q`2)^2) < min(s-G*(1,j)`2,G*(1,j+1 )`2-s) by A19,Th9; A22: (s - q`2)^2 >= 0 by SQUARE_1:72; 0 <= (r - q`1)^2 by SQUARE_1:72; then (s - q`2)^2 + 0 <= (r - q`1)^2 + (s - q`2)^2 by AXIOMS:24; then sqrt (s - q`2)^2 <= sqrt ((r - q`1)^2 + (s - q`2)^2) by A22,SQUARE_1:94; then sqrt (s - q`2)^2 <= min(s-G*(1,j)`2,G* (1,j+1)`2-s) by A21,AXIOMS:22; then abs(s-q`2) <= min(s-G*(1,j)`2,G*(1,j+1)`2-s) by SQUARE_1:91; then A23: abs(s-q`2) <= s-G*(1,j)`2 & abs(s-q`2) <= G* (1,j+1)`2-s by SQUARE_1:39; per cases; suppose A24: s <= q`2; then A25: q`2-s >= 0 by SQUARE_1:12; abs(s-q`2) = abs(-(s-q`2)) by ABSVALUE:17 .= abs(q`2 - s) by XCMPLX_1:143 .= q`2 - s by A25,ABSVALUE:def 1; then A26: q`2 <= G*(1,j+1)`2 by A23,REAL_1:54; G*(1,j)`2 <= q`2 by A12,A24,AXIOMS:22; hence y in h_strip(G,j) by A2,A18,A20,A26; suppose A27: s >= q`2; then s-q`2 >= 0 by SQUARE_1:12; then abs(s-q`2) = s - q`2 by ABSVALUE:def 1; then A28: G*(1,j)`2 <= q`2 by A23,REAL_2:105; q`2 <= G*(1,j+1)`2 by A13,A27,AXIOMS:22; hence y in h_strip(G,j) by A2,A18,A20,A28; end; Ball(u,min(s-G*(1,j)`2,G*(1,j+1)`2-s)) is Subset of TOP-REAL2 by TOPREAL3:13; then reconsider B = Ball(u,min(s-G*(1,j)`2,G*(1,j+1)`2-s)) as Subset of TOP-REAL2; B is open by Th6; hence x in Int h_strip(G,j) by A11,A15,A16,TOPS_1:54; end; theorem Th21: Int cell(G,0,0) = { |[r,s]| : r < G*(1,1)`1 & s < G*(1,1)`2 } proof cell(G,0,0) = v_strip(G,0) /\ h_strip(G,0) by GOBOARD5:def 3; then A1: Int cell(G,0,0) = Int v_strip(G,0) /\ Int h_strip(G,0) by TOPS_1:46; A2: Int v_strip(G,0) = { |[r,s]| : r < G*(1,1)`1 } by Th15; A3: Int h_strip(G,0) = { |[r,s]| : s < G*(1,1)`2 } by Th18; thus Int cell(G,0,0) c= { |[r,s]| : r < G*(1,1)`1 & s < G*(1,1)`2 } proof let x be set; assume A4: x in Int cell(G,0,0); then x in Int v_strip(G,0) by A1,XBOOLE_0:def 3; then consider r1,s1 such that A5: x = |[r1,s1]| and A6: r1 < G*(1,1)`1 by A2; x in Int h_strip(G,0) by A1,A4,XBOOLE_0:def 3; then consider r2,s2 such that A7: x = |[r2,s2]| and A8: s2 < G*(1,1)`2 by A3; r1 = r2 & s1 = s2 by A5,A7,SPPOL_2:1; hence thesis by A5,A6,A8; end; let x be set; assume x in { |[r,s]| : r < G*(1,1)`1 & s < G*(1,1)`2 }; then ex r,s st x = |[r,s]| & r < G*(1,1)`1 & s < G*(1,1)`2; then x in Int v_strip(G,0) & x in Int h_strip(G,0) by A2,A3; hence thesis by A1,XBOOLE_0:def 3; end; theorem Th22: Int cell(G,0,width G) = { |[r,s]| : r < G*(1,1)`1 & G*(1,width G)`2 < s } proof cell(G,0,width G) = v_strip(G,0) /\ h_strip(G,width G) by GOBOARD5:def 3 ; then A1: Int cell(G,0,width G) = Int v_strip(G,0) /\ Int h_strip(G,width G) by TOPS_1:46; A2: Int v_strip(G,0) = { |[r,s]| : r < G*(1,1)`1 } by Th15; A3: Int h_strip(G,width G) = { |[r,s]| : G*(1,width G)`2 < s } by Th19; thus Int cell(G,0,width G) c= { |[r,s]| : r < G*(1,1)`1 & G*(1,width G)`2 < s } proof let x be set; assume A4: x in Int cell(G,0,width G); then x in Int v_strip(G,0) by A1,XBOOLE_0:def 3; then consider r1,s1 such that A5: x = |[r1,s1]| and A6: r1 < G*(1,1)`1 by A2; x in Int h_strip(G,width G) by A1,A4,XBOOLE_0:def 3; then consider r2,s2 such that A7: x = |[r2,s2]| and A8: G*(1,width G)`2 < s2 by A3; r1 = r2 & s1 = s2 by A5,A7,SPPOL_2:1; hence thesis by A5,A6,A8; end; let x be set; assume x in { |[r,s]| : r < G*(1,1)`1 & G*(1,width G)`2 < s }; then ex r,s st x = |[r,s]| & r < G*(1,1)`1 & G*(1,width G)`2 < s; then x in Int v_strip(G,0) & x in Int h_strip(G,width G) by A2,A3; hence thesis by A1,XBOOLE_0:def 3; end; theorem Th23: 1 <= j & j < width G implies Int cell(G,0,j) = { |[r,s]| : r < G*(1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2 } proof assume A1: 1 <= j & j < width G; cell(G,0,j) = v_strip(G,0) /\ h_strip(G,j) by GOBOARD5:def 3; then A2: Int cell(G,0,j) = Int v_strip(G,0) /\ Int h_strip(G,j) by TOPS_1:46 ; A3: Int v_strip(G,0) = { |[r,s]| : r < G*(1,1)`1 } by Th15; A4: Int h_strip(G,j) = { |[r,s]| : G*(1,j)`2 < s & s < G* (1,j+1)`2 } by A1,Th20 ; thus Int cell(G,0,j) c= { |[r,s]| : r < G*(1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2 } proof let x be set; assume A5: x in Int cell(G,0,j); then x in Int v_strip(G,0) by A2,XBOOLE_0:def 3; then consider r1,s1 such that A6: x = |[r1,s1]| and A7: r1 < G*(1,1)`1 by A3; x in Int h_strip(G,j) by A2,A5,XBOOLE_0:def 3; then consider r2,s2 such that A8: x = |[r2,s2]| and A9: G*(1,j)`2 < s2 & s2 < G*(1,j+1)`2 by A4; r1 = r2 & s1 = s2 by A6,A8,SPPOL_2:1; hence thesis by A6,A7,A9; end; let x be set; assume x in { |[r,s]| : r < G*(1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2 }; then ex r,s st x = |[r,s]| & r < G*(1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2; then x in Int v_strip(G,0) & x in Int h_strip(G,j) by A3,A4; hence thesis by A2,XBOOLE_0:def 3; end; theorem Th24: Int cell(G,len G,0) = { |[r,s]| : G*(len G,1)`1 < r & s < G*(1,1)`2 } proof cell(G,len G,0) = v_strip(G,len G) /\ h_strip(G,0) by GOBOARD5:def 3; then A1: Int cell(G,len G,0) = Int v_strip(G,len G) /\ Int h_strip(G,0) by TOPS_1:46; A2: Int v_strip(G,len G) = { |[r,s]| : G*(len G,1)`1 < r } by Th16; A3: Int h_strip(G,0) = { |[r,s]| : s < G*(1,1)`2 } by Th18; thus Int cell(G,len G,0) c= { |[r,s]| : G*(len G,1)`1 < r & s < G*(1,1)`2 } proof let x be set; assume A4: x in Int cell(G,len G,0); then x in Int v_strip(G,len G) by A1,XBOOLE_0:def 3; then consider r1,s1 such that A5: x = |[r1,s1]| and A6: G*(len G,1)`1 < r1 by A2; x in Int h_strip(G,0) by A1,A4,XBOOLE_0:def 3; then consider r2,s2 such that A7: x = |[r2,s2]| and A8: s2 < G*(1,1)`2 by A3; r1 = r2 & s1 = s2 by A5,A7,SPPOL_2:1; hence thesis by A5,A6,A8; end; let x be set; assume x in { |[r,s]| : G*(len G,1)`1 < r & s < G*(1,1)`2 }; then ex r,s st x = |[r,s]| & G*(len G,1)`1 < r & s < G*(1,1)`2; then x in Int v_strip(G,len G) & x in Int h_strip(G,0) by A2,A3; hence thesis by A1,XBOOLE_0:def 3; end; theorem Th25: Int cell(G,len G,width G) = { |[r,s]| : G*(len G,1)`1 < r & G*(1,width G)`2 < s } proof cell(G,len G,width G) = v_strip(G,len G) /\ h_strip(G,width G) by GOBOARD5:def 3; then A1: Int cell(G,len G,width G) = Int v_strip(G,len G) /\ Int h_strip(G, width G) by TOPS_1:46; A2: Int v_strip(G,len G) = { |[r,s]| : G*(len G,1)`1 < r } by Th16; A3: Int h_strip(G,width G) = { |[r,s]| : G*(1,width G)`2 < s } by Th19; thus Int cell(G,len G,width G) c= { |[r,s]| : G*(len G,1)`1 < r & G*(1,width G)`2 < s } proof let x be set; assume A4: x in Int cell(G,len G,width G); then x in Int v_strip(G,len G) by A1,XBOOLE_0:def 3; then consider r1,s1 such that A5: x = |[r1,s1]| and A6: G*(len G,1)`1 < r1 by A2; x in Int h_strip(G,width G) by A1,A4,XBOOLE_0:def 3; then consider r2,s2 such that A7: x = |[r2,s2]| and A8: G*(1,width G)`2 < s2 by A3; r1 = r2 & s1 = s2 by A5,A7,SPPOL_2:1; hence thesis by A5,A6,A8; end; let x be set; assume x in { |[r,s]| : G*(len G,1)`1 < r & G*(1,width G)`2 < s }; then ex r,s st x = |[r,s]| & G*(len G,1)`1 < r & G*(1,width G)`2 < s; then x in Int v_strip(G,len G) & x in Int h_strip(G,width G) by A2,A3; hence thesis by A1,XBOOLE_0:def 3; end; theorem Th26: 1 <= j & j < width G implies Int cell(G,len G,j) = { |[r,s]| : G*(len G,1)`1 < r & G*(1,j)`2 < s & s < G*(1,j+1)`2 } proof assume A1: 1 <= j & j < width G; cell(G,len G,j) = v_strip(G,len G) /\ h_strip(G,j) by GOBOARD5:def 3; then A2: Int cell(G,len G,j) = Int v_strip(G,len G) /\ Int h_strip(G,j) by TOPS_1:46; A3: Int v_strip(G,len G) = { |[r,s]| : G*(len G,1)`1 < r } by Th16; A4: Int h_strip(G,j) = { |[r,s]| : G*(1,j)`2 < s & s < G* (1,j+1)`2 } by A1,Th20 ; thus Int cell(G,len G,j) c= { |[r,s]| : G*(len G,1)`1 < r & G*(1,j)`2 < s & s < G*(1,j+1)`2 } proof let x be set; assume A5: x in Int cell(G,len G,j); then x in Int v_strip(G,len G) by A2,XBOOLE_0:def 3; then consider r1,s1 such that A6: x = |[r1,s1]| and A7: G*(len G,1)`1 < r1 by A3; x in Int h_strip(G,j) by A2,A5,XBOOLE_0:def 3; then consider r2,s2 such that A8: x = |[r2,s2]| and A9: G*(1,j)`2 < s2 & s2 < G*(1,j+1)`2 by A4; r1 = r2 & s1 = s2 by A6,A8,SPPOL_2:1; hence thesis by A6,A7,A9; end; let x be set; assume x in { |[r,s]| : G*(len G,1)`1 < r & G*(1,j)`2 < s & s < G* (1,j+1)`2 }; then ex r,s st x = |[r,s]| & G*(len G,1)`1 < r & G*(1,j)`2 < s & s < G*(1,j+1)`2; then x in Int v_strip(G,len G) & x in Int h_strip(G,j) by A3,A4; hence thesis by A2,XBOOLE_0:def 3; end; theorem Th27: 1 <= i & i < len G implies Int cell(G,i,0) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & s < G*(1,1)`2 } proof assume A1: 1 <= i & i < len G; cell(G,i,0) = v_strip(G,i) /\ h_strip(G,0) by GOBOARD5:def 3; then A2: Int cell(G,i,0) = Int v_strip(G,i) /\ Int h_strip(G,0) by TOPS_1:46 ; A3: Int v_strip(G,i) = { |[r,s]| : G*(i,1)`1 < r & r < G* (i+1,1)`1 } by A1,Th17 ; A4: Int h_strip(G,0) = { |[r,s]| : s < G*(1,1)`2 } by Th18; thus Int cell(G,i,0) c= { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & s < G*(1,1)`2 } proof let x be set; assume A5: x in Int cell(G,i,0); then x in Int v_strip(G,i) by A2,XBOOLE_0:def 3; then consider r1,s1 such that A6: x = |[r1,s1]| and A7: G*(i,1)`1 < r1 & r1 < G*(i+1,1)`1 by A3; x in Int h_strip(G,0) by A2,A5,XBOOLE_0:def 3; then consider r2,s2 such that A8: x = |[r2,s2]| and A9: s2 < G*(1,1)`2 by A4; r1 = r2 & s1 = s2 by A6,A8,SPPOL_2:1; hence thesis by A6,A7,A9; end; let x be set; assume x in { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & s < G*(1,1)`2 }; then ex r,s st x = |[r,s]| & G*(i,1)`1 < r & r < G*(i+1,1)`1 & s < G*(1,1)`2; then x in Int v_strip(G,i) & x in Int h_strip(G,0) by A3,A4; hence thesis by A2,XBOOLE_0:def 3; end; theorem Th28: 1 <= i & i < len G implies Int cell(G,i,width G) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,width G)`2 < s } proof assume A1: 1 <= i & i < len G; cell(G,i,width G) = v_strip(G,i) /\ h_strip(G,width G) by GOBOARD5:def 3; then A2: Int cell(G,i,width G) = Int v_strip(G,i) /\ Int h_strip(G,width G) by TOPS_1:46; A3: Int v_strip(G,i) = { |[r,s]| : G*(i,1)`1 < r & r < G* (i+1,1)`1 } by A1,Th17 ; A4: Int h_strip(G,width G) = { |[r,s]| : G*(1,width G)`2 < s } by Th19; thus Int cell(G,i,width G) c= { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,width G)`2 < s } proof let x be set; assume A5: x in Int cell(G,i,width G); then x in Int v_strip(G,i) by A2,XBOOLE_0:def 3; then consider r1,s1 such that A6: x = |[r1,s1]| and A7: G*(i,1)`1 < r1 & r1 < G*(i+1,1)`1 by A3; x in Int h_strip(G,width G) by A2,A5,XBOOLE_0:def 3; then consider r2,s2 such that A8: x = |[r2,s2]| and A9: G*(1,width G)`2 < s2 by A4; r1 = r2 & s1 = s2 by A6,A8,SPPOL_2:1; hence thesis by A6,A7,A9; end; let x be set; assume x in { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,width G)`2 < s }; then ex r,s st x = |[r,s]| & G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,width G)`2 < s; then x in Int v_strip(G,i) & x in Int h_strip(G,width G) by A3,A4; hence thesis by A2,XBOOLE_0:def 3; end; theorem Th29: 1 <= i & i < len G & 1 <= j & j < width G implies Int cell(G,i,j) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2 } proof assume that A1: 1 <= i & i < len G and A2: 1 <= j & j < width G; cell(G,i,j) = v_strip(G,i) /\ h_strip(G,j) by GOBOARD5:def 3; then A3: Int cell(G,i,j) = Int v_strip(G,i) /\ Int h_strip(G,j) by TOPS_1:46 ; A4: Int v_strip(G,i) = { |[r,s]| : G*(i,1)`1 < r & r < G* (i+1,1)`1 } by A1,Th17 ; A5: Int h_strip(G,j) = { |[r,s]| : G*(1,j)`2 < s & s < G* (1,j+1)`2 } by A2,Th20 ; thus Int cell(G,i,j) c= { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2 } proof let x be set; assume A6: x in Int cell(G,i,j); then x in Int v_strip(G,i) by A3,XBOOLE_0:def 3; then consider r1,s1 such that A7: x = |[r1,s1]| and A8: G*(i,1)`1 < r1 & r1 < G*(i+1,1)`1 by A4; x in Int h_strip(G,j) by A3,A6,XBOOLE_0:def 3; then consider r2,s2 such that A9: x = |[r2,s2]| and A10: G*(1,j)`2 < s2 & s2 < G*(1,j+1)`2 by A5; r1 = r2 & s1 = s2 by A7,A9,SPPOL_2:1; hence thesis by A7,A8,A10; end; let x be set; assume x in { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2 }; then ex r,s st x = |[r,s]| & G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2; then x in Int v_strip(G,i) & x in Int h_strip(G,j) by A4,A5; hence thesis by A3,XBOOLE_0:def 3; end; theorem 1 <= j & j <= width G & p in Int h_strip(G,j) implies p`2 > G*(1,j)`2 proof assume that A1: 1 <= j & j <= width G and A2: p in Int h_strip(G,j); per cases by A1,AXIOMS:21; suppose j = width G; then Int h_strip(G,j) = { |[r,s]| : G*(1,j)`2 < s } by Th19; then consider r,s such that A3: p = |[r,s]| and A4: G*(1,j)`2 < s by A2; thus p`2 > G*(1,j)`2 by A3,A4,EUCLID:56; suppose j < width G; then Int h_strip(G,j) = { |[r,s]| : G*(1,j)`2 < s & s < G*(1,j+1)`2 } by A1,Th20; then consider r,s such that A5: p = |[r,s]| and A6: G*(1,j)`2 < s and s < G*(1,j+1)`2 by A2; thus p`2 > G*(1,j)`2 by A5,A6,EUCLID:56; end; theorem j < width G & p in Int h_strip(G,j) implies p`2 < G*(1,j+1)`2 proof assume that A1: j < width G and A2: p in Int h_strip(G,j); per cases by RLVECT_1:99; suppose j = 0; then Int h_strip(G,j) = { |[r,s]| : s < G*(1,j+1)`2 } by Th18; then consider r,s such that A3: p = |[r,s]| and A4: G*(1,j+1)`2 > s by A2; thus p`2 < G*(1,j+1)`2 by A3,A4,EUCLID:56; suppose j >= 1; then Int h_strip(G,j) = { |[r,s]| : G*(1,j)`2 < s & s < G*(1,j+1)`2 } by A1,Th20; then consider r,s such that A5: p = |[r,s]| and G*(1,j)`2 < s and A6: s < G*(1,j+1)`2 by A2; thus p`2 < G*(1,j+1)`2 by A5,A6,EUCLID:56; end; theorem 1 <= i & i <= len G & p in Int v_strip(G,i) implies p`1 > G*(i,1)`1 proof assume that A1: 1 <= i & i <= len G and A2: p in Int v_strip(G,i); per cases by A1,AXIOMS:21; suppose i = len G; then Int v_strip(G,i) = { |[r,s]| : G*(i,1)`1 < r } by Th16; then consider r,s such that A3: p = |[r,s]| and A4: G*(i,1)`1 < r by A2; thus p`1 > G*(i,1)`1 by A3,A4,EUCLID:56; suppose i < len G; then Int v_strip(G,i) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 } by A1,Th17; then consider r,s such that A5: p = |[r,s]| and A6: G*(i,1)`1 < r and r < G*(i+1,1)`1 by A2; thus p`1 > G*(i,1)`1 by A5,A6,EUCLID:56; end; theorem i < len G & p in Int v_strip(G,i) implies p`1 < G*(i+1,1)`1 proof assume that A1: i < len G and A2: p in Int v_strip(G,i); per cases by RLVECT_1:99; suppose i = 0; then Int v_strip(G,i) = { |[r,s]| : r < G*(i+1,1)`1 } by Th15; then consider r,s such that A3: p = |[r,s]| and A4: G*(i+1,1)`1 > r by A2; thus p`1 < G*(i+1,1)`1 by A3,A4,EUCLID:56; suppose i >= 1; then Int v_strip(G,i) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 } by A1,Th17; then consider r,s such that A5: p = |[r,s]| and G*(i,1)`1 < r and A6: r < G*(i+1,1)`1 by A2; thus p`1 < G*(i+1,1)`1 by A5,A6,EUCLID:56; end; theorem Th34: 1 <= i & i+1 <= len G & 1 <= j & j+1 <= width G implies 1/2*(G*(i,j)+G*(i+1,j+1)) in Int cell(G,i,j) proof assume that A1: 1 <= i & i+1 <= len G and A2: 1 <= j & j+1 <= width G; set r1 = G*(i,j)`1, s1 = G*(i,j)`2, r2 = G*(i+1,j+1)`1, s2 = G* (i+1,j+1)`2; A3: G*(i,j) = |[r1,s1]| by EUCLID:57; G*(i+1,j+1) = |[r2,s2]| by EUCLID:57; then G*(i,j)+G*(i+1,j+1) = |[r1+r2,s1+s2]| by A3,EUCLID:60; then A4: 1/2*(G*(i,j)+G*(i+1,j+1)) = |[1/2*(r1+r2),1/2*(s1+s2)]| by EUCLID: 62; A5: 1/2*r1 = r1/2 by XCMPLX_1:100; A6: 1/2*r2 = r2/2 by XCMPLX_1:100; A7: 1/2*s1 = s1/2 by XCMPLX_1:100; A8: 1/2*s2 = s2/2 by XCMPLX_1:100; i <= i+1 & j <= j+1 by NAT_1:29; then A9: i <= len G & j <= width G by A1,A2,AXIOMS:22; A10: 1 <= i+1 & 1 <= j+1 by NAT_1:29; A11: G*(i,1)`1 = r1 by A1,A2,A9,GOBOARD5:3; A12: G*(i+1,1)`1 = r2 by A1,A2,A10,GOBOARD5:3; A13: G*(1,j)`2 = s1 by A1,A2,A9,GOBOARD5:2; A14: G*(1,j+1)`2 = s2 by A1,A2,A10,GOBOARD5:2; 1 <= width G & i < i+1 by A2,A9,AXIOMS:22,REAL_1:69; then A15: r1 < r2 by A1,A11,A12,GOBOARD5:4; then r1+r1 < r1+r2 by REAL_1:53; then 1/2*(r1+r1) < 1/2*(r1+r2) by REAL_1:70; then 1/2*r1+1/2*r1 < 1/2*(r1+r2) by XCMPLX_1:8; then A16: G*(i,1)`1 < 1/2*(r1+r2) by A5,A11,XCMPLX_1:66; r1+r2 < r2+r2 by A15,REAL_1:53; then 1/2*(r1+r2) < 1/2*(r2+r2) by REAL_1:70; then 1/2*(r1+r2) < 1/2*r2+1/2*r2 by XCMPLX_1:8; then A17: 1/2*(r1+r2) < G*(i+1,1)`1 by A6,A12,XCMPLX_1:66; 1 <= len G & j < j+1 by A1,A9,AXIOMS:22,REAL_1:69; then A18: s1 < s2 by A2,A13,A14,GOBOARD5:5; then s1+s1 < s1+s2 by REAL_1:53; then 1/2*(s1+s1) < 1/2*(s1+s2) by REAL_1:70; then 1/2*s1+1/2*s1 < 1/2*(s1+s2) by XCMPLX_1:8; then A19: G*(1,j)`2 < 1/2*(s1+s2) by A7,A13,XCMPLX_1:66; s1+s2 < s2+s2 by A18,REAL_1:53; then 1/2*(s1+s2) < 1/2*(s2+s2) by REAL_1:70; then 1/2*(s1+s2) < 1/2*s2+1/2*s2 by XCMPLX_1:8; then A20: 1/2*(s1+s2) < G*(1,j+1)`2 by A8,A14,XCMPLX_1:66; A21: 1 <= i & i < len G by A1,NAT_1:38; 1 <= j & j < width G by A2,NAT_1:38; then Int cell(G,i,j) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2 } by A21,Th29; hence 1/2*(G*(i,j)+G*(i+1,j+1)) in Int cell(G,i,j) by A4,A16,A17,A19,A20; end; theorem Th35: 1 <= i & i+1 <= len G implies 1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]| in Int cell(G,i,width G) proof assume that A1: 1 <= i & i+1 <= len G; set r1 = G*(i,width G)`1, s1 = G*(i,width G)`2, r2 = G*(i+1,width G)`1; A2: i < len G by A1,NAT_1:38; width G <> 0 by GOBOARD1:def 5; then A3: 1 <= i+1 & 1 <= width G by NAT_1:29,RLVECT_1:99; A4: 1/2*s1 = s1/2 by XCMPLX_1:100; A5: 1/2*(s1+s1) = 1/2*s1+1/2*s1 by XCMPLX_1:8 .= s1 by A4,XCMPLX_1:66; A6: G*(i,width G) = |[r1,s1]| by EUCLID:57; A7: G*(1,width G)`2 = s1 by A1,A2,A3,GOBOARD5:2; G*(1,width G)`2 = G*(i+1,width G)`2 by A1,A3,GOBOARD5:2; then G*(i+1,width G) = |[r2,s1]| by A7,EUCLID:57; then G*(i,width G)+G*(i+1,width G) = |[r1+r2,s1+s1]| by A6,EUCLID:60; then 1/2*(G*(i,width G)+G*(i+1,width G))= |[1/2*(r1+r2),s1]| by A5,EUCLID:62; then A8: 1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]| = |[1/2*(r1+r2)+0,s1+1 ]| by EUCLID:60; A9: 1/2*r1 = r1/2 by XCMPLX_1:100; A10: 1/2*r2 = r2/2 by XCMPLX_1:100; A11: G*(i,1)`1 = r1 by A1,A2,A3,GOBOARD5:3; A12: G*(i+1,1)`1 = r2 by A1,A3,GOBOARD5:3; width G <> 0 by GOBOARD1:def 5; then 1 <= width G & i < i+1 by REAL_1:69,RLVECT_1:99; then A13: r1 < r2 by A1,GOBOARD5:4; then r1+r1 < r1+r2 by REAL_1:53; then 1/2*(r1+r1) < 1/2*(r1+r2) by REAL_1:70; then 1/2*r1+1/2*r1 < 1/2*(r1+r2) by XCMPLX_1:8; then A14: G*(i,1)`1 < 1/2*(r1+r2) by A9,A11,XCMPLX_1:66; r1+r2 < r2+r2 by A13,REAL_1:53; then 1/2*(r1+r2) < 1/2*(r2+r2) by REAL_1:70; then 1/2*(r1+r2) < 1/2*r2+1/2*r2 by XCMPLX_1:8; then A15: 1/2*(r1+r2) < G*(i+1,1)`1 by A10,A12,XCMPLX_1:66; A16: G*(1,width G)`2 < s1+1 by A7,REAL_1:69; 1 <= i & i < len G by A1,NAT_1:38; then Int cell(G,i,width G) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & G* (1,width G)`2 < s } by Th28 ; hence 1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]| in Int cell(G,i,width G) by A8,A14,A15,A16; end; theorem Th36: 1 <= i & i+1 <= len G implies 1/2*(G*(i,1)+G*(i+1,1))-|[0,1]| in Int cell(G,i,0) proof assume that A1: 1 <= i & i+1 <= len G; set r1 = G*(i,1)`1, s1 = G*(i,1)`2, r2 = G*(i+1,1)`1; A2: i < len G by A1,NAT_1:38; width G <> 0 by GOBOARD1:def 5; then A3: 1 <= i+1 & 1 <= width G by NAT_1:29,RLVECT_1:99; A4: 1/2*s1 = s1/2 by XCMPLX_1:100; A5: 1/2*(s1+s1) = 1/2*s1+1/2*s1 by XCMPLX_1:8 .= s1 by A4,XCMPLX_1:66; A6: G*(i,1) = |[r1,s1]| by EUCLID:57; A7: G*(1,1)`2 = s1 by A1,A2,A3,GOBOARD5:2; G*(1,1)`2 = G*(i+1,1)`2 by A1,A3,GOBOARD5:2; then G*(i+1,1) = |[r2,s1]| by A7,EUCLID:57; then G*(i,1)+G*(i+1,1) = |[r1+r2,s1+s1]| by A6,EUCLID:60; then 1/2*(G*(i,1)+G*(i+1,1))= |[1/2*(r1+r2),s1]| by A5,EUCLID:62; then A8: 1/2*(G*(i,1)+G*(i+1,1))-|[0,1]| = |[1/2*(r1+r2)-0,s1-1]| by EUCLID :66 .= |[1/2*(r1+r2),s1-1]|; A9: 1/2*r1 = r1/2 by XCMPLX_1:100; A10: 1/2*r2 = r2/2 by XCMPLX_1:100; width G <> 0 by GOBOARD1:def 5; then 1 <= width G & i < i+1 by REAL_1:69,RLVECT_1:99; then A11: r1 < r2 by A1,GOBOARD5:4; then r1+r1 < r1+r2 by REAL_1:53; then 1/2*(r1+r1) < 1/2*(r1+r2) by REAL_1:70; then 1/2*r1+1/2*r1 < 1/2*(r1+r2) by XCMPLX_1:8; then A12: G*(i,1)`1 < 1/2*(r1+r2) by A9,XCMPLX_1:66; r1+r2 < r2+r2 by A11,REAL_1:53; then 1/2*(r1+r2) < 1/2*(r2+r2) by REAL_1:70; then 1/2*(r1+r2) < 1/2*r2+1/2*r2 by XCMPLX_1:8; then A13: 1/2*(r1+r2) < G*(i+1,1)`1 by A10,XCMPLX_1:66; s1 < G*(1,1)`2+1 by A7,REAL_1:69; then A14: s1-1 < G*(1,1)`2 by REAL_1:84; 1 <= i & i < len G by A1,NAT_1:38; then Int cell(G,i,0) = { |[r,s]| : G*(i,1)`1 < r & r < G*(i+1,1)`1 & s < G*(1,1)`2 } by Th27; hence 1/2*(G*(i,1)+G*(i+1,1))-|[0,1]| in Int cell(G,i,0) by A8,A12,A13,A14; end; theorem Th37: 1 <= j & j+1 <= width G implies 1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]| in Int cell(G,len G,j) proof assume that A1: 1 <= j & j+1 <= width G; set s1 = G*(len G,j)`2, r1 = G*(len G,j)`1, s2 = G*(len G,j+1)`2; A2: j < width G by A1,NAT_1:38; len G <> 0 by GOBOARD1:def 5; then A3: 1 <= j+1 & 1 <= len G by NAT_1:29,RLVECT_1:99; A4: 1/2*r1 = r1/2 by XCMPLX_1:100; A5: 1/2*(r1+r1) = 1/2*r1+1/2*r1 by XCMPLX_1:8 .= r1 by A4,XCMPLX_1:66; A6: G*(len G,j) = |[r1,s1]| by EUCLID:57; A7: G*(len G,1)`1 = r1 by A1,A2,A3,GOBOARD5:3; G*(len G,1)`1 = G*(len G,j+1)`1 by A1,A3,GOBOARD5:3; then G*(len G,j+1) = |[r1,s2]| by A7,EUCLID:57; then G*(len G,j)+G*(len G,j+1) = |[r1+r1,s1+s2]| by A6,EUCLID:60; then 1/2*(G*(len G,j)+G*(len G,j+1))= |[r1,1/2*(s1+s2)]| by A5,EUCLID:62; then A8: 1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]| = |[r1+1,1/2*(s1+s2)+0]| by EUCLID:60; A9: 1/2*s1 = s1/2 by XCMPLX_1:100; A10: 1/2*s2 = s2/2 by XCMPLX_1:100; A11: G*(1,j)`2 = s1 by A1,A2,A3,GOBOARD5:2; A12: G*(1,j+1)`2 = s2 by A1,A3,GOBOARD5:2; len G <> 0 by GOBOARD1:def 5; then 1 <= len G & j < j+1 by REAL_1:69,RLVECT_1:99; then A13: s1 < s2 by A1,GOBOARD5:5; then s1+s1 < s1+s2 by REAL_1:53; then 1/2*(s1+s1) < 1/2*(s1+s2) by REAL_1:70; then 1/2*s1+1/2*s1 < 1/2*(s1+s2) by XCMPLX_1:8; then A14: G*(1,j)`2 < 1/2*(s1+s2) by A9,A11,XCMPLX_1:66; s1+s2 < s2+s2 by A13,REAL_1:53; then 1/2*(s1+s2) < 1/2*(s2+s2) by REAL_1:70; then 1/2*(s1+s2) < 1/2*s2+1/2*s2 by XCMPLX_1:8; then A15: 1/2*(s1+s2) < G*(1,j+1)`2 by A10,A12,XCMPLX_1:66; A16: G*(len G,1)`1 < r1+1 by A7,REAL_1:69; 1 <= j & j < width G by A1,NAT_1:38; then Int cell(G,len G,j) = { |[r,s]| : G*(len G,1)`1 < r & G*(1,j)`2 < s & s < G* (1,j+1)`2 } by Th26; hence 1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]| in Int cell(G,len G,j) by A8,A14,A15,A16; end; theorem Th38: 1 <= j & j+1 <= width G implies 1/2*(G*(1,j)+G*(1,j+1))-|[1,0]| in Int cell(G,0,j) proof assume that A1: 1 <= j & j+1 <= width G; set s1 = G*(1,j)`2, r1 = G*(1,j)`1, s2 = G*(1,j+1)`2; A2: j < width G by A1,NAT_1:38; len G <> 0 by GOBOARD1:def 5; then A3: 1 <= j+1 & 1 <= len G by NAT_1:29,RLVECT_1:99; A4: 1/2*r1 = r1/2 by XCMPLX_1:100; A5: 1/2*(r1+r1) = 1/2*r1+1/2*r1 by XCMPLX_1:8 .= r1 by A4,XCMPLX_1:66; A6: G*(1,j) = |[r1,s1]| by EUCLID:57; A7: G*(1,1)`1 = r1 by A1,A2,A3,GOBOARD5:3; G*(1,1)`1 = G*(1,j+1)`1 by A1,A3,GOBOARD5:3; then G*(1,j+1) = |[r1,s2]| by A7,EUCLID:57; then G*(1,j)+G*(1,j+1) = |[r1+r1,s1+s2]| by A6,EUCLID:60; then 1/2*(G*(1,j)+G*(1,j+1))= |[r1,1/2*(s1+s2)]| by A5,EUCLID:62; then A8: 1/2*(G*(1,j)+G*(1,j+1))-|[1,0]| = |[r1-1,1/2*(s1+s2)-0]| by EUCLID :66 .