title: Converting a set to a list in Isabelle
body: <p>How can I convert a set to a list in Isabelle?</p>
  
  <p>I am interested in a function definition, with the signature:</p>
  
  <pre><code>"'a set =&gt; 'a list"
  </code></pre>
  
  <p>How can I define this?</p>