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:20;
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_1:8;
hence
f is continuous
by A1, TOPMETR:20; ( 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_1:9
.=
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:18;
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:18;
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_1:9
.=
1
by TREAL_1:def 2
;
hence
( f . 0 = b & f . 1 = a )
by A2, A3, A5, A4, FUNCT_1:13; verum