anchor.diff:  
   RETURN:         The list of step-break-entry functions remaining.
   "
  -  `(setf *break-entry-functions* (set-difference *break-entry-functions* ',fnames
  +  `(setf *break-functions-entry* (set-difference *break-functions-entry* ',fnames
                                                    :test (function equal))))
   
   
  
positive.code: 
  RETURN:         The list of function names added.
  "
    `(setf *break-entry-functions*
           (delete-duplicates (union *break-entry-functions* ',fnames
                                     :test (function equal))
                              :test (function equal))))
  
  
negative.code: 
  RETURN:         The list of function names added.
  "
    `(setf *break-functions-exit*
           (delete-duplicates (union *break-functions-exit* ',fnames
                                     :test (function equal))
                              :test (function equal))))
  
  