proposition: Lemma rpred_rat (S : divringClosed R) a : ratr a \in S.
proof: Proof. by rewrite rpred_div ?rpred_int. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg countalg div ssrnum) mathcomp(ssrint prime archimedean)