∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {X Y : C} [inst_1 : CategoryTheory.Limits.HasPullbacks C]
  {S T : C} (f : X ⟶ T) (g : Y ⟶ T) (i : T ⟶ S) [inst_2 : CategoryTheory.Limits.HasPullback f g],
  CategoryTheory.IsIso
    (CategoryTheory.Limits.pullback.map
      (CategoryTheory.CategoryStruct.comp f
        (CategoryTheory.inv (CategoryTheory.Limits.pullback.fst i (CategoryTheory.CategoryStruct.id S))))
      (CategoryTheory.CategoryStruct.comp g
        (CategoryTheory.inv (CategoryTheory.Limits.pullback.fst i (CategoryTheory.CategoryStruct.id S))))
      f g (CategoryTheory.CategoryStruct.id X) (CategoryTheory.CategoryStruct.id Y)
      (CategoryTheory.Limits.pullback.fst i (CategoryTheory.CategoryStruct.id S)) ⋯ ⋯)