∀ {C : Type u_1} [inst : CategoryTheory.Category.{u_2, u_1} C] [inst_1 : CategoryTheory.MonoidalCategory C]
  (X₁ X₂ : Cᵒᵖ),
  (CategoryTheory.MonoidalCategoryStruct.tensorHom (CategoryTheory.CategoryStruct.id X₁).unop
        (CategoryTheory.CategoryStruct.id X₂).unop).op =
    CategoryTheory.CategoryStruct.id
      (Opposite.op (CategoryTheory.MonoidalCategoryStruct.tensorObj (Opposite.unop X₁) (Opposite.unop X₂)))