Opaque MultTwoPowerLength_e.
(** Def 14 of (Rose) *)
Definition DivTwoPower'_e : Cobham :=
Rec2
(Proj 1 0)
(Comp 3 Div2_e [Proj 3 1])
(Proj 2 1).

Lemma DivTwoPower'_correct_bs : forall l,
Sem DivTwoPower'_e l =
fun_power (length (hd nil l)) (@tl _) (hd nil (tl l)).