(defun min_n(l1 l2)
 (cond
  ((> l1 l2) l2)
  (null l1)
 )
)

(defun min(l1 l2)
 (cond
   ((null (cdr l2)) (min_n l1 (car l2)))
   (null (min l1 (min (car l2) (cdr l2)) ) )
 )
)

(min '(8 5 1 3))
(system)