title: Lisp Append Not Working Properly
body: <p>Hi I am trying append a simple element to a lisp list.</p>
  
  <pre><code>(append queue1 (pop stack1))
  </code></pre>
  
  <p>I thought the above code would append the first element of stack1 to queue1. Does <code>queue1</code> need to be non nil? Thanks.</p>