proposition: Lemma PoszM : {morph Posz : n m / (n * m)%N >-> n * m}.
proof: Proof. by []. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)