                   note: <code class="computeroutput"><span class="identifier">u</span></code> may have
                    a singular value.
                  </p>
                </td>
</tr>
<tr>
<td>
                  <p>
                    <code class="computeroutput"><span class="special">++</span><span class="identifier">r</span></code>
                  </p>
                </td>
<td>
                  <p>
                    <code class="computeroutput"><span class="identifier">X</span><span class=