proposition: Lemma tail_poly_opp {R: ringType} (q: {poly R}): tail_poly (-q) = -tail_poly q.
proof: Proof. apply coef_poly_eq => i. by rewrite coefN !coef_Poly !nth_behead coefN. Qed.
imports: Relational(OrderEnrichedCategory GenericRulesSimple) mathcomp(all_ssreflect all_algebra reals distr realsum ssrnat ssreflect ssrfun ssrbool ssrnum eqtype choice seq) Mon(SPropBase) Crypt(Axioms ChoiceAsOrd SubDistr Couplings UniformDistrLemmas FreeProbProg Theta_dens RulesStateProb pkg_core_definition choice_type pkg_composition pkg_rhl Package Prelude) extructures(ord fset fmap) Equations(Equations)