∀ {R : Type u_1} {A : Type u_2} {B : Type u_3} [inst : CommSemiring R] [inst_1 : Semiring A] [inst_2 : Semiring B]
  [inst_3 : Algebra R A] [inst_4 : Algebra R B] (f : A →ₐ[R] B) (ι : Type u_4) (h : ι → A) (a : ι),
  (f.compLeft ι) h a = (⇑f ∘ h) a