English
Equality of MonoidHom M (MonoidHom N P) is equivalent to pointwise equality of the induced maps; this extends extensionality to function spaces.
Русский
Равенство гомоморфизмов MonoidHom M (MonoidHom N P) эквивалентно попиксному равенству соответствующих отображений.
LaTeX
$$$f=g\;\Longleftrightarrow\;\forall x,y, f x y = g x y$ with appropriate currying, i.e. extensionality for higher-arity homs.$$
Lean4
@[to_additive]
theorem ext_iff₂ {_ : MulOneClass M} {_ : MulOneClass N} {_ : CommMonoid P} {f g : M →* N →* P} :
f = g ↔ ∀ x y, f x y = g x y :=
DFunLike.ext_iff.trans <| forall_congr' fun _ => DFunLike.ext_iff