proposition: Lemma dvdz_trans n d m : (d %| n -> n %| m -> d %| m)%Z.
proof: Proof. by rewrite !dvdzE; apply: dvdn_trans. 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)