l class="definitions"><li><tt>Key = any()</tt></li><li><tt>N = pos_integer()</tt></li><li><tt>TupleIterator = <a href="#type-iterator">iterator()</a></tt></li></ul></p>
<p> </p>
</div><p><p>
  Returns <code>true</code> if there is a tuple in <code>TupleIterator</code> whose <code>N</code>th
  element compares equal to <code>Key</code>, otherwise <code>false</code>.</p>
 
  The iterator will be evaluated until a match is found. If no match
  is found, infinite iterators will never return.</p>

<h3 class="fun