Opaque Mod2_e.
(** Def 6 of (Rose) *)
Definition Length_e : Cobham :=
Rec2
Zero
(Comp 2 Succ_e [Proj 2 1])
(Proj 1 0).

(* Specifications: *)
Lemma arity_Length : arity Length_e = ok_arity 1.
Lemma rec_bounded_Length :
rec_bounded Length_e.
Lemma Length_correct : forall l,
bs2nat (Sem Length_e l) = length (hd nil l).