protected void setStringToPush(String stringToPush) {
		/*
		 * if (!automata.StringChecker.isAlphanumeric(stringToPush)) throw new
		 * IllegalArgumentException("Push string must "+ "be alphanumeric!");
		 */
		PushdownAutomaton myPDA = (PushdownAutomaton) this.getAutomaton();
		if (myPDA.singleInputPDA && stringToPush.length() > 1)
			throw new IllegalArgumentException(
					"Push string must have no more than one character!");
		myStringToPush = stringToPush;
	}