(** Properties of [deleteMax]. *)

(* Specifications: *)
Lemma In_deleteMax:
forall h x y,
findMax h = Some x ->
(In y h <-> E.eq y x \/ In y (deleteMax h)).
Lemma In_deleteMax:
forall h x y,
findMax h = Some x ->
(In y h <-> E.eq y x \/ In y (deleteMax h)).