∀ {R : Type u_1} {M : Type u_2} [inst : CommSemiring R] [inst_1 : AddCommMonoid M] [inst_2 : Module R M] {n : ℕ} (r : R)
  (a : TensorPower R n M), (TensorPower.cast R M ⋯) (GradedMonoid.GMul.mul (TensorPower.algebraMap₀ r) a) = r • a