∀ {A : Type u_4} {B : Type u_2} {C : Type u_6} [inst : CategoryTheory.Category.{u_3, u_4} A]
  [inst_1 : CategoryTheory.Category.{u_1, u_2} B] [inst_2 : CategoryTheory.Category.{u_5, u_6} C]
  {F : CategoryTheory.Functor A B} {G : CategoryTheory.Functor C B}
  {x y : CategoryTheory.Limits.CategoricalPullback F G} (eₗ : x.fst ≅ y.fst) (eᵣ : x.snd ≅ y.snd),
  CategoryTheory.CategoryStruct.comp (F.map eₗ.hom) y.iso.hom =
      CategoryTheory.CategoryStruct.comp x.iso.hom (G.map eᵣ.hom) →
    CategoryTheory.CategoryStruct.comp (F.map eₗ.inv) x.iso.hom =
      CategoryTheory.CategoryStruct.comp y.iso.hom (G.map eᵣ.inv)