span><span class="p">)</span> <span class="kd">::</span> <span class="n">fRE_HxPR</span>

    <span class="n">fRE_HxPR</span> <span class="o">=</span> <span class="n">fRE_H</span><span class="p">(</span><span class="n">eta</span><span class="p">,</span><span class="n">g</span><span class="p">)</span><span class="o">*</span><span class="n">PR</span><span class="p">(</span><span class="n">eta</span><span class="p">,</span><span class="nb">SQRT</span><span class="p">(</span><span class="n">g</span><span class=