if(start < 0) start += getLength();
  public int lastIndexOf(ATerm el, int start)  {    int index = 0, last = -1;    for(ATermList cur = this; !cur.isEmpty() && index<=start; 				cur = cur.getNext()) {      if(cur.getFirst().equals(el))				last = index;      index++;    }    return last;  }