measured 
         (<a href="ftp://ibiblio.org/pub/docs/books/gutenberg/etext02/mtent12.zip">mtent12.txt</a>
         from <a href="http://promo.net/pg/">Project Gutenberg</a>, 19Mb).&nbsp;</p>
      <P><table border="1" cellspacing="1">
            <tr>
               <td><strong>Expression</strong></td>
               <td><strong>GRETA</strong></td>
               <td><strong>GRETA<BR>
                     (non-recursive mode)</strong></td>
               <td><strong>Boost</strong></td>
               <td