∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {W X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z) (g' : W ⟶ Y)
  [inst_1 : CategoryTheory.Limits.HasPullback f g]
  [inst_2 : CategoryTheory.Limits.HasPullback (CategoryTheory.Limits.pullback.snd f g) g'] {Z_1 : C} (h : W ⟶ Z_1),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.pullbackLeftPullbackSndIso f g g').hom
      (CategoryTheory.CategoryStruct.comp
        (CategoryTheory.Limits.pullback.snd f (CategoryTheory.CategoryStruct.comp g' g)) h) =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.pullback.snd (CategoryTheory.Limits.pullback.snd f g) g')
      h