SICP 問題 4.59

(meeting accounting (Monday 9am))
(meeting administration (Monday 10am))
(meeting computer (Wednesday 3pm))
(meeting administration (Friday 1pm))
(meeting whole-company (Wednesday 4pm))

;; a 金曜の朝に今日ある会議をすべて質問する
(meeting ?all (Friday ?time))

;; b ある人の会議は，全社会議とその人の部門会議をすべて含む
(rule (meeting-time ?person ?day-and-time)
      (or (meeting whole-company ?day-and-time)
          (and (job ?person (?division . ?rest))
               (meeting ?division ?day-and-time))))

;; c Alyssaが水曜に会議の時間を質問する
(meeting-time (Hacker Alyssa P) (Wednesday ?time))