∀ {C : Type u} {𝒞 : CategoryTheory.Category.{v, u} C} [self : CategoryTheory.MonoidalCategory C] {X₁ Y₁ Z₁ X₂ Y₂ Z₂ : C}
  (f₁ : X₁ ⟶ Y₁) (f₂ : X₂ ⟶ Y₂) (g₁ : Y₁ ⟶ Z₁) (g₂ : Y₂ ⟶ Z₂),
  CategoryTheory.MonoidalCategoryStruct.tensorHom (CategoryTheory.CategoryStruct.comp f₁ g₁)
      (CategoryTheory.CategoryStruct.comp f₂ g₂) =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.MonoidalCategoryStruct.tensorHom f₁ f₂)
      (CategoryTheory.MonoidalCategoryStruct.tensorHom g₁ g₂)