title: LISP creating an array
body: <p>When I use this function to create an array, I get the following error:</p>
  
  <pre><code>&gt; (defun f1(lst)
     (setf m (make-array '((length lst) 3))))
  F1
  &gt; (f1 '(1 2 3))
  Error: Not a nonnegative integer - (LENGTH LST)    
  </code></pre>
  
  <p>The length of the list should be a nonnegative integer, 3 in this case, so why am I getting this error and what can I do instead?</p>
  
  <pre><code>&gt; (length '(1 2 3))
  3
  </code></pre>