proposition: Lemma pow2_wplus_wzero sz: $(pow2 sz) ^+ $(pow2 sz) = wzero (sz + 1).
proof: Proof. apply wordToNat_eq2. rewrite <- natToWord_plus. rewrite <- mul2_add. assert (pow2_1_mul: pow2 1 = 2) by auto. rewrite <- pow2_1_mul at 2. rewrite <- pow2_add_mul. rewrite pow2_wzero; auto. 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