><span>| </span><span><span class="constructor">More</span></span></code></li></ol></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-singleton_or_more"><a href="#val-singleton_or_more" class="anchor"></a><code><span><span class="keyword">val</span> singleton_or_more : 
  <span><span class="label">fold</span>:<span><span>(<span class="type-var">'t</span>, <span class="type-var">'a</span>, <span><span class="type-var">'a</span> <a href="#type-singleton_or_more">singleton_or_more</a><