//
// ack:
//    This is the Ackermann test - it's a a sort of compiler
//    recustion stress test. I'm using it as just that, and
//    as a baseline benchmark for some run-time tuning.
//
NUMFORMAT (5, 0)
PRINT 
PRINT "The Ackermann test. Expect this to run in about"
PRINT "0.5 seconds on a 2GHz Intel CPU."
PRINT 
PRINT "Start"
start = TIME
FOR y = 0 TO 3 CYCLE 
  FOR x = 0 TO 7 CYCLE 
    z = FN ackermann(y, x)
    PRINT z;  " ";  
  REPEAT 
  PRINT 
REPEAT 
NUMFORMAT (5, 3)
PRINT "Done in ";  (TIME - start) / 1000;  " seconds."
END 
//
DEF FN ackermann(m, n)
IF m = 0 THEN  = n + 1
IF n = 0 THEN  = FN ackermann(m - 1, 1)
 = FN ackermann(m - 1, FN ackermann(m, n - 1))