proposition: Lemma var_compare_eq : forall (x y:var), var_compare x y = isTrue (x = y).
proof: Proof. Proof using. unfold var. intros x; induction x; intros y; destruct y; simpl; rew_bool_eq; try nat_math. rewrite IHx. rew_bool_eq. nat_math. Qed.
imports: TLC(LibTactics LibList LibLogic LibNat LibEpsilon LibReflect)