proposition: Lemma zcontents_eq0 p : (zcontents p == 0) = (p == 0).
proof: Proof. by rewrite -sgz_eq0 sgz_contents sgz_eq0 lead_coef_eq0. 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)