proposition: Lemma eval_pol_sub : forall env lhs rhs, eval_pol env (psub lhs rhs) = eval_pol env lhs - eval_pol env rhs.
proof: Proof. intros. apply (eval_pol_sub Zsor ZSORaddon). Qed.
imports: List Bool OrderedRing RingMicromega ZCoeff Refl ZArith_base ZArithRing Ztac EnvRing