proposition: Lemma natr_nat n : n%:R \is a nat_num.
proof: Proof. by rewrite natrE natrK. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)