(** * Extraction of minimum binding *)

Lemma remove_min_mapsto : forall l x e r h y e',
MapsTo y e' (Node l x e r h) <->
((X.eq y (remove_min l x e r)#2#1) /\ e' = (remove_min l x e r)#2#2)
\/ MapsTo y e' (remove_min l x e r)#1.