proposition: Lemma mulBA n (p q r: BITS n) : mulB p (mulB q r) = mulB (mulB p q) r.
proof: Proof. destruct n; first apply trivialBits. apply toZp_inj. autorewrite with ZpHom. by rewrite GRing.mulrA. 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)