title: converting number to string in lisp
body: <p>I tried to find a lisp function to convert between numbers and strings and after a little googling I fond a function with the same name. when I entered <code>(itoa 1)</code> SLIME printed: </p>
  
  <pre><code>Undefined function ITOA called with arguments (1) .
  </code></pre>
  
  <p>How can I do the conversion?</p>