function ack(m,n)
  if m==0 then
    return n+1
  elseif n == 0 then
    return ack(m-1,1)
  else return ack(m-1,ack(m,n-1)) end
end

for i = 0,3 do
   for j = 0,8 do
      print($"A({i},{j})={ack(i,j)}")
   end
end