filter cons X Y 0 M cons 0 n__filter activate Y M M filter cons X Y s N M cons X n__filter activate Y N M sieve cons 0 Y cons 0 n__sieve activate Y sieve cons s N Y cons s N n__sieve filter activate Y N N nats N cons N n__nats s N zprimes sieve nats s s 0 filter X1 X2 X3 n__filter X1 X2 X3 sieve X n__sieve X nats X n__nats X activate n__filter X1 X2 X3 filter X1 X2 X3 activate n__sieve X sieve X activate n__nats X nats X activate X X filter 3 cons 2 0 0 n__filter 3 activate 1 s 1 sieve 1 n__sieve 1 nats 1 n__nats 1 zprimes 0 FULL ./TRS/TRCSR/Ex9_BLR02_Z.trs