∀ {J : Type u_1} [inst : CategoryTheory.Category.{u_4, u_1} J] {C : Type u_2}
  [inst_1 : CategoryTheory.Category.{u_3, u_2} C] {F : CategoryTheory.Functor J C} (c : CategoryTheory.Limits.Cone F),
  Function.LeftInverse (fun h s => { default := h.from s, uniq := ⋯ }) fun x =>
    CategoryTheory.Limits.IsTerminal.ofUnique c