 a
type language ]<br>
      </td>
    </tr>
    <tr>
      <td style="vertical-align: top;"><span style="font-family: arial;">instance</span>(<span
 style="font-style: italic; font-weight: bold;">L</span>) = <span
 style="font-family: arial;">model</span>(<span
 style="font-style: italic; font-weight: bold;">L</span>)<br>
      <span style="font-family: arial;">type</span>(<span
 style="font-style: italic; font-weight: bold;">L</span>) = <span
 style="font-family: arial;">expression</span>(<span
 style="fo