lisp -how to check if all the list is numbers
<p>I build this function to check if all the "var" on the list are numbers.
This what i tried to do</p>

<pre><code>(defun check6 (list) 
(if  (null list) 'TRUE)
(if (not (numberp(first list))) nil)
(check6 (rest list)))
</code></pre>

<p>But always i get stack overflow.</p>

<p>Why please?</p>