Open Scope R_scope.
(*=========================================================== COMPLEMENTS FOR orbits AND rem , BOUNDS (AUGUST 08) ==========================================================*)
(* ANY orbit IS INCLUDED IN THE hmap SUPPORT: OK: *)

(* Specifications: *)
Lemma incls_orbit:forall(m:fmap)(x:dart),
inv_hmap m -> exd m x ->
incls (Iter_orb m x) (fmap_to_set m).
Lemma exds_orb_exd:forall(m:fmap)(x z:dart),
inv_hmap m -> exd m x ->
exds (Iter_orb m x) z -> exd m z.