proposition: Lemma deg2_poly_root1 : root p r1.
proof: Proof. by apply: deg2_poly_root1; 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)