class item { 
   item  
  
  public item(String x) { _name = x; _self = null; }
  
  String name() { return exists()?self().name():_name; }
  
  public void redirect(item x) { _self = x; } 
  
  boolean exists() { return _self != null; }
  public item self() { return exists()?_self.self():this; }
  
  item _self;
  String _name;
  };