∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.NonPreadditiveAbelian C] {X Y : C}
  (f : X ⟶ Y) {Z : C} (h : Y ⨯ Y ⟶ Z),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.prod.lift (CategoryTheory.CategoryStruct.id X) 0)
      (CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.prod.map f f) h) =
    CategoryTheory.CategoryStruct.comp f
      (CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.prod.lift (CategoryTheory.CategoryStruct.id Y) 0) h)