'(= (Machine_Beam_Length ?X) (+ 6 (Machine_Beam_Support_Bottom_To_Machine_Room_Top_Spec ?X)))
(<= (Has-Constraint $X Machine_Beam_Length_C) (Elevator $X)) (Inherited-Slot-Value Elevator Has-Constraint Machine_Beam_Length_C)
;; BUG: missing constraint ;; ;; There is no constraint for computing the value of ;; machine_beam_length ;; It should be 6 inches longer than ;; machine_beam_support_bottom_to_machine_room_top_spec ;; (Sec. 4.5).