(** ** Operations *)
(** Identity *)

(* Specifications: *)
Lemma continuity_pt_id :
forall x, continuity_pt (fun x => x) x.
Lemma continuity_2d_pt_id1 :
forall x y, continuity_2d_pt (fun u v => u) x y.
Lemma continuity_2d_pt_id2 :
forall x y, continuity_2d_pt (fun u v => v) x y.