proposition: Lemma Npow2_nat' {size} : Npow2 size = N.of_nat (pow2 size).
proof: Proof. intros; apply N2Nat.inj; rewrite Nat2N.id, Npow2_nat; reflexivity. Qed.
imports: Fiat.Common.Coq__8_4__8_5__Compat CertifiedExtraction.Extraction.BinEncoders.Basics Coq.Lists.List Bedrock.Word Program