= |[r1-1,1/2*(s1+s2)]|; A9: 1/2*s1 = s1/2 by XCMPLX_1:100; A10: 1/2*s2 = s2/2 by XCMPLX_1:100; len G <> 0 by GOBOARD1:def 5; then 1 <= len G & j < j+1 by REAL_1:69,RLVECT_1:99; then A11: s1 < s2 by A1,GOBOARD5:5; then s1+s1 < s1+s2 by REAL_1:53; then 1/2*(s1+s1) < 1/2*(s1+s2) by REAL_1:70; then 1/2*s1+1/2*s1 < 1/2*(s1+s2) by XCMPLX_1:8; then A12: G*(1,j)`2 < 1/2*(s1+s2) by A9,XCMPLX_1:66; s1+s2 < s2+s2 by A11,REAL_1:53; then 1/2*(s1+s2) < 1/2*(s2+s2) by REAL_1:70; then 1/2*(s1+s2) < 1/2*s2+1/2*s2 by XCMPLX_1:8; then A13: 1/2*(s1+s2) < G*(1,j+1)`2 by A10,XCMPLX_1:66; r1 < G*(1,1)`1+1 by A7,REAL_1:69; then A14: r1-1 < G*(1,1)`1 by REAL_1:84; 1 <= j & j < width G by A1,NAT_1:38; then Int cell(G,0,j) = { |[r,s]| : r < G*(1,1)`1 & G*(1,j)`2 < s & s < G*(1,j+1)`2 } by Th23; hence 1/2*(G*(1,j)+G*(1,j+1))-|[1,0]| in Int cell(G,0,j) by A8,A12,A13,A14; end; theorem Th39: G*(1,1)-|[1,1]| in Int cell(G,0,0) proof set s1 = G*(1,1)`2, r1 = G*(1,1)`1; G*(1,1) = |[r1,s1]| by EUCLID:57; then A1: G*(1,1)-|[1,1]| = |[r1-1,s1-1]| by EUCLID:66; s1 < G*(1,1)`2+1 by REAL_1:69; then A2: s1-1 < G*(1,1)`2 by REAL_1:84; r1 < G*(1,1)`1+1 by REAL_1:69; then A3: r1-1 < G*(1,1)`1 by REAL_1:84; Int cell(G,0,0) = { |[r,s]| : r < G*(1,1)`1 & s < G*(1,1)`2 } by Th21; hence G*(1,1)-|[1,1]| in Int cell(G,0,0) by A1,A2,A3; end; theorem Th40: G*(len G,width G)+|[1,1]| in Int cell(G,len G,width G) proof set s1 = G*(len G,width G)`2, r1 = G*(len G,width G)`1; width G <> 0 by GOBOARD1:def 5; then A1: 1 <= width G by RLVECT_1:99; len G <> 0 by GOBOARD1:def 5; then A2: 1 <= len G by RLVECT_1:99; then A3: G*(len G,1)`1 = r1 by A1,GOBOARD5:3; A4: G*(1,width G)`2 = s1 by A1,A2,GOBOARD5:2; G*(len G,width G) = |[r1,s1]| by EUCLID:57; then A5: G*(len G,width G)+|[1,1]| = |[r1+1,s1+1]| by EUCLID:60; A6: s1+1 > G*(1,width G)`2 by A4,REAL_1:69; A7: r1+1 > G*(len G,1)`1 by A3,REAL_1:69; Int cell(G,len G,width G) = { |[r,s]| : G*(len G,1)`1 < r & G*(1,width G)`2 < s } by Th25; hence G*(len G,width G)+|[1,1]| in Int cell(G,len G,width G) by A5,A6,A7; end; theorem Th41: G*(1,width G)+|[-1,1]| in Int cell(G,0,width G) proof set s1 = G*(1,width G)`2, r1 = G*(1,width G)`1; width G <> 0 by GOBOARD1:def 5; then A1: 1 <= width G by RLVECT_1:99; len G <> 0 by GOBOARD1:def 5; then 1 <= len G by RLVECT_1:99; then A2: G*(1,1)`1 = r1 by A1,GOBOARD5:3; G*(1,width G) = |[r1,s1]| by EUCLID:57; then A3: G*(1,width G)+|[-1,1]| = |[r1+-1,s1+1]| by EUCLID:60 .= |[r1-1,s1+1]| by XCMPLX_0:def 8; A4: s1+1 > G*(1,width G)`2 by REAL_1:69; r1 < G*(1,1)`1+1 by A2,REAL_1:69; then A5: r1-1 < G*(1,1)`1 by REAL_1:84; Int cell(G,0,width G) = { |[r,s]| : r < G*(1,1)`1 & G*(1,width G)`2 < s } by Th22; hence G*(1,width G)+|[-1,1]| in Int cell(G,0,width G) by A3,A4,A5; end; theorem Th42: G*(len G,1)+|[1,-1]| in Int cell(G,len G,0) proof set s1 = G*(len G,1)`2, r1 = G*(len G,1)`1; width G <> 0 by GOBOARD1:def 5; then A1: 1 <= width G by RLVECT_1:99; len G <> 0 by GOBOARD1:def 5; then 1 <= len G by RLVECT_1:99; then A2: G*(1,1)`2 = s1 by A1,GOBOARD5:2; G*(len G,1) = |[r1,s1]| by EUCLID:57; then A3: G*(len G,1)+|[1,-1]| = |[r1+1,s1+-1]| by EUCLID:60 .= |[r1+1,s1-1]| by XCMPLX_0:def 8; s1 < G*(1,1)`2+1 by A2,REAL_1:69; then A4: s1-1 < G*(1,1)`2 by REAL_1:84; A5: r1+1 > G*(len G,1)`1 by REAL_1:69; Int cell(G,len G,0) = { |[r,s]| : G*(len G,1)`1 < r & s < G* (1,1)`2 } by Th24 ; hence G*(len G,1)+|[1,-1]| in Int cell(G,len G,0) by A3,A4,A5; end; theorem Th43: 1 <= i & i < len G & 1 <= j & j < width G implies LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i,j)+G*(i,j+1))) c= Int cell(G,i,j) \/ { 1/2*(G*(i,j)+G*(i,j+1)) } proof assume A1: 1 <= i & i < len G & 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i,j)+G*(i,j+1))); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,j)+G*(i+1,j+1)))+r*(1/2*(G*(i,j)+G*(i,j+1))) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(1/2*(G*(i,j)+G*(i,j+1))) by A4,EUCLID:33 .= 1*(1/2*(G*(i,j)+G*(i,j+1))) by EUCLID:31 .= 1/2*(G*(i,j)+G*(i,j+1)) by EUCLID:33; hence p in { 1/2*(G*(i,j)+G*(i,j+1)) } by TARSKI:def 1; case A5: r < 1; set r1 = G*(i,1)`1, r2 = G*(i+1,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; A7: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; A8: G*(i,j) = |[G*(i,j)`1,G*(i,j)`2]| by EUCLID:57 .= |[r1,G*(i,j)`2]| by A1,GOBOARD5:3 .= |[r1,s1]| by A1,GOBOARD5:2; A9: G*(i+1,j+1) = |[G*(i+1,j+1)`1,G*(i+1,j+1)`2]| by EUCLID:57 .= |[r2,G*(i+1,j+1)`2]| by A6,A7,GOBOARD5:3 .= |[r2,s2]| by A6,A7,GOBOARD5:2; A10: G*(i,j+1) = |[G*(i,j+1)`1,G*(i,j+1)`2]| by EUCLID:57 .= |[r1,G*(i,j+1)`2]| by A1,A6,GOBOARD5:3 .= |[r1,s2]| by A1,A6,GOBOARD5:2; set r3 = (1-r)*(1/2), s3 = r*(1/2); A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: (1/2)*s1 = s1/2 by XCMPLX_1:100; A14: (1/2)*s2 = s2/2 by XCMPLX_1:100; A15: p = r3*(G*(i,j)+G*(i+1,j+1))+r*(1/2*(G*(i,j)+G* (i,j+1))) by A4,EUCLID:34 .= r3*(G*(i,j)+G*(i+1,j+1))+s3*(G*(i,j)+G*(i,j+1)) by EUCLID:34 .= r3*|[r1+r2,s1+s2]|+s3*(G*(i,j)+G*(i,j+1)) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s1+s2]|+s3*|[r1+r1,s1+s2]| by A8,A10,EUCLID:60 .= |[r3*(r1+r2),r3*(s1+s2)]|+s3*|[r1+r1,s1+s2]| by EUCLID:62 .= |[r3*(r1+r2),r3*(s1+s2)]|+|[s3*(r1+r1),s3*(s1+s2)]| by EUCLID:62 .= |[r3*(r1+r2)+s3*(r1+r1),r3*(s1+s2)+s3*(s1+s2)]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A16: r3 > (1/2)*0 by REAL_1:70; 0 <> width G by GOBOARD1:def 5; then A17: 1 <= width G by RLVECT_1:99; i < i+1 by REAL_1:69; then A18: r1 < r2 by A1,A7,A17,GOBOARD5:4; then r1+r1 < r1+r2 by REAL_1:53; then A19: r3*(r1+r1) < r3*(r1+r2) by A16,REAL_1:70; 0 <> len G by GOBOARD1:def 5; then A20: 1 <= len G by RLVECT_1:99; j < j+1 by REAL_1:69; then A21: s1 < s2 by A1,A6,A20,GOBOARD5:5; r3*(r1+r1)+s3*(r1+r1) = (r3+s3)*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A22: r1 < r3*(r1+r2)+s3*(r1+r1) by A19,REAL_1:53; A23: s3 >= 0 by A3,REAL_2:121; r1+r2 < r2+r2 by A18,REAL_1:53; then A24: r3*(r1+r2) < r3*(r2+r2) by A16,REAL_1:70; r1+r1 < r2+r2 by A18,REAL_1:67; then A25: s3*(r1+r1) <= s3*(r2+r2) by A23,AXIOMS:25; r3*(r2+r2)+s3*(r2+r2) = (r3+s3)*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A26: r3*(r1+r2)+s3*(r1+r1) < r2 by A24,A25,REAL_1:67; A27: s1+s1 < s1+s2 by A21,REAL_1:53; then A28: r3*(s1+s1) < r3*(s1+s2) by A16,REAL_1:70; A29: s3*(s1+s1) <= s3*(s1+s2) by A23,A27,AXIOMS:25; r3*(s1+s1)+s3*(s1+s1) = (r3+s3)*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A13,XCMPLX_1:66; then A30: s1 < r3*(s1+s2)+s3*(s1+s2) by A28,A29,REAL_1:67; A31: s1+s2 < s2+s2 by A21,REAL_1:53; then A32: r3*(s1+s2) < r3*(s2+s2) by A16,REAL_1:70; A33: s3*(s1+s2) <= s3*(s2+s2) by A23,A31,AXIOMS:25; r3*(s2+s2)+s3*(s2+s2) = (r3+s3)*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A14,XCMPLX_1:66; then A34: r3*(s1+s2)+s3*(s1+s2) < s2 by A32,A33,REAL_1:67; Int cell(G,i,j) = { |[r',s']| : r1 < r' & r' < r2 & s1 < s' & s' < s2 } by A1,Th29; hence p in Int cell(G,i,j) by A15,A22,A26,A30,A34; end; hence x in Int cell(G,i,j) \/ { 1/2*(G*(i,j)+G*(i,j+1)) } by XBOOLE_0:def 2; end; theorem Th44: 1 <= i & i < len G & 1 <= j & j < width G implies LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i,j+1)+G*(i+1,j+1))) c= Int cell(G,i,j) \/ { 1/2*(G*(i,j+1)+G*(i+1,j+1)) } proof assume A1: 1 <= i & i < len G & 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i,j+1)+G*(i+1,j+1))); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,j)+G*(i+1,j+1)))+r*(1/2*(G*(i,j+1)+G*(i+1,j+1))) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(1/2*(G*(i,j+1)+G*(i+1,j+1))) by A4,EUCLID:33 .= 1*(1/2*(G*(i,j+1)+G*(i+1,j+1))) by EUCLID:31 .= 1/2*(G*(i,j+1)+G*(i+1,j+1)) by EUCLID:33; hence p in { 1/2*(G*(i,j+1)+G*(i+1,j+1)) } by TARSKI:def 1; case A5: r < 1; set r1 = G*(i,1)`1, r2 = G*(i+1,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; A7: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; A8: G*(i,j) = |[G*(i,j)`1,G*(i,j)`2]| by EUCLID:57 .= |[r1,G*(i,j)`2]| by A1,GOBOARD5:3 .= |[r1,s1]| by A1,GOBOARD5:2; A9: G*(i+1,j+1) = |[G*(i+1,j+1)`1,G*(i+1,j+1)`2]| by EUCLID:57 .= |[r2,G*(i+1,j+1)`2]| by A6,A7,GOBOARD5:3 .= |[r2,s2]| by A6,A7,GOBOARD5:2; A10: G*(i,j+1) = |[G*(i,j+1)`1,G*(i,j+1)`2]| by EUCLID:57 .= |[r1,G*(i,j+1)`2]| by A1,A6,GOBOARD5:3 .= |[r1,s2]| by A1,A6,GOBOARD5:2; set r3 = (1-r)*(1/2), s3 = r*(1/2); A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: (1/2)*s1 = s1/2 by XCMPLX_1:100; A14: (1/2)*s2 = s2/2 by XCMPLX_1:100; A15: p = r3*(G*(i,j)+G*(i+1,j+1))+r*(1/2*(G*(i,j+1)+G*(i+1,j+1))) by A4,EUCLID :34 .= r3*(G*(i,j)+G*(i+1,j+1))+s3*(G*(i,j+1)+G*(i+1,j+1)) by EUCLID:34 .= r3*|[r1+r2,s1+s2]|+s3*(G*(i,j+1)+G*(i+1,j+1)) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s1+s2]|+s3*|[r1+r2,s2+s2]| by A9,A10,EUCLID:60 .= |[r3*(r1+r2),r3*(s1+s2)]|+s3*|[r1+r2,s2+s2]| by EUCLID:62 .= |[r3*(r1+r2),r3*(s1+s2)]|+|[s3*(r1+r2),s3*(s2+s2)]| by EUCLID:62 .= |[r3*(r1+r2)+s3*(r1+r2),r3*(s1+s2)+s3*(s2+s2)]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A16: r3 > (1/2)*0 by REAL_1:70; 0 <> width G by GOBOARD1:def 5; then A17: 1 <= width G by RLVECT_1:99; i < i+1 by REAL_1:69; then A18: r1 < r2 by A1,A7,A17,GOBOARD5:4; then A19: r1+r1 < r1+r2 by REAL_1:53; then A20: r3*(r1+r1) < r3*(r1+r2) by A16,REAL_1:70; 0 <> len G by GOBOARD1:def 5; then A21: 1 <= len G by RLVECT_1:99; j < j+1 by REAL_1:69; then A22: s1 < s2 by A1,A6,A21,GOBOARD5:5; A23: s3 >= 0 by A3,REAL_2:121; then A24: s3*(r1+r1) <= s3*(r1+r2) by A19,AXIOMS:25; r3*(r1+r1)+s3*(r1+r1) = (r3+s3)*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A25: r1 < r3*(r1+r2)+s3*(r1+r2) by A20,A24,REAL_1:67; r1+r2 < r2+r2 by A18,REAL_1:53; then A26: r3*(r1+r2) < r3*(r2+r2) by A16,REAL_1:70; r1+r2 < r2+r2 by A18,REAL_1:67; then A27: s3*(r1+r2) <= s3*(r2+r2) by A23,AXIOMS:25; r3*(r2+r2)+s3*(r2+r2) = (r3+s3)*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A28: r3*(r1+r2)+s3*(r1+r2) < r2 by A26,A27,REAL_1:67; A29: s1+s1 < s1+s2 by A22,REAL_1:53; then A30: r3*(s1+s1) < r3*(s1+s2) by A16,REAL_1:70; s1+s2 < s2+s2 by A22,REAL_1:53; then s1+s1 < s2+s2 by A29,AXIOMS:22; then A31: s3*(s1+s1) <= s3*(s2+s2) by A23,AXIOMS:25; r3*(s1+s1)+s3*(s1+s1) = (r3+s3)*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A13,XCMPLX_1:66; then A32: s1 < r3*(s1+s2)+s3*(s2+s2) by A30,A31,REAL_1:67; s1+s2 < s2+s2 by A22,REAL_1:53; then A33: r3*(s1+s2) < r3*(s2+s2) by A16,REAL_1:70; r3*(s2+s2)+s3*(s2+s2) = (r3+s3)*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A14,XCMPLX_1:66; then A34: r3*(s1+s2)+s3*(s2+s2) < s2 by A33,REAL_1:67; Int cell(G,i,j) = { |[r',s']| : r1 < r' & r' < r2 & s1 < s' & s' < s2 } by A1,Th29; hence p in Int cell(G,i,j) by A15,A25,A28,A32,A34; end; hence x in Int cell(G,i,j) \/ { 1/2*(G*(i,j+1)+G* (i+1,j+1)) } by XBOOLE_0:def 2; end; theorem Th45: 1 <= i & i < len G & 1 <= j & j < width G implies LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i+1,j)+G*(i+1,j+1))) c= Int cell(G,i,j) \/ { 1/2*(G*(i+1,j)+G*(i+1,j+1)) } proof assume A1: 1 <= i & i < len G & 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i+1,j)+G*(i+1,j+1))); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,j)+G*(i+1,j+1)))+r*(1/2*(G*(i+1,j)+G*(i+1,j+1))) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(1/2*(G*(i+1,j)+G*(i+1,j+1))) by A4,EUCLID:33 .= 1*(1/2*(G*(i+1,j)+G*(i+1,j+1))) by EUCLID:31 .= 1/2*(G*(i+1,j)+G*(i+1,j+1)) by EUCLID:33; hence p in { 1/2*(G*(i+1,j)+G*(i+1,j+1)) } by TARSKI:def 1; case A5: r < 1; set r1 = G*(i,1)`1, r2 = G*(i+1,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; A7: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; A8: G*(i,j) = |[G*(i,j)`1,G*(i,j)`2]| by EUCLID:57 .= |[r1,G*(i,j)`2]| by A1,GOBOARD5:3 .= |[r1,s1]| by A1,GOBOARD5:2; A9: G*(i+1,j+1) = |[G*(i+1,j+1)`1,G*(i+1,j+1)`2]| by EUCLID:57 .= |[r2,G*(i+1,j+1)`2]| by A6,A7,GOBOARD5:3 .= |[r2,s2]| by A6,A7,GOBOARD5:2; A10: G*(i+1,j) = |[G*(i+1,j)`1,G*(i+1,j)`2]| by EUCLID:57 .= |[r2,G*(i+1,j)`2]| by A1,A7,GOBOARD5:3 .= |[r2,s1]| by A1,A7,GOBOARD5:2; set r3 = (1-r)*(1/2), s3 = r*(1/2); A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: (1/2)*s1 = s1/2 by XCMPLX_1:100; A14: (1/2)*s2 = s2/2 by XCMPLX_1:100; A15: p = r3*(G*(i,j)+G*(i+1,j+1))+r*(1/2*(G*(i+1,j)+G*(i+1,j+1))) by A4,EUCLID :34 .= r3*(G*(i,j)+G*(i+1,j+1))+s3*(G*(i+1,j)+G*(i+1,j+1)) by EUCLID:34 .= r3*|[r1+r2,s1+s2]|+s3*(G*(i+1,j)+G*(i+1,j+1)) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s1+s2]|+s3*|[r2+r2,s1+s2]| by A9,A10,EUCLID:60 .= |[r3*(r1+r2),r3*(s1+s2)]|+s3*|[r2+r2,s1+s2]| by EUCLID:62 .= |[r3*(r1+r2),r3*(s1+s2)]|+|[s3*(r2+r2),s3*(s1+s2)]| by EUCLID:62 .= |[r3*(r1+r2)+s3*(r2+r2),r3*(s1+s2)+s3*(s1+s2)]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A16: r3 > (1/2)*0 by REAL_1:70; 0 <> width G by GOBOARD1:def 5; then A17: 1 <= width G by RLVECT_1:99; i < i+1 by REAL_1:69; then A18: r1 < r2 by A1,A7,A17,GOBOARD5:4; then A19: r1+r1 < r1+r2 by REAL_1:53; then A20: r3*(r1+r1) < r3*(r1+r2) by A16,REAL_1:70; 0 <> len G by GOBOARD1:def 5; then A21: 1 <= len G by RLVECT_1:99; j < j+1 by REAL_1:69; then A22: s1 < s2 by A1,A6,A21,GOBOARD5:5; A23: s3 >= 0 by A3,REAL_2:121; r1+r2 < r2+r2 by A18,REAL_1:53; then r1+r1 < r2+r2 by A19,AXIOMS:22; then A24: s3*(r1+r1) <= s3*(r2+r2) by A23,AXIOMS:25; r3*(r1+r1)+s3*(r1+r1) = (r3+s3)*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A25: r1 < r3*(r1+r2)+s3*(r2+r2) by A20,A24,REAL_1:67; r1+r2 < r2+r2 by A18,REAL_1:53; then A26: r3*(r1+r2) < r3*(r2+r2) by A16,REAL_1:70; r3*(r2+r2)+s3*(r2+r2) = (r3+s3)*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A27: r3*(r1+r2)+s3*(r2+r2) < r2 by A26,REAL_1:67; A28: s1+s1 < s1+s2 by A22,REAL_1:53; then A29: r3*(s1+s1) < r3*(s1+s2) by A16,REAL_1:70; A30: s3*(s1+s1) <= s3*(s1+s2) by A23,A28,AXIOMS:25; r3*(s1+s1)+s3*(s1+s1) = (r3+s3)*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A13,XCMPLX_1:66; then A31: s1 < r3*(s1+s2)+s3*(s1+s2) by A29,A30,REAL_1:67; A32: s1+s2 < s2+s2 by A22,REAL_1:53; then A33: r3*(s1+s2) < r3*(s2+s2) by A16,REAL_1:70; A34: s3*(s1+s2) <= s3*(s2+s2) by A23,A32,AXIOMS:25; r3*(s2+s2)+s3*(s2+s2) = (r3+s3)*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A14,XCMPLX_1:66; then A35: r3*(s1+s2)+s3*(s1+s2) < s2 by A33,A34,REAL_1:67; Int cell(G,i,j) = { |[r',s']| : r1 < r' & r' < r2 & s1 < s' & s' < s2 } by A1,Th29; hence p in Int cell(G,i,j) by A15,A25,A27,A31,A35; end; hence x in Int cell(G,i,j) \/ { 1/2*(G*(i+1,j)+G* (i+1,j+1)) } by XBOOLE_0:def 2; end; theorem Th46: 1 <= i & i < len G & 1 <= j & j < width G implies LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i,j)+G*(i+1,j))) c= Int cell(G,i,j) \/ { 1/2*(G*(i,j)+G*(i+1,j)) } proof assume A1: 1 <= i & i < len G & 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i,j)+G*(i+1,j))); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,j)+G*(i+1,j+1)))+r*(1/2*(G*(i,j)+G*(i+1,j))) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(1/2*(G*(i,j)+G*(i+1,j))) by A4,EUCLID:33 .= 1*(1/2*(G*(i,j)+G*(i+1,j))) by EUCLID:31 .= 1/2*(G*(i,j)+G*(i+1,j)) by EUCLID:33; hence p in { 1/2*(G*(i,j)+G*(i+1,j)) } by TARSKI:def 1; case A5: r < 1; set r1 = G*(i,1)`1, r2 = G*(i+1,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; A7: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; A8: G*(i,j) = |[G*(i,j)`1,G*(i,j)`2]| by EUCLID:57 .= |[r1,G*(i,j)`2]| by A1,GOBOARD5:3 .= |[r1,s1]| by A1,GOBOARD5:2; A9: G*(i+1,j+1) = |[G*(i+1,j+1)`1,G*(i+1,j+1)`2]| by EUCLID:57 .= |[r2,G*(i+1,j+1)`2]| by A6,A7,GOBOARD5:3 .= |[r2,s2]| by A6,A7,GOBOARD5:2; A10: G*(i+1,j) = |[G*(i+1,j)`1,G*(i+1,j)`2]| by EUCLID:57 .= |[r2,G*(i+1,j)`2]| by A1,A7,GOBOARD5:3 .= |[r2,s1]| by A1,A7,GOBOARD5:2; set r3 = (1-r)*(1/2), s3 = r*(1/2); A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: (1/2)*s1 = s1/2 by XCMPLX_1:100; A14: (1/2)*s2 = s2/2 by XCMPLX_1:100; A15: p = r3*(G*(i,j)+G*(i+1,j+1))+r*(1/2*(G*(i,j)+G* (i+1,j))) by A4,EUCLID:34 .= r3*(G*(i,j)+G*(i+1,j+1))+s3*(G*(i,j)+G*(i+1,j)) by EUCLID:34 .= r3*|[r1+r2,s1+s2]|+s3*(G*(i,j)+G*(i+1,j)) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s1+s2]|+s3*|[r1+r2,s1+s1]| by A8,A10,EUCLID:60 .= |[r3*(r1+r2),r3*(s1+s2)]|+s3*|[r1+r2,s1+s1]| by EUCLID:62 .= |[r3*(r1+r2),r3*(s1+s2)]|+|[s3*(r1+r2),s3*(s1+s1)]| by EUCLID:62 .= |[r3*(r1+r2)+s3*(r1+r2),r3*(s1+s2)+s3*(s1+s1)]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A16: r3 > (1/2)*0 by REAL_1:70; 0 <> width G by GOBOARD1:def 5; then A17: 1 <= width G by RLVECT_1:99; i < i+1 by REAL_1:69; then A18: r1 < r2 by A1,A7,A17,GOBOARD5:4; then A19: r1+r1 < r1+r2 by REAL_1:53; then A20: r3*(r1+r1) < r3*(r1+r2) by A16,REAL_1:70; 0 <> len G by GOBOARD1:def 5; then A21: 1 <= len G by RLVECT_1:99; j < j+1 by REAL_1:69; then A22: s1 < s2 by A1,A6,A21,GOBOARD5:5; A23: s3 >= 0 by A3,REAL_2:121; then A24: s3*(r1+r1) <= s3*(r1+r2) by A19,AXIOMS:25; r3*(r1+r1)+s3*(r1+r1) = (r3+s3)*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A25: r1 < r3*(r1+r2)+s3*(r1+r2) by A20,A24,REAL_1:67; r1+r2 < r2+r2 by A18,REAL_1:53; then A26: r3*(r1+r2) < r3*(r2+r2) by A16,REAL_1:70; r1+r2 < r2+r2 by A18,REAL_1:67; then A27: s3*(r1+r2) <= s3*(r2+r2) by A23,AXIOMS:25; r3*(r2+r2)+s3*(r2+r2) = (r3+s3)*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A28: r3*(r1+r2)+s3*(r1+r2) < r2 by A26,A27,REAL_1:67; A29: s1+s1 < s1+s2 by A22,REAL_1:53; then A30: r3*(s1+s1) < r3*(s1+s2) by A16,REAL_1:70; r3*(s1+s1)+s3*(s1+s1) = (r3+s3)*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A13,XCMPLX_1:66; then A31: s1 < r3*(s1+s2)+s3*(s1+s1) by A30,REAL_1:67; s1+s2 < s2+s2 by A22,REAL_1:53; then A32: r3*(s1+s2) < r3*(s2+s2) by A16,REAL_1:70; s1+s2 < s2+s2 by A22,REAL_1:53; then s1+s1 < s2+s2 by A29,AXIOMS:22; then A33: s3*(s1+s1) <= s3*(s2+s2) by A23,AXIOMS:25; r3*(s2+s2)+s3*(s2+s2) = (r3+s3)*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A14,XCMPLX_1:66; then A34: r3*(s1+s2)+s3*(s1+s1) < s2 by A32,A33,REAL_1:67; Int cell(G,i,j) = { |[r',s']| : r1 < r' & r' < r2 & s1 < s' & s' < s2 } by A1,Th29; hence p in Int cell(G,i,j) by A15,A25,A28,A31,A34; end; hence x in Int cell(G,i,j) \/ { 1/2*(G*(i,j)+G*(i+1,j)) } by XBOOLE_0:def 2; end; theorem Th47: 1 <= j & j < width G implies LSeg(1/2*(G*(1,j)+G*(1,j+1)) - |[1,0]|,1/2*(G*(1,j)+G*(1,j+1))) c= Int cell(G,0,j) \/ { 1/2*(G*(1,j)+G*(1,j+1)) } proof assume A1: 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|,1/2*(G*(1,j)+G*(1,j+1))); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|)+r*(1/2*(G*(1,j)+G* (1,j+1))) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(1/2*(G*(1,j)+G*(1,j+1))) by A4,EUCLID:33 .= 1*(1/2*(G*(1,j)+G*(1,j+1))) by EUCLID:31 .= 1/2*(G*(1,j)+G*(1,j+1)) by EUCLID:33; hence p in { 1/2*(G*(1,j)+G*(1,j+1)) } by TARSKI:def 1; case A5: r < 1; set r2 = G*(1,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(1,j+1) = |[G*(1,j+1)`1,G*(1,j+1)`2]| by EUCLID:57 .= |[r2,s2]| by A6,A7,GOBOARD5:3; A9: G*(1,j) = |[G*(1,j)`1,G*(1,j)`2]| by EUCLID:57 .= |[r2,s1]| by A1,A7,GOBOARD5:3; set r3 = (1-r)*(1/2), s3 = r*(1/2); A10: (1/2)*r2 = r2/2 by XCMPLX_1:100; A11: (1/2)*s1 = s1/2 by XCMPLX_1:100; A12: (1/2)*s2 = s2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(1,j)+G*(1,j+1)))-(1-r)*|[1,0]| +r*(1/2*(G*(1,j)+G*(1,j+1))) by A4,EUCLID:53 .= r3*(G*(1,j)+G*(1,j+1))-(1-r)*|[1,0]|+r*(1/2*(G*(1,j)+G*(1,j+1))) by EUCLID:34 .= r3*(G*(1,j)+G*(1,j+1))-|[(1-r)*1,(1-r)*0]|+r*(1/2*(G*(1,j)+G* (1,j+1))) by EUCLID:62 .= r3*(G*(1,j)+G*(1,j+1))-|[1-r,0]|+s3*(G*(1,j)+G* (1,j+1)) by EUCLID:34 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+s3*(G*(1,j)+G*(1,j+1)) by A8,A9,EUCLID:60 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+s3*|[r2+r2,s1+s2]| by A8,A9,EUCLID:60 .= |[r3*(r2+r2),r3*(s1+s2)]|-|[1-r,0]|+s3*|[r2+r2,s1+s2]| by EUCLID:62 .= |[r3*(r2+r2),r3*(s1+s2)]|-|[1-r,0]|+|[s3*(r2+r2),s3*(s1+s2)]| by EUCLID:62 .= |[r3*(r2+r2)-(1-r),r3*(s1+s2)-0]|+|[s3*(r2+r2),s3*(s1+s2)]| by EUCLID:66 .= |[r3*(r2+r2)-(1-r)+s3*(r2+r2),r3*(s1+s2)+s3*(s1+s2)]| by EUCLID:60; A14: 1 - r > 0 by A5,SQUARE_1:11; then A15: r3 > (1/2)*0 by REAL_1:70; j < j+1 by REAL_1:69; then A16: s1 < s2 by A1,A6,A7,GOBOARD5:5; A17: s3 >= 0 by A3,REAL_2:121; r2 < r2+(1-r) by A14,REAL_1:69; then A18: r2-(1-r) < r2 by REAL_1:84; A19: r3*(r2+r2)-(1-r)+s3*(r2+r2) = r3*(r2+r2)+s3*(r2+r2)-(1-r) by XCMPLX_1:29 .= (r3+s3)*(r2+r2)-(1-r) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2)-(1-r) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2)-(1-r) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2-(1-r) by XCMPLX_1:8 .= r2-(1-r) by A10,XCMPLX_1:66; A20: s1+s1 < s1+s2 by A16,REAL_1:53; then A21: r3*(s1+s1) < r3*(s1+s2) by A15,REAL_1:70; A22: s3*(s1+s1) <= s3*(s1+s2) by A17,A20,AXIOMS:25; r3*(s1+s1)+s3*(s1+s1) = (r3+s3)*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A11,XCMPLX_1:66; then A23: s1 < r3*(s1+s2)+s3*(s1+s2) by A21,A22,REAL_1:67; A24: s1+s2 < s2+s2 by A16,REAL_1:53; then A25: r3*(s1+s2) < r3*(s2+s2) by A15,REAL_1:70; A26: s3*(s1+s2) <= s3*(s2+s2) by A17,A24,AXIOMS:25; r3*(s2+s2)+s3*(s2+s2) = (r3+s3)*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A12,XCMPLX_1:66; then A27: r3*(s1+s2)+s3*(s1+s2) < s2 by A25,A26,REAL_1:67; Int cell(G,0,j) = { |[r',s']| : r' < G*(1,1)`1 & G*(1,j)`2 < s' & s' < G*(1,j+1)`2 } by A1,Th23; hence p in Int cell(G,0,j) by A13,A18,A19,A23,A27; end; hence x in Int cell(G,0,j) \/ { 1/2*(G*(1,j)+G*(1,j+1)) } by XBOOLE_0:def 2; end; theorem Th48: 1 <= j & j < width G implies LSeg(1/2*(G*(len G,j)+G*(len G,j+1)) + |[1,0]|,1/2*(G*(len G,j)+G*(len G,j+1))) c= Int cell(G,len G,j) \/ { 1/2*(G*(len G,j)+G*(len G,j+1)) } proof assume A1: 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|, 1/2*(G*(len G,j)+G*(len G,j+1))); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|) +r*(1/2*(G*(len G,j)+G*(len G,j+1))) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(1/2*(G*(len G,j)+G*(len G,j+1))) by A4,EUCLID:33 .= 1*(1/2*(G*(len G,j)+G*(len G,j+1))) by EUCLID:31 .= 1/2*(G*(len G,j)+G*(len G,j+1)) by EUCLID:33; hence p in { 1/2*(G*(len G,j)+G*(len G,j+1)) } by TARSKI:def 1; case A5: r < 1; set r2 = G*(len G,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(len G,j+1) = |[G*(len G,j+1)`1,G*(len G,j+1)`2]| by EUCLID:57 .= |[r2,G*(len G,j+1)`2]| by A6,A7,GOBOARD5:3 .= |[r2,s2]| by A6,A7,GOBOARD5:2; A9: G*(len G,j) = |[G*(len G,j)`1,G*(len G,j)`2]| by EUCLID:57 .= |[r2,G*(len G,j)`2]| by A1,A7,GOBOARD5:3 .= |[r2,s1]| by A1,A7,GOBOARD5:2; set r3 = (1-r)*(1/2), s3 = r*(1/2); A10: (1/2)*r2 = r2/2 by XCMPLX_1:100; A11: (1/2)*s1 = s1/2 by XCMPLX_1:100; A12: (1/2)*s2 = s2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(len G,j)+G*(len G,j+1)))+(1-r)*|[1,0]| +r*(1/2*(G*(len G,j)+G*(len G,j+1))) by A4,EUCLID:36 .= r3*(G*(len G,j)+G*(len G,j+1))+(1-r)*|[1,0]|+ r*(1/2*(G*(len G,j)+G*(len G,j+1))) by EUCLID:34 .= r3*(G*(len G,j)+G*(len G,j+1))+|[(1-r)*1,(1-r)*0]|+ r*(1/2*(G*(len G,j)+G*(len G,j+1))) by EUCLID:62 .= r3*(G*(len G,j)+G*(len G,j+1))+|[1-r,0]|+ s3*(G*(len G,j)+G*(len G,j+1)) by EUCLID:34 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+s3*(G*(len G,j)+G*(len G,j+1)) by A8,A9,EUCLID:60 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+s3*|[r2+r2,s1+s2]| by A8,A9,EUCLID:60 .