proposition: Lemma ler0n n : 0 <= n%:R :> R.
proof: Proof. by rewrite -nnegrE rpred_nat. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)