lass="special">::</span><span class="identifier">ellint_1</span><span class="special">(</span><span class="identifier">k</span><span class="special">);</span>
      <span class="identifier">T</span> <span class="identifier">fx</span> <span class="special">=</span> <span class="number">4</span> <span class="special">*</span> <span class="identifier">a</span> <span class="special">*</span> <span class="identifier">Ek</span> <span class="special">-</span> <span class="identifier">m_arc</span><span class="speci