title: What does interdiff do that diff cannot?
body: <p>If I'm trying to find the diff between two diffs, why can't I just <code>diff</code> the two diffs? </p>
  
  <blockquote>
    <p>I have tested <code>diff diff1 diff2</code> and <code>interdiff diff1 diff2</code> and have not found any difference in the output. In what case would they be different?</p>
  </blockquote>
  
  <p>(I am fully aware that interdiff's stated purpose is to find the changes between two patches.)</p>