proposition: Lemma shiftr_lxor : forall a b n, (lxor a b) >> n == lxor (a >> n) (b >> n).
proof: Proof. intros. bitwise. now rewrite !shiftr_spec, lxor_spec. Qed.
imports: Bool ZAxioms ZMulOrder ZPow ZDivFloor ZSgnAbs ZParity NZLog