Opaque PlusOneMinus'_e.
Definition PlusOneMinus_e : Cobham :=
Comp 2 PlusOneMinus'_e [Proj 2 0; Comp 2 Normalize_e [Proj 2 1] ].

(* Specifications: *)
Lemma arity_PlusOneMinus : arity PlusOneMinus_e = ok_arity 2.
Lemma rec_bounded_PlusOneMinus :
rec_bounded PlusOneMinus_e.
Lemma PlusOneMinus_correct : forall l,
bs2nat (Sem PlusOneMinus_e l) = bs2nat (hd nil l) + (1 - bs2nat (hd nil (tl l))).
Lemma PlusOneMinus_length : forall l,
length (Sem PlusOneMinus_e [nth 0 l nil; nth 1 l nil]) <= S (length (nth 0 l nil)).