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2.3 ルールの保存 

  (set-up-rules
   'c+q
   '((rule1     (?x is a woman)
                ==> (?x is human))
     (rule2     (?x is a man)
                ==> (?x is human))
     (rule3     (?x is human)
                ==> (?x is a carnivore))
     (rule4     (?x is human)
                (?x eats meat)
                ==> (?x is a carnivore))
     (rule5     (?x is human)
                (?x eats vegetables)
                ==> (?x is a vegetarian))
     (rule6     (?x is a carnivore)
                ==> (?x is a living-thing))
     (rule7     (?x is a vegetarian)
                ==> (?x is a living-thing))))
set-up-rulesは以下のように*rules*のruleset-name属性に各ルール名のリス トが入る． 個々のルールの条件部，行動部はルール名のシンボルのantecedent 属性，および，concequent属性に保存される(store-rule)． 
(defvar *rules* nil
  "Holds the ruleset to the interpreted.")
(defun set-up-rules (ruleset-name rules)
  (setf (get '*rules* ruleset-name)
        (mapcar #'store-rule rules)))

(defun store-rule (rule)
  (let ((pos
         (position '==> rule :test #'eq)))
    (setf (get (car rule) 'consequent)
          (subseq rule (+ 1 pos)))
    (setf (get (car rule) 'antecedent)
          (subseq rule 1 pos))
    (car rule)))
ルールからデータをとってくる関数をつくっておく． 

(defun antecedent (rule) (get rule 'antecedent))
(defun consequent (rule) (get rule 'consequent))

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