proposition: Lemma dvdz_mull d m n : (d %| n)%Z -> (d %| m * n)%Z.
proof: Proof. by rewrite !dvdzE abszM; apply: dvdn_mull. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype tuple finfun bigop prime order) mathcomp(ssralg poly ssrnum ssrint archimedean rat matrix) mathcomp(polydiv perm zmodp mxalgebra vector)