(** Def 3 of (Rose) *)

Definition OneMinus'_e : Cobham :=
  Rec2
    (One_e 0)
    (Zero_e 2)
    (One_e 1).

Lemma OneMinus'_correct : forall l, hd nil l = nil \/ bs2nat (hd nil l) <> 0 -> bs2nat (Sem OneMinus'_e l) = 1 - bs2nat (hd nil l).