iangulated using order 3 triangles.
      <ul>
        <li>
          <a href = "ell_nodes.txt">ell_nodes.txt</a>,
          the node file.
        </li>
        <li>
          <a href = "ell_elements.txt">ell_elements.txt</a>,
          the triangles.
        </li>
        <li>
          <a href = "ell_output.txt">ell_output.txt</a>,
          the printed output from a run of the sample program.
        </li>
        <li>
          <a href = "ell_boundary_edges.txt">
          ell_boundary_edges.txt</a>,
 