(** Def 5 of (Rose) *)

Definition Mod2_e : Cobham :=
  Rec
    Zero
    (False_e 2)
    (One_e 2)
    (One_e 1).

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