In State v. Bates, 889 S.W.2d 306, 309 (Tex. Crim. App. 1994) the Court acknowledged former Rules of Appellate Procedure 30, 33, and 36, which permitted a trial court "to modify, correct or set aside judgments and orders through motions for new trial, motions to arrest judgment and motions for judgment nunc pro tunc." The Court noted that Rule 36 in particular vested a court "with the authority to correct mistakes or errors in a judgment or order after the expiration of the court's plenary power, via entry of a judgment nunc pro tunc." The substance of those rules is now located in Rules 21, 22 and 23. Though the phrase "plenary power" is no longer used, the concept is the same: the trial court has some power to act in a case after judgment is entered. But that "plenary power," under the Rules, exists for a limited time.