anchor.diff:  (defun describe-objects (loc objs obj-loc)
     (labels ((describe-obj (obj)
   	     `(you see a ,obj on the floor.)))
  -    (apply #'append (mapcar #'describe-obj (object-at loc objs obj-loc)))))
  +    (apply #'append (mapcar #'describe-obj (objects-at loc objs obj-loc)))))
   
   (defun look ()
     (append (describe-location *location* *nodes*)
  
positive.code: 
  (defun inventory ()
    (cons 'items- (objects-at 'body *objects* *object-locations*)))
  
negative.code: 
  (defparameter *location* 'living-room)
  
  (defparameter *allowed-commands* '(look walk pickup inventory))
  
  (defun describe-location (location nodes)
    (cadr (assoc location nodes)))
  
  