          <span class="serif_italic">p = 0.5 + atan(x)/π</span>
                    </p></blockquote></div>
                  <p>
                    But that suffers from cancellation error as x -&gt; -∞. So recall
                    that for <code class="computeroutput"><span class="identifier">x</span> <span class="special">&lt;</span>
                    <span class="number">0</span></code>:
                  </p>
                  <div class="blockquote"><blockquote class="blockquote"><p>
         