adding numbers">Sum - adding
      numbers</a>
</h3></div></div></div>
<p>
        Here's a parser that sums a comma-separated list of numbers.
      </p>
<p>
        Ok we've glossed over some details in our previous examples. First, our includes:
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="