∀ {R : Type u} {M : Type v} [inst : Monoid R] [inst_1 : AddMonoid M] [inst_2 : DistribMulAction R M]
  [inst_3 : DistribMulAction Rᵐᵒᵖ M] (r : R) (n : ℕ), TrivSqZeroExt.inl r ^ n = TrivSqZeroExt.inl (r ^ n)