let P, Q be Path of a,b; :: thesis: ( ex f being Function of [:I[01] ,I[01] :],T st
( f is continuous & ( for t being Point of I[01] holds
( f . t,0 = P . t & f . t,1 = Q . t & f . 0 ,t = a & f . 1,t = b ) ) ) implies ex f being Function of [:I[01] ,I[01] :],T st
( f is continuous & ( for t being Point of I[01] holds
( f . t,0 = Q . t & f . t,1 = P . t & f . 0 ,t = a & f . 1,t = b ) ) ) )
given f being Function of [:I[01] ,I[01] :],T such that A1:
( f is continuous & ( for s being Point of I[01] holds
( f . s,0 = P . s & f . s,1 = Q . s & f . 0 ,s = a & f . 1,s = b ) ) )
; :: thesis: ex f being Function of [:I[01] ,I[01] :],T st
( f is continuous & ( for t being Point of I[01] holds
( f . t,0 = Q . t & f . t,1 = P . t & f . 0 ,t = a & f . 1,t = b ) ) )
id the carrier of I[01] = id I[01]
;
then reconsider fA = id the carrier of I[01] as continuous Function of I[01] ,I[01] ;
reconsider fB = L[01] (0 ,1 (#) ),((#) 0 ,1) as continuous Function of I[01] ,I[01] by TOPMETR:27, TREAL_1:11;
set F = [:fA,fB:];
A2:
[:fA,fB:] is continuous
by Th12;
A3:
dom (L[01] (0 ,1 (#) ),((#) 0 ,1)) = the carrier of I[01]
by FUNCT_2:def 1, TOPMETR:27;
set LL = L[01] (0 ,1 (#) ),((#) 0 ,1);
reconsider ff = f * [:fA,fB:] as Function of [:I[01] ,I[01] :],T ;
A4:
ff is continuous
by A1, A2, TOPS_2:58;
A5:
for s being Point of I[01] holds
( ff . s,0 = Q . s & ff . s,1 = P . s )
proof
let s be
Point of
I[01] ;
:: thesis: ( ff . s,0 = Q . s & ff . s,1 = P . s )
A6:
for
t being
Point of
I[01] for
t' being
Real st
t = t' holds
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1
- t'
proof
let t be
Point of
I[01] ;
:: thesis: for t' being Real st t = t' holds
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1 - t'let t' be
Real;
:: thesis: ( t = t' implies (L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1 - t' )
assume A7:
t = t'
;
:: thesis: (L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1 - t'
reconsider ee =
t as
Point of
(Closed-Interval-TSpace 0 ,1) by TOPMETR:27;
A8:
(
0 ,1
(#) = 1 &
(#) 0 ,1
= 0 )
by TREAL_1:def 1, TREAL_1:def 2;
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t =
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . ee
.=
((0 - 1) * t') + 1
by A7, A8, TREAL_1:10
.=
1
- (1 * t')
;
hence
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1
- t'
;
:: thesis: verum
end;
dom (id the carrier of I[01] ) = the
carrier of
I[01]
by FUNCT_2:def 1;
then A9:
(
s in dom (id the carrier of I[01] ) &
0 in dom (L[01] (0 ,1 (#) ),((#) 0 ,1)) & 1
in dom (L[01] (0 ,1 (#) ),((#) 0 ,1)) )
by A3, Lm1;
then A10:
[:fA,fB:] . s,
0 =
[((id the carrier of I[01] ) . s),((L[01] (0 ,1 (#) ),((#) 0 ,1)) . 0 )]
by FUNCT_3:def 9
.=
[s,((L[01] (0 ,1 (#) ),((#) 0 ,1)) . 0[01] )]
by FUNCT_1:35
.=
[s,(1 - 0 )]
by A6
.=
[s,1]
;
A11:
[:fA,fB:] . s,1 =
[((id the carrier of I[01] ) . s),((L[01] (0 ,1 (#) ),((#) 0 ,1)) . 1)]
by A9, FUNCT_3:def 9
.=
[s,((L[01] (0 ,1 (#) ),((#) 0 ,1)) . 1[01] )]
by FUNCT_1:35
