∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] [inst_1 : CategoryTheory.MonoidalCategory C] (X Y : C),
  Opposite.op (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y) =
    CategoryTheory.MonoidalCategoryStruct.tensorObj (Opposite.op X) (Opposite.op Y)