(LETREC PRIMES
	(PRIMES LAMBDA (X)
		(LET (SIEVE X INTSFROM2)
			(INTSFROM2 INTS (QUOTE 1))))
	(SIEVE LAMBDA (X STREAM)
		(IF (EQ X (QUOTE 0)) (QUOTE NIL)
			(CONS (CAR STREAM) 
				  (SIEVE (SUB X (QUOTE 1)) 
				  		 (FILTER (CAR STREAM) (FORCE (CDR STREAM)))))))
	(INTS LAMBDA (X) 
	    (LET (CONS Y (DELAY (INTS Y)))
			(Y ADD X (QUOTE 1))))
	(FILTER LAMBDA(P Y)
		(IF (EQ (REM (CAR Y) P) (QUOTE 0))
			(FILTER P (FORCE (CDR Y)))
			(CONS (CAR Y) (DELAY (FILTER P (FORCE (CDR Y))))))))&