span class="emphasis"><em><span class="bold"><strong>Symmetric difference</strong></span></em></span></a>
              </p>
              </td></tr>
<tr><td>
              <p>
                <a class="link" href="subtraction.html" title="Subtraction"><span class="emphasis"><em><span class="bold"><strong>Subtraction</strong></span></em></span></a>
              </p>
              </td></tr>
<tr><td>
              <p>
                <a class="link" href="addition.html" title="Addition"><span class="emphasi