proposition: Lemma sqrtC_lt0 x : (sqrtC x < 0) = false.
proof: Proof. exact: rootC_lt0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)