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