∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] {D : Type u₂} [inst_1 : CategoryTheory.Category.{v₂, u₂} D]
  (G : CategoryTheory.Functor C D) {X Y Z : C} {f : X ⟶ Y} {g : X ⟶ Z} [inst_2 : CategoryTheory.Limits.HasPushout f g]
  [inst_3 : CategoryTheory.Limits.HasPushout (G.map f) (G.map g)]
  [i : CategoryTheory.IsIso (CategoryTheory.Limits.pushoutComparison G f g)],
  CategoryTheory.Limits.PreservesColimit (CategoryTheory.Limits.span f g) G