title: Is this regular expression interview question a fair question for a Senior Programmer position?
body: <blockquote>
    <p>Which of the following regular
    expressions cannot be transformed into
    one using just the base operators of
    <code>|</code> and <code>*</code> (Kleene star) and grouping
    <code>( () ) *</code></p>
  </blockquote>
  
  <pre><code>/adt[ui]t+\S?/ 
  /b[^e]ac?h+\s\s\sBALL/i 
  /he{5}[Ly]+o\bwo[^r]L(?!d)/ 
  /ab?c+(de{1,3})/ 
  </code></pre>
  
  <p>Would this be a fair question to administer for a Senior Programmer position?</p>