= |[r3*(r2+r2),r3*(s1+s2)]|+|[1-r,0]|+s3*|[r2+r2,s1+s2]| by EUCLID:62 .= |[r3*(r2+r2),r3*(s1+s2)]|+|[1-r,0]|+|[s3*(r2+r2),s3*(s1+s2)]| by EUCLID:62 .= |[r3*(r2+r2)+(1-r),r3*(s1+s2)+0]|+|[s3*(r2+r2),s3*(s1+s2)]| by EUCLID:60 .= |[r3*(r2+r2)+(1-r)+s3*(r2+r2),r3*(s1+s2)+s3*(s1+s2)]| by EUCLID:60; A14: 1 - r > 0 by A5,SQUARE_1:11; then A15: r3 > (1/2)*0 by REAL_1:70; j < j+1 by REAL_1:69; then A16: s1 < s2 by A1,A6,A7,GOBOARD5:5; A17: s3 >= 0 by A3,REAL_2:121; A18: r2+(1-r) > r2 by A14,REAL_1:69; A19: r3*(r2+r2)+(1-r)+s3*(r2+r2) = r3*(r2+r2)+s3*(r2+r2)+(1-r) by XCMPLX_1:1 .= (r3+s3)*(r2+r2)+(1-r) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2)+(1-r) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2)+(1-r) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2+(1-r) by XCMPLX_1:8 .= r2+(1-r) by A10,XCMPLX_1:66; A20: s1+s1 < s1+s2 by A16,REAL_1:53; then A21: r3*(s1+s1) < r3*(s1+s2) by A15,REAL_1:70; A22: s3*(s1+s1) <= s3*(s1+s2) by A17,A20,AXIOMS:25; r3*(s1+s1)+s3*(s1+s1) = (r3+s3)*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A11,XCMPLX_1:66; then A23: s1 < r3*(s1+s2)+s3*(s1+s2) by A21,A22,REAL_1:67; A24: s1+s2 < s2+s2 by A16,REAL_1:53; then A25: r3*(s1+s2) < r3*(s2+s2) by A15,REAL_1:70; A26: s3*(s1+s2) <= s3*(s2+s2) by A17,A24,AXIOMS:25; r3*(s2+s2)+s3*(s2+s2) = (r3+s3)*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A12,XCMPLX_1:66; then A27: r3*(s1+s2)+s3*(s1+s2) < s2 by A25,A26,REAL_1:67; Int cell(G,len G,j) = { |[r',s']| : G*(len G,1)`1 < r' & G*(1,j)`2 < s' & s' < G*(1,j+1)`2 } by A1,Th26; hence p in Int cell(G,len G,j) by A13,A18,A19,A23,A27; end; hence x in Int cell(G,len G,j) \/ { 1/2*(G*(len G,j)+G*(len G,j+1)) } by XBOOLE_0:def 2; end; theorem Th49: 1 <= i & i < len G implies LSeg(1/2*(G*(i,1)+G*(i+1,1)) - |[0,1]|,1/2*(G*(i,1)+G*(i+1,1))) c= Int cell(G,i,0) \/ { 1/2*(G*(i,1)+G*(i+1,1)) } proof assume A1: 1 <= i & i < len G; let x be set; assume A2: x in LSeg(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|,1/2*(G*(i,1)+G*(i+1,1))); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|)+r*(1/2*(G*(i,1)+G* (i+1,1))) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(1/2*(G*(i,1)+G*(i+1,1))) by A4,EUCLID:33 .= 1*(1/2*(G*(i,1)+G*(i+1,1))) by EUCLID:31 .= 1/2*(G*(i,1)+G*(i+1,1)) by EUCLID:33; hence p in { 1/2*(G*(i,1)+G*(i+1,1)) } by TARSKI:def 1; case A5: r < 1; set s2 = G*(1,1)`2, r1 = G*(i,1)`1, r2 = G*(i+1,1)`1; A6: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; 0 <> width G by GOBOARD1:def 5; then A7: 1 <= width G by RLVECT_1:99; A8: G*(i+1,1) = |[G*(i+1,1)`1,G*(i+1,1)`2]| by EUCLID:57 .= |[r2,s2]| by A6,A7,GOBOARD5:2; A9: G*(i,1) = |[G*(i,1)`1,G*(i,1)`2]| by EUCLID:57 .= |[r1,s2]| by A1,A7,GOBOARD5:2; set r3 = (1-r)*(1/2), s3 = r*(1/2); A10: (1/2)*s2 = s2/2 by XCMPLX_1:100; A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(i,1)+G*(i+1,1)))-(1-r)*|[0,1]| +r*(1/2*(G*(i,1)+G*(i+1,1))) by A4,EUCLID:53 .= r3*(G*(i,1)+G*(i+1,1))-(1-r)*|[0,1]|+r*(1/2*(G*(i,1)+G*(i+1,1))) by EUCLID:34 .= r3*(G*(i,1)+G*(i+1,1))-|[(1-r)*0,(1-r)*1]|+r*(1/2*(G*(i,1)+G* (i+1,1))) by EUCLID:62 .= r3*(G*(i,1)+G*(i+1,1))-|[0,1-r]|+s3*(G*(i,1)+G* (i+1,1)) by EUCLID:34 .= r3*|[r1+r2,s2+s2]|-|[0,1-r]|+s3*(G*(i,1)+G*(i+1,1)) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s2+s2]|-|[0,1-r]|+s3*|[r1+r2,s2+s2]| by A8,A9,EUCLID:60 .= |[r3*(r1+r2),r3*(s2+s2)]|-|[0,1-r]|+s3*|[r1+r2,s2+s2]| by EUCLID:62 .= |[r3*(r1+r2),r3*(s2+s2)]|-|[0,1-r]|+|[s3*(r1+r2),s3*(s2+s2)]| by EUCLID:62 .= |[r3*(r1+r2)-0,r3*(s2+s2)-(1-r)]|+|[s3*(r1+r2),s3*(s2+s2)]| by EUCLID:66 .= |[r3*(r1+r2)+s3*(r1+r2),r3*(s2+s2)-(1-r)+s3*(s2+s2)]| by EUCLID:60; A14: 1 - r > 0 by A5,SQUARE_1:11; then A15: r3 > (1/2)*0 by REAL_1:70; i < i+1 by REAL_1:69; then A16: r1 < r2 by A1,A6,A7,GOBOARD5:4; A17: s3 >= 0 by A3,REAL_2:121; s2 < s2+(1-r) by A14,REAL_1:69; then A18: s2-(1-r) < s2 by REAL_1:84; A19: r3*(s2+s2)-(1-r)+s3*(s2+s2) = r3*(s2+s2)+s3*(s2+s2)-(1-r) by XCMPLX_1:29 .= (r3+s3)*(s2+s2)-(1-r) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2)-(1-r) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2)-(1-r) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2-(1-r) by XCMPLX_1:8 .= s2-(1-r) by A10,XCMPLX_1:66; A20: r1+r1 < r1+r2 by A16,REAL_1:53; then A21: r3*(r1+r1) < r3*(r1+r2) by A15,REAL_1:70; A22: s3*(r1+r1) <= s3*(r1+r2) by A17,A20,AXIOMS:25; r3*(r1+r1)+s3*(r1+r1) = (r3+s3)*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A23: r1 < r3*(r1+r2)+s3*(r1+r2) by A21,A22,REAL_1:67; A24: r1+r2 < r2+r2 by A16,REAL_1:53; then A25: r3*(r1+r2) < r3*(r2+r2) by A15,REAL_1:70; A26: s3*(r1+r2) <= s3*(r2+r2) by A17,A24,AXIOMS:25; r3*(r2+r2)+s3*(r2+r2) = (r3+s3)*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A27: r3*(r1+r2)+s3*(r1+r2) < r2 by A25,A26,REAL_1:67; Int cell(G,i,0) = { |[r',s']| : G*(i,1)`1 < r' & r' < G*(i+1,1)`1 & s' < G*(1,1)`2 } by A1,Th27; hence p in Int cell(G,i,0) by A13,A18,A19,A23,A27; end; hence x in Int cell(G,i,0) \/ { 1/2*(G*(i,1)+G*(i+1,1)) } by XBOOLE_0:def 2; end; theorem Th50: 1 <= i & i < len G implies LSeg(1/2*(G*(i,width G)+G*(i+1,width G))+ |[0,1]|, 1/2*(G*(i,width G)+G*(i+1,width G))) c= Int cell(G,i,width G) \/ { 1/2*(G*(i,width G)+G*(i+1,width G)) } proof assume A1: 1 <= i & i < len G; let x be set; assume A2: x in LSeg(1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|, 1/2*(G*(i,width G)+G*(i+1,width G))); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|) +r*(1/2*(G*(i,width G)+G*(i+1,width G))) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(1/2*(G*(i,width G)+G*(i+1,width G))) by A4,EUCLID: 33 .= 1*(1/2*(G*(i,width G)+G*(i+1,width G))) by EUCLID:31 .= 1/2*(G*(i,width G)+G*(i+1,width G)) by EUCLID:33; hence p in { 1/2*(G*(i,width G)+G*(i+1,width G)) } by TARSKI:def 1; case A5: r < 1; set s2 = G*(1,width G)`2, r1 = G*(i,1)`1, r2 = G*(i+1,1)`1; A6: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; 0 <> width G by GOBOARD1:def 5; then A7: 1 <= width G by RLVECT_1:99; A8: G*(i+1,width G) = |[G*(i+1,width G)`1,G*(i+1,width G)`2]| by EUCLID:57 .= |[G*(i+1,width G)`1,s2]| by A6,A7,GOBOARD5:2 .= |[r2,s2]| by A6,A7,GOBOARD5:3; A9: G*(i,width G) = |[G*(i,width G)`1,G*(i,width G)`2]| by EUCLID:57 .= |[G*(i,width G)`1,s2]| by A1,A7,GOBOARD5:2 .= |[r1,s2]| by A1,A7,GOBOARD5:3; set r3 = (1-r)*(1/2), s3 = r*(1/2); A10: (1/2)*s2 = s2/2 by XCMPLX_1:100; A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(i,width G)+G*(i+1,width G)))+(1-r)*|[0,1]| +r*(1/2*(G*(i,width G)+G* (i+1,width G))) by A4,EUCLID:36 .= r3*(G*(i,width G)+G*(i+1,width G))+(1-r)*|[0,1]|+ r*(1/2*(G*(i,width G)+G*(i+1,width G))) by EUCLID:34 .= r3*(G*(i,width G)+G*(i+1,width G))+|[(1-r)*0,(1-r)*1]|+ r*(1/2*(G*(i,width G)+G*(i+1,width G))) by EUCLID:62 .= r3*(G*(i,width G)+G*(i+1,width G))+|[0,1-r]|+ s3*(G*(i,width G)+G*(i+1,width G)) by EUCLID:34 .= r3*|[r1+r2,s2+s2]|+|[0,1-r]|+s3*(G*(i,width G)+G*(i+1,width G)) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s2+s2]|+|[0,1-r]|+s3*|[r1+r2,s2+s2]| by A8,A9,EUCLID:60 .= |[r3*(r1+r2),r3*(s2+s2)]|+|[0,1-r]|+s3*|[r1+r2,s2+s2]| by EUCLID:62 .= |[r3*(r1+r2),r3*(s2+s2)]|+|[0,1-r]|+|[s3*(r1+r2),s3*(s2+s2)]| by EUCLID:62 .= |[r3*(r1+r2)+0,r3*(s2+s2)+(1-r)]|+|[s3*(r1+r2),s3*(s2+s2)]| by EUCLID:60 .= |[r3*(r1+r2)+s3*(r1+r2),r3*(s2+s2)+(1-r)+s3*(s2+s2)]| by EUCLID:60; A14: 1 - r > 0 by A5,SQUARE_1:11; then A15: r3 > (1/2)*0 by REAL_1:70; i < i+1 by REAL_1:69; then A16: r1 < r2 by A1,A6,A7,GOBOARD5:4; A17: s3 >= 0 by A3,REAL_2:121; A18: s2+(1-r) > s2 by A14,REAL_1:69; A19: r3*(s2+s2)+(1-r)+s3*(s2+s2) = r3*(s2+s2)+s3*(s2+s2)+(1-r) by XCMPLX_1:1 .= (r3+s3)*(s2+s2)+(1-r) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2)+(1-r) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2)+(1-r) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2+(1-r) by XCMPLX_1:8 .= s2+(1-r) by A10,XCMPLX_1:66; A20: r1+r1 < r1+r2 by A16,REAL_1:53; then A21: r3*(r1+r1) < r3*(r1+r2) by A15,REAL_1:70; A22: s3*(r1+r1) <= s3*(r1+r2) by A17,A20,AXIOMS:25; r3*(r1+r1)+s3*(r1+r1) = (r3+s3)*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A23: r1 < r3*(r1+r2)+s3*(r1+r2) by A21,A22,REAL_1:67; A24: r1+r2 < r2+r2 by A16,REAL_1:53; then A25: r3*(r1+r2) < r3*(r2+r2) by A15,REAL_1:70; A26: s3*(r1+r2) <= s3*(r2+r2) by A17,A24,AXIOMS:25; r3*(r2+r2)+s3*(r2+r2) = (r3+s3)*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A27: r3*(r1+r2)+s3*(r1+r2) < r2 by A25,A26,REAL_1:67; Int cell(G,i,width G) = { |[r',s']| : G*(i,1)`1 < r' & r' < G*(i+1,1)`1 & G* (1,width G)`2 < s' } by A1,Th28; hence p in Int cell(G,i,width G) by A13,A18,A19,A23,A27; end; hence x in Int cell(G,i,width G) \/ { 1/2*(G*(i,width G)+G*(i+1,width G)) } by XBOOLE_0:def 2; end; theorem Th51: 1 <= j & j < width G implies LSeg(1/2*(G*(1,j)+G*(1,j+1)) - |[1,0]|,G*(1,j) - |[1,0]|) c= Int cell(G,0,j) \/ { G*(1,j) - |[1,0]| } proof assume A1: 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|,G*(1,j) - |[1,0]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|)+r*(G*(1,j) - |[1,0]|) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(1,j) - |[1,0]|) by A4,EUCLID:33 .= 1*(G*(1,j) - |[1,0]|) by EUCLID:31 .= (G*(1,j) - |[1,0]|) by EUCLID:33; hence p in { G*(1,j) - |[1,0]| } by TARSKI:def 1; case A5: r < 1; set r2 = G*(1,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(1,j+1) = |[G*(1,j+1)`1,G*(1,j+1)`2]| by EUCLID:57 .= |[r2,s2]| by A6,A7,GOBOARD5:3; A9: G*(1,j) = |[G*(1,j)`1,G*(1,j)`2]| by EUCLID:57 .= |[r2,s1]| by A1,A7,GOBOARD5:3; set r3 = (1-r)*(1/2); A10: (1/2)*r2 = r2/2 by XCMPLX_1:100; A11: (1/2)*s1 = s1/2 by XCMPLX_1:100; A12: (1/2)*s2 = s2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(1,j)+G*(1,j+1)))-(1-r)*|[1,0]| +r*(G*(1,j) - |[1,0]|) by A4,EUCLID:53 .= r3*(G*(1,j)+G*(1,j+1))-(1-r)*|[1,0]|+r*(G* (1,j) - |[1,0]|) by EUCLID:34 .= r3*(G*(1,j)+G*(1,j+1))-|[(1-r)*1,(1-r)*0]|+r*(G*(1,j) - |[1,0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+r*(|[r2,s1]| - |[1,0]|) by A8,A9,EUCLID:60 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+(r*|[r2,s1]| - r*|[1,0]|) by EUCLID:53 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+(|[r*r2,r*s1]| - r*|[1,0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+(|[r*r2,r*s1]| - |[r*1,r*0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+|[r*r2-r,r*s1-0]| by EUCLID:66 .= |[r3*(r2+r2),r3*(s1+s2)]|-|[1-r,0]|+|[r*r2-r,r*s1-0]| by EUCLID:62 .= |[r3*(r2+r2)-(1-r),r3*(s1+s2)-0]|+|[r*r2-r,r*s1-0]| by EUCLID:66 .= |[r3*(r2+r2)-(1-r)+(r*r2-r),r3*(s1+s2)+r*s1]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A14: r3 > (1/2)*0 by REAL_1:70; j < j+1 by REAL_1:69; then A15: s1 < s2 by A1,A6,A7,GOBOARD5:5; r2 < r2+1 by REAL_1:69; then A16: r2-1 < r2 by REAL_1:84; A17: r3*(r2+r2)-(1-r)+(r*r2-r) = (1-r)*((1/2)*(r2+r2))-(1-r)+(r*r2-r) by XCMPLX_1:4 .= (1-r)*((1/2)*r2+(1/2)*r2)-(1-r)+(r*r2-r) by XCMPLX_1:8 .= (1-r)*r2-(1-r)+(r*r2-r) by A10,XCMPLX_1:66 .= (1-r)*r2-(1-r)+r*r2-r by XCMPLX_1:29 .= (1-r)*r2+r*r2-(1-r)-r by XCMPLX_1:29 .= ((1-r)+r)*r2-(1-r)-r by XCMPLX_1:8 .= 1*r2-(1-r)-r by XCMPLX_1:27 .= r2-((1-r)+r) by XCMPLX_1:36 .= r2-1 by XCMPLX_1:27; s1+s1 < s1+s2 by A15,REAL_1:53; then A18: r3*(s1+s1) < r3*(s1+s2) by A14,REAL_1:70; r3*(s1+s1)+r*s1 = r3*(s1+s1)+r*(1/2*s1+1/2*s1) by A11,XCMPLX_1:66 .= r3*(s1+s1)+r*((1/2)*(s1+s1)) by XCMPLX_1:8 .= r3*(s1+s1)+(r*(1/2))*(s1+s1) by XCMPLX_1:4 .= (r3+r*(1/2))*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A11,XCMPLX_1:66; then A19: s1 < r3*(s1+s2)+r*s1 by A18,REAL_1:53; s1+s2 < s2+s2 by A15,REAL_1:53; then A20: r3*(s1+s2) < r3*(s2+s2) by A14,REAL_1:70; A21: r*s1 <= r*s2 by A3,A15,AXIOMS:25; r3*(s2+s2)+r*s2 = r3*(s2+s2)+r*(1/2*s2+1/2*s2) by A12,XCMPLX_1:66 .= r3*(s2+s2)+r*((1/2)*(s2+s2)) by XCMPLX_1:8 .= r3*(s2+s2)+(r*(1/2))*(s2+s2) by XCMPLX_1:4 .= (r3+r*(1/2))*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A12,XCMPLX_1:66; then A22: r3*(s1+s2)+r*s1 < s2 by A20,A21,REAL_1:67; Int cell(G,0,j) = { |[r',s']| : r' < G*(1,1)`1 & G*(1,j)`2 < s' & s' < G*(1,j+1)`2 } by A1,Th23; hence p in Int cell(G,0,j) by A13,A16,A17,A19,A22; end; hence x in Int cell(G,0,j) \/ { G*(1,j) - |[1,0]| } by XBOOLE_0:def 2; end; theorem Th52: 1 <= j & j < width G implies LSeg(1/2*(G*(1,j)+G*(1,j+1)) - |[1,0]|,G*(1,j+1) - |[1,0]|) c= Int cell(G,0,j) \/ { G*(1,j+1) - |[1,0]| } proof assume A1: 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|,G*(1,j+1) - |[1,0]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|)+r*(G*(1,j+1) - |[1,0]|) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(1,j+1) - |[1,0]|) by A4,EUCLID:33 .= 1*(G*(1,j+1) - |[1,0]|) by EUCLID:31 .= (G*(1,j+1) - |[1,0]|) by EUCLID:33; hence p in { G*(1,j+1) - |[1,0]| } by TARSKI:def 1; case A5: r < 1; set r2 = G*(1,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(1,j+1) = |[G*(1,j+1)`1,G*(1,j+1)`2]| by EUCLID:57 .= |[r2,s2]| by A6,A7,GOBOARD5:3; A9: G*(1,j) = |[G*(1,j)`1,G*(1,j)`2]| by EUCLID:57 .= |[r2,s1]| by A1,A7,GOBOARD5:3; set r3 = (1-r)*(1/2); A10: (1/2)*r2 = r2/2 by XCMPLX_1:100; A11: (1/2)*s1 = s1/2 by XCMPLX_1:100; A12: (1/2)*s2 = s2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(1,j)+G*(1,j+1)))-(1-r)*|[1,0]| +r*(G*(1,j+1) - |[1,0]|) by A4,EUCLID:53 .= r3*(G*(1,j)+G*(1,j+1))-(1-r)*|[1,0]|+r*(G*(1,j+1) - |[1,0]|) by EUCLID:34 .= r3*(G*(1,j)+G*(1,j+1))-|[(1-r)*1,(1-r)*0]|+r*(G*(1,j+1) - |[1,0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+r*(|[r2,s2]| - |[1,0]|) by A8,A9,EUCLID:60 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+(r*|[r2,s2]| - r*|[1,0]|) by EUCLID:53 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+(|[r*r2,r*s2]| - r*|[1,0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+(|[r*r2,r*s2]| - |[r*1,r*0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|-|[1-r,0]|+|[r*r2-r,r*s2-0]| by EUCLID:66 .= |[r3*(r2+r2),r3*(s1+s2)]|-|[1-r,0]|+|[r*r2-r,r*s2-0]| by EUCLID:62 .= |[r3*(r2+r2)-(1-r),r3*(s1+s2)-0]|+|[r*r2-r,r*s2-0]| by EUCLID:66 .= |[r3*(r2+r2)-(1-r)+(r*r2-r),r3*(s1+s2)+r*s2]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A14: r3 > (1/2)*0 by REAL_1:70; j < j+1 by REAL_1:69; then A15: s1 < s2 by A1,A6,A7,GOBOARD5:5; r2 < r2+1 by REAL_1:69; then A16: r2-1 < r2 by REAL_1:84; A17: r3*(r2+r2)-(1-r)+(r*r2-r) = (1-r)*((1/2)*(r2+r2))-(1-r)+(r*r2-r) by XCMPLX_1:4 .= (1-r)*((1/2)*r2+(1/2)*r2)-(1-r)+(r*r2-r) by XCMPLX_1:8 .= (1-r)*r2-(1-r)+(r*r2-r) by A10,XCMPLX_1:66 .= (1-r)*r2-(1-r)+r*r2-r by XCMPLX_1:29 .= (1-r)*r2+r*r2-(1-r)-r by XCMPLX_1:29 .= ((1-r)+r)*r2-(1-r)-r by XCMPLX_1:8 .= 1*r2-(1-r)-r by XCMPLX_1:27 .= r2-((1-r)+r) by XCMPLX_1:36 .= r2-1 by XCMPLX_1:27; s1+s1 < s1+s2 by A15,REAL_1:53; then A18: r3*(s1+s1) < r3*(s1+s2) by A14,REAL_1:70; A19: r*s1 <= r*s2 by A3,A15,AXIOMS:25; r3*(s1+s1)+r*s1 = r3*(s1+s1)+r*(1/2*s1+1/2*s1) by A11,XCMPLX_1:66 .= r3*(s1+s1)+r*((1/2)*(s1+s1)) by XCMPLX_1:8 .= r3*(s1+s1)+(r*(1/2))*(s1+s1) by XCMPLX_1:4 .= (r3+r*(1/2))*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A11,XCMPLX_1:66; then A20: s1 < r3*(s1+s2)+r*s2 by A18,A19,REAL_1:67; s1+s2 < s2+s2 by A15,REAL_1:53; then A21: r3*(s1+s2) < r3*(s2+s2) by A14,REAL_1:70; r3*(s2+s2)+r*s2 = r3*(s2+s2)+r*(1/2*s2+1/2*s2) by A12,XCMPLX_1:66 .= r3*(s2+s2)+r*((1/2)*(s2+s2)) by XCMPLX_1:8 .= r3*(s2+s2)+(r*(1/2))*(s2+s2) by XCMPLX_1:4 .= (r3+r*(1/2))*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A12,XCMPLX_1:66; then A22: r3*(s1+s2)+r*s2 < s2 by A21,REAL_1:67; Int cell(G,0,j) = { |[r',s']| : r' < G*(1,1)`1 & G*(1,j)`2 < s' & s' < G*(1,j+1)`2 } by A1,Th23; hence p in Int cell(G,0,j) by A13,A16,A17,A20,A22; end; hence x in Int cell(G,0,j) \/ { G*(1,j+1) - |[1,0]| } by XBOOLE_0:def 2; end; theorem Th53: 1 <= j & j < width G implies LSeg(1/2*(G*(len G,j)+G*(len G,j+1)) + |[1,0]|,G*(len G,j) + |[1,0]|) c= Int cell(G,len G,j) \/ { G*(len G,j) + |[1,0]| } proof assume A1: 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|,G* (len G,j) + |[1,0]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|)+ r*(G*(len G,j) + |[1,0]|) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(len G,j) + |[1,0]|) by A4,EUCLID:33 .= 1*(G*(len G,j) + |[1,0]|) by EUCLID:31 .= (G*(len G,j) + |[1,0]|) by EUCLID:33; hence p in { G*(len G,j) + |[1,0]| } by TARSKI:def 1; case A5: r < 1; set r2 = G*(len G,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(len G,j+1) = |[G*(len G,j+1)`1,G*(len G,j+1)`2]| by EUCLID:57 .= |[r2,G*(len G,j+1)`2]| by A6,A7,GOBOARD5:3 .= |[r2,s2]| by A6,A7,GOBOARD5:2; A9: G*(len G,j) = |[G*(len G,j)`1,G*(len G,j)`2]| by EUCLID:57 .= |[r2,G*(len G,j)`2]| by A1,A7,GOBOARD5:3 .= |[r2,s1]| by A1,A7,GOBOARD5:2; set r3 = (1-r)*(1/2); A10: (1/2)*r2 = r2/2 by XCMPLX_1:100; A11: (1/2)*s1 = s1/2 by XCMPLX_1:100; A12: (1/2)*s2 = s2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(len G,j)+G*(len G,j+1)))+(1-r)*|[1,0]| +r*(G*(len G,j) + |[1,0]|) by A4,EUCLID:36 .= r3*(G*(len G,j)+G*(len G,j+1))+(1-r)*|[1,0]|+r*(G* (len G,j) + |[1,0]|) by EUCLID:34 .= r3*(G*(len G,j)+G*(len G,j+1))+|[(1-r)*1,(1-r)*0]|+ r*(G*(len G,j) + |[1,0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+r*(|[r2,s1]| + |[1,0]|) by A8,A9,EUCLID:60 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+(r*|[r2,s1]| + r*|[1,0]|) by EUCLID:36 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+(|[r*r2,r*s1]| + r*|[1,0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+(|[r*r2,r*s1]| + |[r*1,r*0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+|[r*r2+r,r*s1+0]| by EUCLID:60 .= |[r3*(r2+r2),r3*(s1+s2)]|+|[1-r,0]|+|[r*r2+r,r*s1+0]| by EUCLID:62 .= |[r3*(r2+r2)+(1-r),r3*(s1+s2)+0]|+|[r*r2+r,r*s1+0]| by EUCLID:60 .= |[r3*(r2+r2)+(1-r)+(r*r2+r),r3*(s1+s2)+r*s1]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A14: r3 > (1/2)*0 by REAL_1:70; j < j+1 by REAL_1:69; then A15: s1 < s2 by A1,A6,A7,GOBOARD5:5; A16: r2 < r2+1 by REAL_1:69; A17: r3*(r2+r2)+(1-r)+(r*r2+r) = (1-r)*((1/2)*(r2+r2))+(1-r)+(r*r2+r) by XCMPLX_1:4 .= (1-r)*((1/2)*r2+(1/2)*r2)+(1-r)+(r*r2+r) by XCMPLX_1:8 .= (1-r)*r2+(1-r)+(r*r2+r) by A10,XCMPLX_1:66 .= (1-r)*r2+(1-r)+r*r2+r by XCMPLX_1:1 .= (1-r)*r2+r*r2+(1-r)+r by XCMPLX_1:1 .= ((1-r)+r)*r2+(1-r)+r by XCMPLX_1:8 .= 1*r2+(1-r)+r by XCMPLX_1:27 .= r2+((1-r)+r) by XCMPLX_1:1 .= r2+1 by XCMPLX_1:27; s1+s1 < s1+s2 by A15,REAL_1:53; then A18: r3*(s1+s1) < r3*(s1+s2) by A14,REAL_1:70; r3*(s1+s1)+r*s1 = r3*(s1+s1)+r*(1/2*s1+1/2*s1) by A11,XCMPLX_1:66 .= r3*(s1+s1)+r*((1/2)*(s1+s1)) by XCMPLX_1:8 .= r3*(s1+s1)+(r*(1/2))*(s1+s1) by XCMPLX_1:4 .= (r3+r*(1/2))*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A11,XCMPLX_1:66; then A19: s1 < r3*(s1+s2)+r*s1 by A18,REAL_1:53; s1+s2 < s2+s2 by A15,REAL_1:53; then A20: r3*(s1+s2) < r3*(s2+s2) by A14,REAL_1:70; A21: r*s1 <= r*s2 by A3,A15,AXIOMS:25; r3*(s2+s2)+r*s2 = r3*(s2+s2)+r*(1/2*s2+1/2*s2) by A12,XCMPLX_1:66 .= r3*(s2+s2)+r*((1/2)*(s2+s2)) by XCMPLX_1:8 .= r3*(s2+s2)+(r*(1/2))*(s2+s2) by XCMPLX_1:4 .= (r3+r*(1/2))*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A12,XCMPLX_1:66; then A22: r3*(s1+s2)+r*s1 < s2 by A20,A21,REAL_1:67; Int cell(G,len G,j) = { |[r',s']| : G*(len G,1)`1 < r' & G*(1,j)`2 < s' & s' < G*(1,j+1)`2 } by A1,Th26; hence p in Int cell(G,len G,j) by A13,A16,A17,A19,A22; end; hence x in Int cell(G,len G,j) \/ { G*(len G,j) + |[1,0]| } by XBOOLE_0:def 2 ; end; theorem Th54: 1 <= j & j < width G implies LSeg(1/2*(G*(len G,j)+G*(len G,j+1)) + |[1,0]|,G*(len G,j+1) + |[1,0]|) c= Int cell(G,len G,j) \/ { G*(len G,j+1) + |[1,0]| } proof assume A1: 1 <= j & j < width G; let x be set; assume A2: x in LSeg(1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|,G* (len G,j+1) + |[1,0]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|)+ r*(G*(len G,j+1) + |[1,0]|) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(len G,j+1) + |[1,0]|) by A4,EUCLID:33 .= 1*(G*(len G,j+1) + |[1,0]|) by EUCLID:31 .= (G*(len G,j+1) + |[1,0]|) by EUCLID:33; hence p in { G*(len G,j+1) + |[1,0]| } by TARSKI:def 1; case A5: r < 1; set r2 = G*(len G,1)`1, s1 = G*(1,j)`2, s2 = G*(1,j+1)`2; A6: 1 <= j+1 & j+1 <= width G by A1,NAT_1:38; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(len G,j+1) = |[G*(len G,j+1)`1,G*(len G,j+1)`2]| by EUCLID:57 .= |[r2,G*(len G,j+1)`2]| by A6,A7,GOBOARD5:3 .= |[r2,s2]| by A6,A7,GOBOARD5:2; A9: G*(len G,j) = |[G*(len G,j)`1,G*(len G,j)`2]| by EUCLID:57 .= |[r2,G*(len G,j)`2]| by A1,A7,GOBOARD5:3 .= |[r2,s1]| by A1,A7,GOBOARD5:2; set r3 = (1-r)*(1/2); A10: (1/2)*r2 = r2/2 by XCMPLX_1:100; A11: (1/2)*s1 = s1/2 by XCMPLX_1:100; A12: (1/2)*s2 = s2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(len G,j)+G*(len G,j+1)))+(1-r)*|[1,0]| +r*(G*(len G,j+1) + |[1,0]|) by A4,EUCLID:36 .= r3*(G*(len G,j)+G*(len G,j+1))+(1-r)*|[1,0]|+ r*(G*(len G,j+1) + |[1,0]|) by EUCLID:34 .= r3*(G*(len G,j)+G*(len G,j+1))+|[(1-r)*1,(1-r)*0]|+ r*(G*(len G,j+1) + |[1,0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+r*(|[r2,s2]| + |[1,0]|) by A8,A9,EUCLID:60 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+(r*|[r2,s2]| + r*|[1,0]|) by EUCLID:36 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+(|[r*r2,r*s2]| + r*|[1,0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+(|[r*r2,r*s2]| + |[r*1,r*0]|) by EUCLID:62 .= r3*|[r2+r2,s1+s2]|+|[1-r,0]|+|[r*r2+r,r*s2+0]| by EUCLID:60 .= |[r3*(r2+r2),r3*(s1+s2)]|+|[1-r,0]|+|[r*r2+r,r*s2+0]| by EUCLID:62 .= |[r3*(r2+r2)+(1-r),r3*(s1+s2)+0]|+|[r*r2+r,r*s2+0]| by EUCLID:60 .= |[r3*(r2+r2)+(1-r)+(r*r2+r),r3*(s1+s2)+r*s2]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A14: r3 > (1/2)*0 by REAL_1:70; j < j+1 by REAL_1:69; then A15: s1 < s2 by A1,A6,A7,GOBOARD5:5; A16: r2+1 > r2 by REAL_1:69; A17: r3*(r2+r2)+(1-r)+(r*r2+r) = (1-r)*((1/2)*(r2+r2))+(1-r)+(r*r2+r) by XCMPLX_1:4 .= (1-r)*((1/2)*r2+(1/2)*r2)+(1-r)+(r*r2+r) by XCMPLX_1:8 .= (1-r)*r2+(1-r)+(r*r2+r) by A10,XCMPLX_1:66 .= (1-r)*r2+(1-r)+r*r2+r by XCMPLX_1:1 .= (1-r)*r2+r*r2+(1-r)+r by XCMPLX_1:1 .= ((1-r)+r)*r2+(1-r)+r by XCMPLX_1:8 .= 1*r2+(1-r)+r by XCMPLX_1:27 .= r2+((1-r)+r) by XCMPLX_1:1 .= r2+1 by XCMPLX_1:27; s1+s1 < s1+s2 by A15,REAL_1:53; then A18: r3*(s1+s1) < r3*(s1+s2) by A14,REAL_1:70; A19: r*s1 <= r*s2 by A3,A15,AXIOMS:25; r3*(s1+s1)+r*s1 = r3*(s1+s1)+r*(1/2*s1+1/2*s1) by A11,XCMPLX_1:66 .= r3*(s1+s1)+r*((1/2)*(s1+s1)) by XCMPLX_1:8 .= r3*(s1+s1)+(r*(1/2))*(s1+s1) by XCMPLX_1:4 .= (r3+r*(1/2))*(s1+s1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s1+s1) by XCMPLX_1:8 .= 1*(1/2)*(s1+s1) by XCMPLX_1:27 .= (1/2)*s1+(1/2)*s1 by XCMPLX_1:8 .= s1 by A11,XCMPLX_1:66; then A20: s1 < r3*(s1+s2)+r*s2 by A18,A19,REAL_1:67; s1+s2 < s2+s2 by A15,REAL_1:53; then A21: r3*(s1+s2) < r3*(s2+s2) by A14,REAL_1:70; r3*(s2+s2)+r*s2 = r3*(s2+s2)+r*(1/2*s2+1/2*s2) by A12,XCMPLX_1:66 .= r3*(s2+s2)+r*((1/2)*(s2+s2)) by XCMPLX_1:8 .= r3*(s2+s2)+(r*(1/2))*(s2+s2) by XCMPLX_1:4 .= (r3+r*(1/2))*(s2+s2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(s2+s2) by XCMPLX_1:8 .= 1*(1/2)*(s2+s2) by XCMPLX_1:27 .= (1/2)*s2+(1/2)*s2 by XCMPLX_1:8 .