title: Merge-Sort(array, first, last): Can first ever exceed last?
body: <pre><code>MERGE-SORT(a[], first, last)
  {
       if first &gt;= last
           return
  
       mid = first + (last - first) / 2
       MERGE-SORT(a, first, mid)
       MERGE-SORT(a, mid + 1, last)
       MERGE(a, first, mid, last)
  }
  </code></pre>
  <p>Is there a case where the first will ever be bigger than the last? If not, then the '&gt;' in the if statement got no use I guess, right?</p>