∀ (C : Type u₁) [inst : CategoryTheory.Category.{v₁, u₁} C] [inst_1 : CategoryTheory.MonoidalCategory C],
  CategoryTheory.Functor.OplaxMonoidal.η (CategoryTheory.MonoidalOpposite.mopMopEquivalence C).functor =
    CategoryTheory.CategoryStruct.id (CategoryTheory.MonoidalCategoryStruct.tensorUnit C)