><span class="op">(</span><span class="fl">2</span><span class="op">)</span>  ,  <span class="fl">4</span>  <span class="op">|</span></span>
<span>   <span class="st">"c"</span>    , <span class="op">(</span><span class="fl">3</span><span class="op">+</span><span class="fl">2</span><span class="op">)</span>   ,  <span class="fl">9</span>  <span class="op">|</span></span>
<span>   <span class="st">"d"</span>    , <span class="fl">4</span>       , <span class="fl">16</span>  <span class="op">)</span></span></