sidef/scripts/ackermann_function.sf

#!/usr/bin/ruby

func A(m, n) {
    m == 0 ? (n + 1)
           : (n == 0 ? (A(m - 1, 1))
                     : (A(m - 1, A(m, n - 1))));
};

say A(3, 2);     # prints: 29