canner</tt> will only work for phrase level scanners. </p>
<h2><a name="as_lower_scanner"></a>as_lower_scanner</h2>
<p>Similarly, the <tt>as_lower_d</tt> does its work by filtering and converting 
  all characters received from the scanner to lower case. This is also done by 
  tweaking the <a href="scanner.html">scanner</a>. Then again, all parsers inside 
  the <tt>as_lower_d</tt> gets a transformed scanner type. If a rule must be used 
  inside a <tt>as_lower_d</tt>, the rule's type must be:</p>
<pre>   