proposition: Lemma rootC_gt0 n x : (n > 0)%N -> (n.-root x > 0) = (x > 0).
proof: Proof. by move=> n_gt0; rewrite !lt0r rootC_ge0 ?rootC_eq0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)