ding to a comparison
   function.  The comparison function must return 0 if its arguments
   compare as equal, a positive integer if the first is greater,
   and a negative integer if the first is smaller (see Array.sort for
   a complete specification).  For example,
   <a href="Pervasives.html#VALcompare"><code class="code">compare</code></a> is a suitable comparison function.
   The resulting list is sorted in increasing order.
   <code class="code"><span class="constructor">List</span>.sort</code> is gu