(* Two corollaries more usable: *)

(* Specifications: *)
Lemma exd_clos_r : forall (m:fmap)(x:dart),
inv_qhmap m -> exd m x -> exd (clos m) x.
Lemma exd_clos_qmap_l : forall (m:fmap)(x:dart),
inv_qhmap m -> exd (clos m) x -> exd m x.