(*===========================================================
                expe AND bottom
============================================================*)

(* expo and between in an edge: *)

Definition expe(m:fmap)(z t:dart):=
  MA0.expo m z t.Definition betweene(m:fmap)(z v t:dart):=
  MA0.between m z v t.

Lemma Iter_f_L_B: forall(m:fmap)(k:dim)(x z:dart)(i:nat), inv_hmap m -> succ m k x -> let m0:= L (B m k x) k (top m k x) (bottom m k x) in Iter (MF.f m0) i z = Iter (MF.f m) i z.