parameter"><code>x</code></em>[<span class="emphasis"><em>i</em></span>] is posititve or negative floating point NaN (Not a Number) and false otherwise.
                        NaNs may not be supported by the implementation, in which case <code class="function">isnan</code> returns false.
        </p>
      </div>
      {$pipelinestall}{$examples}
      <div class="refsect1" id="versions">
        <h2>Version Support</h2>
        <div class="informaltable">
          <table style="border-collapse: collapse