proposition: Lemma Ratio0 x : Ratio x 0 = ratio0.
proof: Proof. by rewrite /Ratio /insubd; case: insubP; rewrite //= eqxx. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(ssrAC choice tuple bigop ssralg poly polydiv) mathcomp(generic_quotient)