set e = L[01] (0 ,1 (#) ),((#) 0 ,1);
let T be non empty TopSpace; for a, b being Point of T st ex f being Function of I[01] ,T st
( f is continuous & f . 0 = a & f . 1 = b ) holds
ex g being Function of I[01] ,T st
( g is continuous & g . 0 = b & g . 1 = a )
let a, b be Point of T; ( ex f being Function of I[01] ,T st
( f is continuous & f . 0 = a & f . 1 = b ) implies ex g being Function of I[01] ,T st
( g is continuous & g . 0 = b & g . 1 = a ) )
given P being Function of I[01] ,T such that A1:
P is continuous
and
A2:
( P . 0 = a & P . 1 = b )
; ex g being Function of I[01] ,T st
( g is continuous & g . 0 = b & g . 1 = a )
set f = P * (L[01] (0 ,1 (#) ),((#) 0 ,1));
reconsider f = P * (L[01] (0 ,1 (#) ),((#) 0 ,1)) as Function of I[01] ,T by TOPMETR:27;
take
f
; ( f is continuous & f . 0 = b & f . 1 = a )
L[01] (0 ,1 (#) ),((#) 0 ,1) is continuous Function of (Closed-Interval-TSpace 0 ,1),(Closed-Interval-TSpace 0 ,1)
by TREAL_1:11;
hence
f is continuous
by A1, TOPMETR:27; ( f . 0 = b & f . 1 = a )
A3: (L[01] (0 ,1 (#) ),((#) 0 ,1)) . 1 =
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . (0 ,1 (#) )
by TREAL_1:def 2
.=
(#) 0 ,1
by TREAL_1:12
.=
0
by TREAL_1:def 1
;
1 in [.0 ,1.]
by XXREAL_1:1;
then
1 in the carrier of (Closed-Interval-TSpace 0 ,1)
by TOPMETR:25;
then A4:
1 in dom (L[01] (0 ,1 (#) ),((#) 0 ,1))
by FUNCT_2:def 1;
0 in [.0 ,1.]
by XXREAL_1:1;
then
0 in the carrier of (Closed-Interval-TSpace 0 ,1)
by TOPMETR:25;
then A5:
0 in dom (L[01] (0 ,1 (#) ),((#) 0 ,1))
by FUNCT_2:def 1;
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . 0 =
(L[01] (0 ,1 (#) ),((#) 0 ,1)) . ((#) 0 ,1)
by TREAL_1:def 1
.=
0 ,1 (#)
by TREAL_1:12
.=
1
by TREAL_1:def 2
;
hence
( f . 0 = b & f . 1 = a )
by A2, A3, A5, A4, FUNCT_1:23; verum