"                0.) Return to main menu." crlf
  "                1.) Gas seal noise." crlf
  "                2.) Knocking noise." crlf
  "                3.) Hitting noise." crlf
  "                4.) Other." crlf
  "        Choice: ")
  (bind ?response (read))
  (assert (possible-cause engine-noise ?response))
  (printout t crlf))
;;
;;*************************************************
;; This rule replaces the users numeric input for *
;; the possible cause of insufficient compression *
;; to the textual representation.  This rule uses * 
;; a variable for the problem field so it is not  * 
;; tied to any particular problem.                *
;;                                                *
;; Variables:                                     *
;;   ?ml - used for retracting the menu level.    *
;;   ?pc - used for retracting the possible cause *
;;         fact.                                  *
;;   ?problem - the problem selected by the user. *
;;*************************************************
(defrule numeric-to-text-insufficient-compression-1-1
  (troubleshoot-mode engine)
  ?ml <- (menu-level engine possible-causes-1-1)
  ?pc <- (possible-cause ?problem 1)
=>
  (retract ?ml)
  (assert (menu-level engine possible-causes-1-1-1))
  (retract ?pc)
  (assert (possible-cause ?problem insufficient-compression)))
;;
;;**************************************************
;; This rule replaces the users numeric input for  *
;; the possible cause of malfunction in combustion *
;; chamber to the textual representation.  This    * 
;; rule is for switching from the ABNORMAL         *
;; COMBUSTION menu to the sub menu.                *
;;                                                 *
;; Variables:                                      *
;;   ?ml - used for retracting the menu level.     *
;;   ?pc - used for retracting the possible cause  *
;;         fact.                                   *
;;   ?problem - the problem selected by the user.  *
;;**************************************************
(defrule numeric-to-text-malfunction-in-combustion-chamber-1-2
  (troubleshoot-mode engine)
  ?ml <- (menu-level engine possible-causes-1-2)
  ?pc <- (possible-cause ?problem 1)
=>
  (retract ?ml)
  (assert (menu-level engine possible-causes-1-2-1))
  (retract ?pc)
  (assert (possible-cause ?problem malfunction-in-combustion-chamber)))
;;
;;**************************************************
;; This rule replaces the users numeric input for  *
;; the possible cause of leakage into combustion   *
;; chamber to the textual representation.  This    * 
;; rule is for switching from the EXCESSIVE OIL    *
;; CONSUMPTION menu to the sub menu.               *
;;                                                 *
;; Variables:                                      *
;;   ?ml - used for retracting the menu level.     *
;;   ?pc - used for retracting the possible cause  *
;;         fact.                                   *
;;   ?problem - the problem selected by the user.  *
;;**************************************************
(defrule numeric-to-text-leakage-into-combustion-chamber-1-3
  (troubleshoot-mode engine)
  ?ml <- (menu-level engine possible-causes-1-3)
  ?pc <- (possible-cause ?problem 1)
=>
  (retract ?ml)
  (assert (menu-level engine possible-causes-1-3-1))
  (retract ?pc)
  (assert (possible-cause ?problem leakage-into-combustion-chamber)))
;;
;;**************************************************
;; This rule replaces the users numeric input for  *
;; the possible cause of leakage into coolant      *
;; passages to the textual representation.  This   * 
;; rule is for switching from the EXCESSIVE OIL    *
;; CONSUMPTION menu to the sub menu.               *
;;                                                 *
;; Variables:                                      *
;;   ?ml - used for retracting the menu level.     *
;;   ?pc - used for retracting the possible cause  *
;;         fact.                                   *
;;   ?problem - the problem selected by the user.  *
;;**************************************************
(defrule numeric-to-text-leakage-into-coolant-passages-1-3
  (troubleshoot-mode engine)
  ?ml <- (menu-level engine possible-causes-1-3)
  ?pc <- (possible-cause ?problem 2)
=>
  (retract ?ml)
  (assert (menu-level engine possible-causes-1-3-2))
  (retract ?pc)
