f</span><span class="special">(</span><span class="identifier">e</span><span class="special">)</span></code> is a valid expression, convertible
                      to <code class="computeroutput"><span class="keyword">bool</span></code>, for every
                      element <code class="computeroutput"><span class="identifier">e</span></code> in
                      <code class="computeroutput"><span class="identifier">seq</span></code>
                    </p>
                  </td>
<td>
           