tastee(tuna).
smelly(tuna).
eats(tuna, minnows).
cute(goldfish).
tastee(goldfish).
plays(goldfish, minnows).
bad(X) :- eats(X, minnows).
good(X) :- eats(X, Z), bad(Z).
bad(X) :- eats(X, Z), cute(Z).
eats(tuna, goldfish).