environ vocabulary ARYTM_1, BORSUK_1, PRE_TOPC, EUCLID, MCART_1, TOPREAL1, RCOMP_1, FINSEQ_1, RELAT_1, TOPS_2, FUNCT_1, TOPMETR, ARYTM_3, SUBSET_1, BOOLE, TREAL_1, SEQ_1, FUNCT_4, COMPTS_1, TARSKI, ORDINAL2, PCOMPS_1, METRIC_1, JORDAN3, RFINSEQ, FINSEQ_5, GROUP_2, SEQM_3, GOBOARD5, GOBOARD2, TREES_1, TOPREAL4, GOBOARD1, MATRIX_1, FINSEQ_4; notation TARSKI, XBOOLE_0, XREAL_0, REAL_1, NAT_1, BINARITH, RCOMP_1, RELAT_1, FINSEQ_1, FUNCT_1, FUNCT_2, TOPMETR, FINSEQ_4, JORDAN3, STRUCT_0, TOPREAL1, RFINSEQ, PRE_TOPC, TOPS_2, COMPTS_1, BORSUK_1, EUCLID, TREAL_1, METRIC_1, GOBOARD1, GOBOARD2, MATRIX_1, TOPREAL4, GOBOARD5, FUNCT_4, FINSEQ_5, PCOMPS_1; constructors REAL_1, FUNCT_4, RFINSEQ, TOPREAL4, SEQM_3, TOPS_2, COMPTS_1, RCOMP_1, TREAL_1, FINSEQ_5, GOBOARD5, JORDAN3, GOBOARD2, BINARITH, FINSEQ_4, INT_1, SEQ_4; clusters BORSUK_1, EUCLID, FUNCT_1, PRE_TOPC, RELSET_1, GOBOARD5, GOBOARD2, STRUCT_0, TOPMETR, TOPREAL1, METRIC_1, INT_1, JORDAN3, XREAL_0, MEMBERED; requirements REAL, NUMERALS, BOOLE, SUBSET, ARITHM; begin :: Preliminaries theorem :: JORDAN5B:1 for i1 being Nat st 1 <= i1 holds i1-'1<i1; theorem :: JORDAN5B:2 for i, k being Nat holds i+1 <= k implies 1 <= k-'i; theorem :: JORDAN5B:3 for i, k being Nat holds 1 <= i & 1 <= k implies (k-'i)+1 <= k; theorem :: JORDAN5B:4 for r being Real st r in the carrier of I[01] holds 1-r in the carrier of I[01]; theorem :: JORDAN5B:5 for p, q, p1 being Point of TOP-REAL 2 st p`2 <> q`2 & p1 in LSeg (p, q) holds ( p1`2 = p`2 implies p1 = p ); theorem :: JORDAN5B:6 for p, q, p1 being Point of TOP-REAL 2 st p`1 <> q`1 & p1 in LSeg (p, q) holds ( p1`1 = p`1 implies p1 = p ); theorem :: JORDAN5B:7 for f being FinSequence of TOP-REAL 2, P being non empty Subset of TOP-REAL 2, F being map of I[01], (TOP-REAL 2) | P, i being Nat st 1 <= i & i+1 <= len f & f is_S-Seq & P = L~f & F is_homeomorphism & F.0 = f/.1 & F.1 = f/.len f ex p1, p2 being Real st p1 < p2 & 0 <= p1 & p1 <= 1 & 0 <= p2 & p2 <= 1 & LSeg (f, i) = F.:[.p1, p2.] & F.p1 = f/.i & F.p2 = f/.(i+1); theorem :: JORDAN5B:8 for f being FinSequence of TOP-REAL 2, Q, R being non empty Subset of TOP-REAL 2, F being map of I[01], (TOP-REAL 2)|Q, i being Nat, P being non empty Subset of I[01] st f is_S-Seq & F is_homeomorphism & F.0 = f/.1 & F.1 = f/.len f & 1 <= i & i+1 <= len f & F.:P = LSeg (f,i) & Q = L~f & R = LSeg(f,i) ex G being map of I[01]|P, (TOP-REAL 2)|R st G = F|P & G is_homeomorphism; begin :: Some properties of real intervals theorem :: JORDAN5B:9 for p1, p2, p being Point of TOP-REAL 2 st p1 <> p2 & p in LSeg(p1,p2) holds LE p,p,p1,p2; theorem :: JORDAN5B:10 for p, p1, p2 being Point of TOP-REAL 2 st p1 <> p2 & p in LSeg(p1,p2) holds LE p1,p,p1,p2; theorem :: JORDAN5B:11 for p, p1, p2 being Point of TOP-REAL 2 st p in LSeg(p1,p2) & p1 <> p2 holds LE p,p2,p1,p2; theorem :: JORDAN5B:12 for p1, p2, q1, q2, q3 being Point of TOP-REAL 2 st p1 <> p2 & LE q1,q2,p1,p2 & LE q2,q3,p1,p2 holds LE q1,q3,p1,p2; theorem :: JORDAN5B:13 for p, q being Point of TOP-REAL 2 st p <> q holds LSeg (p, q) = { p1 where p1 is Point of TOP-REAL 2 : LE p, p1, p, q & LE p1, q, p, q }; theorem :: JORDAN5B:14 for n being Nat, P being Subset of TOP-REAL n, p1, p2 being Point of TOP-REAL n st P is_an_arc_of p1,p2 holds P is_an_arc_of p2,p1; theorem :: JORDAN5B:15 for i being Nat, f being FinSequence of TOP-REAL 2, P being Subset of TOP-REAL 2 st f is_S-Seq & 1 <= i & i+1 <= len f & P = LSeg(f,i) holds P is_an_arc_of f/.i, f/.