Comment éliminer if-then-else dans CLIPS pour mieux optimiser le code

Question

Je suis nouveau sur CLIPS et le paradigme du backtracking fait mal à la tête.

On me pose une question où je dois produire la sortie suivante.

Q: Is the patient's temperature more than 39? [yes/no]: yes 
    The patient has fever 
Q: Does the patient sick over a month? [yes/no]: yes 
    We suspect the patient has bacterial infection 
Q: How about sore throat? [yes/no]: yes 
    We believe the patient has strep throat 

Si nécessaire, j'ai défini quelques règles pour le faire fonctionner.

(defrule rule_1 
    (THE-PATIENT-HAS-A-SORE-THROAT) 
    (WE-SUSPECT-A-BACTERIAL-INFECTION) => 
    (assert(WE-BELIEVE-THE-PATIENT-HAS-STREP-THROAT)) 
    (printout t "We believe the patient has strep throat" crlf)) 

(defrule rule_2 
    (THE-PATIENT-TEMPERATURE-IS-40C) => 
    (assert(THE-PATIENT-HAS-A-FEVER))) 

(defrule rule_3 
    (THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH) 
    (THE-PATIENT-HAS-A-FEVER) => 
    (assert(WE-SUSPECT-A-BACTERIAL-INFECTION))) 

(defrule ask-sick 
    (start-question) => 
    (printout t "Q: Is the patient's temperature more than 39? [yes/no]: ") 
    (bind ?input (readline)) 
    (if (neq ?input "no") 
    then 
     (assert (THE-PATIENT-TEMPERATURE-IS-40C)) 
     (printout t "The patient has fever" crlf) 
     (printout t "Q: Does the patient sick over a month? [yes/no]: ") 
     (bind ?input2 (readline)) 
     (if (neq ?input2 "no") 
     then 
      (assert (THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH)) 
      (printout t "We suspect the patient has bacterial infection" crlf) 
      (printout t "Q: How about sore throat? [yes/no]: ") 
      (bind ?input3 (readline)) 
      (if (neq ?input3 "no") 
      then 
       (assert (THE-PATIENT-HAS-A-SORE-THROAT)) 
     ) 
    ) 
) 
) 

(deffacts start 
    (start-question) 
) 

Finalement, j'ai réussi à faire vivre le programme. Le problème est, à la règle demander-malade, je devais incorporer un tas de if-then-else pour faire fonctionner le programme où il n'est pas très conforme au paradigme de retour arrière.

Quelqu'un peut-il me dire comment dois-je optimiser comme il sait où procéder, règle1 -> règle2/Règle3, etc.

Answer 1

est ici une approche:

(deffunction ask-question (?question $?allowed-values) 
    (printout t "Q: " ?question " [" (implode$ ?allowed-values) "] ") 
    (bind ?answer (read)) 
    (if (lexemep ?answer) 
     then (bind ?answer (lowcase ?answer))) 
    (while (not (member ?answer ?allowed-values)) do 
     (printout t "Q: " ?question " [" (implode$ ?allowed-values) "] ") 
     (bind ?answer (read)) 
     (if (lexemep ?answer) 
      then (bind ?answer (lowcase ?answer)))) 
    ?answer) 

(deffunction yes-or-no (?question) 
    (ask-question ?question yes no)) 

(defrule ask-temperature 
    => 
    (bind ?input (yes-or-no "Is the patient's temperature more than 39?")) 
    (assert (THE-PATIENT-TEMPERATURE-IS-40C ?input))) 

(defrule ask-sick-for-over-a-month 
    (THE-PATIENT-HAS-A-FEVER yes) 
    => 
    (bind ?input (yes-or-no "Does the patient sick over a month?")) 
    (assert (THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH ?input))) 

(defrule ask-sore-throat 
    (WE-SUSPECT-A-BACTERIAL-INFECTION yes) 
    => 
    (bind ?input (yes-or-no "How about sore throat?")) 
    (assert (THE-PATIENT-HAS-A-SORE-THROAT ?input))) 

