proposition: Lemma zcontents_monic p : p \is monic -> zcontents p = 1.
proof: Proof. move=> mon_p; rewrite /zcontents polySpred ?monic_neq0 //. by rewrite big_ord_recr /= -lead_coefE (monicP mon_p) gcdn1. 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)