(i+1); begin :: Cutting off sequences theorem :: JORDAN5B:16 for g1 being FinSequence of TOP-REAL 2, i being Nat st 1 <= i & i <= len g1 & g1 is_S-Seq holds g1/.1 in L~mid(g1, i, len g1) implies i = 1; theorem :: JORDAN5B:17 for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq & p = f.len f holds L_Cut (f,p) = <*p*>; canceled 3; theorem :: JORDAN5B:21 for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f & p <> f.len f & f is_S-Seq holds Index (p, L_Cut(f,p)) = 1; theorem :: JORDAN5B:22 for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f & f is_S-Seq & p <> f.len f holds p in L~L_Cut (f,p); theorem :: JORDAN5B:23 for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f & f is_S-Seq & p <> f.1 holds p in L~R_Cut (f,p); theorem :: JORDAN5B:24 for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f & f is_S-Seq holds B_Cut(f,p,p) = <*p*>; theorem :: JORDAN5B:25 for f being non empty FinSequence of TOP-REAL 2, p, q being Point of TOP-REAL 2 st p in L~f & q in L~f & q <> f.len f & p = f.len f & f is_S-Seq holds p in L~L_Cut(f,q); theorem :: JORDAN5B:26 for f being non empty FinSequence of TOP-REAL 2, p, q being Point of TOP-REAL 2 st (p <> f.len f or q <> f.len f) & p in L~f & q in L~f & f is_S-Seq holds p in L~L_Cut(f,q) or q in L~L_Cut(f,p); theorem :: JORDAN5B:27 for f being non empty FinSequence of TOP-REAL 2, p, q being Point of TOP-REAL 2 st p in L~f & q in L~f & f is_S-Seq holds L~B_Cut(f,p,q) c= L~f; theorem :: JORDAN5B:28 for f being non constant standard special_circular_sequence, i, j being Nat st 1 <= i & j <= len GoB f & i < j holds LSeg((GoB f)*(1,width GoB f), (GoB f)*(i,width GoB f)) /\ LSeg((GoB f)*(j,width GoB f), (GoB f)*(len GoB f,width GoB f)) = {}; theorem :: JORDAN5B:29 for f being non constant standard special_circular_sequence, i, j being Nat st 1 <= i & j <= width GoB f & i < j holds LSeg((GoB f)*(len GoB f,1), (GoB f)*(len GoB f,i)) /\ LSeg((GoB f)*(len GoB f,j), (GoB f)*(len GoB f,width GoB f)) = {}; theorem :: JORDAN5B:30 for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq holds L_Cut (f,f/.1) = f; theorem :: JORDAN5B:31 for f being non empty FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st f is_S-Seq holds R_Cut (f,f/.len f) = f; theorem :: JORDAN5B:32 for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL 2 st p in L~f holds p in LSeg ( f/.Index(p,f), f/.(Index(p,f)+1) ); theorem :: JORDAN5B:33 for f be FinSequence of TOP-REAL 2 for p be Point of TOP-REAL 2 for i be Nat st f is unfolded s.n.c. one-to-one & len f >= 2 & f/.1 in LSeg (f,i) holds i = 1; theorem :: JORDAN5B:34 for f be non constant standard special_circular_sequence, j be Nat, P be Subset of TOP-REAL 2 st 1 <= j & j <= width GoB f & P = LSeg ((GoB f)*(1,j), (GoB f)*(len (GoB f),j)) holds P is_S-P_arc_joining (GoB f)*(1,j), (GoB f)*(len (GoB f),j); theorem :: JORDAN5B:35 for f be non constant standard special_circular_sequence, j be Nat, P be Subset of TOP-REAL 2 st 1 <= j & j <= len GoB f & P = LSeg ((GoB f)*(j,1), (GoB f)*(j,width GoB f)) holds P is_S-P_arc_joining (GoB f)*(j,1), (GoB f)*(j,width GoB f);