HOW TO RETURN m ack n:
    SELECT:
        m=0: RETURN n+1
        m>0 AND n=0: RETURN (m-1) ack 1
        m>0 AND n>0: RETURN (m-1) ack (m ack (n-1))

FOR m IN {0..3}:
    FOR n IN {0..8}:
        WRITE (m ack n)>>6
    WRITE /