         the boundary edge file.
        </li>
      </ul>
    </p>

    <p>
      <b>LAKE</b> is an irregular lake-shaped region with an "island",
      which means the boundary is made of two components.
      It is triangulated using order 3 triangles.
      <ul>
        <li>
          <a href = "lake_nodes.txt">lake_nodes.txt</a>,
          the node file.
        </li>
        <li>
          <a href = "lake_elements.txt">lake_elements.txt</a>,
          the triangles.
        </li>
        <li>
        