= s2 by A12,XCMPLX_1:66; then A22: r3*(s1+s2)+r*s2 < s2 by A21,REAL_1:67; Int cell(G,len G,j) = { |[r',s']| : G*(len G,1)`1 < r' & G*(1,j)`2 < s' & s' < G*(1,j+1)`2 } by A1,Th26; hence p in Int cell(G,len G,j) by A13,A16,A17,A20,A22; end; hence x in Int cell(G,len G,j) \/ { G*(len G,j+1) + |[1,0]| } by XBOOLE_0:def 2; end; theorem Th55: 1 <= i & i < len G implies LSeg(1/2*(G*(i,1)+G*(i+1,1)) - |[0,1]|,G*(i,1) - |[0,1]|) c= Int cell(G,i,0) \/ { G*(i,1) - |[0,1]| } proof assume A1: 1 <= i & i < len G; let x be set; assume A2: x in LSeg(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|,G*(i,1) - |[0,1]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|)+r*(G*(i,1) - |[0,1]|) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(i,1) - |[0,1]|) by A4,EUCLID:33 .= 1*(G*(i,1) - |[0,1]|) by EUCLID:31 .= (G*(i,1) - |[0,1]|) by EUCLID:33; hence p in { G*(i,1) - |[0,1]| } by TARSKI:def 1; case A5: r < 1; set s1 = G*(1,1)`2, r1 = G*(i,1)`1, r2 = G*(i+1,1)`1; A6: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; 0 <> width G by GOBOARD1:def 5; then A7: 1 <= width G by RLVECT_1:99; A8: G*(i+1,1) = |[G*(i+1,1)`1,G*(i+1,1)`2]| by EUCLID:57 .= |[r2,s1]| by A6,A7,GOBOARD5:2; A9: G*(i,1) = |[G*(i,1)`1,G*(i,1)`2]| by EUCLID:57 .= |[r1,s1]| by A1,A7,GOBOARD5:2; set r3 = (1-r)*(1/2); A10: (1/2)*s1 = s1/2 by XCMPLX_1:100; A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(i,1)+G*(i+1,1)))-(1-r)*|[0,1]| +r*(G*(i,1) - |[0,1]|) by A4,EUCLID:53 .= r3*(G*(i,1)+G*(i+1,1))-(1-r)*|[0,1]|+r*(G* (i,1) - |[0,1]|) by EUCLID:34 .= r3*(G*(i,1)+G*(i+1,1))-|[(1-r)*0,(1-r)*1]|+r*(G*(i,1) - |[0,1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+r*(|[r1,s1]| - |[0,1]|) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+(r*|[r1,s1]| - r*|[0,1]|) by EUCLID:53 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+(|[r*r1,r*s1]| - r*|[0,1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+(|[r*r1,r*s1]| - |[r*0,r*1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+|[r*r1-0,r*s1-r]| by EUCLID:66 .= |[r3*(r1+r2),r3*(s1+s1)]|-|[0,1-r]|+|[r*r1-0,r*s1-r]| by EUCLID:62 .= |[r3*(r1+r2)-0,r3*(s1+s1)-(1-r)]|+|[r*r1-0,r*s1-r]| by EUCLID:66 .= |[r3*(r1+r2)+r*r1,r3*(s1+s1)-(1-r)+(r*s1-r)]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A14: r3 > (1/2)*0 by REAL_1:70; i < i+1 by REAL_1:69; then A15: r1 < r2 by A1,A6,A7,GOBOARD5:4; s1 < s1+1 by REAL_1:69; then A16: s1-1 < s1 by REAL_1:84; A17: r3*(s1+s1)-(1-r)+(r*s1-r) = (1-r)*((1/2)*(s1+s1))-(1-r)+(r*s1-r) by XCMPLX_1:4 .= (1-r)*((1/2)*s1+(1/2)*s1)-(1-r)+(r*s1-r) by XCMPLX_1:8 .= (1-r)*s1-(1-r)+(r*s1-r) by A10,XCMPLX_1:66 .= (1-r)*s1-(1-r)+r*s1-r by XCMPLX_1:29 .= (1-r)*s1+r*s1-(1-r)-r by XCMPLX_1:29 .= ((1-r)+r)*s1-(1-r)-r by XCMPLX_1:8 .= 1*s1-(1-r)-r by XCMPLX_1:27 .= s1-((1-r)+r) by XCMPLX_1:36 .= s1-1 by XCMPLX_1:27; r1+r1 < r1+r2 by A15,REAL_1:53; then A18: r3*(r1+r1) < r3*(r1+r2) by A14,REAL_1:70; r3*(r1+r1)+r*r1 = r3*(r1+r1)+r*(1/2*r1+1/2*r1) by A11,XCMPLX_1:66 .= r3*(r1+r1)+r*((1/2)*(r1+r1)) by XCMPLX_1:8 .= r3*(r1+r1)+(r*(1/2))*(r1+r1) by XCMPLX_1:4 .= (r3+r*(1/2))*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A19: r1 < r3*(r1+r2)+r*r1 by A18,REAL_1:53; r1+r2 < r2+r2 by A15,REAL_1:53; then A20: r3*(r1+r2) < r3*(r2+r2) by A14,REAL_1:70; A21: r*r1 <= r*r2 by A3,A15,AXIOMS:25; r3*(r2+r2)+r*r2 = r3*(r2+r2)+r*(1/2*r2+1/2*r2) by A12,XCMPLX_1:66 .= r3*(r2+r2)+r*((1/2)*(r2+r2)) by XCMPLX_1:8 .= r3*(r2+r2)+(r*(1/2))*(r2+r2) by XCMPLX_1:4 .= (r3+r*(1/2))*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A22: r3*(r1+r2)+r*r1 < r2 by A20,A21,REAL_1:67; Int cell(G,i,0) = { |[r',s']| : G*(i,1)`1 < r' & r' < G*(i+1,1)`1 & s' < G*(1,1)`2 } by A1,Th27; hence p in Int cell(G,i,0) by A13,A16,A17,A19,A22; end; hence x in Int cell(G,i,0) \/ { G*(i,1) - |[0,1]| } by XBOOLE_0:def 2; end; theorem Th56: 1 <= i & i < len G implies LSeg(1/2*(G*(i,1)+G*(i+1,1)) - |[0,1]|,G*(i+1,1) - |[0,1]|) c= Int cell(G,i,0) \/ { G*(i+1,1) - |[0,1]| } proof assume A1: 1 <= i & i < len G; let x be set; assume A2: x in LSeg(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|,G*(i+1,1) - |[0,1]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|)+r*(G*(i+1,1) - |[0,1]|) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(i+1,1) - |[0,1]|) by A4,EUCLID:33 .= 1*(G*(i+1,1) - |[0,1]|) by EUCLID:31 .= (G*(i+1,1) - |[0,1]|) by EUCLID:33; hence p in { G*(i+1,1) - |[0,1]| } by TARSKI:def 1; case A5: r < 1; set s1 = G*(1,1)`2, r1 = G*(i,1)`1, r2 = G*(i+1,1)`1; A6: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; 0 <> width G by GOBOARD1:def 5; then A7: 1 <= width G by RLVECT_1:99; A8: G*(i+1,1) = |[G*(i+1,1)`1,G*(i+1,1)`2]| by EUCLID:57 .= |[r2,s1]| by A6,A7,GOBOARD5:2; A9: G*(i,1) = |[G*(i,1)`1,G*(i,1)`2]| by EUCLID:57 .= |[r1,s1]| by A1,A7,GOBOARD5:2; set r3 = (1-r)*(1/2); A10: (1/2)*s1 = s1/2 by XCMPLX_1:100; A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(i,1)+G*(i+1,1)))-(1-r)*|[0,1]| +r*(G*(i+1,1) - |[0,1]|) by A4,EUCLID:53 .= r3*(G*(i,1)+G*(i+1,1))-(1-r)*|[0,1]|+r*(G*(i+1,1) - |[0,1]|) by EUCLID:34 .= r3*(G*(i,1)+G*(i+1,1))-|[(1-r)*0,(1-r)*1]|+r*(G*(i+1,1) - |[0,1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+r*(|[r2,s1]| - |[0,1]|) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+(r*|[r2,s1]| - r*|[0,1]|) by EUCLID:53 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+(|[r*r2,r*s1]| - r*|[0,1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+(|[r*r2,r*s1]| - |[r*0,r*1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|-|[0,1-r]|+|[r*r2-0,r*s1-r]| by EUCLID:66 .= |[r3*(r1+r2),r3*(s1+s1)]|-|[0,1-r]|+|[r*r2-0,r*s1-r]| by EUCLID:62 .= |[r3*(r1+r2)-0,r3*(s1+s1)-(1-r)]|+|[r*r2-0,r*s1-r]| by EUCLID:66 .= |[r3*(r1+r2)+r*r2,r3*(s1+s1)-(1-r)+(r*s1-r)]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A14: r3 > (1/2)*0 by REAL_1:70; i < i+1 by REAL_1:69; then A15: r1 < r2 by A1,A6,A7,GOBOARD5:4; s1 < s1+1 by REAL_1:69; then A16: s1-1 < s1 by REAL_1:84; A17: r3*(s1+s1)-(1-r)+(r*s1-r) = (1-r)*((1/2)*(s1+s1))-(1-r)+(r*s1-r) by XCMPLX_1:4 .= (1-r)*((1/2)*s1+(1/2)*s1)-(1-r)+(r*s1-r) by XCMPLX_1:8 .= (1-r)*s1-(1-r)+(r*s1-r) by A10,XCMPLX_1:66 .= (1-r)*s1-(1-r)+r*s1-r by XCMPLX_1:29 .= (1-r)*s1+r*s1-(1-r)-r by XCMPLX_1:29 .= ((1-r)+r)*s1-(1-r)-r by XCMPLX_1:8 .= 1*s1-(1-r)-r by XCMPLX_1:27 .= s1-((1-r)+r) by XCMPLX_1:36 .= s1-1 by XCMPLX_1:27; r1+r1 < r1+r2 by A15,REAL_1:53; then A18: r3*(r1+r1) < r3*(r1+r2) by A14,REAL_1:70; A19: r*r1 <= r*r2 by A3,A15,AXIOMS:25; r3*(r1+r1)+r*r1 = r3*(r1+r1)+r*(1/2*r1+1/2*r1) by A11,XCMPLX_1:66 .= r3*(r1+r1)+r*((1/2)*(r1+r1)) by XCMPLX_1:8 .= r3*(r1+r1)+(r*(1/2))*(r1+r1) by XCMPLX_1:4 .= (r3+r*(1/2))*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A20: r1 < r3*(r1+r2)+r*r2 by A18,A19,REAL_1:67; r1+r2 < r2+r2 by A15,REAL_1:53; then A21: r3*(r1+r2) < r3*(r2+r2) by A14,REAL_1:70; r3*(r2+r2)+r*r2 = r3*(r2+r2)+r*(1/2*r2+1/2*r2) by A12,XCMPLX_1:66 .= r3*(r2+r2)+r*((1/2)*(r2+r2)) by XCMPLX_1:8 .= r3*(r2+r2)+(r*(1/2))*(r2+r2) by XCMPLX_1:4 .= (r3+r*(1/2))*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A22: r3*(r1+r2)+r*r2 < r2 by A21,REAL_1:67; Int cell(G,i,0) = { |[r',s']| : G*(i,1)`1 < r' & r' < G*(i+1,1)`1 & s' < G*(1,1)`2 } by A1,Th27; hence p in Int cell(G,i,0) by A13,A16,A17,A20,A22; end; hence x in Int cell(G,i,0) \/ { G*(i+1,1) - |[0,1]| } by XBOOLE_0:def 2; end; theorem Th57: 1 <= i & i < len G implies LSeg(1/2*(G*(i,width G)+G*(i+1,width G)) + |[0,1]|,G* (i,width G) + |[0,1]|) c= Int cell(G,i,width G) \/ { G*(i,width G) + |[0,1]| } proof assume A1: 1 <= i & i < len G; let x be set; assume A2: x in LSeg(1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|, G*(i,width G) + |[0,1]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|)+ r*(G*(i,width G) + |[0,1]|) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(i,width G) + |[0,1]|) by A4,EUCLID:33 .= 1*(G*(i,width G) + |[0,1]|) by EUCLID:31 .= (G*(i,width G) + |[0,1]|) by EUCLID:33; hence p in { G*(i,width G) + |[0,1]| } by TARSKI:def 1; case A5: r < 1; set s1 = G*(1,width G)`2, r1 = G*(i,1)`1, r2 = G*(i+1,1)`1; A6: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; 0 <> width G by GOBOARD1:def 5; then A7: 1 <= width G by RLVECT_1:99; A8: G*(i+1,width G) = |[G*(i+1,width G)`1,G*(i+1,width G)`2]| by EUCLID:57 .= |[G*(i+1,width G)`1,s1]| by A6,A7,GOBOARD5:2 .= |[r2,s1]| by A6,A7,GOBOARD5:3; A9: G*(i,width G) = |[G*(i,width G)`1,G*(i,width G)`2]| by EUCLID:57 .= |[G*(i,width G)`1,s1]| by A1,A7,GOBOARD5:2 .= |[r1,s1]| by A1,A7,GOBOARD5:3; set r3 = (1-r)*(1/2); A10: (1/2)*s1 = s1/2 by XCMPLX_1:100; A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(i,width G)+G*(i+1,width G)))+(1-r)*|[0,1]| +r*(G*(i,width G) + |[0,1]|) by A4,EUCLID:36 .= r3*(G*(i,width G)+G*(i+1,width G))+(1-r)*|[0,1]|+ r*(G*(i,width G) + |[0,1]|) by EUCLID:34 .= r3*(G*(i,width G)+G*(i+1,width G))+|[(1-r)*0,(1-r)*1]|+ r*(G*(i,width G) + |[0,1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+r*(|[r1,s1]| + |[0,1]|) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+(r*|[r1,s1]| + r*|[0,1]|) by EUCLID:36 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+(|[r*r1,r*s1]| + r*|[0,1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+(|[r*r1,r*s1]| + |[r*0,r*1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+|[r*r1+0,r*s1+r]| by EUCLID:60 .= |[r3*(r1+r2),r3*(s1+s1)]|+|[0,1-r]|+|[r*r1+0,r*s1+r]| by EUCLID:62 .= |[r3*(r1+r2)+0,r3*(s1+s1)+(1-r)]|+|[r*r1+0,r*s1+r]| by EUCLID:60 .= |[r3*(r1+r2)+r*r1,r3*(s1+s1)+(1-r)+(r*s1+r)]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A14: r3 > (1/2)*0 by REAL_1:70; i < i+1 by REAL_1:69; then A15: r1 < r2 by A1,A6,A7,GOBOARD5:4; A16: s1 < s1+1 by REAL_1:69; A17: r3*(s1+s1)+(1-r)+(r*s1+r) = (1-r)*((1/2)*(s1+s1))+(1-r)+(r*s1+r) by XCMPLX_1:4 .= (1-r)*((1/2)*s1+(1/2)*s1)+(1-r)+(r*s1+r) by XCMPLX_1:8 .= (1-r)*s1+(1-r)+(r*s1+r) by A10,XCMPLX_1:66 .= (1-r)*s1+(1-r)+r*s1+r by XCMPLX_1:1 .= (1-r)*s1+r*s1+(1-r)+r by XCMPLX_1:1 .= ((1-r)+r)*s1+(1-r)+r by XCMPLX_1:8 .= 1*s1+(1-r)+r by XCMPLX_1:27 .= s1+((1-r)+r) by XCMPLX_1:1 .= s1+1 by XCMPLX_1:27; r1+r1 < r1+r2 by A15,REAL_1:53; then A18: r3*(r1+r1) < r3*(r1+r2) by A14,REAL_1:70; r3*(r1+r1)+r*r1 = r3*(r1+r1)+r*(1/2*r1+1/2*r1) by A11,XCMPLX_1:66 .= r3*(r1+r1)+r*((1/2)*(r1+r1)) by XCMPLX_1:8 .= r3*(r1+r1)+(r*(1/2))*(r1+r1) by XCMPLX_1:4 .= (r3+r*(1/2))*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A19: r1 < r3*(r1+r2)+r*r1 by A18,REAL_1:53; r1+r2 < r2+r2 by A15,REAL_1:53; then A20: r3*(r1+r2) < r3*(r2+r2) by A14,REAL_1:70; A21: r*r1 <= r*r2 by A3,A15,AXIOMS:25; r3*(r2+r2)+r*r2 = r3*(r2+r2)+r*(1/2*r2+1/2*r2) by A12,XCMPLX_1:66 .= r3*(r2+r2)+r*((1/2)*(r2+r2)) by XCMPLX_1:8 .= r3*(r2+r2)+(r*(1/2))*(r2+r2) by XCMPLX_1:4 .= (r3+r*(1/2))*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A22: r3*(r1+r2)+r*r1 < r2 by A20,A21,REAL_1:67; Int cell(G,i,width G) = { |[r',s']| : G*(i,1)`1 < r' & r' < G*(i+1,1)`1 & G*(1,width G)`2 < s' } by A1,Th28; hence p in Int cell(G,i,width G) by A13,A16,A17,A19,A22; end; hence x in Int cell(G,i,width G) \/ { G*(i,width G) + |[0,1]| } by XBOOLE_0:def 2; end; theorem Th58: 1 <= i & i < len G implies LSeg(1/2*(G*(i,width G)+G*(i+1,width G)) + |[0,1]|,G* (i+1,width G) + |[0,1]|) c= Int cell(G,i,width G) \/ { G*(i+1,width G) + |[0,1]| } proof assume A1: 1 <= i & i < len G; let x be set; assume A2: x in LSeg(1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|, G*(i+1,width G) + |[0,1]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A3: 0<=r & r<=1 and A4: p = (1-r)*(1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|)+ r*(G*(i+1,width G) + |[0,1]|) by A2,SPPOL_1:21; now per cases by A3,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(i+1,width G) + |[0,1]|) by A4,EUCLID:33 .= 1*(G*(i+1,width G) + |[0,1]|) by EUCLID:31 .= (G*(i+1,width G) + |[0,1]|) by EUCLID:33; hence p in { G*(i+1,width G) + |[0,1]| } by TARSKI:def 1; case A5: r < 1; set s1 = G*(1,width G)`2, r1 = G*(i,1)`1, r2 = G*(i+1,1)`1; A6: 1 <= i+1 & i+1 <= len G by A1,NAT_1:38; 0 <> width G by GOBOARD1:def 5; then A7: 1 <= width G by RLVECT_1:99; A8: G*(i+1,width G) = |[G*(i+1,width G)`1,G*(i+1,width G)`2]| by EUCLID:57 .= |[G*(i+1,width G)`1,s1]| by A6,A7,GOBOARD5:2 .= |[r2,s1]| by A6,A7,GOBOARD5:3; A9: G*(i,width G) = |[G*(i,width G)`1,G*(i,width G)`2]| by EUCLID:57 .= |[G*(i,width G)`1,s1]| by A1,A7,GOBOARD5:2 .= |[r1,s1]| by A1,A7,GOBOARD5:3; set r3 = (1-r)*(1/2); A10: (1/2)*s1 = s1/2 by XCMPLX_1:100; A11: (1/2)*r1 = r1/2 by XCMPLX_1:100; A12: (1/2)*r2 = r2/2 by XCMPLX_1:100; A13: p = (1-r)*(1/2*(G*(i,width G)+G*(i+1,width G)))+(1-r)*|[0,1]| +r*(G*(i+1,width G) + |[0,1]|) by A4,EUCLID:36 .= r3*(G*(i,width G)+G*(i+1,width G))+(1-r)*|[0,1]|+ r*(G*(i+1,width G) + |[0,1]|) by EUCLID:34 .= r3*(G*(i,width G)+G*(i+1,width G))+|[(1-r)*0,(1-r)*1]|+ r*(G*(i+1,width G) + |[0,1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+r*(|[r2,s1]| + |[0,1]|) by A8,A9,EUCLID:60 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+(r*|[r2,s1]| + r*|[0,1]|) by EUCLID:36 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+(|[r*r2,r*s1]| + r*|[0,1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+(|[r*r2,r*s1]| + |[r*0,r*1]|) by EUCLID:62 .= r3*|[r1+r2,s1+s1]|+|[0,1-r]|+|[r*r2+0,r*s1+r]| by EUCLID:60 .= |[r3*(r1+r2),r3*(s1+s1)]|+|[0,1-r]|+|[r*r2+0,r*s1+r]| by EUCLID:62 .= |[r3*(r1+r2)+0,r3*(s1+s1)+(1-r)]|+|[r*r2+0,r*s1+r]| by EUCLID:60 .= |[r3*(r1+r2)+r*r2,r3*(s1+s1)+(1-r)+(r*s1+r)]| by EUCLID:60; 1 - r > 0 by A5,SQUARE_1:11; then A14: r3 > (1/2)*0 by REAL_1:70; i < i+1 by REAL_1:69; then A15: r1 < r2 by A1,A6,A7,GOBOARD5:4; A16: s1+1 > s1 by REAL_1:69; A17: r3*(s1+s1)+(1-r)+(r*s1+r) = (1-r)*((1/2)*(s1+s1))+(1-r)+(r*s1+r) by XCMPLX_1:4 .= (1-r)*((1/2)*s1+(1/2)*s1)+(1-r)+(r*s1+r) by XCMPLX_1:8 .= (1-r)*s1+(1-r)+(r*s1+r) by A10,XCMPLX_1:66 .= (1-r)*s1+(1-r)+r*s1+r by XCMPLX_1:1 .= (1-r)*s1+r*s1+(1-r)+r by XCMPLX_1:1 .= ((1-r)+r)*s1+(1-r)+r by XCMPLX_1:8 .= 1*s1+(1-r)+r by XCMPLX_1:27 .= s1+((1-r)+r) by XCMPLX_1:1 .= s1+1 by XCMPLX_1:27; r1+r1 < r1+r2 by A15,REAL_1:53; then A18: r3*(r1+r1) < r3*(r1+r2) by A14,REAL_1:70; A19: r*r1 <= r*r2 by A3,A15,AXIOMS:25; r3*(r1+r1)+r*r1 = r3*(r1+r1)+r*(1/2*r1+1/2*r1) by A11,XCMPLX_1:66 .= r3*(r1+r1)+r*((1/2)*(r1+r1)) by XCMPLX_1:8 .= r3*(r1+r1)+(r*(1/2))*(r1+r1) by XCMPLX_1:4 .= (r3+r*(1/2))*(r1+r1) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r1+r1) by XCMPLX_1:8 .= 1*(1/2)*(r1+r1) by XCMPLX_1:27 .= (1/2)*r1+(1/2)*r1 by XCMPLX_1:8 .= r1 by A11,XCMPLX_1:66; then A20: r1 < r3*(r1+r2)+r*r2 by A18,A19,REAL_1:67; r1+r2 < r2+r2 by A15,REAL_1:53; then A21: r3*(r1+r2) < r3*(r2+r2) by A14,REAL_1:70; r3*(r2+r2)+r*r2 = r3*(r2+r2)+r*(1/2*r2+1/2*r2) by A12,XCMPLX_1:66 .= r3*(r2+r2)+r*((1/2)*(r2+r2)) by XCMPLX_1:8 .= r3*(r2+r2)+(r*(1/2))*(r2+r2) by XCMPLX_1:4 .= (r3+r*(1/2))*(r2+r2) by XCMPLX_1:8 .= ((1-r)+r)*(1/2)*(r2+r2) by XCMPLX_1:8 .= 1*(1/2)*(r2+r2) by XCMPLX_1:27 .= (1/2)*r2+(1/2)*r2 by XCMPLX_1:8 .= r2 by A12,XCMPLX_1:66; then A22: r3*(r1+r2)+r*r2 < r2 by A21,REAL_1:67; Int cell(G,i,width G) = { |[r',s']| : G*(i,1)`1 < r' & r' < G*(i+1,1)`1 & G*(1,width G)`2 < s' } by A1,Th28; hence p in Int cell(G,i,width G) by A13,A16,A17,A20,A22; end; hence x in Int cell(G,i,width G) \/ { G*(i+1,width G) + |[0,1]| } by XBOOLE_0:def 2 ; end; theorem Th59: LSeg(G*(1,1) - |[1,1]|,G*(1,1) - |[1,0]|) c= Int cell(G,0,0) \/ { G*(1,1) - |[1,0]| } proof let x be set; assume A1: x in LSeg(G*(1,1)-|[1,1]|,G*(1,1) - |[1,0]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A2: 0<=r & r<=1 and A3: p = (1-r)*(G*(1,1)-|[1,1]|)+r*(G*(1,1) - |[1,0]|) by A1,SPPOL_1:21; set r1 = G*(1,1)`1, s1 = G*(1,1)`2; now per cases by A2,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(1,1) - |[1,0]|) by A3,EUCLID:33 .= 1*(G*(1,1) - |[1,0]|) by EUCLID:31 .= G*(1,1) - |[1,0]| by EUCLID:33; hence p in { G*(1,1) - |[1,0]| } by TARSKI:def 1; case r < 1; then 1 - r > 0 by SQUARE_1:11; then s1 < s1 +(1-r) by REAL_1:69; then A4: s1-(1-r) < s1 by REAL_1:84; A5: G*(1,1) = |[r1,s1]| by EUCLID:57; A6: p = (1-r)*(G*(1,1))-(1-r)*|[1,1]|+r*(G*(1,1) - |[1,0]|) by A3,EUCLID:53 .= (1-r)*(G*(1,1))-(1-r)*|[1,1]|+(r*(G*(1,1)) - r*|[1,0]|) by EUCLID:53 .= r*(G*(1,1)) + ((1-r)*(G*(1,1))-(1-r)*|[1,1]|) - r*|[1,0]| by EUCLID:49 .= r*(G*(1,1)) + (1-r)*(G*(1,1))-(1-r)*|[1,1]| - r*|[1,0]| by EUCLID:49 .= (r+(1-r))*(G*(1,1)) -(1-r)*|[1,1]| - r*|[1,0]| by EUCLID:37 .= 1 * (G*(1,1)) -(1-r)*|[1,1]| - r*|[1,0]| by XCMPLX_1:27 .= G*(1,1) -(1-r)*|[1,1]| - r*|[1,0]| by EUCLID:33 .= G*(1,1)-|[(1-r)*1,(1-r)*1]| - r*|[1,0]| by EUCLID:62 .= G*(1,1)-|[1-r,1-r]| - |[r*1,r*0]| by EUCLID:62 .= |[r1-(1-r),s1-(1-r)]| - |[r,0]| by A5,EUCLID:66 .= |[r1-(1-r)-r,s1-(1-r)-0]| by EUCLID:66 .= |[r1-((1-r)+r),s1-(1-r)]| by XCMPLX_1:36 .= |[r1-1,s1-(1-r)]| by XCMPLX_1:27; r1 < r1+1 by REAL_1:69; then A7: r1-1 < r1 by REAL_1:84; Int cell(G,0,0) = { |[r',s']| : r' < G*(1,1)`1 & s' < G* (1,1)`2 } by Th21; hence p in Int cell(G,0,0) by A4,A6,A7; end; hence x in Int cell(G,0,0) \/ { G*(1,1) - |[1,0]| } by XBOOLE_0:def 2; end; theorem Th60: LSeg(G*(len G,1) + |[1,-1]|,G*(len G,1) + |[1,0]|) c= Int cell(G,len G,0) \/ { G*(len G,1) + |[1,0]| } proof let x be set; assume A1: x in LSeg(G*(len G,1)+|[1,-1]|,G*(len G,1) + |[1,0]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A2: 0<=r & r<=1 and A3: p = (1-r)*(G*(len G,1)+|[1,-1]|)+r*(G*(len G,1) + |[1,0]|) by A1,SPPOL_1:21; set r1 = G*(len G,1)`1, s1 = G*(1,1)`2; now per cases by A2,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(len G,1) + |[1,0]|) by A3,EUCLID:33 .= 1*(G*(len G,1) + |[1,0]|) by EUCLID:31 .= G*(len G,1) + |[1,0]| by EUCLID:33; hence p in { G*(len G,1) + |[1,0]| } by TARSKI:def 1; case r < 1; then 1 - r > 0 by SQUARE_1:11; then A4: s1 < s1 +(1-r) by REAL_1:69; s1+(r-1) = s1-(1-r) by XCMPLX_1:38; then A5: s1+(r-1) < s1 by A4,REAL_1:84; 0 <> width G by GOBOARD1:def 5; then A6: 1 <= width G by RLVECT_1:99; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(len G,1) = |[r1,G*(len G,1)`2]| by EUCLID:57 .= |[r1,s1]| by A6,A7,GOBOARD5:2; A9: p = (1-r)*(G*(len G,1))+(1-r)*|[1,-1]|+r*(G*(len G,1) + |[1,0]|) by A3, EUCLID:36 .= (1-r)*(G*(len G,1))+(1-r)*|[1,-1]|+(r*(G*(len G,1)) + r*|[1,0]|) by EUCLID:36 .= r*(G*(len G,1)) + ((1-r)*(G*(len G,1))+(1-r)*|[1,-1]|) + r*|[1,0]| by EUCLID:30 .= r*(G*(len G,1)) + (1-r)*(G*(len G,1))+(1-r)*|[1,-1]| + r*|[1,0]| by EUCLID:30 .= (r+(1-r))*(G*(len G,1)) +(1-r)*|[1,-1]| + r*|[1,0]| by EUCLID:37 .= 1*(G*(len G,1)) +(1-r)*|[1,-1]| + r*|[1,0]| by XCMPLX_1:27 .= G*(len G,1) +(1-r)*|[1,-1]| + r*|[1,0]| by EUCLID:33 .= G*(len G,1)+|[(1-r)*1,(1-r)*(-1)]| + r*|[1,0]| by EUCLID:62 .= G*(len G,1)+|[1-r,-(1-r)]| + r*|[1,0]| by XCMPLX_1:180 .= G*(len G,1)+|[1-r,r-1]| + r*|[1,0]| by XCMPLX_1:143 .= G*(len G,1)+|[1-r,r-1]| + |[r*1,r*0]| by EUCLID:62 .= |[r1+(1-r),s1+(r-1)]| + |[r,0]| by A8,EUCLID:60 .= |[r1+(1-r)+r,s1+(r-1)+0]| by EUCLID:60 .= |[r1+((1-r)+r),s1+(r-1)]| by XCMPLX_1:1 .= |[r1+1,s1+(r-1)]| by XCMPLX_1:27; A10: r1 < r1+1 by REAL_1:69; Int cell(G,len G,0) = { |[r',s']| : G*(len G,1)`1 < r' & s' < G*(1,1)`2 } by Th24; hence p in Int cell(G,len G,0) by A5,A9,A10; end; hence x in Int cell(G,len G,0) \/ { G*(len G,1) + |[1,0]| } by XBOOLE_0:def 2 ; end; theorem Th61: LSeg(G*(1,width G) + |[-1,1]|,G*(1,width G) - |[1,0]|) c= Int cell(G,0,width G) \/ { G*(1,width G) - |[1,0]| } proof let x be set; assume A1: x in LSeg(G*(1,width G)+|[-1,1]|,G*(1,width G) - |[1,0]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A2: 0<=r & r<=1 and A3: p = (1-r)*(G*(1,width G)+|[-1,1]|)+r*(G*(1,width G) - |[1,0]|) by A1,SPPOL_1:21; set r1 = G*(1,1)`1, s1 = G*(1,width G)`2; now per cases by A2,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(1,width G) - |[1,0]|) by A3,EUCLID:33 .= 1*(G*(1,width G) - |[1,0]|) by EUCLID:31 .= G*(1,width G) - |[1,0]| by EUCLID:33; hence p in { G*(1,width G) - |[1,0]| } by TARSKI:def 1; case r < 1; then 1 - r > 0 by SQUARE_1:11; then A4: s1 < s1 +(1-r) by REAL_1:69; 0 <> width G by GOBOARD1:def 5; then A5: 1 <= width G by RLVECT_1:99; 0 <> len G by GOBOARD1:def 5; then A6: 1 <= len G by RLVECT_1:99; A7: G*(1,width G) = |[G*(1,width G)`1,s1]| by EUCLID:57 .= |[r1,s1]| by A5,A6,GOBOARD5:3; A8: p = (1-r)*(G*(1,width G))+(1-r)*|[-1,1]|+r*(G*(1,width G) - |[1,0]|) by A3,EUCLID:36 .= (1-r)*(G*(1,width G))+(1-r)*|[-1,1]|+(r*(G*(1,width G)) - r*|[1,0]|) by EUCLID:53 .= r*(G*(1,width G)) + ((1-r)*(G* (1,width G))+(1-r)*|[-1,1]|) - r*|[1,0]| by EUCLID:49 .= r*(G*(1,width G)) + (1-r)*(G*(1,width G))+(1-r)*|[-1,1]| - r*|[1,0]| by EUCLID:30 .= (r+(1-r))*(G*(1,width G)) +(1-r)*|[-1,1]| - r*|[1,0]| by EUCLID:37 .= 1*(G*(1,width G)) +(1-r)*|[-1,1]| - r*|[1,0]| by XCMPLX_1:27 .= G*(1,width G) +(1-r)*|[-1,1]| - r*|[1,0]| by EUCLID:33 .= G*(1,width G)+|[(1-r)*(-1),(1-r)*1]| - r*|[1,0]| by EUCLID:62 .= G*(1,width G)+|[-(1-r),(1-r)*1]| - r*|[1,0]| by XCMPLX_1:180 .= G*(1,width G)+|[r-1,(1-r)*1]| - r*|[1,0]| by XCMPLX_1:143 .= G*(1,width G)+|[r-1,1-r]| - |[r*1,r*0]| by EUCLID:62 .= |[r1+(r-1),s1+(1-r)]| - |[r,0]| by A7,EUCLID:60 .= |[r1+(r-1)-r,s1+(1-r)-0]| by EUCLID:66 .= |[r1+((r-1)-r),s1+(1-r)]| by XCMPLX_1:29 .= |[r1-(r-(r-1)),s1+(1-r)]| by XCMPLX_1:38 .= |[r1-1,s1+(1-r)]| by XCMPLX_1:18; r1 < r1+1 by REAL_1:69; then A9: r1-1 < r1 by REAL_1:84; Int cell(G,0,width G) = { |[r',s']| : r' < G*(1,1)`1 & G*(1,width G)`2 < s' } by Th22; hence p in Int cell(G,0,width G) by A4,A8,A9; end; hence x in Int cell(G,0,width G) \/ { G*(1,width G) - |[1,0]| } by XBOOLE_0:def 2; end; theorem Th62: LSeg(G*(len G,width G) + |[1,1]|,G*(len G,width G) + |[1,0]|) c= Int cell(G,len G,width G) \/ { G*(len G,width G) + |[1,0]| } proof let x be set; assume A1: x in LSeg(G*(len G,width G)+|[1,1]|,G*(len G,width G) + |[1,0]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A2: 0<=r & r<=1 and A3: p = (1-r)*(G*(len G,width G)+|[1,1]|)+r*(G*(len G,width G) + |[1,0]|) by A1,SPPOL_1:21; set r1 = G*(len G,1)`1, s1 = G*(1,width G)`2; now per cases by A2,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(len G,width G) + |[1,0]|) by A3,EUCLID:33 .= 1*(G*(len G,width G) + |[1,0]|) by EUCLID:31 .= G*(len G,width G) + |[1,0]| by EUCLID:33; hence p in { G*(len G,width G) + |[1,0]| } by TARSKI:def 1; case r < 1; then 1 - r > 0 by SQUARE_1:11; then A4: s1 < s1 +(1-r) by REAL_1:69; 0 <> width G by GOBOARD1:def 5; then A5: 1 <= width G by RLVECT_1:99; 0 <> len G by GOBOARD1:def 5; then A6: 1 <= len G by RLVECT_1:99; A7: G*(len G,width G) = |[G*(len G,width G)`1,G*(len G,width G)`2]| by EUCLID:57 .= |[r1,G*(len G,width G)`2]| by A5,A6,GOBOARD5:3 .= |[r1,s1]| by A5,A6,GOBOARD5:2; A8: p = (1-r)*(G*(len G,width G))+(1-r)*|[1,1]|+r*(G* (len G,width G) + |[1,0]|) by A3,EUCLID:36 .= (1-r)*(G*(len G,width G))+(1-r)*|[1,1]|+(r*(G* (len G,width G)) + r*|[1,0]|) by EUCLID:36 .= r*(G*(len G,width G))+((1-r)*(G* (len G,width G))+(1-r)*|[1,1]|) + r*|[1,0]| by EUCLID:30 .= r*(G*(len G,width G)) + (1-r)*(G* (len G,width G))+(1-r)*|[1,1]| + r*|[1,0]| by EUCLID:30 .= (r+(1-r))*(G*(len G,width G)) +(1-r)*|[1,1]| + r*|[1,0]| by EUCLID:37 .= 1 * (G*(len G,width G)) +(1-r)*|[1,1]| + r*|[1,0]| by XCMPLX_1:27 .= G*(len G,width G) +(1-r)*|[1,1]| + r*|[1,0]| by EUCLID:33 .