(* WITH Iter: *)

Lemma Iter_cF_L_B:
forall (m:fmap)(k:dim)(x:dart)(i:nat)( z:dart),
inv_hmap m -> succ m k x ->
let y:= A m k x in
Iter (cF (L (B m k x) k x (A m k x))) i z
=   Iter (cF m) i z.