anchor.diff:  					record
   					&optional errorp)
     (declare (ignore record errorp))
  -  (let ((pcache (parent-cache child))
  -	(parent-updating (parent-updating-output child)))
  +  (let ((pcache (parent-cache child)))
       (delete-from-map pcache
   		     (output-record-unique-id child)
  -		     (output-record-id-test child))
  -    (when parent-updating
  -      (setf (children-updating-output parent-updating)
  -	    (delete child (children-updating-output parent-updating)
  -		    :test #'eq)))))
  +		     (output-record-id-test child))))
   
   
   (defclass standard-updating-output-record (updating-output-record-mixin
  
positive.code:    (stream :accessor updating-output-stream :initarg :stream :initform nil
  	   :documentation "Capture the screen in order to restrict update to
  					visible records")
     (children-updating-output :accessor children-updating-output :initform nil
  			     :documentation "A list of updating-output records
  that are children (but not necessarily direct) of this record.")
     (parent-updating-output :accessor parent-updating-output
  			   :initarg :parent-updating-output :initform nil
  			   :documentation "A backlink to the
  
negative.code: ;;; XXX still needed?
  (defmethod add-output-record :after
      ((child updating-output-record-mixin) record)
    (declare (ignore record child)))
  
  
  ;;; Prevent deleted output records from coming back from the dead.
  