proposition: Lemma addB_subBK n (p: BITS n) q : addB p (subB q p) = q.
proof: Proof. destruct n; first apply trivialBits. apply toZp_inj. rewrite toZp_addB toZp_subB. by rewrite addrCA addrN addr0. 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)