        <p>
                0.707106
              </p>
            </td>
<td>
            </td>
</tr>
<tr>
<td>
              <p>
                ln_two
              </p>
            </td>
<td>
              <p>
                ln(2)
              </p>
            </td>
<td>
              <p>
                0.693147
              </p>
            </td>
<td>
              <p>
                Equivalent to POSIX constant M_LN2
              </p>
            </td>
</tr>
<tr>
<td>
              <p>
         