;;; Written by Benjamin Kuipers, University of Texas, 1993
;;; Updated by Micheal Hewett for Algernon in Java, 2003
;;;
;;; Load this file into Algernon to run it.
;;; ---------------------------------------------------------
;;;                        ****** FLU ******
;;;
;;; This example illustrates the use of Algernon to build a very simple
;;; expert system.  In particular it illustrates the use of the :ask
;;; form to query the user.
;;;
;;; Expected results:
;;;   Temperature >  99 and Nausea:   John has the Flu
;;;   Temperature > 102 and Nodules:  John has the Plague
;;;   Note that both answer can be true if the temperature
;;;   is above 102 and John has both Nausea and Nodules
;;; ---------------------------------------------------------

;; Create a new KB.
(tell ((:USE-KB :FLU-EXAMPLE-KB Protege )))


;; Declare basic facts

(tell ((:TRACE :NORMAL)))

;; Define the basic taxonomy
(tell ((:taxonomy (:THING
                     (Objects
		      (Symptoms Fever High-Fever Nausea Nodules)
	              (Physical-Objects
		       (People)
		       (Diseases Flu Plague)))))))


  ;; Four new slots:
  ;;  (has-disease x d) = x has disease d.
  ;;  (has-symptom x s) = x has symptom s.
  ;;  (temperature x t) = x has temperature t.
  ;;  (symptom d s)     = disease d causes symptom s.
  ;;

(tell ((:add-relation has-disease (People   Diseases) :max-cardinality :ANY)
       (:add-relation has-symptom (People   Symptoms) :max-cardinality :ANY)
       (:add-relation symptom     (Diseases Symptoms) :max-cardinality :ANY)
       (:add-relation temperature (Physical-Objects :integer) :max-cardinality 1)
       ))

;; Backward-chaining rules to do the basic fact-finding.
(tell ((:add-rule People
         ((has-symptom ?p Fever)      <- (temperature ?p ?t) (:test (:LISP (> ?t 99))))   ;; Rule1
         ((has-symptom ?p High-Fever) <- (temperature ?p ?t) (:test (:LISP (> ?t 102))))  ;; Rule2
         ((has-symptom ?p Nausea)     <- (:ask (has-symptom ?p Nausea)))                  ;; Rule3
         ((has-symptom ?p Nodules)    <- (:ask (has-symptom ?p Nodules)))                 ;; Rule4
         ((temperature ?p ?t)         <- (:ask (temperature ?p ?t)))                      ;; Rule5
         )))

;; Backward-chaining rules for diagnosis
;; A person has a disease if they have all symptoms of the disease ...
;; Rule6 and Rule7

;; This version of the rules orders the queries so the
;; user is not asked unnecessary questions.
;; For example, if the patient does not have a High-Fever,
;; the user will not be asked if they have Nodules.
;; See flu2.txt for an alternative way of implementing this rule.
(tell ((:add-rule People
        ((has-disease ?x Flu)     <-  (has-symptom ?x Fever)      (has-symptom ?x Nausea))
        ((has-disease ?x Plague)  <-  (has-symptom ?x High-Fever) (has-symptom ?x Nodules))
        )))



;; Start the process

(ask ((:the-instance (?j People) (:NAME ?j "John"))
      (:trace :normal)
      (has-disease ?j ?d)
      (:PRINTLN ?j " has the " ?d)
      ))