title: Common Lisp: Working with &rest parameters
body: <p>Can anyone tell me how to work with the parameters stored in the value specified by &amp;rest.</p>
  
  <p>I've read around a lot and it seems as if authors only know how to list all the parameters as so.</p>
  
  <pre><code>(defun test (a &amp;rest b) b)
  </code></pre>
  
  <p>This is nice to see, but not really that useful.</p>
  
  <p>The best I've found so far is to use first, second, and so on to get the parameter you are looking for.</p>
  
  <pre><code>(defun test (a &amp;rest b)
      (first b))
  </code></pre>
  
  <p>I noticed this method stops working at the tenth parameter, but the specification (from what I've read) supports a minimum of 50. Even if the chances are slim that I'll use 50 parameters, I'd like to know how to access them all.</p>
  
  <p>Thanks</p>