pan> <span>next:<a href="index.html#type-t">t</a></span> <span>&#45;&gt;</span> <span>num_iters:int</span> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a></code></dt></dl></details></div></div></div><dl><dt class="spec value" id="val-top"><a href="#val-top" class="anchor"></a><code><span class="keyword">val</span> top : <a href="index.html#type-t">t</a></code></dt><dt class="spec value" id="val-is_top"><a href="#val-is_top" class="anchor"></a><code><span class="keyword">val</span> is_top : <a href=