proposition: Lemma pow2_wneg: forall sz, wneg (natToWord (S sz) (pow2 sz)) = natToWord (S sz) (pow2 sz).
proof: Proof. unfold wneg; intros. rewrite <-Npow2_nat, <-NToWord_nat. rewrite wordToN_NToWord_2 by (apply Nlt_in; do 2 rewrite Npow2_nat; pose proof (zero_lt_pow2 sz); simpl; lia). rewrite Npow2_S. f_equal; nomega. Qed.
imports: Coq.Classes.Morphisms Coq.Classes.Morphisms_Prop Coq.Classes.Equivalence Coq.Arith.PeanoNat Coq.ZArith.BinInt  Coq.Arith.Arith Coq.NArith.NArith Coq.Bool.Bool Coq.ZArith.ZArith Coq.Logic.Eqdep_dec Coq.Logic.EqdepFacts Coq.Program.Tactics Coq.Program.Equality Coq.setoid_ring.Ring Coq.setoid_ring.Ring_polynom bbv.Nomega bbv.ZLib bbv.NatLib bbv.NLib bbv.N_Z_nat_conversions bbv.DepEq bbv.DepEqNat bbv.ReservedNotations Coq.micromega.Lia