∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] {X : C} (S : CategoryTheory.Sieve X) (X_1 : Cᵒᵖ)
  (a : CategoryTheory.uliftFunctor.{w, v₁}.obj (S.functor.obj X_1)),
  S.uliftFunctorInclusion.app X_1 a = { down := ↑a.down }