yword">const</span><span class="special">;</span> <span class="comment">// required successes always one,</span>
<span class="comment">// included for compatibility with negative binomial distribution</span>
<span class="comment">// with successes r == 1.</span>
</pre>
<p>
          Returns unity.
        </p>
<p>
          The following functions are equivalent to those provided for the negative
          binomial, with successes = 1, but are provided here for completeness.
        </p>
<p>
          The b