public String toString()	{
		if (stringResult == null)	{
			StringBuffer sb = new StringBuffer();
			for (int i = 0; sequenceList != null && i < sequenceList.size(); i++)	{
				Object o = sequenceList.get(i);
				if (o instanceof ResultTree)
					sb.append(((ResultTree)o).toString());
				else
					sb.append(o.toString());
					// since JDK 1.4: sb.append((StringBuffer) o);	// is faster than o.toString()
			}
			stringResult = sb.toString();
		}
		return stringResult;
	}