public static String transformLabel(Tree<String> tree) {
		String transformedLabel = tree.getLabel();
	      int cutIndex = transformedLabel.indexOf('-');
	      int cutIndex2 = transformedLabel.indexOf('=');
	      int cutIndex3 = transformedLabel.indexOf('^');
	      if (cutIndex2 > 0 && (cutIndex2 < cutIndex || cutIndex == -1))
	        cutIndex = cutIndex2;
	      if (cutIndex3 > 0 && (cutIndex3 < cutIndex || cutIndex == -1 )) {
	    	 cutIndex = cutIndex3;
	      }
	      
	      if (cutIndex > 0 && ! tree.isLeaf()) {
	        transformedLabel = new String(transformedLabel.substring(0,cutIndex));
	      }
	      return transformedLabel;
	}