xes : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="../../../IStdlib/index.html#module-IntSet">IStdlib.IntSet</a>.t</code></dt><dt class="spec value" id="val-append"><a href="#val-append" class="anchor"></a><code><span class="keyword">val</span> append : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="../../../Absint/CallSite/index.html#type-t">Absint.CallSite.t</a> <span>&#45;&gt;</span> <a href="index.html#type-