PatternReference(String reference, int depth) {
		Pattern pattern = Pattern.compile("([A-Z_]+)\\(([0-9]+|\\-)\\)");
		Matcher matcher =  pattern.matcher(reference);
		if (matcher.find())
		{
			String argument = matcher.group(2);
			if (argument.equals("-"))
			{
				this.limit = depth-1;
			} else
			{
				this.limit  = Integer.parseInt(matcher.group(2));
			}
			this.reference = matcher.group(1);
		} else {
			this.reference = reference;
		}
	}