<h3> </h3>
      .

<h4> </h4>

<table border=1>
<tr>
  <th></th>
  <th></th>
</tr>
<tr>
  <td>
    <tt>_</tt><br>
    <tt>"_"</tt>
  </td>
  <td>  <tt>_</tt></td>
</tr>
<tr><td>'<tt>string</tt>'</td><td></td></tr>
<tr><td><tt>number</tt></td><td></td></tr>
<tr><td>NULL</td><td> " "</td></tr>
<tr><td>exp(<tt>a</tt>)</td><td> e   <tt>a</tt></td></tr>
<tr><td>ln(<tt>a</tt>)</td><td>  ( e)  <tt>a</tt></td></tr>
<tr><td>log10(<tt>a</tt>)</td><td>  ( 10)  <tt>a</tt></td></tr>
<tr><td>log(<tt>a</tt>,<tt>b</tt>)</td><td>   <tt>b</tt>  <tt>a</tt></td></tr>
<tr><td>sqrt(<tt>a</tt>)</td><td> </td></tr>
<tr><td>sin(<tt>a</tt>)</td><td>  <tt>a</tt></td></tr>
<tr><td>cos(<tt>a</tt>)</td><td>  <tt>b</tt></td></tr>
<tr><td>tan(<tt>a</tt>)</td><td>  <tt>a</tt></td></tr>
<tr><td>asin(<tt>a</tt>)</td><td>  <tt>a</tt></td></tr>
<tr><td>acos(<tt>a</tt>)</td><td>  <tt>a</tt></td></tr>
<tr><td>atan(<tt>a</tt>)</td><td>  <tt>a</tt></td></tr>
<tr><td>to int(<tt>a</tt>)</td><td>  <tt>a</tt>   </td></tr>
<tr><td>to real(<tt>a</tt>)</td><td>  <tt>a</tt>   </td></tr>
<tr><td>to string(<tt>a</tt>)</td><td>  <tt>a</tt>  </td></tr>
<tr><td>lower(<tt>a</tt>)</td><td>  <tt>a</tt>   </td></tr>
<tr><td>upper(<tt>a</tt>)</td><td>  <tt>a</tt>   </td></tr>
<tr><td>length(<tt>a</tt>)</td><td>  <tt>a</tt></td></tr>
<tr><td>atan2(<tt>y</tt>,<tt>x</tt>)</td><td> <tt>y</tt>/<tt>x</tt>        .</td></tr>
<tr><td>replace(<tt>a</tt>,<tt>replacethis</tt>,<tt>withthat</tt>)</td><td>  <tt>replacethis</tt>   <tt>withthat</tt>   <tt>a</tt></td></td>
<tr><td>regexp_replace(<tt>a</tt>,<tt>replacethis</tt>,<tt>withthat</tt>)</td><td>   <tt>replacethis</tt>   <tt>withthat</tt>   <tt>a</tt></td></td>
<tr><td>substr(<tt>a</tt>,<tt>from</tt>,<tt>len</tt>)</td><td>  <tt>len</tt>    <tt>a</tt>   <tt>from</tt> (    1)</td></td>
<tr><td><tt>a</tt> || <tt>b</tt></td><td>  <tt>a</tt>  <tt>b</tt></td></tr>
<tr><td>$rownum</td><td>  </td></tr>
<tr><td>$area</td><td> </td></tr>
<tr><td>$perimeter</td><td> </td></tr>
<tr><td>$length</td><td> </td></tr>
<tr><td>$id</td><td>id </td></tr>
<tr><td>$x</td><td> X </td></tr>
<tr><td>$y</td><td> Y </td></tr>
<tr><td>xat(<tt>n</tt>)</td><td> X <tt>n</tt>-   (   0;       )</td></tr>
<tr><td>yat(<tt>n</tt>)</td><td> Y <tt>n</tt>-   (   0;       )</td></tr>
<tr><td><tt>a</tt> ^ <tt>b</tt></td><td><tt>a</tt>   <tt>b</tt></td></tr>
<tr><td><tt>a</tt> * <tt>b</tt></td><td><tt>a</tt>   <tt>b</tt></td></tr>
<tr><td><tt>a</tt> / <tt>b</tt></td><td><tt>a</tt>   <tt>b</tt></td></tr>
<tr><td><tt>a</tt> + <tt>b</tt></td><td><tt>a</tt>  <tt>b</tt></td></tr>
<tr><td><tt>a</tt> - <tt>b</tt></td><td><tt>a</tt> minus <tt>b</tt></td></tr>
<tr><td>+<tt>a</tt></td><td> </td></tr>
<tr><td>-<tt>a</tt></td><td>  <tt>a</tt></td></tr>
</table>
