 href="Elt/index.html#type-t">Elt.t</a></span></code></div></div><div class="odoc-spec"><div class="spec value" id="val-singleton" class="anchored"><a href="#val-singleton" class="anchor"></a><code><span><span class="keyword">val</span> singleton : <span><a href="#type-elt">elt</a> <span class="arrow">&#45;&gt;</span></span> <span><span>(<a href="#type-elt">elt</a>, <a href="Elt/index.html#type-comparator_witness">Elt.comparator_witness</a>)</span> <span class="xref-unresolved">Base</span>.Set.t</span></sp