RosettaCodeData/Task/Ackermann-function/MAXScript/ackermann-function.max

fn ackermann m n =
(
    if m == 0 then
    (
        return n + 1
    )
    else if n == 0 then
    (
        ackermann (m-1) 1
    )
    else
    (
        ackermann (m-1) (ackermann m (n-1))
    )
)