proposition: Lemma shrB_mul2 n (p: BITS n.+1) : msb p == false -> shrB (p *# 2) = p.
proof: Proof. move => H. rewrite -shlB_asMul. by apply shrB_shlB. 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)