let P be Subset of (TOP-REAL 2); :: thesis: for p1, p2, q1, q2 being Point of (TOP-REAL 2)
for g being Function of I[01],((TOP-REAL 2) | P)
for s1, s2 being Real st P is_an_arc_of p1,p2 & g is being_homeomorphism & g . 0 = p1 & g . 1 = p2 & g . s1 = q1 & 0 <= s1 & s1 <= 1 & g . s2 = q2 & 0 <= s2 & s2 <= 1 & s1 <= s2 holds
LE q1,q2,P,p1,p2

let p1, p2, q1, q2 be Point of (TOP-REAL 2); :: thesis: for g being Function of I[01],((TOP-REAL 2) | P)
for s1, s2 being Real st P is_an_arc_of p1,p2 & g is being_homeomorphism & g . 0 = p1 & g . 1 = p2 & g . s1 = q1 & 0 <= s1 & s1 <= 1 & g . s2 = q2 & 0 <= s2 & s2 <= 1 & s1 <= s2 holds
LE q1,q2,P,p1,p2

let g be Function of I[01],((TOP-REAL 2) | P); :: thesis: for s1, s2 being Real st P is_an_arc_of p1,p2 & g is being_homeomorphism & g . 0 = p1 & g . 1 = p2 & g . s1 = q1 & 0 <= s1 & s1 <= 1 & g . s2 = q2 & 0 <= s2 & s2 <= 1 & s1 <= s2 holds
LE q1,q2,P,p1,p2

let s1, s2 be Real; :: thesis: ( P is_an_arc_of p1,p2 & g is being_homeomorphism & g . 0 = p1 & g . 1 = p2 & g . s1 = q1 & 0 <= s1 & s1 <= 1 & g . s2 = q2 & 0 <= s2 & s2 <= 1 & s1 <= s2 implies LE q1,q2,P,p1,p2 )
assume that
A1: P is_an_arc_of p1,p2 and
A2: g is being_homeomorphism and
A3: g . 0 = p1 and
A4: g . 1 = p2 and
A5: g . s1 = q1 and
A6: ( 0 <= s1 & s1 <= 1 ) and
A7: g . s2 = q2 and
A8: ( 0 <= s2 & s2 <= 1 ) and
A9: s1 <= s2 ; :: thesis: LE q1,q2,P,p1,p2
reconsider P9 = P as non empty Subset of (TOP-REAL 2) by A1, TOPREAL1:1;
s1 in the carrier of I[01] by A6, BORSUK_1:43;
then A10: q1 in [#] ((TOP-REAL 2) | P9) by A5, FUNCT_2:5;
reconsider g = g as Function of I[01],((TOP-REAL 2) | P9) ;
s2 in the carrier of I[01] by A8, BORSUK_1:43;
then g . s2 in the carrier of ((TOP-REAL 2) | P9) by FUNCT_2:5;
then A11: q2 in P by A7, A10, PRE_TOPC:def 5;
A12: now :: thesis: for h being Function of I[01],((TOP-REAL 2) | P9)
for t1, t2 being Real st h is being_homeomorphism & h . 0 = p1 & h . 1 = p2 & h . t1 = q1 & 0 <= t1 & t1 <= 1 & h . t2 = q2 & 0 <= t2 & t2 <= 1 holds
t1 <= t2
reconsider s19 = s1, s29 = s2 as Point of I[01] by A6, A8, BORSUK_1:43;
let h be Function of I[01],((TOP-REAL 2) | P9); :: thesis: for t1, t2 being Real st h is being_homeomorphism & h . 0 = p1 & h . 1 = p2 & h . t1 = q1 & 0 <= t1 & t1 <= 1 & h . t2 = q2 & 0 <= t2 & t2 <= 1 holds
b4 <= b5

let t1, t2 be Real; :: thesis: ( h is being_homeomorphism & h . 0 = p1 & h . 1 = p2 & h . t1 = q1 & 0 <= t1 & t1 <= 1 & h . t2 = q2 & 0 <= t2 & t2 <= 1 implies b2 <= b3 )
assume that
A13: h is being_homeomorphism and
A14: h . 0 = p1 and
A15: h . 1 = p2 and
A16: h . t1 = q1 and
A17: ( 0 <= t1 & t1 <= 1 ) and
A18: h . t2 = q2 and
A19: ( 0 <= t2 & t2 <= 1 ) ; :: thesis: b2 <= b3
A20: h is one-to-one by A13, TOPS_2:def 5;
set hg = (h ") * g;
h " is being_homeomorphism by A13, TOPS_2:56;
then (h ") * g is being_homeomorphism by A2, TOPS_2:57;
then A21: ( (h ") * g is continuous & (h ") * g is one-to-one ) by TOPS_2:def 5;
reconsider hg1 = ((h ") * g) . s19, hg2 = ((h ") * g) . s29 as Real by BORSUK_1:40;
A22: dom g = [#] I[01] by A2, TOPS_2:def 5;
then A23: 0 in dom g by BORSUK_1:43;
A24: dom h = [#] I[01] by A13, TOPS_2:def 5;
then A25: t1 in dom h by A17, BORSUK_1:43;
A26: 0 in dom h by A24, BORSUK_1:43;
rng h = [#] ((TOP-REAL 2) | P) by A13, TOPS_2:def 5;
then h is onto by FUNCT_2:def 3;
then A27: h " = h " by A20, TOPS_2:def 4;
then (h ") . p1 = 0 by A14, A26, A20, FUNCT_1:32;
then A28: ((h ") * g) . 0 = 0 by A3, A23, FUNCT_1:13;
s1 in dom g by A6, A22, BORSUK_1:43;
then A29: ((h ") * g) . s1 = (h ") . q1 by A5, FUNCT_1:13
.= t1 by A16, A20, A25, A27, FUNCT_1:32 ;
A30: t2 in dom h by A19, A24, BORSUK_1:43;
s2 in dom g by A8, A22, BORSUK_1:43;
then A31: ((h ") * g) . s2 = (h ") . q2 by A7, FUNCT_1:13
.= t2 by A18, A20, A30, A27, FUNCT_1:32 ;
A32: 1 in dom g by A22, BORSUK_1:43;
A33: 1 in dom h by A24, BORSUK_1:43;
(h ") . p2 = 1 by A15, A33, A20, A27, FUNCT_1:32;
then A34: ((h ") * g) . 1 = 1 by A4, A32, FUNCT_1:13;
per cases ( s1 < s2 or s1 = s2 ) by A9, XXREAL_0:1;
suppose s1 = s2 ; :: thesis: b2 <= b3
hence t1 <= t2 by A29, A31; :: thesis: verum
end;
end;
end;
q1 in P by A10, PRE_TOPC:def 5;
hence LE q1,q2,P,p1,p2 by A11, A12; :: thesis: verum