let n be Nat; for T being non empty TopSpace
for f, g being Function of T,(TOP-REAL n) holds f <##> g = (TIMES n) .: (f,g)
let T be non empty TopSpace; for f, g being Function of T,(TOP-REAL n) holds f <##> g = (TIMES n) .: (f,g)
set R = TOP-REAL n;
set F = TIMES n;
let f, g be Function of T,(TOP-REAL n); f <##> g = (TIMES n) .: (f,g)
A1:
dom (f <##> g) = (dom f) /\ (dom g)
by VALUED_2:def 47;
dom (TIMES n) =
the carrier of [:(TOP-REAL n),(TOP-REAL n):]
by FUNCT_2:def 1
.=
[: the carrier of (TOP-REAL n), the carrier of (TOP-REAL n):]
by BORSUK_1:def 2
;
then
[:(rng f),(rng g):] c= dom (TIMES n)
by ZFMISC_1:96;
then A2:
dom ((TIMES n) .: (f,g)) = (dom f) /\ (dom g)
by FUNCOP_1:69;
hence
f <##> g = (TIMES n) .: (f,g)
by A1, A2; verum