static <A> L<A> lazyReversed(L<A> l) {
  ret new RandomAccessAbstractList<A> {
    final int size = l(l);

    public int size() { ret l.size(); }
    
    public A get(int i) {
      ret l.get(size()-1-i);
    }
    
    public A set(int i, A a) {
      ret l.set(size()-1-i, a);
    }
  };
}