public static String parentheticRepresentation(Tree T, Position v) { String s = v.element().toString(); // elements must implement toString if (T.isInternal(v)) { Iterator children = T.children(v); // open parenthesis and recursively process the first subtree s += " ( " + parentheticRepresentation(T, (Position) children.next()); while (children.hasNext()) // recursively process the remaining subtrees s += ", " + parentheticRepresentation(T, (Position) children.next()); s += " )"; // close parenthesis } return s; }