proposition: Fact ratzM : {morph ratz : x y / x * y >-> mulq x y}.
proof: Proof. by move=> x y /=; rewrite !ratz_frac //= !mulr1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg countalg div ssrnum) mathcomp(ssrint prime archimedean)