∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {W X Y Z : C}
  [inst_1 : CategoryTheory.Limits.HasBinaryProduct W X] [inst_2 : CategoryTheory.Limits.HasBinaryProduct Y Z]
  (f : W ⟶ Y) (g : X ⟶ Z),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.prod.map f g) CategoryTheory.Limits.prod.snd =
    CategoryTheory.CategoryStruct.comp CategoryTheory.Limits.prod.snd g