proposition: Lemma gcdsr0 : gcdsr (0 : {poly R}) = 0.
proof: Proof. by rewrite polyseq0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(path choice fintype tuple finset ssralg) mathcomp(matrix poly) mathcomp(bigop polydiv) CoqEAL(stronglydiscrete dvdring)