proposition: Lemma deg2_poly_minE : p.[- b / 2] = - delta / 4.
proof: Proof. by rewrite -a2 -a4 deltam deg2_poly_minE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)