 program can update the properties of values, thus changing the order of values in the UpdatableQueue, and notify the UpdatableQueue of the specific values that have a different position in the ordering by calling the <tt>update</tt> member of the UpdatableQueue on each.

<p>A program that modifies the order must notify the UpdatableQueue of values that may have different positions in the ordering since they were inserted or last updated.

<h3>Notation</h3>

<table>
<tr> <td> <tt>Q</tt> </td>  <td> is a typ