"identifier">geometry</span><span class="special">::</span><span class="identifier">sym_difference</span><span class="special">(</span><span class="identifier">green</span><span class="special">,</span> <span class="identifier">blue</span><span class="special">,</span> <span class="identifier">multi</span><span class="special">);</span>

    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span>
        <span class="special">&lt;&lt;</span> <span class="string