anchor.diff:  
   (defun stop-run ()
     (halt (current-engine))
  -  (mapc #'port:kill-process :key #'rest *equipment*)
  +  (mapc #'(lambda (equip)
  +            (port:kill-process (rest equip)))
  +        *equipment*)
     (values nil))
   
   (defimport pump (lisa-user::pump) ())
  
positive.code:            (do ()
                 ((not (intact-p self)))
               (add-water self -1)
               (sleep 0.025))
             (cond ((>= (get-level self) 1000)
                    (format t "Tank ~S exploded!~%" self))
                   ((<= (get-level self) 0)
                    (format t "Tank ~S ran dry and caught fire!~%" self)))))
      (port:make-process
       (concatenate 'string "Tank Process " (get-name self))
       #'adjust-tank-level)))
  
  (defun make-tank (name)
    (make-instance 'tank :name name))
  
negative.code:                  ((not (intact-p tank)) t)
                 (add-water tank (get-flow-rate self))
                 (sleep 0.10)))))
      (with-new-process ((concatenate 'string "Pump:" (get-name self)))
        (add-water-to-tank))))
  
  (defun make-pump (name tank)
    (make-instance 'pump :name name :tank tank))
  