proposition: Lemma sqrtC_ge0 x : (0 <= sqrtC x) = (0 <= x).
proof: Proof. exact: rootC_ge0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)