(defrule start
   (initial-fact)
   =>
   (printout t "What is the problem (wont-start/hesitates-high-speed)? ")
   (assert (problem (read))))

(defrule wont-start
   (problem wont-start)
   =>
   (assert (task test-cranking-system)))

(defrule hesitates-high-speed
   (problem hesitates-high-speed)
   =>
   (assert (task test-fuel-system)))

(defrule test-cranking
   (task test-cranking-system)
   =>
   (printout t "Does the engine turn (yes/no/slowly)? ")
   (assert (engine-turns (read))))

(defrule crank-sys-defect
   ?t <- (task test-cranking-system)
   (engine-turns slowly|no)
   =>
   (assert (defective cranking-system))
   (retract ?t)
   (assert (task test-batt-conn)))

(defrule crank-sys-good
   ?t <- (task test-cranking-system)
   (engine-turns normally|yes)
   =>
   (assert (good cranking-system))
   (retract ?t)
   (assert (task test-ign-sys)))

(defrule test-batt-con
   ?t <- (task test-batt-conn)
   =>
   (printout t "What is the result of the screwdriver test (off/brighten/dont)? ")
   (assert (s-test (read))))

(defrule batt-conn-bad
   (task test-batt-conn)
   (s-test brighten|off)
   =>
   (printout t "The problem is a bad battery connection" crlf))

(defrule batt-conn-good
   ?t <- (task test-batt-conn)
   (s-test dont)
   =>
   (assert (good battery-connection))
   (retract ?t)
   (assert (task test-battery)))