proposition: Lemma lern0 n : (n%:R <= 0 :> R) = (n == 0).
proof: Proof. by rewrite -[0]/0%:R ler_nat leqn0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)