(DEFINE FACTORIAL
,  (LAMBDA (N)
,  ,  (PROG (RESULT COUNTER)
,  ,  ,  (SETQ RESULT 1)
,  ,  ,  (SETQ COUNTER N)
,  ,  ,  LOOP 	(COND ((ZEROP COUNTER) (RETURN RESULT)))
,  ,  ,  (SETQ RESULT (TIMES COUNTER RESULT))
,  ,  ,  (SETQ COUNTER (SUB1 COUNTER))
,  ,  ,  (GO LOOP)
,  ,  ,,,)
,  ,,,)
,,,)