/b>
                |   <b>"+?"</b>
                |   <b>"??"</b>
                |   <i>bound</i> <b>?</b>
</pre>
</td></tr>
</table>

<p>
An atom followed by <tt>*</tt> matches a sequence of 0 or more matches
of the atom.  <tt>+</tt> is similar to <tt>*</tt>, matching a sequence
of 1 or more matches of the atom.  An atom followed by <tt>?</tt>
matches a sequence of 0 or 1 matches of the atom.
</p>

<p>
A <i>bound</i> is one of the following, where <i>m</i> and <i>m</i>
are unsigned decimal integers betw