proposition: Lemma incBK n : cancel (@incB n) decB.
proof: Proof. move => p. destruct n; first apply trivialBits. apply toZp_inj. autorewrite with ZpHom. by rewrite -addrA 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)