∀ {J : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} J] {C : Type u₃} [inst_1 : CategoryTheory.Category.{v₃, u₃} C]
  {F : CategoryTheory.Functor J C} (c : CategoryTheory.Limits.Cone F) (x : Cᵒᵖ)
  (f : ((CategoryTheory.yoneda.obj c.pt).comp CategoryTheory.uliftFunctor.{u₁, v₃}).obj x),
  c.extensions.app x f = CategoryTheory.CategoryStruct.comp ((CategoryTheory.Functor.const J).map f.down) c.π