aluating this function. When two elements compare equal,
  the element from the subiterator with the lowest position in
  <code>IteratorOfIterators</code> is picked and the other is deleted.</p>
 
  The first element of each subiterator will be evaluated.</p>

<h3 class="function"><a name="umerge-2">umerge/2</a></h3>
<div class="spec">
<p><tt>umerge(Iterator1, Iterator2) -&gt; Iterator3</tt>
<ul class="definitions"><li><tt>Iterator1 = <a href="#type-iterator">iterator</a>(A)</tt></li><li><tt>Iterator2 = <a 