ility of obtaining <span class="bold"><strong>more than
                    k failures</strong></span> from k+r trials with success fraction p
                    and success on the last trial. For example:
                  </p>
<pre class="programlisting"><span class="identifier">cdf</span><span class="special">(</span><span class="identifier">complement</span><span class="special">(</span><span class="identifier">negative_binomial</span><span class="special">(</span><span class="identifier">r</span><span