= G*(len G,width G)+|[(1-r)*1,(1-r)*1]| + r*|[1,0]| by EUCLID:62 .= G*(len G,width G)+|[1-r,1-r]| + |[r*1,r*0]| by EUCLID:62 .= |[r1+(1-r),s1+(1-r)]| + |[r,0]| by A7,EUCLID:60 .= |[r1+(1-r)+r,s1+(1-r)+0]| by EUCLID:60 .= |[r1+((1-r)+r),s1+(1-r)]| by XCMPLX_1:1 .= |[r1+1,s1+(1-r)]| by XCMPLX_1:27; A9: r1 < r1+1 by REAL_1:69; Int cell(G,len G,width G) = { |[r',s']| : G*(len G,1)`1 < r' & G*(1,width G)`2 < s' } by Th25; hence p in Int cell(G,len G,width G) by A4,A8,A9; end; hence x in Int cell(G,len G,width G) \/ { G*(len G,width G) + |[1,0]| } by XBOOLE_0:def 2 ; end; theorem Th63: LSeg(G*(1,1) - |[1,1]|,G*(1,1) - |[0,1]|) c= Int cell(G,0,0) \/ { G*(1,1) - |[0,1]| } proof let x be set; assume A1: x in LSeg(G*(1,1)-|[1,1]|,G*(1,1) - |[0,1]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A2: 0<=r & r<=1 and A3: p = (1-r)*(G*(1,1)-|[1,1]|)+r*(G*(1,1) - |[0,1]|) by A1,SPPOL_1:21; set r1 = G*(1,1)`1, s1 = G*(1,1)`2; now per cases by A2,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(1,1) - |[0,1]|) by A3,EUCLID:33 .= 1*(G*(1,1) - |[0,1]|) by EUCLID:31 .= G*(1,1) - |[0,1]| by EUCLID:33; hence p in { G*(1,1) - |[0,1]| } by TARSKI:def 1; case r < 1; then A4: 1 - r > 0 by SQUARE_1:11; s1 < s1 +1 by REAL_1:69; then A5: s1-1 < s1 by REAL_1:84; A6: G*(1,1) = |[r1,s1]| by EUCLID:57; A7: p = (1-r)*(G*(1,1))-(1-r)*|[1,1]|+r*(G*(1,1) - |[0,1]|) by A3,EUCLID:53 .= (1-r)*(G*(1,1))-(1-r)*|[1,1]|+(r*(G*(1,1)) - r*|[0,1]|) by EUCLID:53 .= r*(G*(1,1)) + ((1-r)*(G*(1,1))-(1-r)*|[1,1]|) - r*|[0,1]| by EUCLID:49 .= r*(G*(1,1)) + (1-r)*(G*(1,1))-(1-r)*|[1,1]| - r*|[0,1]| by EUCLID:49 .= (r+(1-r))*(G*(1,1)) -(1-r)*|[1,1]| - r*|[0,1]| by EUCLID:37 .= 1 * (G*(1,1)) -(1-r)*|[1,1]| - r*|[0,1]| by XCMPLX_1:27 .= G*(1,1) -(1-r)*|[1,1]| - r*|[0,1]| by EUCLID:33 .= G*(1,1)-|[(1-r)*1,(1-r)*1]| - r*|[0,1]| by EUCLID:62 .= G*(1,1)-|[1-r,1-r]| - |[r*0,r*1]| by EUCLID:62 .= |[r1-(1-r),s1-(1-r)]| - |[0,r]| by A6,EUCLID:66 .= |[r1-(1-r)-0,s1-(1-r)-r]| by EUCLID:66 .= |[r1-(1-r),s1-((1-r)+r)]| by XCMPLX_1:36 .= |[r1-(1-r),s1-1]| by XCMPLX_1:27; r1 < r1+(1-r) by A4,REAL_1:69; then A8: r1-(1-r) < r1 by REAL_1:84; Int cell(G,0,0) = { |[r',s']| : r' < G*(1,1)`1 & s' < G* (1,1)`2 } by Th21; hence p in Int cell(G,0,0) by A5,A7,A8; end; hence x in Int cell(G,0,0) \/ { G*(1,1) - |[0,1]| } by XBOOLE_0:def 2; end; theorem Th64: LSeg(G*(len G,1) + |[1,-1]|,G*(len G,1) - |[0,1]|) c= Int cell(G,len G,0) \/ { G*(len G,1) - |[0,1]| } proof let x be set; assume A1: x in LSeg(G*(len G,1)+|[1,-1]|,G*(len G,1) - |[0,1]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A2: 0<=r & r<=1 and A3: p = (1-r)*(G*(len G,1)+|[1,-1]|)+r*(G*(len G,1) - |[0,1]|) by A1,SPPOL_1:21; set r1 = G*(len G,1)`1, s1 = G*(1,1)`2; now per cases by A2,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(len G,1) - |[0,1]|) by A3,EUCLID:33 .= 1*(G*(len G,1) - |[0,1]|) by EUCLID:31 .= G*(len G,1) - |[0,1]| by EUCLID:33; hence p in { G*(len G,1) - |[0,1]| } by TARSKI:def 1; case r < 1; then A4: 1 - r > 0 by SQUARE_1:11; s1 < s1+1 by REAL_1:69; then A5: s1-1 < s1 by REAL_1:84; 0 <> width G by GOBOARD1:def 5; then A6: 1 <= width G by RLVECT_1:99; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(len G,1) = |[r1,G*(len G,1)`2]| by EUCLID:57 .= |[r1,s1]| by A6,A7,GOBOARD5:2; A9: p = (1-r)*(G*(len G,1))+(1-r)*|[1,-1]|+r*(G*(len G,1) - |[0,1]|) by A3, EUCLID:36 .= (1-r)*(G*(len G,1))+(1-r)*|[1,-1]|+(r*(G*(len G,1)) - r*|[0,1]|) by EUCLID:53 .= r*(G*(len G,1)) + ((1-r)*(G*(len G,1))+(1-r)*|[1,-1]|) - r*|[0,1]| by EUCLID:49 .= r*(G*(len G,1)) + (1-r)*(G*(len G,1))+(1-r)*|[1,-1]| - r*|[0,1]| by EUCLID:30 .= (r+(1-r))*(G*(len G,1)) +(1-r)*|[1,-1]| - r*|[0,1]| by EUCLID:37 .= 1*(G*(len G,1)) +(1-r)*|[1,-1]| - r*|[0,1]| by XCMPLX_1:27 .= G*(len G,1) +(1-r)*|[1,-1]| - r*|[0,1]| by EUCLID:33 .= G*(len G,1)+|[(1-r)*1,(1-r)*(-1)]| - r*|[0,1]| by EUCLID:62 .= G*(len G,1)+|[1-r,-(1-r)]| - r*|[0,1]| by XCMPLX_1:180 .= G*(len G,1)+|[1-r,r-1]| - r*|[0,1]| by XCMPLX_1:143 .= G*(len G,1)+|[1-r,r-1]| - |[r*0,r*1]| by EUCLID:62 .= |[r1+(1-r),s1+(r-1)]| - |[0,r]| by A8,EUCLID:60 .= |[r1+(1-r)-0,s1+(r-1)-r]| by EUCLID:66 .= |[r1+(1-r),s1+((r-1)-r)]| by XCMPLX_1:29 .= |[r1+(1-r),s1-(r-(r-1))]| by XCMPLX_1:38 .= |[r1+(1-r),s1-1]| by XCMPLX_1:18; A10: r1 < r1+(1-r) by A4,REAL_1:69; Int cell(G,len G,0) = { |[r',s']| : G*(len G,1)`1 < r' & s' < G*(1,1)`2 } by Th24; hence p in Int cell(G,len G,0) by A5,A9,A10; end; hence x in Int cell(G,len G,0) \/ { G*(len G,1) - |[0,1]| } by XBOOLE_0:def 2 ; end; theorem Th65: LSeg(G*(1,width G) + |[-1,1]|,G*(1,width G) + |[0,1]|) c= Int cell(G,0,width G) \/ { G*(1,width G) + |[0,1]| } proof let x be set; assume A1: x in LSeg(G*(1,width G)+|[-1,1]|,G*(1,width G) + |[0,1]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A2: 0<=r & r<=1 and A3: p = (1-r)*(G*(1,width G)+|[-1,1]|)+r*(G*(1,width G) + |[0,1]|) by A1,SPPOL_1:21; set r1 = G*(1,1)`1, s1 = G*(1,width G)`2; now per cases by A2,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(1,width G) + |[0,1]|) by A3,EUCLID:33 .= 1*(G*(1,width G) + |[0,1]|) by EUCLID:31 .= G*(1,width G) + |[0,1]| by EUCLID:33; hence p in { G*(1,width G) + |[0,1]| } by TARSKI:def 1; case r < 1; then A4: 1 - r > 0 by SQUARE_1:11; A5: s1 < s1 +1 by REAL_1:69; 0 <> width G by GOBOARD1:def 5; then A6: 1 <= width G by RLVECT_1:99; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(1,width G) = |[G*(1,width G)`1,s1]| by EUCLID:57 .= |[r1,s1]| by A6,A7,GOBOARD5:3; A9: p = (1-r)*(G*(1,width G))+(1-r)*|[-1,1]|+r*(G*(1,width G) + |[0,1]|) by A3,EUCLID:36 .= (1-r)*(G*(1,width G))+(1-r)*|[-1,1]|+(r*(G*(1,width G)) + r*|[0,1]|) by EUCLID:36 .= r*(G*(1,width G)) + ((1-r)*(G* (1,width G))+(1-r)*|[-1,1]|) + r*|[0,1]| by EUCLID:30 .= r*(G*(1,width G)) + (1-r)*(G*(1,width G))+(1-r)*|[-1,1]| + r*|[0,1]| by EUCLID:30 .= (r+(1-r))*(G*(1,width G)) +(1-r)*|[-1,1]| + r*|[0,1]| by EUCLID:37 .= 1*(G*(1,width G)) +(1-r)*|[-1,1]| + r*|[0,1]| by XCMPLX_1:27 .= G*(1,width G) +(1-r)*|[-1,1]| + r*|[0,1]| by EUCLID:33 .= G*(1,width G)+|[(1-r)*(-1),(1-r)*1]| + r*|[0,1]| by EUCLID:62 .= G*(1,width G)+|[-(1-r),(1-r)*1]| + r*|[0,1]| by XCMPLX_1:180 .= G*(1,width G)+|[r-1,(1-r)*1]| + r*|[0,1]| by XCMPLX_1:143 .= G*(1,width G)+|[r-1,1-r]| + |[r*0,r*1]| by EUCLID:62 .= |[r1+(r-1),s1+(1-r)]| + |[0,r]| by A8,EUCLID:60 .= |[r1+(r-1)+0,s1+(1-r)+r]| by EUCLID:60 .= |[r1+(r-1),s1+((1-r)+r)]| by XCMPLX_1:1 .= |[r1+(r-1),s1+1]| by XCMPLX_1:27 .= |[r1-(1-r),s1+1]| by XCMPLX_1:38; r1 < r1+(1-r) by A4,REAL_1:69; then A10: r1-(1-r) < r1 by REAL_1:84; Int cell(G,0,width G) = { |[r',s']| : r' < G*(1,1)`1 & G*(1,width G)`2 < s' } by Th22; hence p in Int cell(G,0,width G) by A5,A9,A10; end; hence x in Int cell(G,0,width G) \/ { G*(1,width G) + |[0,1]| } by XBOOLE_0:def 2; end; theorem Th66: LSeg(G*(len G,width G) + |[1,1]|,G*(len G,width G) + |[0,1]|) c= Int cell(G,len G,width G) \/ { G*(len G,width G) + |[0,1]| } proof let x be set; assume A1: x in LSeg(G*(len G,width G)+|[1,1]|,G*(len G,width G) + |[0,1]|); then reconsider p = x as Point of TOP-REAL 2; consider r such that A2: 0<=r & r<=1 and A3: p = (1-r)*(G*(len G,width G)+|[1,1]|)+r*(G*(len G,width G) + |[0,1]|) by A1,SPPOL_1:21; set r1 = G*(len G,1)`1, s1 = G*(1,width G)`2; now per cases by A2,AXIOMS:21; case r = 1; then p = 0.REAL 2 + 1*(G*(len G,width G) + |[0,1]|) by A3,EUCLID:33 .= 1*(G*(len G,width G) + |[0,1]|) by EUCLID:31 .= G*(len G,width G) + |[0,1]| by EUCLID:33; hence p in { G*(len G,width G) + |[0,1]| } by TARSKI:def 1; case r < 1; then A4: 1 - r > 0 by SQUARE_1:11; A5: s1 < s1 +1 by REAL_1:69; 0 <> width G by GOBOARD1:def 5; then A6: 1 <= width G by RLVECT_1:99; 0 <> len G by GOBOARD1:def 5; then A7: 1 <= len G by RLVECT_1:99; A8: G*(len G,width G) = |[G*(len G,width G)`1,G*(len G,width G)`2]| by EUCLID:57 .= |[r1,G*(len G,width G)`2]| by A6,A7,GOBOARD5:3 .= |[r1,s1]| by A6,A7,GOBOARD5:2; A9: p = (1-r)*(G*(len G,width G))+(1-r)*|[1,1]|+r*(G* (len G,width G) + |[0,1]|) by A3,EUCLID:36 .= (1-r)*(G*(len G,width G))+(1-r)*|[1,1]|+(r*(G* (len G,width G)) + r*|[0,1]|) by EUCLID:36 .= r*(G*(len G,width G))+((1-r)*(G* (len G,width G))+(1-r)*|[1,1]|) + r*|[0,1]| by EUCLID:30 .= r*(G*(len G,width G)) + (1-r)*(G* (len G,width G))+(1-r)*|[1,1]| + r*|[0,1]| by EUCLID:30 .= (r+(1-r))*(G*(len G,width G)) +(1-r)*|[1,1]| + r*|[0,1]| by EUCLID:37 .= 1 * (G*(len G,width G)) +(1-r)*|[1,1]| + r*|[0,1]| by XCMPLX_1:27 .= G*(len G,width G) +(1-r)*|[1,1]| + r*|[0,1]| by EUCLID:33 .= G*(len G,width G)+|[(1-r)*1,(1-r)*1]| + r*|[0,1]| by EUCLID:62 .= G*(len G,width G)+|[1-r,1-r]| + |[r*0,r*1]| by EUCLID:62 .= |[r1+(1-r),s1+(1-r)]| + |[0,r]| by A8,EUCLID:60 .= |[r1+(1-r)+0,s1+(1-r)+r]| by EUCLID:60 .= |[r1+(1-r),s1+((1-r)+r)]| by XCMPLX_1:1 .= |[r1+(1-r),s1+1]| by XCMPLX_1:27; A10: r1 < r1+(1-r) by A4,REAL_1:69; Int cell(G,len G,width G) = { |[r',s']| : G*(len G,1)`1 < r' & G*(1,width G)`2 < s' } by Th25; hence p in Int cell(G,len G,width G) by A5,A9,A10; end; hence thesis by XBOOLE_0:def 2; end; theorem 1 <= i & i < len G & 1 <= j & j+1 < width G implies LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i,j+1)+G*(i+1,j+2))) c= Int cell(G,i,j) \/ Int cell(G,i,j+1) \/ { 1/2*(G*(i,j+1)+G*(i+1,j+1)) } proof assume A1: 1 <= i & i < len G & 1 <= j & j+1 < width G; set p1 = G*(i,j), p2 = G*(i,j+1), q2 = G*(i+1,j+1), q3 = G*(i+1,j+2), r = (p2`2-p1`2)/(q3`2-p1`2); A2: j+1 >= 1 by NAT_1:29; j <= j+1 by NAT_1:29; then A3: j < width G by A1,AXIOMS:22; then A4: p1`1 = G*(i,1)`1 by A1,GOBOARD5:3 .= p2`1 by A1,A2,GOBOARD5:3; A5: i+1 >= 1 by NAT_1:29; A6: j+1+1 = j+(1+1) by XCMPLX_1:1; then A7: j+(1+1) <= width G by A1,NAT_1:38; A8: j+2 >= 1 by A6,NAT_1:29; A9: i+1 <= len G by A1,NAT_1:38; then A10: q2`1 = G*(i+1,1)`1 by A1,A2,A5,GOBOARD5:3 .= q3`1 by A5,A7,A8,A9,GOBOARD5:3; A11: q2`2 = G*(1,j+1)`2 by A1,A2,A5,A9,GOBOARD5:2 .= p2`2 by A1,A2,GOBOARD5:2; j+1 < j+2 by REAL_1:53; then q2`2 < q3`2 by A2,A5,A7,A9,GOBOARD5:5; then A12: p2`2-p1`2 < q3`2-p1`2 by A11,REAL_1:54; j < j+1 by REAL_1:69; then p1`2 < p2`2 by A1,GOBOARD5:5; then A13: p2`2-p1`2 > 0 by SQUARE_1:11; then q3`2-p1`2 > 0 by A12,AXIOMS:22; then A14: 0 < r by A13,REAL_2:127; A15: r < 1 by A12,A13,REAL_2:142; r*(q3`2-p1`2) = p2`2-p1`2 by A12,A13,XCMPLX_1:88; then A16: p2`2 = p1`2 + r*(q3`2-p1`2) by XCMPLX_1:27 .= p1`2 + (r*q3`2-r*p1`2) by XCMPLX_1:40 .= p1`2 + r*q3`2-r*p1`2 by XCMPLX_1:29 .= 1*p1`2-r*p1`2 + r*q3`2 by XCMPLX_1:29 .= (1-r)*p1`2 +r*q3`2 by XCMPLX_1:40; A17: (p2+q2)`1 = p2`1 + 1*q2`1 by Lm1 .= p2`1+(1-r+r)*q2`1 by XCMPLX_1:27 .= p2`1+((1-r)*q2`1+r*q3`1) by A10,XCMPLX_1:8 .= 1*p2`1+r*q3`1+(1-r)*q2`1 by XCMPLX_1:1 .= (1-r+r)*p2`1+r*q3`1+(1-r)*q2`1 by XCMPLX_1:27 .= ((1-r)*p1`1+r*p2`1)+r*q3`1+(1-r)*q2`1 by A4,XCMPLX_1:8 .= (1-r)*p1`1+(r*p2`1+r*q3`1)+(1-r)*q2`1 by XCMPLX_1:1 .= (1-r)*p1`1+(1-r)*q2`1+(r*p2`1+r*q3`1) by XCMPLX_1:1 .= (1-r)*p1`1+(1-r)*q2`1+r*(p2`1+q3`1) by XCMPLX_1:8 .= (1-r)*(p1`1+q2`1)+r*(p2`1+q3`1) by XCMPLX_1:8 .= (1-r)*(p1+q2)`1+r*(p2`1+q3`1) by Lm1 .= (1-r)*(p1+q2)`1+r*(p2+q3)`1 by Lm1 .= (1-r)*(p1+q2)`1+(r*(p2+q3))`1 by Lm3 .= ((1-r)*(p1+q2))`1+(r*(p2+q3))`1 by Lm3 .= ((1-r)*(p1+q2)+r*(p2+q3))`1 by Lm1; (p2+q2)`2 = p2`2 + 1*q2`2 by Lm1 .= p2`2+(r+(1-r))*q2`2 by XCMPLX_1:27 .= p2`2+(r*p2`2+(1-r)*q2`2) by A11,XCMPLX_1:8 .= p2`2+r*p2`2+(1-r)*q2`2 by XCMPLX_1:1 .= (1-r)*p1`2+(r*p2`2+r*q3`2)+(1-r)*q2`2 by A16,XCMPLX_1:1 .= (1-r)*p1`2+(1-r)*q2`2+(r*p2`2+r*q3`2) by XCMPLX_1:1 .= (1-r)*p1`2+(1-r)*q2`2+r*(p2`2+q3`2) by XCMPLX_1:8 .= (1-r)*(p1`2+q2`2)+r*(p2`2+q3`2) by XCMPLX_1:8 .= (1-r)*(p1`2+q2`2)+r*(p2+q3)`2 by Lm1 .= (1-r)*(p1+q2)`2+r*(p2+q3)`2 by Lm1 .= (1-r)*(p1+q2)`2+(r*(p2+q3))`2 by Lm3 .= ((1-r)*(p1+q2))`2+(r*(p2+q3))`2 by Lm3 .= ((1-r)*(p1+q2)+r*(p2+q3))`2 by Lm1; then (1-r)*(p1+q2)+r*(p2+q3) = |[(p2+q2)`1,(p2+q2)`2]| by A17,EUCLID:57 .= p2+q2 by EUCLID:57; then 1/2*(p2+q2) = (1/2)*((1-r)*(p1+q2))+(1/2)*(r*(p2+q3)) by EUCLID:36 .= 1/2*(1-r)*(p1+q2)+1/2*(r*(p2+q3)) by EUCLID:34 .= (1-r)*(1/2*(p1+q2))+1/2*(r*(p2+q3)) by EUCLID:34 .= (1-r)*(1/2*(p1+q2))+1/2*r*(p2+q3) by EUCLID:34 .= (1-r)*((1/2)*(p1+q2))+r*((1/2)*(p2+q3)) by EUCLID:34; then 1/2*(p2+q2) in LSeg(1/2*(p1+q2),1/2*(p2+q3)) by A14,A15,SPPOL_1:22; then A18: LSeg(1/2*(p1+q2),1/2*(p2+q3)) = LSeg(1/2*(p1+q2),1/2*(p2+q2)) \/ LSeg(1/2*(p2+q2),1/2*(p2+q3)) by TOPREAL1:11; set I1 = Int cell(G,i,j), I2 = Int cell(G,i,j+1); A19: LSeg(1/2*(p1+q2),1/2*(p2+q2)) c= I1 \/ { 1/2*(p2+q2) } by A1,A3,Th44; A20: LSeg(1/2*(p2+q2),1/2*(p2+q3)) c= I2 \/ { 1/2*(p2+q2) } by A1,A2,A6,Th46; I1 \/ I2 \/ { 1/2*(p2+q2) } = I1 \/ (I2 \/ ({ 1/2*(p2+q2) } \/ { 1/2*(p2+q2) })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { 1/2*(p2+q2) } \/ { 1/2*(p2+q2) }) by XBOOLE_1:4 .= I1 \/ { 1/2*(p2+q2) } \/ (I2 \/ { 1/2*(p2+q2) }) by XBOOLE_1:4; hence thesis by A18,A19,A20,XBOOLE_1:13; end; theorem 1 <= j & j < width G & 1 <= i & i+1 < len G implies LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),1/2*(G*(i+1,j)+G*(i+2,j+1))) c= Int cell(G,i,j) \/ Int cell(G,i+1,j) \/ { 1/2*(G*(i+1,j)+G*(i+1,j+1)) } proof assume A1: 1 <= j & j < width G & 1 <= i & i+1 < len G; set p1 = G*(i,j), p2 = G*(i+1,j), q2 = G*(i+1,j+1), q3 = G*(i+2,j+1), r = (p2`1-p1`1)/(q3`1-p1`1); A2: i+1 >= 1 by NAT_1:29; i <= i+1 by NAT_1:29; then A3: i < len G by A1,AXIOMS:22; then A4: p1`2 = G*(1,j)`2 by A1,GOBOARD5:2 .= p2`2 by A1,A2,GOBOARD5:2; A5: j+1 >= 1 by NAT_1:29; A6: i+1+1 = i+(1+1) by XCMPLX_1:1; then A7: i+(1+1) <= len G by A1,NAT_1:38; A8: i+2 >= 1 by A6,NAT_1:29; A9: j+1 <= width G by A1,NAT_1:38; then A10: q2`2 = G*(1,j+1)`2 by A1,A2,A5,GOBOARD5:2 .= q3`2 by A5,A7,A8,A9,GOBOARD5:2; A11: q2`1 = G*(i+1,1)`1 by A1,A2,A5,A9,GOBOARD5:3 .= p2`1 by A1,A2,GOBOARD5:3; i+1 < i+2 by REAL_1:53; then q2`1 < q3`1 by A2,A5,A7,A9,GOBOARD5:4; then A12: p2`1-p1`1 < q3`1-p1`1 by A11,REAL_1:54; i < i+1 by REAL_1:69; then p1`1 < p2`1 by A1,GOBOARD5:4; then A13: p2`1-p1`1 > 0 by SQUARE_1:11; then q3`1-p1`1 > 0 by A12,AXIOMS:22; then A14: 0 < r by A13,REAL_2:127; A15: r < 1 by A12,A13,REAL_2:142; r*(q3`1-p1`1) = p2`1-p1`1 by A12,A13,XCMPLX_1:88; then A16: p2`1 = p1`1 + r*(q3`1-p1`1) by XCMPLX_1:27 .= p1`1 + (r*q3`1-r*p1`1) by XCMPLX_1:40 .= p1`1 + r*q3`1-r*p1`1 by XCMPLX_1:29 .= 1*p1`1-r*p1`1 + r*q3`1 by XCMPLX_1:29 .= (1-r)*p1`1 +r*q3`1 by XCMPLX_1:40; A17: (p2+q2)`2 = p2`2 + 1*q2`2 by Lm1 .= p2`2+(1-r+r)*q2`2 by XCMPLX_1:27 .= p2`2+((1-r)*q2`2+r*q3`2) by A10,XCMPLX_1:8 .= 1*p2`2+r*q3`2+(1-r)*q2`2 by XCMPLX_1:1 .= (1-r+r)*p2`2+r*q3`2+(1-r)*q2`2 by XCMPLX_1:27 .= ((1-r)*p1`2+r*p2`2)+r*q3`2+(1-r)*q2`2 by A4,XCMPLX_1:8 .= (1-r)*p1`2+(r*p2`2+r*q3`2)+(1-r)*q2`2 by XCMPLX_1:1 .= (1-r)*p1`2+(1-r)*q2`2+(r*p2`2+r*q3`2) by XCMPLX_1:1 .= (1-r)*p1`2+(1-r)*q2`2+r*(p2`2+q3`2) by XCMPLX_1:8 .= (1-r)*(p1`2+q2`2)+r*(p2`2+q3`2) by XCMPLX_1:8 .= (1-r)*(p1+q2)`2+r*(p2`2+q3`2) by Lm1 .= (1-r)*(p1+q2)`2+r*(p2+q3)`2 by Lm1 .= (1-r)*(p1+q2)`2+(r*(p2+q3))`2 by Lm3 .= ((1-r)*(p1+q2))`2+(r*(p2+q3))`2 by Lm3 .= ((1-r)*(p1+q2)+r*(p2+q3))`2 by Lm1; (p2+q2)`1 = p2`1 + 1*q2`1 by Lm1 .= p2`1+(r+(1-r))*q2`1 by XCMPLX_1:27 .= p2`1+(r*p2`1+(1-r)*q2`1) by A11,XCMPLX_1:8 .= p2`1+r*p2`1+(1-r)*q2`1 by XCMPLX_1:1 .= (1-r)*p1`1+(r*p2`1+r*q3`1)+(1-r)*q2`1 by A16,XCMPLX_1:1 .= (1-r)*p1`1+(1-r)*q2`1+(r*p2`1+r*q3`1) by XCMPLX_1:1 .= (1-r)*p1`1+(1-r)*q2`1+r*(p2`1+q3`1) by XCMPLX_1:8 .= (1-r)*(p1`1+q2`1)+r*(p2`1+q3`1) by XCMPLX_1:8 .= (1-r)*(p1`1+q2`1)+r*(p2+q3)`1 by Lm1 .= (1-r)*(p1+q2)`1+r*(p2+q3)`1 by Lm1 .= (1-r)*(p1+q2)`1+(r*(p2+q3))`1 by Lm3 .= ((1-r)*(p1+q2))`1+(r*(p2+q3))`1 by Lm3 .= ((1-r)*(p1+q2)+r*(p2+q3))`1 by Lm1; then (1-r)*(p1+q2)+r*(p2+q3) = |[(p2+q2)`1,(p2+q2)`2]| by A17,EUCLID:57 .= p2+q2 by EUCLID:57; then 1/2*(p2+q2) = (1/2)*((1-r)*(p1+q2))+(1/2)*(r*(p2+q3)) by EUCLID:36 .= 1/2*(1-r)*(p1+q2)+1/2*(r*(p2+q3)) by EUCLID:34 .= (1-r)*(1/2*(p1+q2))+1/2*(r*(p2+q3)) by EUCLID:34 .= (1-r)*(1/2*(p1+q2))+1/2*r*(p2+q3) by EUCLID:34 .= (1-r)*((1/2)*(p1+q2))+r*((1/2)*(p2+q3)) by EUCLID:34; then 1/2*(p2+q2) in LSeg(1/2*(p1+q2),1/2*(p2+q3)) by A14,A15,SPPOL_1:22; then A18: LSeg(1/2*(p1+q2),1/2*(p2+q3)) = LSeg(1/2*(p1+q2),1/2*(p2+q2)) \/ LSeg(1/2*(p2+q2),1/2*(p2+q3)) by TOPREAL1:11; set I1 = Int cell(G,i,j), I2 = Int cell(G,i+1,j); A19: LSeg(1/2*(p1+q2),1/2*(p2+q2)) c= I1 \/ { 1/2*(p2+q2) } by A1,A3,Th45; A20: LSeg(1/2*(p2+q2),1/2*(p2+q3)) c= I2 \/ { 1/2*(p2+q2) } by A1,A2,A6,Th43; I1 \/ I2 \/ { 1/2*(p2+q2) } = I1 \/ (I2 \/ ({ 1/2*(p2+q2) } \/ { 1/2*(p2+q2) })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { 1/2*(p2+q2) } \/ { 1/2*(p2+q2) }) by XBOOLE_1:4 .= I1 \/ { 1/2*(p2+q2) } \/ (I2 \/ { 1/2*(p2+q2) }) by XBOOLE_1:4; hence LSeg(1/2*(p1+q2),1/2*(p2+q3)) c= I1 \/ I2 \/ { 1/2*(p2+q2) } by A18,A19,A20,XBOOLE_1:13; end; theorem 1 <= i & i < len G & 1 < width G implies LSeg(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|,1/2*(G*(i,1)+G*(i+1,2))) c= Int cell(G,i,0) \/ Int cell(G,i,1) \/ { 1/2*(G*(i,1)+G*(i+1,1)) } proof assume A1: 1 <= i & i < len G & 1 < width G; set p1 = G*(i,1), q2 = G*(i+1,1), q3 = G*(i+1,2), r = 1/(1/2*(q3`2-p1`2)+1); A2: i+1 >= 1 by NAT_1:29; A3: 0+1+1 = 0+(1+1); A4: 0+(1+1) <= width G by A1,NAT_1:38; A5: i+1 <= len G by A1,NAT_1:38; then A6: q2`1 = q3`1 by A2,A4,GOBOARD5:3; A7: q2`2 = G*(1,0+1)`2 by A1,A2,A5,GOBOARD5:2 .= p1`2 by A1,GOBOARD5:2; then p1`2 < q3`2 by A2,A4,A5,GOBOARD5:5; then q3`2-p1`2 > 0 by SQUARE_1:11; then 1/2*(q3`2-p1`2) > 0 by REAL_2:122; then A8: 1 < 1/2*(q3`2-p1`2)+1 by REAL_1:69; then A9: 1/2*(q3`2-p1`2)+1 > 0 by AXIOMS:22; then A10: 0 < r by REAL_2:127; A11: r < 1 by A8,SQUARE_1:2; r*((1/2)*q3`2)-r*((1/2)*q2`2)+r = r*((1/2)*q3`2-((1/2)*q2`2))+r by XCMPLX_1:40 .= r*((1/2)*(q3`2-q2`2))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q3`2-q2`2)+1) by XCMPLX_1:8 .= 1 by A7,A9,XCMPLX_1:107; then r*((1/2)*q3`2)-r*((1/2)*q2`2) = 1-r by XCMPLX_1:26; then A12: r*((1/2)*q3`2)-(1-r) = r*((1/2)*q2`2) by XCMPLX_1:18; A13: ((1-r)*((1/2)*q2)+r*((1/2)*q3)-(1-r)*|[0,1]|)`1 = ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1-((1-r)*|[0,1]|)`1 by Lm2 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1-|[(1-r)*0,(1-r)*1]|`1 by EUCLID:62 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1-0 by EUCLID:56 .= ((1-r)*((1/2)*q2))`1+(r*((1/2)*q3))`1 by Lm1 .= (1-r)*((1/2)*q2)`1+(r*((1/2)*q3))`1 by Lm3 .= (1-r)*((1/2)*q2)`1+r*((1/2)*q3)`1 by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q3)`1 by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q2`1) by A6,Lm3 .= ((1-r)+r)*((1/2)*q2`1) by XCMPLX_1:8 .= 1*((1/2)*q2`1) by XCMPLX_1:27 .= ((1/2)*q2)`1 by Lm3; ((1-r)*((1/2)*q2)+r*((1/2)*q3)-(1-r)*|[0,1]|)`2 = ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2-((1-r)*|[0,1]|)`2 by Lm2 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2-|[(1-r)*0,(1-r)*1]|`2 by EUCLID:62 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2-(1-r) by EUCLID:56 .= ((1-r)*((1/2)*q2))`2+(r*((1/2)*q3))`2-(1-r) by Lm1 .= (1-r)*((1/2)*q2)`2+(r*((1/2)*q3))`2-(1-r) by Lm3 .= (1-r)*((1/2)*q2)`2+r*((1/2)*q3)`2-(1-r) by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q3)`2-(1-r) by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q3`2)-(1-r) by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q2`2) by A12,XCMPLX_1:29 .= ((1-r)+r)*((1/2)*q2`2) by XCMPLX_1:8 .= 1*((1/2)*q2`2) by XCMPLX_1:27 .= ((1/2)*q2)`2 by Lm3; then A14: (1-r)*((1/2)*q2)+r*((1/2)*q3)-(1-r)*|[0,1]| = |[(1/2*q2)`1,(1/2* q2)`2]| by A13,EUCLID:57 .= 1/2*q2 by EUCLID:57; A15: (1-r)*((1/2)*p1)+r*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*q3) = (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*p1)+r*((1/2)*q3) by EUCLID:30 .= (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+(r*((1/2)*p1)+r*((1/2)*q3)) by EUCLID:30 .= (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*p1+(1/2)*q3) by EUCLID:36 .= (1-r)*((1/2)*p1+(1/2)*q2)+r*((1/2)*p1+(1/2)*q3) by EUCLID:36 .= (1-r)*((1/2)*p1+(1/2)*q2)+r*((1/2)*(p1+q3)) by EUCLID:36 .= (1-r)*((1/2)*(p1+q2))+r*((1/2)*(p1+q3)) by EUCLID:36; 1/2*(p1+q2) = 1/2*p1+1/2*q2 by EUCLID:36 .= 1*((1/2)*p1)+1/2*q2 by EUCLID:33 .= (1-r+r)*((1/2)*p1)+1/2*q2 by XCMPLX_1:27 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+1/2*q2 by EUCLID:37 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+ ((1-r)*((1/2)*q2)+r*((1/2)*q3))-(1-r)*|[0,1]| by A14,EUCLID:49 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+ (1-r)*((1/2)*q2)+r*((1/2)*q3)-(1-r)*|[0,1]| by EUCLID:30 .= (1-r)*((1/2)*(p1+q2))+(r*((1/2)*(p1+q3))-(1-r)*|[0,1]|) by A15,EUCLID:49 .= (1-r)*((1/2)*(p1+q2))+-((1-r)*|[0,1]|-r*((1/2)*(p1+q3))) by EUCLID:48 .= (1-r)*((1/2)*(p1+q2))-((1-r)*|[0,1]|-r*((1/2)*(p1+q3))) by EUCLID:45 .= (1-r)*((1/2)*(p1+q2))-(1-r)*|[0,1]|+r*((1/2)*(p1+q3)) by EUCLID:51 .= (1-r)*((1/2)*(p1+q2)-|[0,1]|)+r*((1/2)*(p1+q3)) by EUCLID:53; then 1/2*(p1+q2) in LSeg(1/2*(p1+q2)-|[0,1]|,1/2*(p1+q3)) by A10,A11,SPPOL_1:22 ; then A16: LSeg(1/2*(p1+q2)-|[0,1]|,1/2*(p1+q3)) = LSeg(1/2*(p1+q2)-|[0,1]|,1/2*(p1+q2)) \/ LSeg(1/2*(p1+q2),1/2*(p1+q3)) by TOPREAL1:11; set I1 = Int cell(G,i,0), I2 = Int cell(G,i,1); A17: LSeg(1/2*(p1+q2)-|[0,1]|,1/2*(p1+q2)) c= I1 \/ { 1/2*(p1+q2) } by A1,Th49; A18: LSeg(1/2*(p1+q2),1/2*(p1+q3)) c= I2 \/ { 1/2*(p1+q2) } by A1,A3,Th46; I1 \/ I2 \/ { 1/2*(p1+q2) } = I1 \/ (I2 \/ ({ 1/2*(p1+q2) } \/ { 1/2*(p1+q2) })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { 1/2*(p1+q2) } \/ { 1/2*(p1+q2) }) by XBOOLE_1:4 .= I1 \/ { 1/2*(p1+q2) } \/ (I2 \/ { 1/2*(p1+q2) }) by XBOOLE_1:4; hence LSeg(1/2*(p1+q2)-|[0,1]|,1/2*(p1+q3)) c= I1 \/ I2 \/ { 1/2*(p1+q2) } by A16,A17,A18,XBOOLE_1:13; end; theorem 1 <= i & i < len G & 1 < width G implies LSeg(1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|, 1/2*(G*(i,width G)+G*(i+1,width G -' 1))) c= Int cell(G,i,width G -'1) \/ Int cell(G,i,width G) \/ { 1/2*(G*(i,width G)+G*(i+1,width G)) } proof assume A1: 1 <= i & i < len G & 1 < width G; set p1 = G*(i,width G), q2 = G*(i+1,width G), q3 = G*(i+1,width G -' 1), r = 1/(1/2*(p1`2-q3`2)+1); A2: width G -'1 + 1 = width G by A1,AMI_5:4; then A3: 1 <= width G -'1 & width G -'1 < width G by A1,NAT_1:38; then A4: G*(i,width G)+G*(i+1,width G -' 1) = G*(i,width G -' 1)+G*(i+1,width G) by A1,A2,Th14; A5: i+1 >= 1 by NAT_1:29; A6: i+1 <= len G by A1,NAT_1:38; then A7: q2`1 = G*(i+1,1)`1 by A1,A5,GOBOARD5:3 .= q3`1 by A3,A5,A6,GOBOARD5:3; A8: q2`2 = G*(1,width G)`2 by A1,A5,A6,GOBOARD5:2 .= p1`2 by A1,GOBOARD5:2; then q3`2 < p1`2 by A3,A5,A6,GOBOARD5:5; then p1`2-q3`2 > 0 by SQUARE_1:11; then 1/2*(p1`2-q3`2) > 0 by REAL_2:122; then A9: 1 < 1/2*(p1`2-q3`2)+1 by REAL_1:69; then A10: 1/2*(p1`2-q3`2)+1 > 0 by AXIOMS:22; then A11: 0 < r by REAL_2:127; A12: r < 1 by A9,SQUARE_1:2; r*((1/2)*q2`2)-r*((1/2)*q3`2)+r = r*((1/2)*q2`2-((1/2)*q3`2))+r by XCMPLX_1:40 .= r*((1/2)*(q2`2-q3`2))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q2`2-q3`2)+1) by XCMPLX_1:8 .