title: Why is [a..b] an empty list when a > b?
body: <p>If I enter <code>[5..1]</code> into the Haskell console it returns <code>[]</code>, whereas I expected <code>[5, 4, 3, 2, 1]</code>. </p>
  
  <p>In general, <code>[a..b] = []</code> if <code>a &gt; b</code>. Why?</p>