∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {X Y Z : C} (f : X ⟶ Y) (g : X ⟶ Z)
  [inst_1 : CategoryTheory.IsIso f] (s : CategoryTheory.Limits.PushoutCocone f g),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.pushoutCoconeOfLeftIso f g).inl s.inr = s.inl ∧
    CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.pushoutCoconeOfLeftIso f g).inr s.inr = s.inr ∧
      ∀ {m : (CategoryTheory.Limits.pushoutCoconeOfLeftIso f g).pt ⟶ s.pt},
        CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.pushoutCoconeOfLeftIso f g).inl m = s.inl →
          CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.pushoutCoconeOfLeftIso f g).inr m = s.inr →
            m = s.inr