∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.CartesianMonoidalCategory C]
  (M : CategoryTheory.Mon C),
  {
      app := fun Y =>
        MonCat.ofHom
          { toFun := fun x => CategoryTheory.CategoryStruct.comp x (CategoryTheory.CategoryStruct.id M).hom,
            map_one' := ⋯, map_mul' := ⋯ },
      naturality := ⋯ } =
    CategoryTheory.CategoryStruct.id (CategoryTheory.yonedaMonObj M.X)