    But neither of:
      </p>
<pre class="programlisting"><span class="identifier">a</span>
<span class="identifier">aaaa</span>
</pre>
<p>
        It is an error to use a repeat operator, if the preceding construct can not
        be repeated, for example:
      </p>
<pre class="programlisting"><span class="identifier">a</span><span class="special">(*)</span>
</pre>
<p>
        Will raise an error, as there is nothing for the <code class="computeroutput"><span class="special">*</span></code>
        opera