(* THEN: *)

(* Specifications: *)
Lemma expe_top_A:forall(m:fmap)(z:dart),
inv_hmap m -> succ m zero z ->
expe m (top m zero z) (A m zero z).
Lemma upb_pos_aux:forall(m:fmap)(z:dart),
exd m z ->
(card (Iter_rem m z) < ndN m)%nat.