= 1 by A8,A10,XCMPLX_1:107; then r*((1/2)*q2`2)-r*((1/2)*q3`2) = 1-r by XCMPLX_1:26; then A13: r*((1/2)*q3`2)+(1-r) = r*((1/2)*q2`2) by XCMPLX_1:27; A14: ((1-r)*((1/2)*q2)+r*((1/2)*q3)+(1-r)*|[0,1]|)`1 = ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1+((1-r)*|[0,1]|)`1 by Lm1 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1+|[(1-r)*0,(1-r)*1]|`1 by EUCLID:62 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1+0 by EUCLID:56 .= ((1-r)*((1/2)*q2))`1+(r*((1/2)*q3))`1 by Lm1 .= (1-r)*((1/2)*q2)`1+(r*((1/2)*q3))`1 by Lm3 .= (1-r)*((1/2)*q2)`1+r*((1/2)*q3)`1 by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q3)`1 by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q2`1) by A7,Lm3 .= ((1-r)+r)*((1/2)*q2`1) by XCMPLX_1:8 .= 1*((1/2)*q2`1) by XCMPLX_1:27 .= ((1/2)*q2)`1 by Lm3; ((1-r)*((1/2)*q2)+r*((1/2)*q3)+(1-r)*|[0,1]|)`2 = ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2+((1-r)*|[0,1]|)`2 by Lm1 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2+|[(1-r)*0,(1-r)*1]|`2 by EUCLID:62 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2+(1-r) by EUCLID:56 .= ((1-r)*((1/2)*q2))`2+(r*((1/2)*q3))`2+(1-r) by Lm1 .= (1-r)*((1/2)*q2)`2+(r*((1/2)*q3))`2+(1-r) by Lm3 .= (1-r)*((1/2)*q2)`2+r*((1/2)*q3)`2+(1-r) by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q3)`2+(1-r) by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q3`2)+(1-r) by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q2`2) by A13,XCMPLX_1:1 .= ((1-r)+r)*((1/2)*q2`2) by XCMPLX_1:8 .= 1*((1/2)*q2`2) by XCMPLX_1:27 .= ((1/2)*q2)`2 by Lm3; then A15: (1-r)*((1/2)*q2)+r*((1/2)*q3)+(1-r)*|[0,1]| = |[(1/2*q2)`1,(1/2* q2)`2]| by A14,EUCLID:57 .= 1/2*q2 by EUCLID:57; A16: (1-r)*((1/2)*p1)+r*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*q3) = (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*p1)+r*((1/2)*q3) by EUCLID:30 .= (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+(r*((1/2)*p1)+r*((1/2)*q3)) by EUCLID:30 .= (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*p1+(1/2)*q3) by EUCLID:36 .= (1-r)*((1/2)*p1+(1/2)*q2)+r*((1/2)*p1+(1/2)*q3) by EUCLID:36 .= (1-r)*((1/2)*p1+(1/2)*q2)+r*((1/2)*(p1+q3)) by EUCLID:36 .= (1-r)*((1/2)*(p1+q2))+r*((1/2)*(p1+q3)) by EUCLID:36; 1/2*(p1+q2) = 1/2*p1+1/2*q2 by EUCLID:36 .= 1*((1/2)*p1)+1/2*q2 by EUCLID:33 .= (1-r+r)*((1/2)*p1)+1/2*q2 by XCMPLX_1:27 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+1/2*q2 by EUCLID:37 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+ ((1-r)*((1/2)*q2)+r*((1/2)*q3))+(1-r)*|[0,1]| by A15,EUCLID:30 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+ (1-r)*((1/2)*q2)+r*((1/2)*q3)+(1-r)*|[0,1]| by EUCLID:30 .= (1-r)*((1/2)*(p1+q2))+(1-r)*|[0,1]|+r*((1/2)*(p1+q3)) by A16,EUCLID:30 .= (1-r)*((1/2)*(p1+q2)+|[0,1]|)+r*((1/2)*(p1+q3)) by EUCLID:36; then 1/2*(p1+q2) in LSeg(1/2*(p1+q2)+|[0,1]|,1/2*(p1+q3)) by A11,A12,SPPOL_1:22 ; then A17: LSeg(1/2*(p1+q2)+|[0,1]|,1/2*(p1+q3)) = LSeg(1/2*(p1+q2)+|[0,1]|,1/2*(p1+q2)) \/ LSeg(1/2*(p1+q2),1/2*(p1+q3)) by TOPREAL1:11; set I1 = Int cell(G,i,width G -'1), I2 = Int cell(G,i,width G); A18: LSeg(1/2*(p1+q2)+|[0,1]|,1/2*(p1+q2)) c= I2 \/ { 1/2*(p1+q2) } by A1,Th50; A19: LSeg(1/2*(p1+q2),1/2*(p1+q3)) c= I1 \/ { 1/2*(p1+q2) } by A1,A2,A3,A4,Th44; I1 \/ I2 \/ { 1/2*(p1+q2) } = I1 \/ (I2 \/ ({ 1/2*(p1+q2) } \/ { 1/2*(p1+q2) })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { 1/2*(p1+q2) } \/ { 1/2*(p1+q2) }) by XBOOLE_1:4 .= I1 \/ { 1/2*(p1+q2) } \/ (I2 \/ { 1/2*(p1+q2) }) by XBOOLE_1:4; hence LSeg(1/2*(p1+q2)+|[0,1]|,1/2*(p1+q3)) c= I1 \/ I2 \/ { 1/2*(p1+q2) } by A17,A18,A19,XBOOLE_1:13; end; theorem 1 <= j & j < width G & 1 < len G implies LSeg(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|,1/2*(G*(1,j)+G*(2,j+1))) c= Int cell(G,0,j) \/ Int cell(G,1,j) \/ { 1/2*(G*(1,j)+G*(1,j+1)) } proof assume A1: 1 <= j & j < width G & 1 < len G; set p1 = G*(1,j), q2 = G*(1,j+1), q3 = G*(2,j+1), r = 1/(1/2*(q3`1-p1`1)+1); A2: j+1 >= 1 by NAT_1:29; A3: 0+1+1 = 0+(1+1); A4: 0+(1+1) <= len G by A1,NAT_1:38; A5: j+1 <= width G by A1,NAT_1:38; then A6: q2`2 = q3`2 by A2,A4,GOBOARD5:2; A7: q2`1 = G*(1,1)`1 by A1,A2,A5,GOBOARD5:3 .= p1`1 by A1,GOBOARD5:3; then p1`1 < q3`1 by A2,A4,A5,GOBOARD5:4; then q3`1-p1`1 > 0 by SQUARE_1:11; then 1/2*(q3`1-p1`1) > 0 by REAL_2:122; then A8: 1 < 1/2*(q3`1-p1`1)+1 by REAL_1:69; then A9: 1/2*(q3`1-p1`1)+1 > 0 by AXIOMS:22; then A10: 0 < r by REAL_2:127; A11: r < 1 by A8,SQUARE_1:2; r*((1/2)*q3`1)-r*((1/2)*q2`1)+r = r*((1/2)*q3`1-((1/2)*q2`1))+r by XCMPLX_1:40 .= r*((1/2)*(q3`1-q2`1))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q3`1-q2`1)+1) by XCMPLX_1:8 .= 1 by A7,A9,XCMPLX_1:107; then r*((1/2)*q3`1)-r*((1/2)*q2`1) = 1-r by XCMPLX_1:26; then A12: r*((1/2)*q3`1)-(1-r) = r*((1/2)*q2`1) by XCMPLX_1:18; A13: ((1-r)*((1/2)*q2)+r*((1/2)*q3)-(1-r)*|[1,0]|)`2 = ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2-((1-r)*|[1,0]|)`2 by Lm2 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2-|[(1-r)*1,(1-r)*0]|`2 by EUCLID:62 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2-0 by EUCLID:56 .= ((1-r)*((1/2)*q2))`2+(r*((1/2)*q3))`2 by Lm1 .= (1-r)*((1/2)*q2)`2+(r*((1/2)*q3))`2 by Lm3 .= (1-r)*((1/2)*q2)`2+r*((1/2)*q3)`2 by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q3)`2 by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q2`2) by A6,Lm3 .= ((1-r)+r)*((1/2)*q2`2) by XCMPLX_1:8 .= 1*((1/2)*q2`2) by XCMPLX_1:27 .= ((1/2)*q2)`2 by Lm3; ((1-r)*((1/2)*q2)+r*((1/2)*q3)-(1-r)*|[1,0]|)`1 = ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1-((1-r)*|[1,0]|)`1 by Lm2 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1-|[(1-r)*1,(1-r)*0]|`1 by EUCLID:62 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1-(1-r) by EUCLID:56 .= ((1-r)*((1/2)*q2))`1+(r*((1/2)*q3))`1-(1-r) by Lm1 .= (1-r)*((1/2)*q2)`1+(r*((1/2)*q3))`1-(1-r) by Lm3 .= (1-r)*((1/2)*q2)`1+r*((1/2)*q3)`1-(1-r) by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q3)`1-(1-r) by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q3`1)-(1-r) by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q2`1) by A12,XCMPLX_1:29 .= ((1-r)+r)*((1/2)*q2`1) by XCMPLX_1:8 .= 1*((1/2)*q2`1) by XCMPLX_1:27 .= ((1/2)*q2)`1 by Lm3; then A14: (1-r)*((1/2)*q2)+r*((1/2)*q3)-(1-r)*|[1,0]| = |[(1/2*q2)`1,(1/2* q2)`2]| by A13,EUCLID:57 .= 1/2*q2 by EUCLID:57; A15: (1-r)*((1/2)*p1)+r*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*q3) = (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*p1)+r*((1/2)*q3) by EUCLID:30 .= (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+(r*((1/2)*p1)+r*((1/2)*q3)) by EUCLID:30 .= (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*p1+(1/2)*q3) by EUCLID:36 .= (1-r)*((1/2)*p1+(1/2)*q2)+r*((1/2)*p1+(1/2)*q3) by EUCLID:36 .= (1-r)*((1/2)*p1+(1/2)*q2)+r*((1/2)*(p1+q3)) by EUCLID:36 .= (1-r)*((1/2)*(p1+q2))+r*((1/2)*(p1+q3)) by EUCLID:36; 1/2*(p1+q2) = 1/2*p1+1/2*q2 by EUCLID:36 .= 1*((1/2)*p1)+1/2*q2 by EUCLID:33 .= (1-r+r)*((1/2)*p1)+1/2*q2 by XCMPLX_1:27 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+1/2*q2 by EUCLID:37 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+ ((1-r)*((1/2)*q2)+r*((1/2)*q3))-(1-r)*|[1,0]| by A14,EUCLID:49 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+ (1-r)*((1/2)*q2)+r*((1/2)*q3)-(1-r)*|[1,0]| by EUCLID:30 .= (1-r)*((1/2)*(p1+q2))+(r*((1/2)*(p1+q3))-(1-r)*|[1,0]|) by A15,EUCLID:49 .= (1-r)*((1/2)*(p1+q2))+-((1-r)*|[1,0]|-r*((1/2)*(p1+q3))) by EUCLID:48 .= (1-r)*((1/2)*(p1+q2))-((1-r)*|[1,0]|-r*((1/2)*(p1+q3))) by EUCLID:45 .= (1-r)*((1/2)*(p1+q2))-(1-r)*|[1,0]|+r*((1/2)*(p1+q3)) by EUCLID:51 .= (1-r)*((1/2)*(p1+q2)-|[1,0]|)+r*((1/2)*(p1+q3)) by EUCLID:53; then 1/2*(p1+q2) in LSeg(1/2*(p1+q2)-|[1,0]|,1/2*(p1+q3)) by A10,A11,SPPOL_1:22 ; then A16: LSeg(1/2*(p1+q2)-|[1,0]|,1/2*(p1+q3)) = LSeg(1/2*(p1+q2)-|[1,0]|,1/2*(p1+q2)) \/ LSeg(1/2*(p1+q2),1/2*(p1+q3)) by TOPREAL1:11; set I1 = Int cell(G,0,j), I2 = Int cell(G,1,j); A17: LSeg(1/2*(p1+q2)-|[1,0]|,1/2*(p1+q2)) c= I1 \/ { 1/2*(p1+q2) } by A1,Th47; A18: LSeg(1/2*(p1+q2),1/2*(p1+q3)) c= I2 \/ { 1/2*(p1+q2) } by A1,A3,Th43; I1 \/ I2 \/ { 1/2*(p1+q2) } = I1 \/ (I2 \/ ({ 1/2*(p1+q2) } \/ { 1/2*(p1+q2) })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { 1/2*(p1+q2) } \/ { 1/2*(p1+q2) }) by XBOOLE_1:4 .= I1 \/ { 1/2*(p1+q2) } \/ (I2 \/ { 1/2*(p1+q2) }) by XBOOLE_1:4; hence LSeg(1/2*(p1+q2)-|[1,0]|,1/2*(p1+q3)) c= I1 \/ I2 \/ { 1/2*(p1+q2) } by A16,A17,A18,XBOOLE_1:13; end; theorem 1 <= j & j < width G & 1 < len G implies LSeg(1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|, 1/2*(G*(len G,j)+G*(len G -' 1,j+1))) c= Int cell(G,len G -' 1,j) \/ Int cell(G,len G,j) \/ { 1/2*(G*(len G,j)+G*(len G,j+1)) } proof assume A1: 1 <= j & j < width G & 1 < len G; set p1 = G*(len G,j), q2 = G*(len G,j+1), q3 = G*(len G -' 1,j+1), r = 1/(1/2*(p1`1-q3`1)+1); A2: len G -'1 + 1 = len G by A1,AMI_5:4; then A3: 1 <= len G -'1 & len G -'1 < len G by A1,NAT_1:38; then A4: G*(len G -' 1,j)+G*(len G,j+1) = G*(len G,j)+G* (len G -' 1,j+1) by A1,A2,Th14; A5: j+1 >= 1 by NAT_1:29; A6: j+1 <= width G by A1,NAT_1:38; then A7: q2`2 = G*(1,j+1)`2 by A1,A5,GOBOARD5:2 .= q3`2 by A3,A5,A6,GOBOARD5:2; A8: q2`1 = G*(len G,1)`1 by A1,A5,A6,GOBOARD5:3 .= p1`1 by A1,GOBOARD5:3; then q3`1 < p1`1 by A3,A5,A6,GOBOARD5:4; then p1`1-q3`1 > 0 by SQUARE_1:11; then 1/2*(p1`1-q3`1) > 0 by REAL_2:122; then A9: 1 < 1/2*(p1`1-q3`1)+1 by REAL_1:69; then A10: 1/2*(p1`1-q3`1)+1 > 0 by AXIOMS:22; then A11: 0 < r by REAL_2:127; A12: r < 1 by A9,SQUARE_1:2; r*((1/2)*q2`1)-r*((1/2)*q3`1)+r = r*((1/2)*q2`1-((1/2)*q3`1))+r by XCMPLX_1:40 .= r*((1/2)*(q2`1-q3`1))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q2`1-q3`1)+1) by XCMPLX_1:8 .= 1 by A8,A10,XCMPLX_1:107; then r*((1/2)*q2`1)-r*((1/2)*q3`1) = 1-r by XCMPLX_1:26; then A13: r*((1/2)*q3`1)+(1-r) = r*((1/2)*q2`1) by XCMPLX_1:27; A14: ((1-r)*((1/2)*q2)+r*((1/2)*q3)+(1-r)*|[1,0]|)`2 = ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2+((1-r)*|[1,0]|)`2 by Lm1 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2+|[(1-r)*1,(1-r)*0]|`2 by EUCLID:62 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`2+0 by EUCLID:56 .= ((1-r)*((1/2)*q2))`2+(r*((1/2)*q3))`2 by Lm1 .= (1-r)*((1/2)*q2)`2+(r*((1/2)*q3))`2 by Lm3 .= (1-r)*((1/2)*q2)`2+r*((1/2)*q3)`2 by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q3)`2 by Lm3 .= (1-r)*((1/2)*q2`2)+r*((1/2)*q2`2) by A7,Lm3 .= ((1-r)+r)*((1/2)*q2`2) by XCMPLX_1:8 .= 1*((1/2)*q2`2) by XCMPLX_1:27 .= ((1/2)*q2)`2 by Lm3; ((1-r)*((1/2)*q2)+r*((1/2)*q3)+(1-r)*|[1,0]|)`1 = ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1+((1-r)*|[1,0]|)`1 by Lm1 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1+|[(1-r)*1,(1-r)*0]|`1 by EUCLID:62 .= ((1-r)*((1/2)*q2)+r*((1/2)*q3))`1+(1-r) by EUCLID:56 .= ((1-r)*((1/2)*q2))`1+(r*((1/2)*q3))`1+(1-r) by Lm1 .= (1-r)*((1/2)*q2)`1+(r*((1/2)*q3))`1+(1-r) by Lm3 .= (1-r)*((1/2)*q2)`1+r*((1/2)*q3)`1+(1-r) by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q3)`1+(1-r) by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q3`1)+(1-r) by Lm3 .= (1-r)*((1/2)*q2`1)+r*((1/2)*q2`1) by A13,XCMPLX_1:1 .= ((1-r)+r)*((1/2)*q2`1) by XCMPLX_1:8 .= 1*((1/2)*q2`1) by XCMPLX_1:27 .= ((1/2)*q2)`1 by Lm3; then A15: (1-r)*((1/2)*q2)+r*((1/2)*q3)+(1-r)*|[1,0]| = |[(1/2*q2)`1,(1/2* q2)`2]| by A14,EUCLID:57 .= 1/2*q2 by EUCLID:57; A16: (1-r)*((1/2)*p1)+r*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*q3) = (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*p1)+r*((1/2)*q3) by EUCLID:30 .= (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+(r*((1/2)*p1)+r*((1/2)*q3)) by EUCLID:30 .= (1-r)*((1/2)*p1)+(1-r)*((1/2)*q2)+r*((1/2)*p1+(1/2)*q3) by EUCLID:36 .= (1-r)*((1/2)*p1+(1/2)*q2)+r*((1/2)*p1+(1/2)*q3) by EUCLID:36 .= (1-r)*((1/2)*p1+(1/2)*q2)+r*((1/2)*(p1+q3)) by EUCLID:36 .= (1-r)*((1/2)*(p1+q2))+r*((1/2)*(p1+q3)) by EUCLID:36; 1/2*(p1+q2) = 1/2*p1+1/2*q2 by EUCLID:36 .= 1*((1/2)*p1)+1/2*q2 by EUCLID:33 .= (1-r+r)*((1/2)*p1)+1/2*q2 by XCMPLX_1:27 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+1/2*q2 by EUCLID:37 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+ ((1-r)*((1/2)*q2)+r*((1/2)*q3))+(1-r)*|[1,0]| by A15,EUCLID:30 .= (1-r)*((1/2)*p1)+r*((1/2)*p1)+ (1-r)*((1/2)*q2)+r*((1/2)*q3)+(1-r)*|[1,0]| by EUCLID:30 .= (1-r)*((1/2)*(p1+q2))+(1-r)*|[1,0]|+r*((1/2)*(p1+q3)) by A16,EUCLID:30 .= (1-r)*((1/2)*(p1+q2)+|[1,0]|)+r*((1/2)*(p1+q3)) by EUCLID:36; then 1/2*(p1+q2) in LSeg(1/2*(p1+q2)+|[1,0]|,1/2*(p1+q3)) by A11,A12,SPPOL_1:22 ; then A17: LSeg(1/2*(p1+q2)+|[1,0]|,1/2*(p1+q3)) = LSeg(1/2*(p1+q2)+|[1,0]|,1/2*(p1+q2)) \/ LSeg(1/2*(p1+q2),1/2*(p1+q3)) by TOPREAL1:11; set I1 = Int cell(G,len G -' 1,j), I2 = Int cell(G,len G,j); A18: LSeg(1/2*(p1+q2)+|[1,0]|,1/2*(p1+q2)) c= I2 \/ { 1/2*(p1+q2) } by A1,Th48; A19: LSeg(1/2*(p1+q2),1/2*(p1+q3)) c= I1 \/ { 1/2*(p1+q2) } by A1,A2,A3,A4,Th45; I1 \/ I2 \/ { 1/2*(p1+q2) } = I1 \/ (I2 \/ ({ 1/2*(p1+q2) } \/ { 1/2*(p1+q2) })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { 1/2*(p1+q2) } \/ { 1/2*(p1+q2) }) by XBOOLE_1:4 .= I1 \/ { 1/2*(p1+q2) } \/ (I2 \/ { 1/2*(p1+q2) }) by XBOOLE_1:4; hence LSeg(1/2*(p1+q2)+|[1,0]|,1/2*(p1+q3)) c= I1 \/ I2 \/ { 1/2*(p1+q2) } by A17,A18,A19,XBOOLE_1:13; end; Lm6: 1/2+1/2 = 1; theorem 1 < len G & 1 <= j & j+1 < width G implies LSeg(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|,1/2*(G*(1,j+1)+G*(1,j+2))-|[1,0]|) c= Int cell(G,0,j) \/ Int cell(G,0,j+1) \/ { G*(1,j+1)-|[1,0]| } proof assume A1: 1 < len G & 1 <= j & j+1 < width G; set p1 = G*(1,j), p2 = G*(1,j+1), q3 = G*(1,j+2), r = (p2`2-p1`2)/(q3`2-p1`2); A2: j+1 >= 1 by NAT_1:29; j <= j+1 by NAT_1:29; then A3: j < width G by A1,AXIOMS:22; then A4: p1`1 = G*(1,1)`1 by A1,GOBOARD5:3 .= p2`1 by A1,A2,GOBOARD5:3; A5: j+1+1 = j+(1+1) by XCMPLX_1:1; then A6: j+(1+1) <= width G by A1,NAT_1:38; A7: j+2 >= 1 by A5,NAT_1:29; A8: p2`1 = G*(1,1)`1 by A1,A2,GOBOARD5:3 .= q3`1 by A1,A6,A7,GOBOARD5:3; j+1 < j+2 by REAL_1:53; then p2`2 < q3`2 by A1,A2,A6,GOBOARD5:5; then A9: p2`2-p1`2 < q3`2-p1`2 by REAL_1:54; j < j+1 by REAL_1:69; then p1`2 < p2`2 by A1,GOBOARD5:5; then A10: p2`2-p1`2 > 0 by SQUARE_1:11; then q3`2-p1`2 > 0 by A9,AXIOMS:22; then A11: 0 < r by A10,REAL_2:127; A12: r < 1 by A9,A10,REAL_2:142; r*(q3`2-p1`2) = p2`2-p1`2 by A9,A10,XCMPLX_1:88; then A13: p2`2 = p1`2 + r*(q3`2-p1`2) by XCMPLX_1:27 .= p1`2 + (r*q3`2-r*p1`2) by XCMPLX_1:40 .= p1`2 + r*q3`2-r*p1`2 by XCMPLX_1:29 .= 1*p1`2-r*p1`2 + r*q3`2 by XCMPLX_1:29 .= (1-r)*p1`2 +r*q3`2 by XCMPLX_1:40; A14: 1*p2`1 = (1-r+r)*p2`1 by XCMPLX_1:27 .= (1-r)*p1`1+r*q3`1 by A4,A8,XCMPLX_1:8 .= ((1-r)*p1)`1+r*q3`1 by Lm3 .= ((1-r)*p1)`1+(r*q3)`1 by Lm3 .= ((1-r)*p1+r*q3)`1 by Lm1; 1*p2`2 = ((1-r)*p1)`2+r*q3`2 by A13,Lm3 .= ((1-r)*p1)`2+(r*q3)`2 by Lm3 .= ((1-r)*p1+(r*q3))`2 by Lm1; then A15: (1-r)*p1+r*q3 = |[p2`1,p2`2]| by A14,EUCLID:57 .= p2 by EUCLID:57; A16: now p2 = 1*p2 by EUCLID:33 .= 1/2*p2+1/2*p2 by Lm6,EUCLID:37 .= 1/2*(1*p2)+1/2*p2 by EUCLID:33 .= 1/2*(((1-r)+r)*p2) + 1/2*((1-r)*p1+r*q3) by A15,XCMPLX_1:27 .= 1/2*((1-r)*p2+r*p2) + 1/2*((1-r)*p1+r*q3) by EUCLID:37 .= 1/2*((1-r)*p2)+1/2*(r*p2) + 1/2*((1-r)*p1+r*q3) by EUCLID:36 .= 1/2*((1-r)*p2)+1/2*(r*p2) + (1/2*((1-r)*p1)+1/2*(r*q3)) by EUCLID:36 .= 1/2*((1-r)*p2)+(1/2*(r*p2) + (1/2*((1-r)*p1)+1/2*(r*q3))) by EUCLID:30 .= 1/2*((1-r)*p2)+(1/2*((1-r)*p1)+(1/2*(r*p2)+1/2*(r*q3))) by EUCLID:30 .= 1/2*((1-r)*p2)+1/2*((1-r)*p1)+(1/2*(r*p2)+1/2*(r*q3)) by EUCLID:30 .= (1/2*((1-r)*p2)+1/2*((1-r)*p1))+1/2*(r*p2)+1/2*(r*q3) by EUCLID:30 .= 1/2*((1-r)*p2+(1-r)*p1)+1/2*(r*p2)+1/2*(r*q3) by EUCLID:36 .= 1/2*((1-r)*(p1+p2))+1/2*(r*p2)+1/2*(r*q3) by EUCLID:36 .= 1/2*(1-r)*(p1+p2)+1/2*(r*p2)+1/2*(r*q3) by EUCLID:34 .= 1/2*(1-r)*(p1+p2)+(1/2*(r*p2)+1/2*(r*q3)) by EUCLID:30 .= 1/2*(1-r)*(p1+p2)+1/2*(r*p2+r*q3) by EUCLID:36 .= 1/2*(1-r)*(p1+p2)+1/2*(r*(p2+q3)) by EUCLID:36; hence p2 = (1-r)*(1/2*(p1+p2))+1/2*(r*(p2+q3)) by EUCLID:34 .= (1-r)*(1/2*(p1+p2))+1/2*r*(p2+q3) by EUCLID:34 .= (1-r)*((1/2)*(p1+p2))+r*((1/2)*(p2+q3)) by EUCLID:34; end; (1-r)*(1/2*(p1+p2)-|[1,0]|)+r*(1/2*(p2+q3)-|[1,0]|) = (1-r)*(1/2*(p1+p2))-(1-r)*|[1,0]|+r*(1/2*(p2+q3)-|[1,0]|) by EUCLID:53 .= (1-r)*(1/2*(p1+p2))-(1-r)*|[1,0]|+(r*(1/2*(p2+q3))-r*|[1,0]|) by EUCLID:53 .= r*(1/2*(p2+q3))+((1-r)*(1/2*(p1+p2))-(1-r)*|[1,0]|)-r*|[1,0]| by EUCLID: 49 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))-(1-r)*|[1,0]|-r*|[1,0]| by EUCLID:49 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))-((1-r)*|[1,0]|+r*|[1,0]|) by EUCLID:50 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))-((1-r)+r)*|[1,0]| by EUCLID:37 .= (1-r)*(1/2*(p1+p2))+r*(1/2*(p2+q3))-1*|[1,0]| by XCMPLX_1:27 .= p2-|[1,0]| by A16,EUCLID:33; then p2-|[1,0]| in LSeg(1/2*(p1+p2)-|[1,0]|,1/2*(p2+q3)-|[1,0]|) by A11,A12,SPPOL_1:22; then A17: LSeg(1/2*(p1+p2)-|[1,0]|,1/2*(p2+q3)-|[1,0]|) = LSeg(1/2*(p1+p2)-|[1,0]|,p2-|[1,0]|) \/ LSeg(p2-|[1,0]|,1/2*(p2+q3)-|[1,0]|) by TOPREAL1:11; set I1 = Int cell(G,0,j), I2 = Int cell(G,0,j+1); A18: LSeg(1/2*(p1+p2)-|[1,0]|,p2-|[1,0]|) c= I1 \/ { p2-|[1,0]| } by A1,A3,Th52; A19: LSeg(1/2*(p2+q3)-|[1,0]|,p2-|[1,0]|) c= I2 \/ { p2-|[1,0]| } by A1,A2,A5,Th51; I1 \/ I2 \/ { p2-|[1,0]| } = I1 \/ (I2 \/ ({ p2-|[1,0]| } \/ { p2-|[1,0]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { p2-|[1,0]| } \/ { p2-|[1,0]| }) by XBOOLE_1:4 .= I1 \/ { p2-|[1,0]| } \/ (I2 \/ { p2-|[1,0]| }) by XBOOLE_1:4; hence LSeg(1/2*(p1+p2)-|[1,0]|,1/2*(p2+q3)-|[1,0]|) c= I1 \/ I2 \/ { p2-|[1,0]| } by A17,A18,A19,XBOOLE_1:13; end; theorem 1 < len G & 1 <= j & j+1 < width G implies LSeg(1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|, 1/2*(G*(len G,j+1)+G*(len G,j+2))+|[1,0]|) c= Int cell(G,len G,j) \/ Int cell(G,len G,j+1) \/ { G*(len G,j+1)+|[1,0]| } proof assume A1: 1 < len G & 1 <= j & j+1 < width G; set p1 = G*(len G,j), p2 = G*(len G,j+1), q3 = G*(len G,j+2), r = (p2`2-p1`2)/(q3`2-p1`2); A2: j+1 >= 1 by NAT_1:29; j <= j+1 by NAT_1:29; then A3: j < width G by A1,AXIOMS:22; then A4: p1`1 = G*(len G,1)`1 by A1,GOBOARD5:3 .= p2`1 by A1,A2,GOBOARD5:3; A5: j+1+1 = j+(1+1) by XCMPLX_1:1; then A6: j+(1+1) <= width G by A1,NAT_1:38; A7: j+2 >= 1 by A5,NAT_1:29; A8: p2`1 = G*(len G,1)`1 by A1,A2,GOBOARD5:3 .= q3`1 by A1,A6,A7,GOBOARD5:3; j+1 < j+2 by REAL_1:53; then p2`2 < q3`2 by A1,A2,A6,GOBOARD5:5; then A9: p2`2-p1`2 < q3`2-p1`2 by REAL_1:54; j < j+1 by REAL_1:69; then p1`2 < p2`2 by A1,GOBOARD5:5; then A10: p2`2-p1`2 > 0 by SQUARE_1:11; then q3`2-p1`2 > 0 by A9,AXIOMS:22; then A11: 0 < r by A10,REAL_2:127; A12: r < 1 by A9,A10,REAL_2:142; r*(q3`2-p1`2) = p2`2-p1`2 by A9,A10,XCMPLX_1:88; then A13: p2`2 = p1`2 + r*(q3`2-p1`2) by XCMPLX_1:27 .= p1`2 + (r*q3`2-r*p1`2) by XCMPLX_1:40 .= p1`2 + r*q3`2-r*p1`2 by XCMPLX_1:29 .= 1*p1`2-r*p1`2 + r*q3`2 by XCMPLX_1:29 .= (1-r)*p1`2 +r*q3`2 by XCMPLX_1:40; A14: 1*p2`1 = (1-r+r)*p2`1 by XCMPLX_1:27 .= (1-r)*p1`1+r*q3`1 by A4,A8,XCMPLX_1:8 .= ((1-r)*p1)`1+r*q3`1 by Lm3 .= ((1-r)*p1)`1+(r*q3)`1 by Lm3 .= ((1-r)*p1+r*q3)`1 by Lm1; 1*p2`2 = ((1-r)*p1)`2+r*q3`2 by A13,Lm3 .= ((1-r)*p1)`2+(r*q3)`2 by Lm3 .= ((1-r)*p1+(r*q3))`2 by Lm1; then A15: (1-r)*p1+r*q3 = |[p2`1,p2`2]| by A14,EUCLID:57 .= p2 by EUCLID:57; A16: now p2 = 1*p2 by EUCLID:33 .= 1/2*p2+1/2*p2 by Lm6,EUCLID:37 .= 1/2*(1*p2)+1/2*p2 by EUCLID:33 .= 1/2*(((1-r)+r)*p2) + 1/2*((1-r)*p1+r*q3) by A15,XCMPLX_1:27 .= 1/2*((1-r)*p2+r*p2) + 1/2*((1-r)*p1+r*q3) by EUCLID:37 .= 1/2*((1-r)*p2)+1/2*(r*p2) + 1/2*((1-r)*p1+r*q3) by EUCLID:36 .= 1/2*((1-r)*p2)+1/2*(r*p2) + (1/2*((1-r)*p1)+1/2*(r*q3)) by EUCLID:36 .= 1/2*((1-r)*p2)+(1/2*(r*p2) + (1/2*((1-r)*p1)+1/2*(r*q3))) by EUCLID:30 .= 1/2*((1-r)*p2)+(1/2*((1-r)*p1)+(1/2*(r*p2)+1/2*(r*q3))) by EUCLID:30 .= 1/2*((1-r)*p2)+1/2*((1-r)*p1)+(1/2*(r*p2)+1/2*(r*q3)) by EUCLID:30 .= (1/2*((1-r)*p2)+1/2*((1-r)*p1))+1/2*(r*p2)+1/2*(r*q3) by EUCLID:30 .= 1/2*((1-r)*p2+(1-r)*p1)+1/2*(r*p2)+1/2*(r*q3) by EUCLID:36 .= 1/2*((1-r)*(p1+p2))+1/2*(r*p2)+1/2*(r*q3) by EUCLID:36 .= 1/2*(1-r)*(p1+p2)+1/2*(r*p2)+1/2*(r*q3) by EUCLID:34; hence p2 = 1/2*(1-r)*(p1+p2)+(1/2*(r*p2)+1/2*(r*q3)) by EUCLID:30 .= 1/2*(1-r)*(p1+p2)+1/2*(r*p2+r*q3) by EUCLID:36 .= 1/2*(1-r)*(p1+p2)+1/2*(r*(p2+q3)) by EUCLID:36 .= (1-r)*(1/2*(p1+p2))+1/2*(r*(p2+q3)) by EUCLID:34 .= (1-r)*(1/2*(p1+p2))+1/2*r*(p2+q3) by EUCLID:34 .= (1-r)*((1/2)*(p1+p2))+r*((1/2)*(p2+q3)) by EUCLID:34; end; (1-r)*(1/2*(p1+p2)+|[1,0]|)+r*(1/2*(p2+q3)+|[1,0]|) = (1-r)*(1/2*(p1+p2))+(1-r)*|[1,0]|+r*(1/2*(p2+q3)+|[1,0]|) by EUCLID:36 .= (1-r)*(1/2*(p1+p2))+(1-r)*|[1,0]|+(r*(1/2*(p2+q3))+r*|[1,0]|) by EUCLID:36 .= r*(1/2*(p2+q3))+((1-r)*(1/2*(p1+p2))+(1-r)*|[1,0]|)+r*|[1,0]| by EUCLID: 30 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))+(1-r)*|[1,0]|+r*|[1,0]| by EUCLID:30 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))+((1-r)*|[1,0]|+r*|[1,0]|) by EUCLID:30 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))+((1-r)+r)*|[1,0]| by EUCLID:37 .= (1-r)*(1/2*(p1+p2))+r*(1/2*(p2+q3))+1*|[1,0]| by XCMPLX_1:27 .= p2+|[1,0]| by A16,EUCLID:33; then p2+|[1,0]| in LSeg(1/2*(p1+p2)+|[1,0]|,1/2*(p2+q3)+|[1,0]|) by A11,A12,SPPOL_1:22; then A17: LSeg(1/2*(p1+p2)+|[1,0]|,1/2*(p2+q3)+|[1,0]|) = LSeg(1/2*(p1+p2)+|[1,0]|,p2+|[1,0]|) \/ LSeg(p2+|[1,0]|,1/2*(p2+q3)+|[1,0]|) by TOPREAL1:11; set I1 = Int cell(G,len G,j), I2 = Int cell(G,len G,j+1); A18: LSeg(1/2*(p1+p2)+|[1,0]|,p2+|[1,0]|) c= I1 \/ { p2+|[1,0]| } by A1,A3,Th54; A19: LSeg(1/2*(p2+q3)+|[1,0]|,p2+|[1,0]|) c= I2 \/ { p2+|[1,0]| } by A1,A2,A5,Th53; I1 \/ I2 \/ { p2+|[1,0]| } = I1 \/ (I2 \/ ({ p2+|[1,0]| } \/ { p2+|[1,0]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { p2+|[1,0]| } \/ { p2+|[1,0]| }) by XBOOLE_1:4 .= I1 \/ { p2+|[1,0]| } \/ (I2 \/ { p2+|[1,0]| }) by XBOOLE_1:4; hence LSeg(1/2*(p1+p2)+|[1,0]|,1/2*(p2+q3)+|[1,0]|) c= I1 \/ I2 \/ { p2+|[1,0]| } by A17,A18,A19,XBOOLE_1:13; end; theorem 1 < width G & 1 <= i & i+1 < len G implies LSeg(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|,1/2*(G*(i+1,1)+G*(i+2,1))-|[0,1]|) c= Int cell(G,i,0) \/ Int cell(G,i+1,0) \/ { G*(i+1,1)-|[0,1]| } proof assume A1: 1 < width G & 1 <= i & i+1 < len G; set p1 = G*(i,1), p2 = G*(i+1,1), q3 = G*(i+2,1), r = (p2`1-p1`1)/(q3`1-p1`1); A2: i+1 >= 1 by NAT_1:29; i <= i+1 by NAT_1:29; then A3: i < len G by A1,AXIOMS:22; then A4: p1`2 = G*(1,1)`2 by A1,GOBOARD5:2 .= p2`2 by A1,A2,GOBOARD5:2; A5: i+1+1 = i+(1+1) by XCMPLX_1:1; then A6: i+(1+1) <= len G by A1,NAT_1:38; A7: i+2 >= 1 by A5,NAT_1:29; A8: p2`2 = G*(1,1)`2 by A1,A2,GOBOARD5:2 .= q3`2 by A1,A6,A7,GOBOARD5:2; i+1 < i+2 by REAL_1:53; then p2`1 < q3`1 by A1,A2,A6,GOBOARD5:4; then A9: p2`1-p1`1 < q3`1-p1`1 by REAL_1:54; i < i+1 by REAL_1:69; then p1`1 < p2`1 by A1,GOBOARD5:4; then A10: p2`1-p1`1 > 0 by SQUARE_1:11; then q3`1-p1`1 > 0 by A9,AXIOMS:22; then A11: 0 < r by A10,REAL_2:127; A12: r < 1 by A9,A10,REAL_2:142; r*(q3`1-p1`1) = p2`1-p1`1 by A9,A10,XCMPLX_1:88; then A13: p2`1 = p1`1 + r*(q3`1-p1`1) by XCMPLX_1:27 .= p1`1 + (r*q3`1-r*p1`1) by XCMPLX_1:40 .= p1`1 + r*q3`1-r*p1`1 by XCMPLX_1:29 .= 1*p1`1-r*p1`1 + r*q3`1 by XCMPLX_1:29 .= (1-r)*p1`1 +r*q3`1 by XCMPLX_1:40; A14: 1*p2`2 = (1-r+r)*p2`2 by XCMPLX_1:27 .= (1-r)*p1`2+r*q3`2 by A4,A8,XCMPLX_1:8 .= ((1-r)*p1)`2+r*q3`2 by Lm3 .= ((1-r)*p1)`2+(r*q3)`2 by Lm3 .