> <span class="special">*</span> <span class="identifier">_2</span> <span class="special">-</span> <span class="identifier">_3</span><span class="special">);</span>          <span class="comment">// --&gt; _1 / _2 + _2</span>
<span class="identifier">invert</span><span class="special">(</span><span class="identifier">if_</span><span class="special">(</span><span class="identifier">_1</span> <span class="special">*</span> <span class="identifier">_4</span><span class="special">)[</span><span class="identifie