title: proofs about regular expressions
body: <p>Does anyone know any examples of the following?</p>
  
  <ol>
  <li>Proof developments about <a href="http://en.wikipedia.org/wiki/Regular_expression#Basic_concepts" rel="noreferrer">regular expressions</a> (possibly extended with <a href="http://en.wikipedia.org/wiki/Regular_expression#Patterns_for_non-regular_languages" rel="noreferrer">backreferences</a>) in proof assistants (such as <a href="http://en.wikipedia.org/wiki/Coq" rel="noreferrer">Coq</a>).</li>
  <li>Programs in dependently-typed languages (such as <a href="http://wiki.portal.chalmers.se/agda/agda.php" rel="noreferrer">Agda</a>) about regular expressions.</li>
  </ol>