(defun inlist? (e l)
  (cond ((endp l) nil)
        ((= (car l) e) T)
        (t (inlist? e (cdr l)))))
 
(defun no-dups (loe)
  (cond ((endp loe) nil)
        ((not (inlist? (car loe) (cdr loe))) (cons (car loe) (no-dups 
(cdr loe))))
        (t (no-dups (cdr loe)))))