∀ {I : Type u_1} [inst : AddMonoid I] {C : Type u_2} [inst_1 : CategoryTheory.Category.{u_3, u_2} C]
  [inst_2 : CategoryTheory.MonoidalCategory C] [inst_3 : ∀ (X₁ X₂ : CategoryTheory.GradedObject I C), X₁.HasTensor X₂]
  (X₁ X₂ : CategoryTheory.GradedObject I C),
  CategoryTheory.GradedObject.Monoidal.tensorHom (CategoryTheory.CategoryStruct.id X₁)
      (CategoryTheory.CategoryStruct.id X₂) =
    CategoryTheory.CategoryStruct.id (CategoryTheory.GradedObject.Monoidal.tensorObj X₁ X₂)