∀ {R : Type u_2} {A : Type u_1} [inst : CommSemiring R] [inst_1 : AddCommMonoid A] [inst_2 : Module R A]
  [inst_3 : Coalgebra R A],
  ↑(TensorProduct.assoc R Aᵐᵒᵖ Aᵐᵒᵖ Aᵐᵒᵖ) ∘ₗ LinearMap.rTensor Aᵐᵒᵖ CoalgebraStruct.comul ∘ₗ CoalgebraStruct.comul =
    LinearMap.lTensor Aᵐᵒᵖ CoalgebraStruct.comul ∘ₗ CoalgebraStruct.comul