∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {X Y : C} (f : X ⟶ Y) (Z : C)
  [inst_1 : CategoryTheory.Limits.HasBinaryProduct Z Y] [inst_2 : CategoryTheory.Limits.HasBinaryProduct Z X]
  [inst_3 : CategoryTheory.Limits.HasPullback CategoryTheory.Limits.prod.snd f],
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.pullbackProdSndIsoProd f Z).hom
      CategoryTheory.Limits.prod.fst =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.pullback.fst CategoryTheory.Limits.prod.snd f)
      CategoryTheory.Limits.prod.fst