∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {X Y : C} {f g : X ⟶ Y}
  {s t : CategoryTheory.Limits.Cofork f g} (hs : CategoryTheory.Limits.IsColimit s),
  CategoryTheory.CategoryStruct.comp s.π (hs.desc t) = t.π