  (assert (possible-cause ?problem leakage-into-coolant-passages)))
;;
;;**************************************************
;; This rule replaces the users numeric input for  *
;; the possible cause of gas seal noise to the     *
;; textual representation.  This rule is for       * 
;; switching from the EXCESSIVE OIL CONSUMPTION    *
;; menu to the sub menu.                           *
;;                                                 *
;; Variables:                                      *
;;   ?ml - used for retracting the menu level.     *
;;   ?pc - used for retracting the possible cause  *
;;         fact.                                   *
;;   ?problem - the problem selected by the user.  *
;;**************************************************
(defrule numeric-to-text-gas-seal-noise-1-4
  (troubleshoot-mode engine)
  ?ml <- (menu-level engine possible-causes-1-4)
  ?pc <- (possible-cause ?problem 1)
=>
  (retract ?ml)
  (assert (menu-level engine possible-causes-1-4-1))
  (retract ?pc)
  (assert (possible-cause ?problem gas-seal-noise)))
;;
;;**************************************************
;; This rule replaces the users numeric input for  *
;; the possible cause of knocking noise to the     *
;; textual representation.  This rule is for       * 
;; switching from the EXCESSIVE OIL CONSUMPTION    *
;; menu to the sub menu.                           *
;;                                                 *
;; Variables:                                      *
;;   ?ml - used for retracting the menu level.     *
;;   ?pc - used for retracting the possible cause  *
;;         fact.                                   *
;;   ?problem - the problem selected by the user.  *
;;**************************************************
(defrule numeric-to-text-knocking-noise-1-4
  (troubleshoot-mode engine)
  ?ml <- (menu-level engine possible-causes-1-4)
  ?pc <- (possible-cause ?problem 2)
=>
  (retract ?ml)
  (assert (menu-level engine possible-causes-1-4-2))
  (retract ?pc)
  (assert (possible-cause ?problem knocking-noise)))
;;
;;**************************************************
;; This rule replaces the users numeric input for  *
;; the possible cause of hitting noise to the      *
;; textual representation.  This rule is for       * 
;; switching from the EXCESSIVE OIL CONSUMPTION    *
;; menu to the sub menu.                           *
;;                                                 *
;; Variables:                                      *
;;   ?ml - used for retracting the menu level.     *
;;   ?pc - used for retracting the possible cause  *
;;         fact.                                   *
;;   ?problem - the problem selected by the user.  *
;;**************************************************
(defrule numeric-to-text-hitting-noise-1-4
  (troubleshoot-mode engine)
  ?ml <- (menu-level engine possible-causes-1-4)
  ?pc <- (possible-cause ?problem 3)
=>
  (retract ?ml)
  (assert (menu-level engine possible-causes-1-4-3))
  (retract ?pc)
  (assert (possible-cause ?problem hitting-noise)))
;;
;;**************************************************
;; This rule replaces the users numeric input for  *
;; the possible cause of other to the textual      *
;; representation.  This rule is for switching     * 
;; from the EXCESSIVE OIL CONSUMPTION menu to the  *
;; sub menu.                                       *
;;                                                 *
;; Variables:                                      *
;;   ?ml - used for retracting the menu level.     *
;;   ?pc - used for retracting the possible cause  *
;;         fact.                                   *
;;   ?problem - the problem selected by the user.  *
;;**************************************************
(defrule numeric-to-text-other-1-4
  (troubleshoot-mode engine)
  ?ml <- (menu-level engine possible-causes-1-4)
  ?pc <- (possible-cause ?problem 4)
=>
  (retract ?ml)
  (assert (menu-level engine possible-causes-1-4-4))
  (retract ?pc)
  (assert (possible-cause ?problem other)))
;;
;;******************************************************
;; If insufficient compression is a possible cause of  *
;;    some problem,                                    *
;; Then present the possible causes of the problem.    *
;;                                                     *
;; Variables:                                          *