(defrule conclude-fever 
    (THE-PATIENT-TEMPERATURE-IS-40C yes) 
    => 
    (assert (THE-PATIENT-HAS-A-FEVER yes)) 
    (printout t "The patient has fever" crlf)) 

(defrule conclude-bacterial-infection 
    (THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH yes) 
    (THE-PATIENT-HAS-A-FEVER yes) 
    => 
    (assert (WE-SUSPECT-A-BACTERIAL-INFECTION yes)) 
    (printout t "We suspect the patient has bacterial infection" crlf)) 

(defrule conclude-strep-throat 
    (THE-PATIENT-HAS-A-SORE-THROAT yes) 
    (WE-SUSPECT-A-BACTERIAL-INFECTION yes) 
    => 
    (assert (WE-BELIEVE-THE-PATIENT-HAS-STREP-THROAT yes)) 
    (printout t "We believe the patient has strep throat" crlf)) 

Et un autre:

(deffunction ask-question (?question $?allowed-values) 
    (printout t "Q: " ?question " [" (implode$ ?allowed-values) "] ") 
    (bind ?answer (read)) 
    (if (lexemep ?answer) 
     then (bind ?answer (lowcase ?answer))) 
    (while (not (member ?answer ?allowed-values)) do 
     (printout t "Q: " ?question " [" (implode$ ?allowed-values) "] ") 
     (bind ?answer (read)) 
     (if (lexemep ?answer) 
      then (bind ?answer (lowcase ?answer)))) 
    ?answer) 

(deffunction yes-or-no (?question) 
    (ask-question ?question yes no)) 

(deftemplate attribute 
    (slot name) 
    (slot value)) 

(deftemplate question 
    (slot text) 
    (slot attribute) 
    (multislot precursors)) 

(deftemplate conclusion 
    (slot text) 
    (slot attribute) 
    (multislot precursors)) 

(deffacts questions 
    (question 
     (text "Is the patient's temperature more than 39?") 
     (attribute THE-PATIENT-TEMPERATURE-IS-40C)) 
    (question 
     (text "Does the patient sick over a month?") 
     (attribute THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH) 
     (precursors THE-PATIENT-HAS-A-FEVER)) 
    (question 
     (text "How about sore throat?") 
     (attribute THE-PATIENT-HAS-A-SORE-THROAT) 
     (precursors WE-SUSPECT-A-BACTERIAL-INFECTION))) 

(deffacts conclusions 
    (conclusion 
     (text "The patient has fever") 
     (attribute THE-PATIENT-HAS-A-FEVER) 
     (precursors THE-PATIENT-TEMPERATURE-IS-40C)) 
    (conclusion 
     (text "We suspect the patient has bacterial infection") 
     (attribute WE-SUSPECT-A-BACTERIAL-INFECTION) 
     (precursors THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH THE-PATIENT-HAS-A-FEVER)) 
    (conclusion 
     (text "We believe the patient has strep throat") 
     (attribute WE-BELIEVE-THE-PATIENT-HAS-STREP-THROAT) 
     (precursors THE-PATIENT-HAS-A-SORE-THROAT WE-SUSPECT-A-BACTERIAL-INFECTION))) 

(defrule ask-question 
    (question (text ?text) 
       (attribute ?attr)) 
    (forall (question (attribute ?attr) 
         (precursors $? ?pre $?)) 
      (attribute (name ?pre) 
         (value yes))) 
    => 
    (bind ?input (yes-or-no ?text)) 
    (assert (attribute (name ?attr) (value ?input)))) 

(defrule conclude 
    (conclusion (text ?text) 
       (attribute ?attr)) 
    (forall (conclusion (attribute ?attr) 
         (precursors $? ?pre $?)) 
      (attribute (name ?pre) 
         (value yes))) 
    => 
    (assert (attribute (name ?attr) (value yes))) 
    (printout t ?text crlf))