h="62%" border="0" align="center">
  <tr>
    <td><img src="theme/scanner1.png"></td>
  </tr>
</table>
<p>The scanner manages various aspects of the parsing process through a set of 
  policies. There are three sets of policies that govern:</p>
<blockquote>
  <p><img src="theme/bullet.gif" width="12" height="12"> Iteration and filtering<br>
    <img src="theme/bullet.gif" width="12" height="12"> Recognition and matching<br>
    <img src="theme/bullet.gif" width="12" height="12"> Handling semantic actions</p