∀ {J : Type u_3} [inst : CategoryTheory.Category.{u_1, u_3} J] {C : Type u_4}
  [inst_1 : CategoryTheory.Category.{u_2, u_4} C] (F : CategoryTheory.Functor J C) (X : CategoryTheory.Limits.Cone F),
  CategoryTheory.CategoryStruct.comp
      ((CategoryTheory.Limits.Cone.toCostructuredArrow F).map
        ((CategoryTheory.NatIso.ofComponents CategoryTheory.Limits.Cones.eta ⋯).hom.app X))
      ((CategoryTheory.NatIso.ofComponents (fun x => x.eta.symm) ⋯).hom.app
        ((CategoryTheory.Limits.Cone.toCostructuredArrow F).obj X)) =
    CategoryTheory.CategoryStruct.id ((CategoryTheory.Limits.Cone.toCostructuredArrow F).obj X)