proposition: Lemma Gauss_gcdpl p m n : coprimep p n -> gcdp p (m * n) %= gcdp p m.
proof: Proof. by move=> co_pn; rewrite mulrC Gauss_gcdpr. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop ssralg poly)