proposition: Lemma deg2_poly_root2 : root p r2.
proof: Proof. by apply: deg2_poly_root2; rewrite ?pnatr_eq0// sqrtCK. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)