;;   ?pc - used for retracting the possible cause.     *
;;   ?problem - the problem selected by the user.      *
;;   ?response - the users response to the menu prompt.*
;;******************************************************
(defrule possible-causes-of-insufficient-compression
  (troubleshoot-mode engine)
  (menu-level engine possible-causes-1-1-1)
  ?pc <- (possible-cause ?problem insufficient-compression)
=>
  (retract ?pc)
  (printout t crlf crlf crlf)
  (printout t
  "        You selected INSUFFICIENT COMPRESSION as a possible cause" crlf
  "        of the problem " ?problem ".  If you change your mind and" crlf
  "        would like to review the previous choices, press 0 now,"   crlf
  "        otherwise select one of the possible causes of INSUFFICIENT" crlf
  "        COMPRESSION listed below." crlf crlf
  "                  0.) Return to previous menu." crlf
  "                  1.) Deformation or abnormal wear of side housing." crlf
  "                  2.) Deformation of abnormal wear of rotor housing." crlf
  "                  3.) Wear of rotor grooves." crlf
  "                  4.) Deformation or poor fastening of gas seals." crlf
  "                  5.) Worn or weak spring." crlf crlf
  "        Choice: ")
    (bind ?response (read))
    (assert (possible-cause ?problem ?response))
    (printout t crlf))
;;
;;******************************************************
;; This is the sub menu for malfunction in combustion  *
;; chamber under problem of abnormal combustion.       *
;; If malfunction in combustion chamber is a possible  *
;;    cause of some problem,                           *
;; Then present the possible causes of malfunction in  *
;;      combustion chamber.                            *
;;                                                     *
;; Variables:                                          *
;;   ?pc - used for retracting the possible cause.     *
;;   ?problem - the problem selected by the user.      *
;;   ?response - the users response to the menu prompt.*
;;******************************************************
(defrule possible-causes-of-malfunction-in-combustion-chamber
  (troubleshoot-mode engine)
  (menu-level engine possible-causes-1-2-1)
  ?pc <- (possible-cause ?problem malfunction-in-combustion-chamber)
=>
  (retract ?pc)
  (printout t crlf crlf crlf)
  (printout t
  "        You selected MALFUNCTION IN COMBUSTION CHAMBER as a possible" crlf
  "        cause of the problem " ?problem ".  If you change your mind" crlf
  "        and would like to review the previous choices, press 0 now,"   crlf
  "        otherwise select the possible cause of MALFUNCTION IN " crlf
  "        COMBUSTION CHAMBER listed below." crlf crlf
  "                  0.) Return to previous menu." crlf
  "                  1.) Carbon accumulation." crlf crlf
  "        Choice: ")
    (bind ?response (read))
    (assert (possible-cause ?problem ?response))
    (printout t crlf))
;;
;;******************************************************
;; This is the sub menu for leakage into combustion    *
;; chamber under problem of excessive oil consumption. *
;; If leakage into combustion chamber is a possible    *
;;    cause of some problem,                           *
;; Then present the possible causes of leakage into    *
;;      combustion chamber.                            *
;;                                                     *
;; Variables:                                          *
;;   ?pc - used for retracting the possible cause.     *
;;   ?problem - the problem selected by the user.      *
;;   ?response - the users response to the menu prompt.*
;;******************************************************
(defrule possible-causes-of-leakage-into-combustion-chamber
  (troubleshoot-mode engine)
  (menu-level engine possible-causes-1-3-1)
  ?pc <- (possible-cause ?problem leakage-into-combustion-chamber)
=>
  (retract ?pc)
  (printout t crlf crlf crlf)
  (printout t
  "        You selected LEAKAGE INTO COMBUSTION CHAMBER as a possible" crlf
  "        cause of the problem " ?problem ".  If you" crlf
  "        change your mind and would like to review the previous" crlf
  "        choices, press 0 now, otherwise select one of the possible" crlf
  "        causes of LEAKAGE INTO COMBUSTION CHAMBER listed below." crlf crlf