proposition: Lemma ltEsig x y : x < y = (tag x <= tag y) && ((tag x >= tag y) ==> (tagged x < tagged_as x y)).
proof: Proof. by []. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)