proposition: Lemma deriv_poly_example : poly_example^`() = 5%:R *: 'X^4 - 4%:R%:P.
proof: Proof. by rewrite /poly_example !derivE addr0 alg_polyC scaler_nat ?addr0. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_fingroup all_algebra) mathcomp(all_solvable all_field polyrcf) Abel(various classic_ext map_gal algR) Abel(char0 cyclotomic_ext real_closed_ext)