; create an array for the sieve
(setf candidates (make-array '(1000)))
; Set all array elements to true. Indices represent the integers
(dotimes (i  999)
	(setf (aref candidates i) t)
)
; zero and one are not prime, turn them off
(setf (aref candidates 0) nil)
(setf (aref candidates 1) nil)
; 500 is good enough, 2*501 is > 1000
(dotimes (i 500)
;	Find first ON element -- must be prime
	(when (aref candidates i)
;		Turn off all multiples of p, starting with 2*p
		(dotimes (j (/ 1000 i))
			(when (<(* i (+ j 2)) 1000)
			    (setf (aref candidates (* i (+ j 2))) nil)
			)
		)
	)
)
; print all primes
(dotimes (i 999)
	(when (aref candidates i)
		(format t "~S is prime~%" i)
				
	)
)