 expression) <code class="computeroutput"><span class="special">[]</span></code>
          </li>
<li class="listitem">
            Grouping <code class="computeroutput"><span class="special">()</span></code>
          </li>
<li class="listitem">
            Single-character-ERE duplication <code class="computeroutput"><span class="special">*</span>
            <span class="special">+</span> <span class="special">?</span>
            <span class="special">{</span><span class="identifier">m</span><span class=