English
For f: P →* M, g: P →* N and f': M →* M', g': N →* N', the equality (f'.prodMap g').comp (f.prod g) = (f'.comp f).prod (g'.comp g) holds.
Русский
Пусть f: P →* M, g: P →* N и f': M →* M', g': N →* N'. Тогда выполняется равенство (f'.prodMap g').comp (f.prod g) = (f'.comp f).prod (g'.comp g).
LaTeX
$$$ (f'.prodMap g').comp (f.prod g) = (f'.comp f).prod (g'.comp g). $$$
Lean4
@[to_additive prod_comp_prodMap]
theorem prod_comp_prodMap (f : P →* M) (g : P →* N) (f' : M →* M') (g' : N →* N') :
(f'.prodMap g').comp (f.prod g) = (f'.comp f).prod (g'.comp g) :=
rfl