proposition: Theorem Npow2_nat : forall n, nat_of_N (Npow2 n) = pow2 n.
proof: Proof. induction n as [|n IHn]; simpl; intuition. rewrite <- IHn; clear IHn. case_eq (Npow2 n); intuition; zify; intuition. Qed.
imports: Coq.Classes.Morphisms Coq.Classes.Morphisms_Prop Coq.Bool.Bool Coq.Arith.Arith Coq.micromega.Lia Coq.NArith.NArith Coq.ZArith.ZArith bbv.N_Z_nat_conversions bbv.Nomega