/span>

            <span class="c1"># Define eta, auxiliary vars for constr. (2).</span>
            <span class="n">E</span> <span class="o">=</span> <span class="p">[</span><span class="n">solver</span><span class="o">.</span><span class="n">NumVar</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">infinity</span><span class="p">,</span> <span class="sa">f</span><span class="s2">&quot;eta_</span><span class="si">{</span><span class="n">i</span><span class="si"