∀ {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.Cocone F) (X : J),
  c.toCostructuredArrowCompToOverCompForget.inv.app X = CategoryTheory.CategoryStruct.id (F.obj X)