proposition: Lemma zcontents_primitive p : zcontents (zprimitive p) = (p != 0).
proof: Proof. have [-> | nz_p] := eqVneq; first by rewrite zprimitive0 zcontents0. apply: (@mulfI _ (zcontents p)); first by rewrite zcontents_eq0. by rewrite mulr1 -zcontentsZ -zpolyEprim. 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)