anchor.diff:  
   (defmethod get-prop ((object thing) property)
     (getf (properties object) property))
  -   
  +
   (defmethod set-prop ((object thing) property value)
     (setf (getf (properties object) property) value))
   
  
positive.code: 
  (defmethod meets-filter ((object thing))
    (reduce (lambda (a b)(and a b))(mapcar (lambda (p)(equal (getf *filters* p)(get-prop object p)))(get-keys *filters*))))
  
  ;;; Functions and Macros for nodes
  (defun node-create (&key (label :default) properties)
  
negative.code: 	   :nodes-linked-from
  	   :nodes-linked-to
  	   :get-prop
  	   :dump-props 
  	   :links-with-type
  	   :links-from-node
  