Set of rules learned by FOIL over the Ackermann input: Ackermann(0,B,C) :- succ(B,C). Ackermann(A,0,C) :- succ(0,D), succ(E,A), Ackermann(E,D,C). Ackermann(A,B,C) :- succ(D,A), succ(E,B), Ackermann(A,E,F), Ackermann(D,F,C).