(SETQ ROOMS 
  '((LIVING-ROOM        (NORTH FRONT-STAIRS)
                        (SOUTH DINING-ROOM)
                        (EAST KITCHEN))
    (UPSTAIRS-BEDROOM   (WEST LIBRARY)
                        (SOUTH FRONT-STAIRS))
    (DINING-ROOM        (NORTH LIVING-ROOM)
                        (EAST PANTRY)
                        (WEST DOWNSTAIRS-BEDROOM))
    (KITCHEN            (WEST LIVING-ROOM)
                        (SOUTH PANTRY))
    (PANTRY             (NORTH KITCHEN)
                        (WEST DINING-ROOM))
    (DOWNSTAIRS-BEDROOM (NORTH BACK-STAIRS)
                        (EAST DINING-ROOM))
    (BACK-STAIRS        (SOUTH DOWNSTAIRS-BEDROOM)
                        (NORTH LIBRARY))
    (FRONT-STAIRS       (NORTH UPSTAIRS-BEDROOM)
                        (SOUTH LIVING-ROOM))
    (LIBRARY            (EAST UPSTAIRS-BEDROOM)
                        (SOUTH BACK-STAIRS))))