 from the files, and displays the surface on the screen.
    </p>

    <h3 align = "center">
      Usage:
    </h3>

    <p>
      <blockquote>
        <b>polygonal_surface_display</b> ( '<i>node_file</i>', '<i>face_file</i>' )
      </blockquote>
      where
      <ul>
        <li>
          '<i>node_file</i>' is the name of the file containing node information;
        </li>
        <li>
          '<i>face_file</i>' is the name of the file containing face information.
        </li>
      </ul>
    </p>

 