= ((1-r)*p1+r*q3)`2 by Lm1; 1*p2`1 = ((1-r)*p1)`1+r*q3`1 by A13,Lm3 .= ((1-r)*p1)`1+(r*q3)`1 by Lm3 .= ((1-r)*p1+(r*q3))`1 by Lm1; then A15: (1-r)*p1+r*q3 = |[p2`1,p2`2]| by A14,EUCLID:57 .= p2 by EUCLID:57; A16: now p2 = 1*p2 by EUCLID:33 .= 1/2*p2+1/2*p2 by Lm6,EUCLID:37 .= 1/2*(1*p2)+1/2*p2 by EUCLID:33 .= 1/2*(((1-r)+r)*p2) + 1/2*((1-r)*p1+r*q3) by A15,XCMPLX_1:27 .= 1/2*((1-r)*p2+r*p2) + 1/2*((1-r)*p1+r*q3) by EUCLID:37 .= 1/2*((1-r)*p2)+1/2*(r*p2) + 1/2*((1-r)*p1+r*q3) by EUCLID:36 .= 1/2*((1-r)*p2)+1/2*(r*p2) + (1/2*((1-r)*p1)+1/2*(r*q3)) by EUCLID:36 .= 1/2*((1-r)*p2)+(1/2*(r*p2) + (1/2*((1-r)*p1)+1/2*(r*q3))) by EUCLID:30 .= 1/2*((1-r)*p2)+(1/2*((1-r)*p1)+(1/2*(r*p2)+1/2*(r*q3))) by EUCLID:30 .= 1/2*((1-r)*p2)+1/2*((1-r)*p1)+(1/2*(r*p2)+1/2*(r*q3)) by EUCLID:30 .= (1/2*((1-r)*p2)+1/2*((1-r)*p1))+1/2*(r*p2)+1/2*(r*q3) by EUCLID:30 .= 1/2*((1-r)*p2+(1-r)*p1)+1/2*(r*p2)+1/2*(r*q3) by EUCLID:36 .= 1/2*((1-r)*(p1+p2))+1/2*(r*p2)+1/2*(r*q3) by EUCLID:36 .= 1/2*(1-r)*(p1+p2)+1/2*(r*p2)+1/2*(r*q3) by EUCLID:34 .= 1/2*(1-r)*(p1+p2)+(1/2*(r*p2)+1/2*(r*q3)) by EUCLID:30 .= 1/2*(1-r)*(p1+p2)+1/2*(r*p2+r*q3) by EUCLID:36; hence p2 = 1/2*(1-r)*(p1+p2)+1/2*(r*(p2+q3)) by EUCLID:36 .= (1-r)*(1/2*(p1+p2))+1/2*(r*(p2+q3)) by EUCLID:34 .= (1-r)*(1/2*(p1+p2))+1/2*r*(p2+q3) by EUCLID:34 .= (1-r)*((1/2)*(p1+p2))+r*((1/2)*(p2+q3)) by EUCLID:34; end; (1-r)*(1/2*(p1+p2)-|[0,1]|)+r*(1/2*(p2+q3)-|[0,1]|) = (1-r)*(1/2*(p1+p2))-(1-r)*|[0,1]|+r*(1/2*(p2+q3)-|[0,1]|) by EUCLID:53 .= (1-r)*(1/2*(p1+p2))-(1-r)*|[0,1]|+(r*(1/2*(p2+q3))-r*|[0,1]|) by EUCLID:53 .= r*(1/2*(p2+q3))+((1-r)*(1/2*(p1+p2))-(1-r)*|[0,1]|)-r*|[0,1]| by EUCLID: 49 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))-(1-r)*|[0,1]|-r*|[0,1]| by EUCLID:49 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))-((1-r)*|[0,1]|+r*|[0,1]|) by EUCLID:50 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))-((1-r)+r)*|[0,1]| by EUCLID:37 .= (1-r)*(1/2*(p1+p2))+r*(1/2*(p2+q3))-1*|[0,1]| by XCMPLX_1:27 .= p2-|[0,1]| by A16,EUCLID:33; then p2-|[0,1]| in LSeg(1/2*(p1+p2)-|[0,1]|,1/2*(p2+q3)-|[0,1]|) by A11,A12,SPPOL_1:22; then A17: LSeg(1/2*(p1+p2)-|[0,1]|,1/2*(p2+q3)-|[0,1]|) = LSeg(1/2*(p1+p2)-|[0,1]|,p2-|[0,1]|) \/ LSeg(p2-|[0,1]|,1/2*(p2+q3)-|[0,1]|) by TOPREAL1:11; set I1 = Int cell(G,i,0), I2 = Int cell(G,i+1,0); A18: LSeg(1/2*(p1+p2)-|[0,1]|,p2-|[0,1]|) c= I1 \/ { p2-|[0,1]| } by A1,A3,Th56; A19: LSeg(1/2*(p2+q3)-|[0,1]|,p2-|[0,1]|) c= I2 \/ { p2-|[0,1]| } by A1,A2,A5,Th55; I1 \/ I2 \/ { p2-|[0,1]| } = I1 \/ (I2 \/ ({ p2-|[0,1]| } \/ { p2-|[0,1]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { p2-|[0,1]| } \/ { p2-|[0,1]| }) by XBOOLE_1:4 .= I1 \/ { p2-|[0,1]| } \/ (I2 \/ { p2-|[0,1]| }) by XBOOLE_1:4; hence LSeg(1/2*(p1+p2)-|[0,1]|,1/2*(p2+q3)-|[0,1]|) c= I1 \/ I2 \/ { p2-|[0,1]| } by A17,A18,A19,XBOOLE_1:13; end; theorem 1 < width G & 1 <= i & i+1 < len G implies LSeg(1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|, 1/2*(G*(i+1,width G)+G*(i+2,width G))+|[0,1]|) c= Int cell(G,i,width G) \/ Int cell(G,i+1,width G) \/ { G*(i+1,width G)+|[0,1]| } proof assume A1: 1 < width G & 1 <= i & i+1 < len G; set p1 = G*(i,width G), p2 = G*(i+1,width G), q3 = G*(i+2,width G), r = (p2`1-p1`1)/(q3`1-p1`1); A2: i+1 >= 1 by NAT_1:29; i <= i+1 by NAT_1:29; then A3: i < len G by A1,AXIOMS:22; then A4: p1`2 = G*(1,width G)`2 by A1,GOBOARD5:2 .= p2`2 by A1,A2,GOBOARD5:2; A5: i+1+1 = i+(1+1) by XCMPLX_1:1; then A6: i+(1+1) <= len G by A1,NAT_1:38; A7: i+2 >= 1 by A5,NAT_1:29; A8: p2`2 = G*(1,width G)`2 by A1,A2,GOBOARD5:2 .= q3`2 by A1,A6,A7,GOBOARD5:2; i+1 < i+2 by REAL_1:53; then p2`1 < q3`1 by A1,A2,A6,GOBOARD5:4; then A9: p2`1-p1`1 < q3`1-p1`1 by REAL_1:54; i < i+1 by REAL_1:69; then p1`1 < p2`1 by A1,GOBOARD5:4; then A10: p2`1-p1`1 > 0 by SQUARE_1:11; then q3`1-p1`1 > 0 by A9,AXIOMS:22; then A11: 0 < r by A10,REAL_2:127; A12: r < 1 by A9,A10,REAL_2:142; r*(q3`1-p1`1) = p2`1-p1`1 by A9,A10,XCMPLX_1:88; then A13: p2`1 = p1`1 + r*(q3`1-p1`1) by XCMPLX_1:27 .= p1`1 + (r*q3`1-r*p1`1) by XCMPLX_1:40 .= p1`1 + r*q3`1-r*p1`1 by XCMPLX_1:29 .= 1*p1`1-r*p1`1 + r*q3`1 by XCMPLX_1:29 .= (1-r)*p1`1 +r*q3`1 by XCMPLX_1:40; A14: 1*p2`2 = (1-r+r)*p2`2 by XCMPLX_1:27 .= (1-r)*p1`2+r*q3`2 by A4,A8,XCMPLX_1:8 .= ((1-r)*p1)`2+r*q3`2 by Lm3 .= ((1-r)*p1)`2+(r*q3)`2 by Lm3 .= ((1-r)*p1+r*q3)`2 by Lm1; 1*p2`1 = ((1-r)*p1)`1+r*q3`1 by A13,Lm3 .= ((1-r)*p1)`1+(r*q3)`1 by Lm3 .= ((1-r)*p1+(r*q3))`1 by Lm1; then A15: (1-r)*p1+r*q3 = |[p2`1,p2`2]| by A14,EUCLID:57 .= p2 by EUCLID:57; A16: now p2 = 1*p2 by EUCLID:33 .= 1/2*p2+1/2*p2 by Lm6,EUCLID:37 .= 1/2*(1*p2)+1/2*p2 by EUCLID:33 .= 1/2*(((1-r)+r)*p2) + 1/2*((1-r)*p1+r*q3) by A15,XCMPLX_1:27 .= 1/2*((1-r)*p2+r*p2) + 1/2*((1-r)*p1+r*q3) by EUCLID:37 .= 1/2*((1-r)*p2)+1/2*(r*p2) + 1/2*((1-r)*p1+r*q3) by EUCLID:36 .= 1/2*((1-r)*p2)+1/2*(r*p2) + (1/2*((1-r)*p1)+1/2*(r*q3)) by EUCLID:36 .= 1/2*((1-r)*p2)+(1/2*(r*p2) + (1/2*((1-r)*p1)+1/2*(r*q3))) by EUCLID:30 .= 1/2*((1-r)*p2)+(1/2*((1-r)*p1)+(1/2*(r*p2)+1/2*(r*q3))) by EUCLID:30 .= 1/2*((1-r)*p2)+1/2*((1-r)*p1)+(1/2*(r*p2)+1/2*(r*q3)) by EUCLID:30 .= (1/2*((1-r)*p2)+1/2*((1-r)*p1))+1/2*(r*p2)+1/2*(r*q3) by EUCLID:30 .= 1/2*((1-r)*p2+(1-r)*p1)+1/2*(r*p2)+1/2*(r*q3) by EUCLID:36 .= 1/2*((1-r)*(p1+p2))+1/2*(r*p2)+1/2*(r*q3) by EUCLID:36 .= 1/2*(1-r)*(p1+p2)+1/2*(r*p2)+1/2*(r*q3) by EUCLID:34; hence p2 = 1/2*(1-r)*(p1+p2)+(1/2*(r*p2)+1/2*(r*q3)) by EUCLID:30 .= 1/2*(1-r)*(p1+p2)+1/2*(r*p2+r*q3) by EUCLID:36 .= 1/2*(1-r)*(p1+p2)+1/2*(r*(p2+q3)) by EUCLID:36 .= (1-r)*(1/2*(p1+p2))+1/2*(r*(p2+q3)) by EUCLID:34 .= (1-r)*(1/2*(p1+p2))+1/2*r*(p2+q3) by EUCLID:34 .= (1-r)*((1/2)*(p1+p2))+r*((1/2)*(p2+q3)) by EUCLID:34; end; (1-r)*(1/2*(p1+p2)+|[0,1]|)+r*(1/2*(p2+q3)+|[0,1]|) = (1-r)*(1/2*(p1+p2))+(1-r)*|[0,1]|+r*(1/2*(p2+q3)+|[0,1]|) by EUCLID:36 .= (1-r)*(1/2*(p1+p2))+(1-r)*|[0,1]|+(r*(1/2*(p2+q3))+r*|[0,1]|) by EUCLID:36 .= r*(1/2*(p2+q3))+((1-r)*(1/2*(p1+p2))+(1-r)*|[0,1]|)+r*|[0,1]| by EUCLID: 30 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))+(1-r)*|[0,1]|+r*|[0,1]| by EUCLID:30 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))+((1-r)*|[0,1]|+r*|[0,1]|) by EUCLID:30 .= r*(1/2*(p2+q3))+(1-r)*(1/2*(p1+p2))+((1-r)+r)*|[0,1]| by EUCLID:37 .= (1-r)*(1/2*(p1+p2))+r*(1/2*(p2+q3))+1*|[0,1]| by XCMPLX_1:27 .= p2+|[0,1]| by A16,EUCLID:33; then p2+|[0,1]| in LSeg(1/2*(p1+p2)+|[0,1]|,1/2*(p2+q3)+|[0,1]|) by A11,A12,SPPOL_1:22; then A17: LSeg(1/2*(p1+p2)+|[0,1]|,1/2*(p2+q3)+|[0,1]|) = LSeg(1/2*(p1+p2)+|[0,1]|,p2+|[0,1]|) \/ LSeg(p2+|[0,1]|,1/2*(p2+q3)+|[0,1]|) by TOPREAL1:11; set I1 = Int cell(G,i,width G), I2 = Int cell(G,i+1,width G); A18: LSeg(1/2*(p1+p2)+|[0,1]|,p2+|[0,1]|) c= I1 \/ { p2+|[0,1]| } by A1,A3,Th58; A19: LSeg(1/2*(p2+q3)+|[0,1]|,p2+|[0,1]|) c= I2 \/ { p2+|[0,1]| } by A1,A2,A5,Th57; I1 \/ I2 \/ { p2+|[0,1]| } = I1 \/ (I2 \/ ({ p2+|[0,1]| } \/ { p2+|[0,1]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { p2+|[0,1]| } \/ { p2+|[0,1]| }) by XBOOLE_1:4 .= I1 \/ { p2+|[0,1]| } \/ (I2 \/ { p2+|[0,1]| }) by XBOOLE_1:4; hence LSeg(1/2*(p1+p2)+|[0,1]|,1/2*(p2+q3)+|[0,1]|) c= I1 \/ I2 \/ { p2+|[0,1]| } by A17,A18,A19,XBOOLE_1:13; end; theorem 1 < len G & 1 < width G implies LSeg(G*(1,1)-|[1,1]|,1/2*(G*(1,1)+G*(1,2))-|[1,0]|) c= Int cell(G,0,0) \/ Int cell(G,0,1) \/ { G*(1,1)-|[1,0]| } proof assume A1: 1 < len G & 1 < width G; set q2 = G*(1,1), q3 = G*(1,2), r = 1/(1/2*(q3`2-q2`2)+1); A2: 0+1+1 = 0+(1+1); A3: 0+(1+1) <= width G by A1,NAT_1:38; then A4: q2`1 = q3`1 by A1,GOBOARD5:3; q2`2 < q3`2 by A1,A3,GOBOARD5:5; then q3`2-q2`2 > 0 by SQUARE_1:11; then 1/2*(q3`2-q2`2) > 0 by REAL_2:122; then A5: 1 < 1/2*(q3`2-q2`2)+1 by REAL_1:69; then A6: 1/2*(q3`2-q2`2)+1 > 0 by AXIOMS:22; then A7: 0 < r by REAL_2:127; A8: r < 1 by A5,SQUARE_1:2; r*((1/2)*q3`2)-r*((1/2)*q2`2)+r = r*((1/2)*q3`2-((1/2)*q2`2))+r by XCMPLX_1:40 .= r*((1/2)*(q3`2-q2`2))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q3`2-q2`2)+1) by XCMPLX_1:8 .= 1 by A6,XCMPLX_1:107; then r*((1/2)*q3`2)-r*((1/2)*q2`2) = 1-r by XCMPLX_1:26; then A9: r*((1/2)*q3`2)-(1-r) = r*((1/2)*q2`2) by XCMPLX_1:18; A10: ((1-r)*(q2-|[1,1]|)+r*(1/2*(q2+q3)-|[1,0]|))`2 = ((1-r)*(q2-|[1,1]|))`2+(r*(1/2*(q2+q3)-|[1,0]|))`2 by Lm1 .= ((1-r)*q2-(1-r)*|[1,1]|)`2+(r*(1/2*(q2+q3)-|[1,0]|))`2 by EUCLID:53 .= ((1-r)*q2)`2-((1-r)*|[1,1]|)`2+(r*(1/2*(q2+q3)-|[1,0]|))`2 by Lm2 .= ((1-r)*q2)`2-(1-r)*|[1,1]|`2+(r*(1/2*(q2+q3)-|[1,0]|))`2 by Lm3 .= ((1-r)*q2)`2-(1-r)*1+(r*(1/2*(q2+q3)-|[1,0]|))`2 by EUCLID:56 .= (1-r)*q2`2-(1-r)*1+(r*(1/2*(q2+q3)-|[1,0]|))`2 by Lm3 .= (1-r)*q2`2-(1-r)+r*(1/2*(q2+q3)-|[1,0]|)`2 by Lm3 .= (1-r)*q2`2-(1-r)+r*((1/2*(q2+q3))`2-|[1,0]|`2) by Lm2 .= (1-r)*q2`2-(1-r)+r*((1/2*(q2+q3))`2-0) by EUCLID:56 .= (1-r)*q2`2-(1-r)+r*(1/2*(q2+q3)`2) by Lm3 .= (1-r)*q2`2-(1-r)+r*(1/2*(q2`2+q3`2)) by Lm1 .= (1-r)*q2`2-(1-r)+r*(1/2*q2`2+1/2*q3`2) by XCMPLX_1:8 .= (1-r)*q2`2-(1-r)+(r*(1/2*q3`2)+r*(1/2*q2`2)) by XCMPLX_1:8 .= (1-r)*q2`2-(1-r)+r*(1/2*q3`2)+r*(1/2*q2`2) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*q3`2)-(1-r)+r*(1/2*q2`2) by XCMPLX_1:29 .= (1-r)*q2`2+r*(1/2*q2`2)+r*(1/2*q2`2) by A9,XCMPLX_1:29 .= (1-r)*q2`2+(r*(1/2*q2`2)+r*(1/2*q2`2)) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*q2`2+1/2*q2`2) by XCMPLX_1:8 .= (1-r)*q2`2+r*(1*q2`2) by Lm6,XCMPLX_1:8 .= (1-r+r)*q2`2 by XCMPLX_1:8 .= 1*q2`2 by XCMPLX_1:27 .= q2`2-0 .= q2`2-|[1,0]|`2 by EUCLID:56 .= (q2-|[1,0]|)`2 by Lm2; ((1-r)*(q2-|[1,1]|)+r*(1/2*(q2+q3)-|[1,0]|))`1 = ((1-r)*(q2-|[1,1]|))`1+(r*(1/2*(q2+q3)-|[1,0]|))`1 by Lm1 .= (1-r)*(q2-|[1,1]|)`1+(r*(1/2*(q2+q3)-|[1,0]|))`1 by Lm3 .= (1-r)*(q2-|[1,1]|)`1+r*(1/2*(q2+q3)-|[1,0]|)`1 by Lm3 .= (1-r)*(q2`1-|[1,1]|`1)+r*(1/2*(q2+q3)-|[1,0]|)`1 by Lm2 .= (1-r)*(q2`1-|[1,1]|`1)+r*((1/2*(q2+q3))`1-|[1,0]|`1) by Lm2 .= (1-r)*(q2`1-1)+r*((1/2*(q2+q3))`1-|[1,0]|`1) by EUCLID:56 .= (1-r)*(q2`1-1)+r*((1/2*(q2+q3))`1-1) by EUCLID:56 .= (1-r)*q2`1-(1-r)*1+r*((1/2*(q2+q3))`1-1) by XCMPLX_1:40 .= (1-r)*q2`1-(1-r)+(r*(1/2*(q2+q3))`1-r*1) by XCMPLX_1:40 .= (1-r)*q2`1-(1-r)+r*(1/2*(q2+q3))`1-r by XCMPLX_1:29 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1-(1-r)-r by XCMPLX_1:29 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1-((1-r)+r) by XCMPLX_1:36 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1-1 by XCMPLX_1:27 .= (1-r)*q2`1+r*(1/2*(q2+q3)`1)-1 by Lm3 .= (1-r)*q2`1+r*(1/2*(q2`1+q2`1))-1 by A4,Lm1 .= (1-r)*q2`1+r*(1/2*(2*q2`1))-1 by XCMPLX_1:11 .= (1-r)*q2`1+r*(1/2*2*q2`1)-1 by XCMPLX_1:4 .= (1-r+r)*q2`1-1 by XCMPLX_1:8 .= 1*q2`1-1 by XCMPLX_1:27 .= q2`1-|[1,0]|`1 by EUCLID:56 .= (q2-|[1,0]|)`1 by Lm2; then (1-r)*(q2-|[1,1]|)+r*(1/2*(q2+q3)-|[1,0]|) = |[(q2-|[1,0]|)`1,(q2-|[1,0]|)`2]| by A10,EUCLID:57 .= q2-|[1,0]| by EUCLID:57; then q2-|[1,0]| in LSeg(q2-|[1,1]|,1/2*(q2+q3)-|[1,0]|) by A7,A8,SPPOL_1:22; then A11: LSeg(q2-|[1,1]|,1/2*(q2+q3)-|[1,0]|) = LSeg(q2-|[1,1]|,q2-|[1,0]|) \/ LSeg(q2-|[1,0]|,1/2*(q2+q3)-|[1,0]|) by TOPREAL1:11; set I1 = Int cell(G,0,0), I2 = Int cell(G,0,1); A12: LSeg(q2-|[1,1]|,q2-|[1,0]|) c= I1 \/ { q2-|[1,0]| } by Th59; A13: LSeg(q2-|[1,0]|,1/2*(q2+q3)-|[1,0]|) c= I2 \/ { q2-|[1,0]| } by A1,A2,Th51; I1 \/ I2 \/ { q2-|[1,0]| } = I1 \/ (I2 \/ ({ q2-|[1,0]| } \/ { q2-|[1,0]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { q2-|[1,0]| } \/ { q2-|[1,0]| }) by XBOOLE_1:4 .= I1 \/ { q2-|[1,0]| } \/ (I2 \/ { q2-|[1,0]| }) by XBOOLE_1:4; hence LSeg(q2-|[1,1]|,1/2*(q2+q3)-|[1,0]|) c= I1 \/ I2 \/ { q2-|[1,0]| } by A11,A12,A13,XBOOLE_1:13; end; theorem 1 < len G & 1 < width G implies LSeg(G*(len G,1)+|[1,-1]|,1/2*(G*(len G,1)+G*(len G,2))+|[1,0]|) c= Int cell(G,len G,0) \/ Int cell(G,len G,1) \/ { G*(len G,1)+|[1,0]| } proof assume A1: 1 < len G & 1 < width G; set q2 = G*(len G,1), q3 = G*(len G,2), r = 1/(1/2*(q3`2-q2`2)+1); A2: 0+1+1 = 0+(1+1); A3: 0+(1+1) <= width G by A1,NAT_1:38; then A4: q2`1 = q3`1 by A1,GOBOARD5:3; q2`2 < q3`2 by A1,A3,GOBOARD5:5; then q3`2-q2`2 > 0 by SQUARE_1:11; then 1/2*(q3`2-q2`2) > 0 by REAL_2:122; then A5: 1 < 1/2*(q3`2-q2`2)+1 by REAL_1:69; then A6: 1/2*(q3`2-q2`2)+1 > 0 by AXIOMS:22; then A7: 0 < r by REAL_2:127; A8: r < 1 by A5,SQUARE_1:2; r*((1/2)*q3`2)-r*((1/2)*q2`2)+r = r*((1/2)*q3`2-((1/2)*q2`2))+r by XCMPLX_1:40 .= r*((1/2)*(q3`2-q2`2))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q3`2-q2`2)+1) by XCMPLX_1:8 .= 1 by A6,XCMPLX_1:107; then r*((1/2)*q3`2)-r*((1/2)*q2`2) = 1-r by XCMPLX_1:26; then A9: r*((1/2)*q3`2)-(1-r) = r*((1/2)*q2`2) by XCMPLX_1:18; A10: ((1-r)*(q2+|[1,-1]|)+r*(1/2*(q2+q3)+|[1,0]|))`2 = ((1-r)*(q2+|[1,-1]|))`2+(r*(1/2*(q2+q3)+|[1,0]|))`2 by Lm1 .= ((1-r)*q2+(1-r)*|[1,-1]|)`2+(r*(1/2*(q2+q3)+|[1,0]|))`2 by EUCLID:36 .= ((1-r)*q2)`2+((1-r)*|[1,-1]|)`2+(r*(1/2*(q2+q3)+|[1,0]|))`2 by Lm1 .= ((1-r)*q2)`2+(1-r)*|[1,-1]|`2+(r*(1/2*(q2+q3)+|[1,0]|))`2 by Lm3 .= ((1-r)*q2)`2+(1-r)*(-1)+(r*(1/2*(q2+q3)+|[1,0]|))`2 by EUCLID:56 .= (1-r)*q2`2+(1-r)*(-1)+(r*(1/2*(q2+q3)+|[1,0]|))`2 by Lm3 .= (1-r)*q2`2+-(1-r)+(r*(1/2*(q2+q3)+|[1,0]|))`2 by XCMPLX_1:180 .= (1-r)*q2`2+-(1-r)+r*(1/2*(q2+q3)+|[1,0]|)`2 by Lm3 .= (1-r)*q2`2-(1-r)+r*(1/2*(q2+q3)+|[1,0]|)`2 by XCMPLX_0:def 8 .= (1-r)*q2`2-(1-r)+r*((1/2*(q2+q3))`2+|[1,0]|`2) by Lm1 .= (1-r)*q2`2-(1-r)+r*((1/2*(q2+q3))`2+0) by EUCLID:56 .= (1-r)*q2`2-(1-r)+r*(1/2*(q2+q3)`2) by Lm3 .= (1-r)*q2`2-(1-r)+r*(1/2*(q2`2+q3`2)) by Lm1 .= (1-r)*q2`2-(1-r)+r*(1/2*q2`2+1/2*q3`2) by XCMPLX_1:8 .= (1-r)*q2`2-(1-r)+(r*(1/2*q3`2)+r*(1/2*q2`2)) by XCMPLX_1:8 .= (1-r)*q2`2-(1-r)+r*(1/2*q3`2)+r*(1/2*q2`2) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*q3`2)-(1-r)+r*(1/2*q2`2) by XCMPLX_1:29 .= (1-r)*q2`2+r*(1/2*q2`2)+r*(1/2*q2`2) by A9,XCMPLX_1:29 .= (1-r)*q2`2+(r*(1/2*q2`2)+r*(1/2*q2`2)) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*q2`2+1/2*q2`2) by XCMPLX_1:8 .= (1-r)*q2`2+r*(1*q2`2) by Lm6,XCMPLX_1:8 .= (1-r+r)*q2`2 by XCMPLX_1:8 .= 1*q2`2 by XCMPLX_1:27 .= q2`2+0 .= q2`2+|[1,0]|`2 by EUCLID:56 .= (q2+|[1,0]|)`2 by Lm1; ((1-r)*(q2+|[1,-1]|)+r*(1/2*(q2+q3)+|[1,0]|))`1 = ((1-r)*(q2+|[1,-1]|))`1+(r*(1/2*(q2+q3)+|[1,0]|))`1 by Lm1 .= (1-r)*(q2+|[1,-1]|)`1+(r*(1/2*(q2+q3)+|[1,0]|))`1 by Lm3 .= (1-r)*(q2+|[1,-1]|)`1+r*(1/2*(q2+q3)+|[1,0]|)`1 by Lm3 .= (1-r)*(q2`1+|[1,-1]|`1)+r*(1/2*(q2+q3)+|[1,0]|)`1 by Lm1 .= (1-r)*(q2`1+|[1,-1]|`1)+r*((1/2*(q2+q3))`1+|[1,0]|`1) by Lm1 .= (1-r)*(q2`1+1)+r*((1/2*(q2+q3))`1+|[1,0]|`1) by EUCLID:56 .= (1-r)*(q2`1+1)+r*((1/2*(q2+q3))`1+1) by EUCLID:56 .= (1-r)*q2`1+(1-r)*1+r*((1/2*(q2+q3))`1+1) by XCMPLX_1:8 .= (1-r)*q2`1+(1-r)+(r*(1/2*(q2+q3))`1+r*1) by XCMPLX_1:8 .= (1-r)*q2`1+(1-r)+r*(1/2*(q2+q3))`1+r by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1+(1-r)+r by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1+((1-r)+r) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1+1 by XCMPLX_1:27 .= (1-r)*q2`1+r*(1/2*(q2+q3)`1)+1 by Lm3 .= (1-r)*q2`1+r*(1/2*(q2`1+q2`1))+1 by A4,Lm1 .= (1-r)*q2`1+r*(1/2*(2*q2`1))+1 by XCMPLX_1:11 .= (1-r)*q2`1+r*(1/2*2*q2`1)+1 by XCMPLX_1:4 .= (1-r+r)*q2`1+1 by XCMPLX_1:8 .= 1*q2`1+1 by XCMPLX_1:27 .= q2`1+|[1,0]|`1 by EUCLID:56 .= (q2+|[1,0]|)`1 by Lm1; then (1-r)*(q2+|[1,-1]|)+r*(1/2*(q2+q3)+|[1,0]|) = |[(q2+|[1,0]|)`1,(q2+|[1,0]|)`2]| by A10,EUCLID:57 .= q2+|[1,0]| by EUCLID:57; then q2+|[1,0]| in LSeg(q2+|[1,-1]|,1/2*(q2+q3)+|[1,0]|) by A7,A8,SPPOL_1:22; then A11: LSeg(q2+|[1,-1]|,1/2*(q2+q3)+|[1,0]|) = LSeg(q2+|[1,-1]|,q2+|[1,0]|) \/ LSeg(q2+|[1,0]|,1/2*(q2+q3)+|[1,0]|) by TOPREAL1:11; set I1 = Int cell(G,len G,0), I2 = Int cell(G,len G,1); A12: LSeg(q2+|[1,-1]|,q2+|[1,0]|) c= I1 \/ { q2+|[1,0]| } by Th60; A13: LSeg(q2+|[1,0]|,1/2*(q2+q3)+|[1,0]|) c= I2 \/ { q2+|[1,0]| } by A1,A2,Th53; I1 \/ I2 \/ { q2+|[1,0]| } = I1 \/ (I2 \/ ({ q2+|[1,0]| } \/ { q2+|[1,0]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { q2+|[1,0]| } \/ { q2+|[1,0]| }) by XBOOLE_1:4 .= I1 \/ { q2+|[1,0]| } \/ (I2 \/ { q2+|[1,0]| }) by XBOOLE_1:4; hence LSeg(q2+|[1,-1]|,1/2*(q2+q3)+|[1,0]|) c= I1 \/ I2 \/ { q2+|[1,0]| } by A11,A12,A13,XBOOLE_1:13; end; theorem 1 < len G & 1 < width G implies LSeg(G*(1,width G)+|[-1,1]|,1/2*(G*(1,width G)+G* (1,width G -' 1))-|[1,0]|) c= Int cell(G,0,width G) \/ Int cell(G,0,width G -' 1) \/ { G*(1,width G)-|[1,0]| } proof assume A1: 1 < len G & 1 < width G; set q2 = G*(1,width G), q3 = G*(1,width G -' 1), r = 1/(1/2*(q2`2-q3`2)+1); A2: width G -' 1 + 1 = width G by A1,AMI_5:4; then A3: width G -' 1 >= 1 by A1,NAT_1:38; A4: width G -'1 < width G by A2,NAT_1:38; A5: q2`1 = G*(1,1)`1 by A1,GOBOARD5:3 .= q3`1 by A1,A3,A4,GOBOARD5:3; q3`2 < q2`2 by A1,A3,A4,GOBOARD5:5; then q2`2-q3`2 > 0 by SQUARE_1:11; then 1/2*(q2`2-q3`2) > 0 by REAL_2:122; then A6: 1 < 1/2*(q2`2-q3`2)+1 by REAL_1:69; then A7: 1/2*(q2`2-q3`2)+1 > 0 by AXIOMS:22; then A8: 0 < r by REAL_2:127; A9: r < 1 by A6,SQUARE_1:2; r*((1/2)*q2`2)-r*((1/2)*q3`2)+r = r*((1/2)*q2`2-((1/2)*q3`2))+r by XCMPLX_1:40 .= r*((1/2)*(q2`2-q3`2))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q2`2-q3`2)+1) by XCMPLX_1:8 .= 1 by A7,XCMPLX_1:107; then r*((1/2)*q2`2)-r*((1/2)*q3`2) = 1-r by XCMPLX_1:26; then A10: r*((1/2)*q3`2)+(1-r) = r*((1/2)*q2`2) by XCMPLX_1:27; A11: ((1-r)*(q2+|[-1,1]|)+r*(1/2*(q2+q3)-|[1,0]|))`2 = ((1-r)*(q2+|[-1,1]|))`2+(r*(1/2*(q2+q3)-|[1,0]|))`2 by Lm1 .= ((1-r)*q2+(1-r)*|[-1,1]|)`2+(r*(1/2*(q2+q3)-|[1,0]|))`2 by EUCLID:36 .= ((1-r)*q2)`2+((1-r)*|[-1,1]|)`2+(r*(1/2*(q2+q3)-|[1,0]|))`2 by Lm1 .= ((1-r)*q2)`2+(1-r)*|[-1,1]|`2+(r*(1/2*(q2+q3)-|[1,0]|))`2 by Lm3 .= ((1-r)*q2)`2+(1-r)*1+(r*(1/2*(q2+q3)-|[1,0]|))`2 by EUCLID:56 .= (1-r)*q2`2+(1-r)*1+(r*(1/2*(q2+q3)-|[1,0]|))`2 by Lm3 .= (1-r)*q2`2+(1-r)+r*(1/2*(q2+q3)-|[1,0]|)`2 by Lm3 .= (1-r)*q2`2+(1-r)+r*((1/2*(q2+q3))`2-|[1,0]|`2) by Lm2 .= (1-r)*q2`2+(1-r)+r*((1/2*(q2+q3))`2-0) by EUCLID:56 .= (1-r)*q2`2+(1-r)+r*(1/2*(q2+q3)`2) by Lm3 .= (1-r)*q2`2+(1-r)+r*(1/2*(q2`2+q3`2)) by Lm1 .= (1-r)*q2`2+(1-r)+r*(1/2*q2`2+1/2*q3`2) by XCMPLX_1:8 .= (1-r)*q2`2+(1-r)+(r*(1/2*q3`2)+r*(1/2*q2`2)) by XCMPLX_1:8 .= (1-r)*q2`2+(1-r)+r*(1/2*q3`2)+r*(1/2*q2`2) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*q2`2)+r*(1/2*q2`2) by A10,XCMPLX_1:1 .= (1-r)*q2`2+(r*(1/2*q2`2)+r*(1/2*q2`2)) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*q2`2+1/2*q2`2) by XCMPLX_1:8 .= (1-r)*q2`2+r*(1*q2`2) by Lm6,XCMPLX_1:8 .= (1-r+r)*q2`2 by XCMPLX_1:8 .= 1*q2`2 by XCMPLX_1:27 .= q2`2-0 .= q2`2-|[1,0]|`2 by EUCLID:56 .= (q2-|[1,0]|)`2 by Lm2; ((1-r)*(q2+|[-1,1]|)+r*(1/2*(q2+q3)-|[1,0]|))`1 = ((1-r)*(q2+|[-1,1]|))`1+(r*(1/2*(q2+q3)-|[1,0]|))`1 by Lm1 .= (1-r)*(q2+|[-1,1]|)`1+(r*(1/2*(q2+q3)-|[1,0]|))`1 by Lm3 .= (1-r)*(q2+|[-1,1]|)`1+r*(1/2*(q2+q3)-|[1,0]|)`1 by Lm3 .= (1-r)*(q2`1+|[-1,1]|`1)+r*(1/2*(q2+q3)-|[1,0]|)`1 by Lm1 .= (1-r)*(q2`1+|[-1,1]|`1)+r*((1/2*(q2+q3))`1-|[1,0]|`1) by Lm2 .= (1-r)*(q2`1+-1)+r*((1/2*(q2+q3))`1-|[1,0]|`1) by EUCLID:56 .= (1-r)*(q2`1-1)+r*((1/2*(q2+q3))`1-|[1,0]|`1) by XCMPLX_0:def 8 .= (1-r)*(q2`1-1)+r*((1/2*(q2+q3))`1-1) by EUCLID:56 .= (1-r)*q2`1-(1-r)*1+r*((1/2*(q2+q3))`1-1) by XCMPLX_1:40 .= (1-r)*q2`1-(1-r)+(r*(1/2*(q2+q3))`1-r*1) by XCMPLX_1:40 .= (1-r)*q2`1-(1-r)+r*(1/2*(q2+q3))`1-r by XCMPLX_1:29 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1-(1-r)-r by XCMPLX_1:29 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1-((1-r)+r) by XCMPLX_1:36 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1-1 by XCMPLX_1:27 .= (1-r)*q2`1+r*(1/2*(q2+q3)`1)-1 by Lm3 .= (1-r)*q2`1+r*(1/2*(q2`1+q2`1))-1 by A5,Lm1 .= (1-r)*q2`1+r*(1/2*(2*q2`1))-1 by XCMPLX_1:11 .= (1-r)*q2`1+r*(1/2*2*q2`1)-1 by XCMPLX_1:4 .= (1-r+r)*q2`1-1 by XCMPLX_1:8 .= 1*q2`1-1 by XCMPLX_1:27 .= q2`1-|[1,0]|`1 by EUCLID:56 .= (q2-|[1,0]|)`1 by Lm2; then (1-r)*(q2+|[-1,1]|)+r*(1/2*(q2+q3)-|[1,0]|) = |[(q2-|[1,0]|)`1,(q2-|[1,0]|)`2]| by A11,EUCLID:57 .= q2-|[1,0]| by EUCLID:57; then q2-|[1,0]| in LSeg(q2+|[-1,1]|,1/2*(q2+q3)-|[1,0]|) by A8,A9,SPPOL_1:22; then A12: LSeg(q2+|[-1,1]|,1/2*(q2+q3)-|[1,0]|) = LSeg(q2+|[-1,1]|,q2-|[1,0]|) \/ LSeg(q2-|[1,0]|,1/2*(q2+q3)-|[1,0]|) by TOPREAL1:11; set I1 = Int cell(G,0,width G), I2 = Int cell(G,0,width G -' 1); A13: LSeg(q2+|[-1,1]|,q2-|[1,0]|) c= I1 \/ { q2-|[1,0]| } by Th61; A14: LSeg(q2-|[1,0]|,1/2*(q2+q3)-|[1,0]|) c= I2 \/ { q2-|[1,0]| } by A2,A3,A4,Th52; I1 \/ I2 \/ { q2-|[1,0]| } = I1 \/ (I2 \/ ({ q2-|[1,0]| } \/ { q2-|[1,0]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { q2-|[1,0]| } \/ { q2-|[1,0]| }) by XBOOLE_1:4 .= I1 \/ { q2-|[1,0]| } \/ (I2 \/ { q2-|[1,0]| }) by XBOOLE_1:4; hence LSeg(q2+|[-1,1]|,1/2*(q2+q3)-|[1,0]|) c= I1 \/ I2 \/ { q2-|[1,0]| } by A12,A13,A14,XBOOLE_1:13; end; theorem 1 < len G & 1 < width G implies LSeg(G*(len G,width G)+|[1,1]|, 1/2*(G*(len G,width G)+G*(len G,width G -' 1))+|[1,0]|) c= Int cell(G,len G,width G) \/ Int cell(G,len G,width G -' 1) \/ { G*(len G,width G)+|[1,0]| } proof assume A1: 1 < len G & 1 < width G; set q2 = G*(len G,width G), q3 = G*(len G,width G -' 1), r = 1/(1/2*(q2`2-q3`2)+1); A2: width G -' 1 + 1 = width G by A1,AMI_5:4; then A3: width G -' 1 >= 1 by A1,NAT_1:38; A4: width G -' 1 < width G by A2,NAT_1:38; A5: q2`1 = G*(len G,1)`1 by A1,GOBOARD5:3 .= q3`1 by A1,A3,A4,GOBOARD5:3; q3`2 < q2`2 by A1,A3,A4,GOBOARD5:5; then q2`2-q3`2 > 0 by SQUARE_1:11; then 1/2*(q2`2-q3`2) > 0 by REAL_2:122; then A6: 1 < 1/2*(q2`2-q3`2)+1 by REAL_1:69; then A7: 1/2*(q2`2-q3`2)+1 > 0 by AXIOMS:22; then A8: 0 < r by REAL_2:127; A9: r < 1 by A6,SQUARE_1:2; r*((1/2)*q2`2)-r*((1/2)*q3`2)+r = r*((1/2)*q2`2-((1/2)*q3`2))+r by XCMPLX_1:40 .= r*((1/2)*(q2`2-q3`2))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q2`2-q3`2)+1) by XCMPLX_1:8 .= 1 by A7,XCMPLX_1:107; then r*((1/2)*q2`2)-r*((1/2)*q3`2) = 1-r by XCMPLX_1:26; then A10: r*((1/2)*q3`2)+(1-r) = r*((1/2)*q2`2) by XCMPLX_1:27; A11: ((1-r)*(q2+|[1,1]|)+r*(1/2*(q2+q3)+|[1,0]|))`2 = ((1-r)*(q2+|[1,1]|))`2+(r*(1/2*(q2+q3)+|[1,0]|))`2 by Lm1 .= ((1-r)*q2+(1-r)*|[1,1]|)`2+(r*(1/2*(q2+q3)+|[1,0]|))`2 by EUCLID:36 .= ((1-r)*q2)`2+((1-r)*|[1,1]|)`2+(r*(1/2*(q2+q3)+|[1,0]|))`2 by Lm1 .= ((1-r)*q2)`2+(1-r)*|[1,1]|`2+(r*(1/2*(q2+q3)+|[1,0]|))`2 by Lm3 .= ((1-r)*q2)`2+(1-r)*1+(r*(1/2*(q2+q3)+|[1,0]|))`2 by EUCLID:56 .= (1-r)*q2`2+(1-r)+(r*(1/2*(q2+q3)+|[1,0]|))`2 by Lm3 .= (1-r)*q2`2+(1-r)+r*(1/2*(q2+q3)+|[1,0]|)`2 by Lm3 .= (1-r)*q2`2+(1-r)+r*((1/2*(q2+q3))`2+|[1,0]|`2) by Lm1 .= (1-r)*q2`2+(1-r)+r*((1/2*(q2+q3))`2+0) by EUCLID:56 .= (1-r)*q2`2+(1-r)+r*(1/2*(q2+q3)`2) by Lm3 .= (1-r)*q2`2+(1-r)+r*(1/2*(q2`2+q3`2)) by Lm1 .= (1-r)*q2`2+(1-r)+r*(1/2*q2`2+1/2*q3`2) by XCMPLX_1:8 .= (1-r)*q2`2+(1-r)+(r*(1/2*q3`2)+r*(1/2*q2`2)) by XCMPLX_1:8 .= (1-r)*q2`2+(1-r)+r*(1/2*q3`2)+r*(1/2*q2`2) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*q2`2)+r*(1/2*q2`2) by A10,XCMPLX_1:1 .= (1-r)*q2`2+(r*(1/2*q2`2)+r*(1/2*q2`2)) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*q2`2+1/2*q2`2) by XCMPLX_1:8 .= (1-r)*q2`2+r*(1*q2`2) by Lm6,XCMPLX_1:8 .= (1-r+r)*q2`2 by XCMPLX_1:8 .= 1*q2`2 by XCMPLX_1:27 .= q2`2+0 .= q2`2+|[1,0]|`2 by EUCLID:56 .= (q2+|[1,0]|)`2 by Lm1; ((1-r)*(q2+|[1,1]|)+r*(1/2*(q2+q3)+|[1,0]|))`1 = ((1-r)*(q2+|[1,1]|))`1+(r*(1/2*(q2+q3)+|[1,0]|))`1 by Lm1 .