lass="programlisting"><span class="keyword">static</span> <span class="identifier">RealType</span> <span class="identifier">find_degrees_of_freedom</span><span class="special">(</span>
   <span class="identifier">RealType</span> <span class="identifier">difference_from_variance</span><span class="special">,</span>
   <span class="identifier">RealType</span> <span class="identifier">alpha</span><span class="special">,</span>
   <span class="identifier">RealType</span> <span class="identifier">beta</span><spa