proposition: Lemma gcdp_polyOver K : {in polyOver K &, forall p q, gcdp p q \is a polyOver K}.
proof: Proof. move=> _ _ /polyOver_subvs[p ->] /polyOver_subvs[q ->]. by apply/polyOver_subvs; exists (gcdp p q); rewrite gcdp_map. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq div) mathcomp(choice fintype tuple finfun bigop ssralg countalg) mathcomp(finalg zmodp matrix vector falgebra poly polydiv) mathcomp(mxpoly generic_quotient)