RosettaCodeData/Task/Ackermann-function/BBC-BASIC/ackermann-function.basic

      PRINT FNackermann(3, 7)
      END

      DEF FNackermann(M%, N%)
      IF M% = 0 THEN = N% + 1
      IF N% = 0 THEN = FNackermann(M% - 1, 1)
      = FNackermann(M% - 1, FNackermann(M%, N%-1))