s compare equal, the element from
  <code>Iterator1</code> is picked and the one from <code>Iterator2</code> is deleted.</p>
 
  The first element of each iterator will be evaluated.</p>

<h3 class="function"><a name="umerge3-3">umerge3/3</a></h3>
<div class="spec">
<p><tt>umerge3(Iterator1, Iterator2, Iterator3) -&gt; Iterator4</tt>
<ul class="definitions"><li><tt>Iterator1 = <a href="#type-iterator">iterator</a>(A)</tt></li><li><tt>Iterator2 = <a href="#type-iterator">iterator</a>(B)</tt></li><li><tt>Iter