proposition: Lemma rootC_eq1 n x : (n > 0)%N -> (n.-root x == 1) = (x == 1).
proof: Proof. by move=> n_gt0; rewrite -{1}(rootC1 n_gt0) eqr_rootC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)