let S, T be non empty TopSpace; :: thesis: for f being continuous Function of S,T
for a, b being Point of S
for P being Path of a,b st a,b are_connected holds
f * P is Path of f . a,f . b
let f be continuous Function of S,T; :: thesis: for a, b being Point of S
for P being Path of a,b st a,b are_connected holds
f * P is Path of f . a,f . b
let a, b be Point of S; :: thesis: for P being Path of a,b st a,b are_connected holds
f * P is Path of f . a,f . b
let P be Path of a,b; :: thesis: ( a,b are_connected implies f * P is Path of f . a,f . b )
assume A1:
a,b are_connected
; :: thesis: f * P is Path of f . a,f . b
then
P is continuous
by BORSUK_2:def 2;
then A2:
f * P is continuous
;
A3: (f * P) . 0 =
f . (P . j0)
by FUNCT_2:21
.=
f . a
by A1, BORSUK_2:def 2
;
A4: (f * P) . 1 =
f . (P . j1)
by FUNCT_2:21
.=
f . b
by A1, BORSUK_2:def 2
;
f . a,f . b are_connected
by A1, Th24;
hence
f * P is Path of f . a,f . b
by A2, A3, A4, BORSUK_2:def 2; :: thesis: verum