&nbsp;=&nbsp;[&nbsp;<span class="keywordsign">`</span><span class="constructor">Abs_top_heap</span>&nbsp;<span class="keywordsign">|</span>&nbsp;<span class="keywordsign">`</span><span class="constructor">Alloc</span>&nbsp;<span class="keywordsign">|</span>&nbsp;<span class="keywordsign">`</span><span class="constructor">Time</span>&nbsp;<span class="keywordsign">|</span>&nbsp;<span class="keywordsign">`</span><span class="constructor">Top_heap</span>&nbsp;]<br>
&nbsp;&nbsp;<span class="keyword">val</span>&