title: too many arguments given a function
body: <p>I'm having an error that i don't understand why...
  "too many arguments given to ULTIMO"
  The purpose of this function is to return the last element of a list</p>
  
  <pre><code>(defun ultimo (lst)
    (cond ((= 1 (length lst))
           (first lst)))
          (t
           (ultimo (rest lst))))
  </code></pre>