(** * [remove] *)

(* Specifications: *)
Lemma remove_1 : forall m (Hm:Sort m) x y, X.eq x y -> ~ In y (remove x m).
Lemma remove_2 : forall m (Hm:Sort m) x y e,
~ X.eq x y -> MapsTo y e m -> MapsTo y e (remove x m).
Lemma remove_3 : forall m (Hm:Sort m) x y e,
MapsTo y e (remove x m) -> MapsTo y e m.
Lemma remove_Inf : forall (m:t elt)(Hm : Sort m)(x x':key)(e':elt),
Inf (x',e') m -> Inf (x',e') (remove x m).