  <td>the value of the n<sup>th</sup> extra argument to
        <code>lpeg.match</code> (matches the empty string)</td></tr>
<tr><td><a href="#cap-b"><code>lpeg.Cb(name)</code></a></td>
    <td>the values produced by the previous
        group capture named <code>name</code>
        (matches the empty string)</td></tr>
<tr><td><a href="#cap-cc"><code>lpeg.Cc(values)</code></a></td>
    <td>the given values (matches the empty string)</td></tr>
<tr><td><a href="#cap-f"><code>lpeg.Cf(patt, func)</code></a></td