∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.CartesianMonoidalCategory C] {X Y : C}
  (f : X ⟶ CategoryTheory.MonoidalCategoryStruct.tensorUnit C) (g : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.CartesianMonoidalCategory.lift f g)
      (CategoryTheory.MonoidalCategoryStruct.leftUnitor Y).hom =
    g