.=
[s,(1 - 1)]
by A6
.=
[s,0 ]
;
A12:
dom [:fA,fB:] = [:(dom (id the carrier of I[01] )),(dom (L[01] (0 ,1 (#) ),((#) 0 ,1))):]
by FUNCT_3:def 9;
then A13:
[s,1] in dom [:fA,fB:]
by A9, ZFMISC_1:106;
[s,0 ] in dom [:fA,fB:]
by A9, A12, ZFMISC_1:106;
then A14:
ff . s,
0 =
f . s,1
by A10, FUNCT_1:23
.=
Q . s
by A1
;
ff . s,1 =
f . s,
0
by A11, A13, FUNCT_1:23
.=
P . s
by A1
;
hence
(
ff . s,
0 = Q . s &
ff . s,1
= P . s )
by A14;
:: thesis: verum
end;
for t being Point of I[01] holds
( ff . 0 ,t = a & ff . 1,t = b )
proof
let t be
Point of
I[01] ;
:: thesis: ( ff . 0 ,t = a & ff . 1,t = b )
A15:
t in the
carrier of
I[01]
;
A16:
dom (L[01] (0 ,1 (#) ),((#) 0 ,1)) = the
carrier of
I[01]
by FUNCT_2:def 1, TOPMETR:27;
reconsider tt =
t as
Real by A15, BORSUK_1:83;
for
t being
Point of
I[01] for
t' being
Real st
t = t' holds
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1
- t'
proof
let t be
Point of
I[01] ;
:: thesis: for t' being Real st t = t' holds
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1 - t'let t' be
Real;
:: thesis: ( t = t' implies (L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1 - t' )
assume A17:
t = t'
;
:: thesis: (L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1 - t'
reconsider ee =
t as
Point of
(Closed-Interval-TSpace 0 ,1) by TOPMETR:27;
A18:
(
0 ,1
(#) = 1 &
(#) 0 ,1
= 0 )
by TREAL_1:def 1, TREAL_1:def 2;
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t =
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . ee
.=
((0 - 1) * t') + 1
by A17, A18, TREAL_1:10
.=
1
- (1 * t')
;
hence
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1
- t'
;
:: thesis: verum
end;
then A19:
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . t = 1
- tt
;
dom (id the carrier of I[01] ) = the
carrier of
I[01]
by FUNCT_2:def 1;
then A20:
(
0 in dom (id the carrier of I[01] ) & 1
in dom (id the carrier of I[01] ) &
t in dom (L[01] (0 ,1 (#) ),((#) 0 ,1)) )
by A16, Lm1;
then A21:
[:fA,fB:] . 0 ,
t =
[((id the carrier of I[01] ) . 0 ),((L[01] (0 ,1 (#) ),((#) 0 ,1)) . t)]
by FUNCT_3:def 9
.=
[0 ,(1 - tt)]
by A19, A20, FUNCT_1:35
;
A22:
[:fA,fB:] . 1,
t =
[((id the carrier of I[01] ) . 1),((L[01] (0 ,1 (#) ),((#) 0 ,1)) . t)]
by A20, FUNCT_3:def 9
.=
[1,(1 - tt)]
by A19, A20, FUNCT_1:35
;
reconsider t' = 1
- tt as
Point of
I[01] by Lm5;
A23:
dom [:fA,fB:] = [:(dom (id the carrier of I[01] )),(dom (L[01] (0 ,1 (#) ),((#) 0 ,1))):]
by FUNCT_3:def 9;
then A24:
[1,t] in dom [:fA,fB:]
by A20, ZFMISC_1:106;
[0 ,t] in dom [:fA,fB:]
by A20, A23, ZFMISC_1:106;
then A25:
ff . 0 ,
t =
f . 0 ,
t'
by A21, FUNCT_1:23
.=
a
by A1
;
ff . 1,
t =
f . 1,
t'
by A22, A24, FUNCT_1:23
.=
b
by A1
;
hence
(
ff . 0 ,
t = a &
ff . 1,
t = b )
by A25;
:: thesis: verum
end;
hence
ex f being Function of [:I[01] ,I[01] :],T st
( f is continuous & ( for t being Point of I[01] holds
( f . t,0 = Q . t & f . t,1 = P . t & f . 0 ,t = a & f . 1,t = b ) ) )
by A4, A5; :: thesis: verum