∀ {R : Type u} {σ : Type u_1} [inst : CommSemiring R] {S : Type u_2} {A : Type u_3} [inst_1 : CommSemiring S]
  [inst_2 : CommSemiring A] [inst_3 : Algebra S R] [inst_4 : Algebra S A] (g : R →ₐ[S] A) (y : σ → A),
  (MvPolynomial.aevalTower g y).comp (IsScalarTower.toAlgHom S R (MvPolynomial σ R)) = g