">=</span> <span class="mi">0</span>
    
    <span class="c1"># Step 2:</span>
    <span class="n">dL</span> <span class="o">=</span> <span class="p">(</span><span class="n">Lr</span> <span class="o">-</span> <span class="n">Lt</span><span class="p">)</span>
    <span class="n">dCp</span> <span class="o">=</span> <span class="p">(</span><span class="n">Cpr</span> <span class="o">-</span> <span class="n">Cpt</span><span class="p">)</span>
    <span class="n">dhp_</span> <span class="o">=</span> <span class=