chapitre 5 La modélisation d'une décision administrative par le génie cognitif

5-3.3 Aperçu du système M-Lex

Un ancien débat en informatique concerne les noms qu'il faut donner à des symboles dans un programme informatique. On peut se poser la même question au sujet des noms des règles et des paramètres. Lors de la création de M-Lex, nous nous sommes fondés sur les considérations suivantes:

• un symbole doit avoir un sens direct, il doit afficher clairement sa fonction.

• les noms de règles doivent être clairement distincts des noms de paramètres (pour augmenter la lisibilité des "traces").

• les noms devraient donner une indication du contexte auquel ils appartiennent.

• ils ne devraient pas être trop longs, car il faut les taper et il faut éviter que les "traces" soient trop grandes.

• les noms de règles commencent par "$" et les noms de paramètres par "*".

• la lettre suivante indique le contexte, par exemple $-t-.... et *-t.... appartiennent au contexte "top".

• les règles qui évaluent un même paramètre devraient avoir un nom similaire, et inclure le nom du paramètre et de la valeur en question. Par exemple, la règle "$t-aut-reg-yes" décide si le paramètre "*t-aut-reg" est "yes".

Les paramètres principaux guidant la décision:

;;; The top-parameter represents the four possible solutions of a case:
;;; authorization, refusal, non-subjection, non-solution
(defparm *t-conc single (aut refus notsub imposs) top)

;;; The authorization regime: subjection or not
(defparm *t-aut-reg yesno (yes no) top inferred)

;;; The acquisition: took place or not
(defparm *t-ac yesno (yes no) top inferred)

;;; The person is foreign, or not, or something special
(defparm *t-for-per single (yes no special) top inferred)

;;; the authorization grounds do exist or not
(defparm *t-aut-mot yesno (yes no) top inferred)

;;; The dummy rule to start the back-chaining
;;; In order to start-up the system we tell him to find a value for
;;; the top parameter *t-conc, i.e. we simply trigger a premisse.

(setq goal-rule
 (defrule $goal-rule
	 (known *t-conc nil)))

;; First we decide whether somebody is subject to the authorization
;; system. If so, we check whether he will receive an
;; authorization.

(defrule $t-decision-yes
 ;; the person is submitted to the authorization regime
 (defis *t-aut-reg yes)
 ;; and he gets an authorization
 (defis *t-aut-mot yes)
 ==>
 (advice-to |The acquisition will be authorized| 1.0)
 (*t-conc aut 1.0)
)

;; Same logic as before, but we check for refusal.
;; We will use eventually the conclusions triggered by $t-decision-yes.

(defrule $t-decision-no
 ;; the person is submitted to the authorization regime
 (defis *t-aut-reg yes)
 ;; and doesn't get an authorization
 (notsame *t-aut-mot yes)
 ==>
 (advice-to |The acquisition will be refused| 1.0)
 (*t-conc refus 1.0)
)

;; Checks whether a person is submitted to the regime of authorization
;; cf. art 2 LFAIE
;; If the person did an acquisition (according to Art.4 and Art.7 LAIE),
;; it is checked whether if is "foreign".

(defrule $t-aut-reg-yes
 ;; the person acquired real estate
 (defis *t-ac yes)
 ;; and it is foreign
 (defis *t-for-per yes)
 ==>
 (*t-aut-reg yes 1.0)
 (advice-to |The acquisition is subject to an authorization| 1.0)
)

;; If the person didn't acquire some real-estate,
;; we can immedialy make the general conclusion of
;; non-subjection.

(defrule $t-aut-reg-no1
 ;; the persone did not acquire a real estate
 (notsame *t-ac yes)
 ==>
 (*t-aut-reg yes -1.0)
 (advice-to |The acquisition is not subject to an authorization| 1.0)
 (*t-conc notsub 1.0)
)

(defrule $t-aut-reg-no2
 ;; the person acquired some real estate
 (defis *t-ac yes)
 ;; his status is known
 (known *t-for-per) ; simplify ?
 ;; but it is not foreign (or under foreign control)
 (notsame *t-for-per yes)
 ==>
 (*t-aut-reg yes -1.0)
 (advice-to |The acquisition is not subject to an authorization| 1.0)
 (*t-conc notsub 1.0)
)

;;; The next two rules are pessimistic about reality and our capacity

(defrule $t-no-conc1
 ;; It cannot be determined whether an acquisition was subject to an auth.
 (notknown *t-aut-reg)
 ==>
 (*t-conc imposs 1.0)
 (advice-to |No conclusion could be reached about the authorization regime | 1.0)
)

(defrule $t-no-conc2
 ;; A person is submitted to the authorization regime
 (defis *t-aut-reg yes)
 ;; ... but no motive can be found
 (notknown *t-aut-mot)
 ==>
 (*t-conc imposs 1.0)
 (advice-to |No conclusion could be reached, No authorization-motive| 1.0)
)

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