proposition: Lemma toNat_shlB n (p: BITS n) : toNat (shlB p) = ((toNat p).*2) %% 2^n.
proof: Proof. by rewrite /shlB toNat_dropmsb toNat_shlBaux. Qed.
imports: HB(structures) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq fintype tuple zmodp div) ssrextra.tuple ssrextra.nat spec spec.properties operations mathcomp(ssralg)