∀ {M : Type u_2} {N : Type u_1} [inst : Mul M] [inst_1 : Mul N] (f : M →ₙ* N),
  (∀ (x y : M), Commute (f x) (f y)) →
    ∀ (x y : M), (MulOpposite.op ∘ ⇑f) (x * y) = (MulOpposite.op ∘ ⇑f) x * (MulOpposite.op ∘ ⇑f) y