todo-datalog.rkt.fail (214B)
1 #lang repltest datalog 2 parent(amy, anabella). 3 parent(john, anabella). 4 parent(anabella, jack). 5 parent(jack, ted). 6 7 grandparent(X, Z) :- parent(X, Y), parent(Y, Z). 8 9 > grandparent(X, ted)? 10 grandparent(anabella, ted).