(defrule start
  (initial-fact)
  => 
  (printout t "Program oblicza pierwiastki rownania kwadratowego: " crlf)
  (printout t "a*x^2 + b*x + c = 0" crlf crlf)
  (printout t "Podaj a: ")
  (bind ?a (read))
  (printout t "Podaj b: ")
  (bind ?b (read))
  (printout t "Podaj c: ")
  (bind ?c (read))
  (assert (a ?a) (b ?b) (c ?c)))

(defrule licz-delta
  (a ?a)
  (b ?b)
  (c ?c)
  => 
  (bind ?delta (- (* ?b ?b) (* 4 ?a ?c)))
  (assert (delta ?delta)))

(defrule delta-rowna-zero
  (delta ?delta)
  (a ?a)
  (b ?b)
  (test (= ?delta 0))
  => 
  (bind ?x1 (/ (- 0 ?b) (* 2 ?a)))
  (bind ?x2 ?x1)
  (assert (x1 ?x1) (x2 ?x2)))

(defrule delta-wieksza-od-zero
  (delta ?delta)
  (a ?a)
  (b ?b)
  (test (> ?delta 0))
  =>
  (bind ?x1 (/ (+ (- ?b) (sqrt ?delta)) (* 2 ?a)))
  (bind ?x2 (/ (- (- ?b) (sqrt ?delta)) (* 2 ?a)))
  (assert (x1 ?x1) (x2 ?x2)))

(defrule delta-ujemna
  (delta ?delta)
  (a ?a)
  (b ?b)
  (test (< ?delta 0))
  =>
  (bind ?realPart (/ (- ?b) (* 2 ?a)))
  (bind ?imagPart (/ (sqrt (- ?delta)) (* 2 ?a)))
  (assert (x1-complex ?realPart ?imagPart) (x2-complex ?realPart (- ?imagPart))))

(defrule pisz-wynik
  (x1 ?x1)
  (x2 ?x2)
  =>
  (printout t "Rozwiazanie: x1 = " ?x1 " x2 = " ?x2 crlf))

(defrule pisz-wynik-zespolony
  (x1-complex ?realPart1 ?imagPart1)
  (x2-complex ?realPart2 ?imagPart2)
  =>
  (printout t "Równanie kwadratowe ma dwa pierwiastki zespolone:" crlf)
  (printout t "x1 = " ?realPart1 " + " ?imagPart1 "i" crlf)
  (printout t "x2 = " ?realPart2 " - " ?imagPart2 "i" crlf))

; Uruchom silnik wnioskujący
(run)