proposition: Lemma toNat_ones_succ n : (toNat (ones n)).+1 = 2^n.
proof: Proof. induction n => //. rewrite /toNat/=. rewrite /toNat/= in IHn. by rewrite expnS mul2n addnC addn1 -doubleS IHn. Qed.
imports: Coq(ZArith.ZArith) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq fintype tuple div zmodp ssralg) ssrextra.nat ssrextra.tuple spec.spec