anchor.diff:  
   (defmethod examine-message ((self base-module)
                              (message irc:irc-nick-message))
  +  (when (member (source message) (authnicks-of self) :test #'string-equal)
  +    (log:log-message :info "De-authenticating ~a due to nick change." (source message))
  +    (setf (authnicks-of self)
  +          (delete (source message) (authnicks-of self) :test #'string-equal)))
     (when (and (string= (source message) (nickname-of self))
                (string/= (nickname (user (connection message)))
                          (nickname-of self)))
  
positive.code: 
  (defmethod examine-message ((self base-module)
                             (message irc:irc-quit-message))
    (when (and (string= (source message) (nickname-of self))
               (string/= (nickname (user (connection message)))
                         (nickname-of self)))
  
negative.code:      for rule in *access-control*
       as consequence = (first rule)
       as patterns = (rest rule)
       do (when (and (or (not (member :user patterns))
                        (string= (getf patterns :user) nick))
                    (or (not (member :auth patterns))
                        (and (getf patterns :auth)
                             (member nick (authnicks-of base-module) :test 'string=)))
                    (or (not (member :channels patterns))
                        (member (first (arguments message))
                                (getf patterns :channels)
  