チト戻って on 7つの言語7つの世界
p.75のfriends.plを確認
cheeseを好きなのは誰か聞いてみる。
1 ?- listing. likes(wallace, cheese). likes(grommit, cheese). likes(wendolene, sheep). friend(A, B) :- \+ A=B, likes(A, C), likes(B, C). true. 2 ?- likes(Who, cheese). Who = wallace ; Who = grommit ; false. 3 ?-