pan><span class="keyword">const</span> <a class="link" href="negative_binom_idp82638048.html" title="Class template negative_binomial_distribution">negative_binomial_distribution</a> <span class="special">&amp;</span> lhs<span class="special">,</span> 
                       <span class="keyword">const</span> <a class="link" href="negative_binom_idp82638048.html" title="Class template negative_binomial_distribution">negative_binomial_distribution</a> <span class="special">&amp;</span> rhs<span class="specia