*)
(* Lemma Forall_isbyte_repr_unsigned: forall l: list int, map Int.repr (map Int.unsigned l) = l.  Lemma map_unsigned_repr_isbyte: forall l : list Z , Forall isbyteZ l -> map Int.unsigned (map Int.repr l) = l. *)

Lemma Zlength_intlist_to_bytelist_app:
forall al bl,  Zlength (intlist_to_bytelist (al++bl)) =
(Zlength (intlist_to_bytelist al) + Zlength (intlist_to_bytelist bl))%Z.