= (1-r)*(q2+|[1,1]|)`1+(r*(1/2*(q2+q3)+|[1,0]|))`1 by Lm3 .= (1-r)*(q2+|[1,1]|)`1+r*(1/2*(q2+q3)+|[1,0]|)`1 by Lm3 .= (1-r)*(q2`1+|[1,1]|`1)+r*(1/2*(q2+q3)+|[1,0]|)`1 by Lm1 .= (1-r)*(q2`1+|[1,1]|`1)+r*((1/2*(q2+q3))`1+|[1,0]|`1) by Lm1 .= (1-r)*(q2`1+1)+r*((1/2*(q2+q3))`1+|[1,0]|`1) by EUCLID:56 .= (1-r)*(q2`1+1)+r*((1/2*(q2+q3))`1+1) by EUCLID:56 .= (1-r)*q2`1+(1-r)*1+r*((1/2*(q2+q3))`1+1) by XCMPLX_1:8 .= (1-r)*q2`1+(1-r)+(r*(1/2*(q2+q3))`1+r*1) by XCMPLX_1:8 .= (1-r)*q2`1+(1-r)+r*(1/2*(q2+q3))`1+r by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1+(1-r)+r by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1+((1-r)+r) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*(q2+q3))`1+1 by XCMPLX_1:27 .= (1-r)*q2`1+r*(1/2*(q2+q3)`1)+1 by Lm3 .= (1-r)*q2`1+r*(1/2*(q2`1+q2`1))+1 by A5,Lm1 .= (1-r)*q2`1+r*(1/2*(2*q2`1))+1 by XCMPLX_1:11 .= (1-r)*q2`1+r*(1/2*2*q2`1)+1 by XCMPLX_1:4 .= (1-r+r)*q2`1+1 by XCMPLX_1:8 .= 1*q2`1+1 by XCMPLX_1:27 .= q2`1+|[1,0]|`1 by EUCLID:56 .= (q2+|[1,0]|)`1 by Lm1; then (1-r)*(q2+|[1,1]|)+r*(1/2*(q2+q3)+|[1,0]|) = |[(q2+|[1,0]|)`1,(q2+|[1,0]|)`2]| by A11,EUCLID:57 .= q2+|[1,0]| by EUCLID:57; then q2+|[1,0]| in LSeg(q2+|[1,1]|,1/2*(q2+q3)+|[1,0]|) by A8,A9,SPPOL_1:22; then A12: LSeg(q2+|[1,1]|,1/2*(q2+q3)+|[1,0]|) = LSeg(q2+|[1,1]|,q2+|[1,0]|) \/ LSeg(q2+|[1,0]|,1/2*(q2+q3)+|[1,0]|) by TOPREAL1:11; set I1 = Int cell(G,len G,width G), I2 = Int cell(G,len G,width G -' 1); A13: LSeg(q2+|[1,1]|,q2+|[1,0]|) c= I1 \/ { q2+|[1,0]| } by Th62; A14: LSeg(q2+|[1,0]|,1/2*(q2+q3)+|[1,0]|) c= I2 \/ { q2+|[1,0]| } by A2,A3,A4,Th54; I1 \/ I2 \/ { q2+|[1,0]| } = I1 \/ (I2 \/ ({ q2+|[1,0]| } \/ { q2+|[1,0]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { q2+|[1,0]| } \/ { q2+|[1,0]| }) by XBOOLE_1:4 .= I1 \/ { q2+|[1,0]| } \/ (I2 \/ { q2+|[1,0]| }) by XBOOLE_1:4; hence LSeg(q2+|[1,1]|,1/2*(q2+q3)+|[1,0]|) c= I1 \/ I2 \/ { q2+|[1,0]| } by A12,A13,A14,XBOOLE_1:13; end; theorem 1 < width G & 1 < len G implies LSeg(G*(1,1)-|[1,1]|,1/2*(G*(1,1)+G*(2,1))-|[0,1]|) c= Int cell(G,0,0) \/ Int cell(G,1,0) \/ { G*(1,1)-|[0,1]| } proof assume A1: 1 < width G & 1 < len G; set q2 = G*(1,1), q3 = G*(2,1), r = 1/(1/2*(q3`1-q2`1)+1); A2: 0+1+1 = 0+(1+1); A3: 0+(1+1) <= len G by A1,NAT_1:38; then A4: q2`2 = q3`2 by A1,GOBOARD5:2; q2`1 < q3`1 by A1,A3,GOBOARD5:4; then q3`1-q2`1 > 0 by SQUARE_1:11; then 1/2*(q3`1-q2`1) > 0 by REAL_2:122; then A5: 1 < 1/2*(q3`1-q2`1)+1 by REAL_1:69; then A6: 1/2*(q3`1-q2`1)+1 > 0 by AXIOMS:22; then A7: 0 < r by REAL_2:127; A8: r < 1 by A5,SQUARE_1:2; r*((1/2)*q3`1)-r*((1/2)*q2`1)+r = r*((1/2)*q3`1-((1/2)*q2`1))+r by XCMPLX_1:40 .= r*((1/2)*(q3`1-q2`1))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q3`1-q2`1)+1) by XCMPLX_1:8 .= 1 by A6,XCMPLX_1:107; then r*((1/2)*q3`1)-r*((1/2)*q2`1) = 1-r by XCMPLX_1:26; then A9: r*((1/2)*q3`1)-(1-r) = r*((1/2)*q2`1) by XCMPLX_1:18; A10: ((1-r)*(q2-|[1,1]|)+r*(1/2*(q2+q3)-|[0,1]|))`1 = ((1-r)*(q2-|[1,1]|))`1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by Lm1 .= ((1-r)*q2-(1-r)*|[1,1]|)`1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by EUCLID:53 .= ((1-r)*q2)`1-((1-r)*|[1,1]|)`1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by Lm2 .= ((1-r)*q2)`1-(1-r)*|[1,1]|`1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by Lm3 .= ((1-r)*q2)`1-(1-r)*1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by EUCLID:56 .= (1-r)*q2`1-(1-r)*1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by Lm3 .= (1-r)*q2`1-(1-r)+r*(1/2*(q2+q3)-|[0,1]|)`1 by Lm3 .= (1-r)*q2`1-(1-r)+r*((1/2*(q2+q3))`1-|[0,1]|`1) by Lm2 .= (1-r)*q2`1-(1-r)+r*((1/2*(q2+q3))`1-0) by EUCLID:56 .= (1-r)*q2`1-(1-r)+r*(1/2*(q2+q3)`1) by Lm3 .= (1-r)*q2`1-(1-r)+r*(1/2*(q2`1+q3`1)) by Lm1 .= (1-r)*q2`1-(1-r)+r*(1/2*q2`1+1/2*q3`1) by XCMPLX_1:8 .= (1-r)*q2`1-(1-r)+(r*(1/2*q3`1)+r*(1/2*q2`1)) by XCMPLX_1:8 .= (1-r)*q2`1-(1-r)+r*(1/2*q3`1)+r*(1/2*q2`1) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*q3`1)-(1-r)+r*(1/2*q2`1) by XCMPLX_1:29 .= (1-r)*q2`1+r*(1/2*q2`1)+r*(1/2*q2`1) by A9,XCMPLX_1:29 .= (1-r)*q2`1+(r*(1/2*q2`1)+r*(1/2*q2`1)) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*q2`1+1/2*q2`1) by XCMPLX_1:8 .= (1-r)*q2`1+r*(1*q2`1) by Lm6,XCMPLX_1:8 .= (1-r+r)*q2`1 by XCMPLX_1:8 .= 1*q2`1 by XCMPLX_1:27 .= q2`1-0 .= q2`1-|[0,1]|`1 by EUCLID:56 .= (q2-|[0,1]|)`1 by Lm2; ((1-r)*(q2-|[1,1]|)+r*(1/2*(q2+q3)-|[0,1]|))`2 = ((1-r)*(q2-|[1,1]|))`2+(r*(1/2*(q2+q3)-|[0,1]|))`2 by Lm1 .= (1-r)*(q2-|[1,1]|)`2+(r*(1/2*(q2+q3)-|[0,1]|))`2 by Lm3 .= (1-r)*(q2-|[1,1]|)`2+r*(1/2*(q2+q3)-|[0,1]|)`2 by Lm3 .= (1-r)*(q2`2-|[1,1]|`2)+r*(1/2*(q2+q3)-|[0,1]|)`2 by Lm2 .= (1-r)*(q2`2-|[1,1]|`2)+r*((1/2*(q2+q3))`2-|[0,1]|`2) by Lm2 .= (1-r)*(q2`2-1)+r*((1/2*(q2+q3))`2-|[0,1]|`2) by EUCLID:56 .= (1-r)*(q2`2-1)+r*((1/2*(q2+q3))`2-1) by EUCLID:56 .= (1-r)*q2`2-(1-r)*1+r*((1/2*(q2+q3))`2-1) by XCMPLX_1:40 .= (1-r)*q2`2-(1-r)+(r*(1/2*(q2+q3))`2-r*1) by XCMPLX_1:40 .= (1-r)*q2`2-(1-r)+r*(1/2*(q2+q3))`2-r by XCMPLX_1:29 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2-(1-r)-r by XCMPLX_1:29 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2-((1-r)+r) by XCMPLX_1:36 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2-1 by XCMPLX_1:27 .= (1-r)*q2`2+r*(1/2*(q2+q3)`2)-1 by Lm3 .= (1-r)*q2`2+r*(1/2*(q2`2+q2`2))-1 by A4,Lm1 .= (1-r)*q2`2+r*(1/2*(2*q2`2))-1 by XCMPLX_1:11 .= (1-r)*q2`2+r*(1/2*2*q2`2)-1 by XCMPLX_1:4 .= (1-r+r)*q2`2-1 by XCMPLX_1:8 .= 1*q2`2-1 by XCMPLX_1:27 .= q2`2-|[0,1]|`2 by EUCLID:56 .= (q2-|[0,1]|)`2 by Lm2; then (1-r)*(q2-|[1,1]|)+r*(1/2*(q2+q3)-|[0,1]|) = |[(q2-|[0,1]|)`1,(q2-|[0,1]|)`2]| by A10,EUCLID:57 .= q2-|[0,1]| by EUCLID:57; then q2-|[0,1]| in LSeg(q2-|[1,1]|,1/2*(q2+q3)-|[0,1]|) by A7,A8,SPPOL_1:22; then A11: LSeg(q2-|[1,1]|,1/2*(q2+q3)-|[0,1]|) = LSeg(q2-|[1,1]|,q2-|[0,1]|) \/ LSeg(q2-|[0,1]|,1/2*(q2+q3)-|[0,1]|) by TOPREAL1:11; set I1 = Int cell(G,0,0), I2 = Int cell(G,1,0); A12: LSeg(q2-|[1,1]|,q2-|[0,1]|) c= I1 \/ { q2-|[0,1]| } by Th63; A13: LSeg(q2-|[0,1]|,1/2*(q2+q3)-|[0,1]|) c= I2 \/ { q2-|[0,1]| } by A1,A2,Th55; I1 \/ I2 \/ { q2-|[0,1]| } = I1 \/ (I2 \/ ({ q2-|[0,1]| } \/ { q2-|[0,1]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { q2-|[0,1]| } \/ { q2-|[0,1]| }) by XBOOLE_1:4 .= I1 \/ { q2-|[0,1]| } \/ (I2 \/ { q2-|[0,1]| }) by XBOOLE_1:4; hence LSeg(q2-|[1,1]|,1/2*(q2+q3)-|[0,1]|) c= I1 \/ I2 \/ { q2-|[0,1]| } by A11,A12,A13,XBOOLE_1:13; end; theorem 1 < width G & 1 < len G implies LSeg(G*(1,width G)+|[-1,1]|,1/2*(G*(1,width G)+G*(2,width G))+|[0,1]|) c= Int cell(G,0,width G) \/ Int cell(G,1,width G) \/ { G*(1,width G)+|[0,1]| } proof assume A1: 1 < width G & 1 < len G; set q2 = G*(1,width G), q3 = G*(2,width G), r = 1/(1/2*(q3`1-q2`1)+1); A2: 0+1+1 = 0+(1+1); A3: 0+(1+1) <= len G by A1,NAT_1:38; then A4: q2`2 = q3`2 by A1,GOBOARD5:2; q2`1 < q3`1 by A1,A3,GOBOARD5:4; then q3`1-q2`1 > 0 by SQUARE_1:11; then 1/2*(q3`1-q2`1) > 0 by REAL_2:122; then A5: 1 < 1/2*(q3`1-q2`1)+1 by REAL_1:69; then A6: 1/2*(q3`1-q2`1)+1 > 0 by AXIOMS:22; then A7: 0 < r by REAL_2:127; A8: r < 1 by A5,SQUARE_1:2; r*((1/2)*q3`1)-r*((1/2)*q2`1)+r = r*((1/2)*q3`1-((1/2)*q2`1))+r by XCMPLX_1:40 .= r*((1/2)*(q3`1-q2`1))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q3`1-q2`1)+1) by XCMPLX_1:8 .= 1 by A6,XCMPLX_1:107; then r*((1/2)*q3`1)-r*((1/2)*q2`1) = 1-r by XCMPLX_1:26; then A9: r*((1/2)*q3`1)-(1-r) = r*((1/2)*q2`1) by XCMPLX_1:18; A10: ((1-r)*(q2+|[-1,1]|)+r*(1/2*(q2+q3)+|[0,1]|))`1 = ((1-r)*(q2+|[-1,1]|))`1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by Lm1 .= ((1-r)*q2+(1-r)*|[-1,1]|)`1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by EUCLID:36 .= ((1-r)*q2)`1+((1-r)*|[-1,1]|)`1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by Lm1 .= ((1-r)*q2)`1+(1-r)*|[-1,1]|`1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by Lm3 .= ((1-r)*q2)`1+(1-r)*(-1)+(r*(1/2*(q2+q3)+|[0,1]|))`1 by EUCLID:56 .= ((1-r)*q2)`1+-(1-r)+(r*(1/2*(q2+q3)+|[0,1]|))`1 by XCMPLX_1:180 .= ((1-r)*q2)`1-(1-r)+(r*(1/2*(q2+q3)+|[0,1]|))`1 by XCMPLX_0:def 8 .= (1-r)*q2`1-(1-r)+(r*(1/2*(q2+q3)+|[0,1]|))`1 by Lm3 .= (1-r)*q2`1-(1-r)+r*(1/2*(q2+q3)+|[0,1]|)`1 by Lm3 .= (1-r)*q2`1-(1-r)+r*((1/2*(q2+q3))`1+|[0,1]|`1) by Lm1 .= (1-r)*q2`1-(1-r)+r*((1/2*(q2+q3))`1+0) by EUCLID:56 .= (1-r)*q2`1-(1-r)+r*(1/2*(q2+q3)`1) by Lm3 .= (1-r)*q2`1-(1-r)+r*(1/2*(q2`1+q3`1)) by Lm1 .= (1-r)*q2`1-(1-r)+r*(1/2*q2`1+1/2*q3`1) by XCMPLX_1:8 .= (1-r)*q2`1-(1-r)+(r*(1/2*q3`1)+r*(1/2*q2`1)) by XCMPLX_1:8 .= (1-r)*q2`1-(1-r)+r*(1/2*q3`1)+r*(1/2*q2`1) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*q3`1)-(1-r)+r*(1/2*q2`1) by XCMPLX_1:29 .= (1-r)*q2`1+r*(1/2*q2`1)+r*(1/2*q2`1) by A9,XCMPLX_1:29 .= (1-r)*q2`1+(r*(1/2*q2`1)+r*(1/2*q2`1)) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*q2`1+1/2*q2`1) by XCMPLX_1:8 .= (1-r)*q2`1+r*(1*q2`1) by Lm6,XCMPLX_1:8 .= (1-r+r)*q2`1 by XCMPLX_1:8 .= 1*q2`1 by XCMPLX_1:27 .= q2`1+0 .= q2`1+|[0,1]|`1 by EUCLID:56 .= (q2+|[0,1]|)`1 by Lm1; ((1-r)*(q2+|[-1,1]|)+r*(1/2*(q2+q3)+|[0,1]|))`2 = ((1-r)*(q2+|[-1,1]|))`2+(r*(1/2*(q2+q3)+|[0,1]|))`2 by Lm1 .= (1-r)*(q2+|[-1,1]|)`2+(r*(1/2*(q2+q3)+|[0,1]|))`2 by Lm3 .= (1-r)*(q2+|[-1,1]|)`2+r*(1/2*(q2+q3)+|[0,1]|)`2 by Lm3 .= (1-r)*(q2`2+|[-1,1]|`2)+r*(1/2*(q2+q3)+|[0,1]|)`2 by Lm1 .= (1-r)*(q2`2+|[-1,1]|`2)+r*((1/2*(q2+q3))`2+|[0,1]|`2) by Lm1 .= (1-r)*(q2`2+1)+r*((1/2*(q2+q3))`2+|[0,1]|`2) by EUCLID:56 .= (1-r)*(q2`2+1)+r*((1/2*(q2+q3))`2+1) by EUCLID:56 .= (1-r)*q2`2+(1-r)*1+r*((1/2*(q2+q3))`2+1) by XCMPLX_1:8 .= (1-r)*q2`2+(1-r)+(r*(1/2*(q2+q3))`2+r*1) by XCMPLX_1:8 .= (1-r)*q2`2+(1-r)+r*(1/2*(q2+q3))`2+r by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2+(1-r)+r by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2+((1-r)+r) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2+1 by XCMPLX_1:27 .= (1-r)*q2`2+r*(1/2*(q2+q3)`2)+1 by Lm3 .= (1-r)*q2`2+r*(1/2*(q2`2+q2`2))+1 by A4,Lm1 .= (1-r)*q2`2+r*(1/2*(2*q2`2))+1 by XCMPLX_1:11 .= (1-r)*q2`2+r*(1/2*2*q2`2)+1 by XCMPLX_1:4 .= (1-r+r)*q2`2+1 by XCMPLX_1:8 .= 1*q2`2+1 by XCMPLX_1:27 .= q2`2+|[0,1]|`2 by EUCLID:56 .= (q2+|[0,1]|)`2 by Lm1; then (1-r)*(q2+|[-1,1]|)+r*(1/2*(q2+q3)+|[0,1]|) = |[(q2+|[0,1]|)`1,(q2+|[0,1]|)`2]| by A10,EUCLID:57 .= q2+|[0,1]| by EUCLID:57; then q2+|[0,1]| in LSeg(q2+|[-1,1]|,1/2*(q2+q3)+|[0,1]|) by A7,A8,SPPOL_1:22; then A11: LSeg(q2+|[-1,1]|,1/2*(q2+q3)+|[0,1]|) = LSeg(q2+|[-1,1]|,q2+|[0,1]|) \/ LSeg(q2+|[0,1]|,1/2*(q2+q3)+|[0,1]|) by TOPREAL1:11; set I1 = Int cell(G,0,width G), I2 = Int cell(G,1,width G); A12: LSeg(q2+|[-1,1]|,q2+|[0,1]|) c= I1 \/ { q2+|[0,1]| } by Th65; A13: LSeg(q2+|[0,1]|,1/2*(q2+q3)+|[0,1]|) c= I2 \/ { q2+|[0,1]| } by A1,A2,Th57; I1 \/ I2 \/ { q2+|[0,1]| } = I1 \/ (I2 \/ ({ q2+|[0,1]| } \/ { q2+|[0,1]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { q2+|[0,1]| } \/ { q2+|[0,1]| }) by XBOOLE_1:4 .= I1 \/ { q2+|[0,1]| } \/ (I2 \/ { q2+|[0,1]| }) by XBOOLE_1:4; hence LSeg(q2+|[-1,1]|,1/2*(q2+q3)+|[0,1]|) c= I1 \/ I2 \/ { q2+|[0,1]| } by A11,A12,A13,XBOOLE_1:13; end; theorem 1 < width G & 1 < len G implies LSeg(G*(len G,1)+|[1,-1]|,1/2*(G*(len G,1)+G*(len G -' 1,1))-|[0,1]|) c= Int cell(G,len G,0) \/ Int cell(G,len G -' 1,0) \/ { G*(len G,1)-|[0,1]| } proof assume A1: 1 < width G & 1 < len G; set q2 = G*(len G,1), q3 = G*(len G -' 1,1), r = 1/(1/2*(q2`1-q3`1)+1); A2: len G -' 1 + 1 = len G by A1,AMI_5:4; then A3: len G -' 1 >= 1 by A1,NAT_1:38; A4: len G -'1 < len G by A2,NAT_1:38; A5: q2`2 = G*(1,1)`2 by A1,GOBOARD5:2 .= q3`2 by A1,A3,A4,GOBOARD5:2; q3`1 < q2`1 by A1,A3,A4,GOBOARD5:4; then q2`1-q3`1 > 0 by SQUARE_1:11; then 1/2*(q2`1-q3`1) > 0 by REAL_2:122; then A6: 1 < 1/2*(q2`1-q3`1)+1 by REAL_1:69; then A7: 1/2*(q2`1-q3`1)+1 > 0 by AXIOMS:22; then A8: 0 < r by REAL_2:127; A9: r < 1 by A6,SQUARE_1:2; r*((1/2)*q2`1)-r*((1/2)*q3`1)+r = r*((1/2)*q2`1-((1/2)*q3`1))+r by XCMPLX_1:40 .= r*((1/2)*(q2`1-q3`1))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q2`1-q3`1)+1) by XCMPLX_1:8 .= 1 by A7,XCMPLX_1:107; then r*((1/2)*q2`1)-r*((1/2)*q3`1) = 1-r by XCMPLX_1:26; then A10: r*((1/2)*q3`1)+(1-r) = r*((1/2)*q2`1) by XCMPLX_1:27; A11: ((1-r)*(q2+|[1,-1]|)+r*(1/2*(q2+q3)-|[0,1]|))`1 = ((1-r)*(q2+|[1,-1]|))`1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by Lm1 .= ((1-r)*q2+(1-r)*|[1,-1]|)`1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by EUCLID:36 .= ((1-r)*q2)`1+((1-r)*|[1,-1]|)`1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by Lm1 .= ((1-r)*q2)`1+(1-r)*|[1,-1]|`1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by Lm3 .= ((1-r)*q2)`1+(1-r)*1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by EUCLID:56 .= (1-r)*q2`1+(1-r)*1+(r*(1/2*(q2+q3)-|[0,1]|))`1 by Lm3 .= (1-r)*q2`1+(1-r)+r*(1/2*(q2+q3)-|[0,1]|)`1 by Lm3 .= (1-r)*q2`1+(1-r)+r*((1/2*(q2+q3))`1-|[0,1]|`1) by Lm2 .= (1-r)*q2`1+(1-r)+r*((1/2*(q2+q3))`1-0) by EUCLID:56 .= (1-r)*q2`1+(1-r)+r*(1/2*(q2+q3)`1) by Lm3 .= (1-r)*q2`1+(1-r)+r*(1/2*(q2`1+q3`1)) by Lm1 .= (1-r)*q2`1+(1-r)+r*(1/2*q2`1+1/2*q3`1) by XCMPLX_1:8 .= (1-r)*q2`1+(1-r)+(r*(1/2*q3`1)+r*(1/2*q2`1)) by XCMPLX_1:8 .= (1-r)*q2`1+(1-r)+r*(1/2*q3`1)+r*(1/2*q2`1) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*q2`1)+r*(1/2*q2`1) by A10,XCMPLX_1:1 .= (1-r)*q2`1+(r*(1/2*q2`1)+r*(1/2*q2`1)) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*q2`1+1/2*q2`1) by XCMPLX_1:8 .= (1-r)*q2`1+r*(1*q2`1) by Lm6,XCMPLX_1:8 .= (1-r+r)*q2`1 by XCMPLX_1:8 .= 1*q2`1 by XCMPLX_1:27 .= q2`1-0 .= q2`1-|[0,1]|`1 by EUCLID:56 .= (q2-|[0,1]|)`1 by Lm2; ((1-r)*(q2+|[1,-1]|)+r*(1/2*(q2+q3)-|[0,1]|))`2 = ((1-r)*(q2+|[1,-1]|))`2+(r*(1/2*(q2+q3)-|[0,1]|))`2 by Lm1 .= (1-r)*(q2+|[1,-1]|)`2+(r*(1/2*(q2+q3)-|[0,1]|))`2 by Lm3 .= (1-r)*(q2+|[1,-1]|)`2+r*(1/2*(q2+q3)-|[0,1]|)`2 by Lm3 .= (1-r)*(q2`2+|[1,-1]|`2)+r*(1/2*(q2+q3)-|[0,1]|)`2 by Lm1 .= (1-r)*(q2`2+|[1,-1]|`2)+r*((1/2*(q2+q3))`2-|[0,1]|`2) by Lm2 .= (1-r)*(q2`2+-1)+r*((1/2*(q2+q3))`2-|[0,1]|`2) by EUCLID:56 .= (1-r)*(q2`2-1)+r*((1/2*(q2+q3))`2-|[0,1]|`2) by XCMPLX_0:def 8 .= (1-r)*(q2`2-1)+r*((1/2*(q2+q3))`2-1) by EUCLID:56 .= (1-r)*q2`2-(1-r)*1+r*((1/2*(q2+q3))`2-1) by XCMPLX_1:40 .= (1-r)*q2`2-(1-r)+(r*(1/2*(q2+q3))`2-r*1) by XCMPLX_1:40 .= (1-r)*q2`2-(1-r)+r*(1/2*(q2+q3))`2-r by XCMPLX_1:29 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2-(1-r)-r by XCMPLX_1:29 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2-((1-r)+r) by XCMPLX_1:36 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2-1 by XCMPLX_1:27 .= (1-r)*q2`2+r*(1/2*(q2+q3)`2)-1 by Lm3 .= (1-r)*q2`2+r*(1/2*(q2`2+q2`2))-1 by A5,Lm1 .= (1-r)*q2`2+r*(1/2*(2*q2`2))-1 by XCMPLX_1:11 .= (1-r)*q2`2+r*(1/2*2*q2`2)-1 by XCMPLX_1:4 .= (1-r+r)*q2`2-1 by XCMPLX_1:8 .= 1*q2`2-1 by XCMPLX_1:27 .= q2`2-|[0,1]|`2 by EUCLID:56 .= (q2-|[0,1]|)`2 by Lm2; then (1-r)*(q2+|[1,-1]|)+r*(1/2*(q2+q3)-|[0,1]|) = |[(q2-|[0,1]|)`1,(q2-|[0,1]|)`2]| by A11,EUCLID:57 .= q2-|[0,1]| by EUCLID:57; then q2-|[0,1]| in LSeg(q2+|[1,-1]|,1/2*(q2+q3)-|[0,1]|) by A8,A9,SPPOL_1:22; then A12: LSeg(q2+|[1,-1]|,1/2*(q2+q3)-|[0,1]|) = LSeg(q2+|[1,-1]|,q2-|[0,1]|) \/ LSeg(q2-|[0,1]|,1/2*(q2+q3)-|[0,1]|) by TOPREAL1:11; set I1 = Int cell(G,len G,0), I2 = Int cell(G,len G -' 1,0); A13: LSeg(q2+|[1,-1]|,q2-|[0,1]|) c= I1 \/ { q2-|[0,1]| } by Th64; A14: LSeg(q2-|[0,1]|,1/2*(q2+q3)-|[0,1]|) c= I2 \/ { q2-|[0,1]| } by A2,A3,A4,Th56; I1 \/ I2 \/ { q2-|[0,1]| } = I1 \/ (I2 \/ ({ q2-|[0,1]| } \/ { q2-|[0,1]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { q2-|[0,1]| } \/ { q2-|[0,1]| }) by XBOOLE_1:4 .= I1 \/ { q2-|[0,1]| } \/ (I2 \/ { q2-|[0,1]| }) by XBOOLE_1:4; hence LSeg(q2+|[1,-1]|,1/2*(q2+q3)-|[0,1]|) c= I1 \/ I2 \/ { q2-|[0,1]| } by A12,A13,A14,XBOOLE_1:13; end; theorem 1 < width G & 1 < len G implies LSeg(G*(len G,width G)+|[1,1]|, 1/2*(G*(len G,width G)+G*(len G -' 1,width G))+|[0,1]|) c= Int cell(G,len G,width G) \/ Int cell(G,len G -' 1,width G) \/ { G*(len G,width G)+|[0,1]| } proof assume A1: 1 < width G & 1 < len G; set q2 = G*(len G,width G), q3 = G*(len G -' 1,width G), r = 1/(1/2*(q2`1-q3`1)+1); A2: len G -' 1 + 1 = len G by A1,AMI_5:4; then A3: len G -' 1 >= 1 by A1,NAT_1:38; A4: len G -' 1 < len G by A2,NAT_1:38; A5: q2`2 = G*(1,width G)`2 by A1,GOBOARD5:2 .= q3`2 by A1,A3,A4,GOBOARD5:2; q3`1 < q2`1 by A1,A3,A4,GOBOARD5:4; then q2`1-q3`1 > 0 by SQUARE_1:11; then 1/2*(q2`1-q3`1) > 0 by REAL_2:122; then A6: 1 < 1/2*(q2`1-q3`1)+1 by REAL_1:69; then A7: 1/2*(q2`1-q3`1)+1 > 0 by AXIOMS:22; then A8: 0 < r by REAL_2:127; A9: r < 1 by A6,SQUARE_1:2; r*((1/2)*q2`1)-r*((1/2)*q3`1)+r = r*((1/2)*q2`1-((1/2)*q3`1))+r by XCMPLX_1:40 .= r*((1/2)*(q2`1-q3`1))+r*1 by XCMPLX_1:40 .= r*((1/2)*(q2`1-q3`1)+1) by XCMPLX_1:8 .= 1 by A7,XCMPLX_1:107; then r*((1/2)*q2`1)-r*((1/2)*q3`1) = 1-r by XCMPLX_1:26; then A10: r*((1/2)*q3`1)+(1-r) = r*((1/2)*q2`1) by XCMPLX_1:27; A11: ((1-r)*(q2+|[1,1]|)+r*(1/2*(q2+q3)+|[0,1]|))`1 = ((1-r)*(q2+|[1,1]|))`1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by Lm1 .= ((1-r)*q2+(1-r)*|[1,1]|)`1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by EUCLID:36 .= ((1-r)*q2)`1+((1-r)*|[1,1]|)`1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by Lm1 .= ((1-r)*q2)`1+(1-r)*|[1,1]|`1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by Lm3 .= ((1-r)*q2)`1+(1-r)*1+(r*(1/2*(q2+q3)+|[0,1]|))`1 by EUCLID:56 .= (1-r)*q2`1+(1-r)+(r*(1/2*(q2+q3)+|[0,1]|))`1 by Lm3 .= (1-r)*q2`1+(1-r)+r*(1/2*(q2+q3)+|[0,1]|)`1 by Lm3 .= (1-r)*q2`1+(1-r)+r*((1/2*(q2+q3))`1+|[0,1]|`1) by Lm1 .= (1-r)*q2`1+(1-r)+r*((1/2*(q2+q3))`1+0) by EUCLID:56 .= (1-r)*q2`1+(1-r)+r*(1/2*(q2+q3)`1) by Lm3 .= (1-r)*q2`1+(1-r)+r*(1/2*(q2`1+q3`1)) by Lm1 .= (1-r)*q2`1+(1-r)+r*(1/2*q2`1+1/2*q3`1) by XCMPLX_1:8 .= (1-r)*q2`1+(1-r)+(r*(1/2*q3`1)+r*(1/2*q2`1)) by XCMPLX_1:8 .= (1-r)*q2`1+(1-r)+r*(1/2*q3`1)+r*(1/2*q2`1) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*q2`1)+r*(1/2*q2`1) by A10,XCMPLX_1:1 .= (1-r)*q2`1+(r*(1/2*q2`1)+r*(1/2*q2`1)) by XCMPLX_1:1 .= (1-r)*q2`1+r*(1/2*q2`1+1/2*q2`1) by XCMPLX_1:8 .= (1-r)*q2`1+r*(1*q2`1) by Lm6,XCMPLX_1:8 .= (1-r+r)*q2`1 by XCMPLX_1:8 .= 1*q2`1 by XCMPLX_1:27 .= q2`1+0 .= q2`1+|[0,1]|`1 by EUCLID:56 .= (q2+|[0,1]|)`1 by Lm1; ((1-r)*(q2+|[1,1]|)+r*(1/2*(q2+q3)+|[0,1]|))`2 = ((1-r)*(q2+|[1,1]|))`2+(r*(1/2*(q2+q3)+|[0,1]|))`2 by Lm1 .= (1-r)*(q2+|[1,1]|)`2+(r*(1/2*(q2+q3)+|[0,1]|))`2 by Lm3 .= (1-r)*(q2+|[1,1]|)`2+r*(1/2*(q2+q3)+|[0,1]|)`2 by Lm3 .= (1-r)*(q2`2+|[1,1]|`2)+r*(1/2*(q2+q3)+|[0,1]|)`2 by Lm1 .= (1-r)*(q2`2+|[1,1]|`2)+r*((1/2*(q2+q3))`2+|[0,1]|`2) by Lm1 .= (1-r)*(q2`2+1)+r*((1/2*(q2+q3))`2+|[0,1]|`2) by EUCLID:56 .= (1-r)*(q2`2+1)+r*((1/2*(q2+q3))`2+1) by EUCLID:56 .= (1-r)*q2`2+(1-r)*1+r*((1/2*(q2+q3))`2+1) by XCMPLX_1:8 .= (1-r)*q2`2+(1-r)+(r*(1/2*(q2+q3))`2+r*1) by XCMPLX_1:8 .= (1-r)*q2`2+(1-r)+r*(1/2*(q2+q3))`2+r by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2+(1-r)+r by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2+((1-r)+r) by XCMPLX_1:1 .= (1-r)*q2`2+r*(1/2*(q2+q3))`2+1 by XCMPLX_1:27 .= (1-r)*q2`2+r*(1/2*(q2+q3)`2)+1 by Lm3 .= (1-r)*q2`2+r*(1/2*(q2`2+q2`2))+1 by A5,Lm1 .= (1-r)*q2`2+r*(1/2*(2*q2`2))+1 by XCMPLX_1:11 .= (1-r)*q2`2+r*(1/2*2*q2`2)+1 by XCMPLX_1:4 .= (1-r+r)*q2`2+1 by XCMPLX_1:8 .= 1*q2`2+1 by XCMPLX_1:27 .= q2`2+|[0,1]|`2 by EUCLID:56 .= (q2+|[0,1]|)`2 by Lm1; then (1-r)*(q2+|[1,1]|)+r*(1/2*(q2+q3)+|[0,1]|) = |[(q2+|[0,1]|)`1,(q2+|[0,1]|)`2]| by A11,EUCLID:57 .= q2+|[0,1]| by EUCLID:57; then q2+|[0,1]| in LSeg(q2+|[1,1]|,1/2*(q2+q3)+|[0,1]|) by A8,A9,SPPOL_1:22; then A12: LSeg(q2+|[1,1]|,1/2*(q2+q3)+|[0,1]|) = LSeg(q2+|[1,1]|,q2+|[0,1]|) \/ LSeg(q2+|[0,1]|,1/2*(q2+q3)+|[0,1]|) by TOPREAL1:11; set I1 = Int cell(G,len G,width G), I2 = Int cell(G,len G -' 1,width G); A13: LSeg(q2+|[1,1]|,q2+|[0,1]|) c= I1 \/ { q2+|[0,1]| } by Th66; A14: LSeg(q2+|[0,1]|,1/2*(q2+q3)+|[0,1]|) c= I2 \/ { q2+|[0,1]| } by A2,A3,A4,Th58; I1 \/ I2 \/ { q2+|[0,1]| } = I1 \/ (I2 \/ ({ q2+|[0,1]| } \/ { q2+|[0,1]| })) by XBOOLE_1:4 .= I1 \/ (I2 \/ { q2+|[0,1]| } \/ { q2+|[0,1]| }) by XBOOLE_1:4 .= I1 \/ { q2+|[0,1]| } \/ (I2 \/ { q2+|[0,1]| }) by XBOOLE_1:4; hence LSeg(q2+|[1,1]|,1/2*(q2+q3)+|[0,1]|) c= I1 \/ I2 \/ { q2+|[0,1]| } by A12,A13,A14,XBOOLE_1:13; end; theorem 1 <= i & i+1 <= len G & 1 <= j & j+1 <= width G implies LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),p) meets Int cell(G,i,j) proof assume that A1: 1 <= i & i+1 <= len G and A2: 1 <= j & j+1 <= width G; now take a = 1/2*(G*(i,j)+G*(i+1,j+1)); thus a in LSeg(1/2*(G*(i,j)+G*(i+1,j+1)),p) by TOPREAL1:6; thus a in Int cell(G,i,j) by A1,A2,Th34; end; hence thesis by XBOOLE_0:3; end; theorem 1 <= i & i+1 <= len G implies LSeg(p,1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|) meets Int cell(G,i,width G) proof assume that A1: 1 <= i & i+1 <= len G; now take a = 1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|; thus a in LSeg(p,1/2*(G*(i,width G)+G*(i+1,width G))+|[0,1]|) by TOPREAL1:6; thus a in Int cell(G,i,width G) by A1,Th35; end; hence thesis by XBOOLE_0:3; end; theorem 1 <= i & i+1 <= len G implies LSeg(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|,p) meets Int cell(G,i,0) proof assume that A1: 1 <= i & i+1 <= len G; now take a = 1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|; thus a in LSeg(1/2*(G*(i,1)+G*(i+1,1))-|[0,1]|,p) by TOPREAL1:6; thus a in Int cell(G,i,0) by A1,Th36; end; hence thesis by XBOOLE_0:3; end; theorem 1 <= j & j+1 <= width G implies LSeg(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|,p) meets Int cell(G,0,j) proof assume that A1: 1 <= j & j+1 <= width G; now take a = 1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|; thus a in LSeg(1/2*(G*(1,j)+G*(1,j+1))-|[1,0]|,p) by TOPREAL1:6; thus a in Int cell(G,0,j) by A1,Th38; end; hence thesis by XBOOLE_0:3; end; theorem 1 <= j & j+1 <= width G implies LSeg(p,1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|) meets Int cell(G,len G,j) proof assume that A1: 1 <= j & j+1 <= width G; now take a = 1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|; thus a in LSeg(p,1/2*(G*(len G,j)+G*(len G,j+1))+|[1,0]|) by TOPREAL1:6; thus a in Int cell(G,len G,j) by A1,Th37; end; hence thesis by XBOOLE_0:3; end; theorem LSeg(p,G*(1,1)-|[1,1]|) meets Int cell(G,0,0) proof now take a = G*(1,1)-|[1,1]|; thus a in LSeg(p,G*(1,1)-|[1,1]|) by TOPREAL1:6; thus a in Int cell(G,0,0) by Th39; end; hence thesis by XBOOLE_0:3; end; theorem LSeg(p,G*(len G,width G)+|[1,1]|) meets Int cell(G,len G,width G) proof now take a = G*(len G,width G)+|[1,1]|; thus a in LSeg(p,G*(len G,width G)+|[1,1]|) by TOPREAL1:6; thus a in Int cell(G,len G,width G) by Th40; end; hence thesis by XBOOLE_0:3; end; theorem LSeg(p,G*(1,width G)+|[-1,1]|) meets Int cell(G,0,width G) proof now take a = G*(1,width G)+|[-1,1]|; thus a in LSeg(p,G*(1,width G)+|[-1,1]|) by TOPREAL1:6; thus a in Int cell(G,0,width G) by Th41; end; hence thesis by XBOOLE_0:3; end; theorem LSeg(p,G*(len G,1)+|[1,-1]|) meets Int cell(G,len G,0) proof now take a = G*(len G,1)+|[1,-1]|; thus a in LSeg(p,G*(len G,1)+|[1,-1]|) by TOPREAL1:6; thus a in Int cell(G,len G,0) by Th42; end; hence thesis by XBOOLE_0:3; end;