protected boolean toPrune(SortedMap items, Item item) { double topProb = ((Double)items.lastKey()).doubleValue();
protected boolean toPrune(int start, int end, Item item) { double topProb = chart[start][end].topLogProb; if (debug) { System.err.println("pruning away item: " + item + " because " + "its prob " + item.logProb() + " is less than " + topProb + " - " + pruneFact + " = " + (topProb - pruneFact)); }
  protected boolean toPrune(SortedMap items, Item item) {    double topProb = ((Double)items.lastKey()).doubleValue();    return item.logProb() < (topProb - pruneFact);  }