n><span class="p">[</span><span class="s2">&quot;e&quot;</span><span class="p">]</span> <span class="o">*</span> <span class="n">r_s</span><span class="p">)</span>
                        <span class="o">*</span> <span class="p">(</span><span class="n">q</span><span class="p">[</span><span class="s2">&quot;f&quot;</span><span class="p">]</span> <span class="o">+</span> <span class="mf">2.0</span> <span class="o">*</span> <span class="n">q</span><span class="p">[</span><span class="s2">&quot;g&quot;</span><s