title: Test whether a list contains a specific value in Clojure
body: <p>What is the best way to test whether a list contains a given value in Clojure?</p>
  
  <p>In particular, the behaviour of <code>contains?</code> is currently confusing me:</p>
  
  <pre><code>(contains? '(100 101 102) 101) =&gt; false
  </code></pre>
  
  <p>I could obviously write a simple function to traverse the list and test for equality, but there must surely be a standard way to do this?</p>