      </em>
              </span>
            </dt>
            <dd>
              <p>
                    Specifies the value to test for NaN.
                </p>
            </dd>
          </dl>
        </div>
      </div>
      <div class="refsect1" id="description">
        <h2>Description</h2>
        <p>
            For each element element <span class="emphasis"><em>i</em></span> of the result, <code class="function">isnan</code> returns <code class="constant">true</code> if
            <em class="