proposition: Lemma mulrzz m n : m *~ n = m * n.
proof: Proof. by rewrite -mulrzr intz. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)