RosettaCodeData/Task/Ackermann_function/Prolog/ackermann_function.pro
Ingy döt Net 80737d5a6a new tasks
2013-04-09 00:46:50 -07:00

3 lines
163 B
Prolog

ack(0, N, Ans) :- Ans is N+1.
ack(M, 0, Ans) :- M>0, X is M-1, ack(X, 1, Ans).
ack(M, N, Ans) :- M>0, N>0, X is M-1, Y is N-1, ack(M, Y, Ans2), ack(X, Ans2, Ans).