proposition: Lemma ratr_nat n : ratr n%:R = n%:R.
proof: Proof. exact: ratr_int n. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg countalg div ssrnum) mathcomp(ssrint prime archimedean)