theorem Th41:
for
C being
Cartesian_category for
a,
b,
c,
d,
e being
Object of
C for
f being
Morphism of
a,
b for
h being
Morphism of
c,
d for
g being
Morphism of
e,
a for
k being
Morphism of
e,
c st
Hom (
a,
b)
<> {} &
Hom (
c,
d)
<> {} &
Hom (
e,
a)
<> {} &
Hom (
e,
c)
<> {} holds
(f [x] h) * <:g,k:> = <:(f * g),(h * k):>