let T, S, V be non empty TopSpace; for P1 being non empty Subset of S
for P2 being Subset of S
for f being Function of T,(S | P1)
for g being Function of (S | P2),V st P1 c= P2 & f is continuous & g is continuous holds
ex h being Function of T,V st
( h = g * f & h is continuous )
let P1 be non empty Subset of S; for P2 being Subset of S
for f being Function of T,(S | P1)
for g being Function of (S | P2),V st P1 c= P2 & f is continuous & g is continuous holds
ex h being Function of T,V st
( h = g * f & h is continuous )
let P2 be Subset of S; for f being Function of T,(S | P1)
for g being Function of (S | P2),V st P1 c= P2 & f is continuous & g is continuous holds
ex h being Function of T,V st
( h = g * f & h is continuous )
let f be Function of T,(S | P1); for g being Function of (S | P2),V st P1 c= P2 & f is continuous & g is continuous holds
ex h being Function of T,V st
( h = g * f & h is continuous )
let g be Function of (S | P2),V; ( P1 c= P2 & f is continuous & g is continuous implies ex h being Function of T,V st
( h = g * f & h is continuous ) )
assume that
A1:
P1 c= P2
and
A2:
f is continuous
and
A3:
g is continuous
; ex h being Function of T,V st
( h = g * f & h is continuous )
reconsider P3 = P2 as non empty Subset of S by A1, XBOOLE_1:3;
A4:
[#] (S | P1) = P1
by PRE_TOPC:def 5;
A5:
[#] (S | P2) = P2
by PRE_TOPC:def 5;
then reconsider f1 = f as Function of T,(S | P3) by A1, A4, FUNCT_2:7;
for F1 being Subset of (S | P2) st F1 is closed holds
f1 " F1 is closed
then
f1 is continuous
;
hence
ex h being Function of T,V st
( h = g * f & h is continuous )
by A3; verum