anchor.diff:        (typecase (process kell)
           (message (setf (process kell) null-process))
           (parallel-composition (setf (messages (process kell))
  -                                    (delete process (messages (process kell))))))
  +                                    (delete process (messages (process kell))))
  +                              (case (length (map-parallel-composition #'identity
  +                                                                      (process kell)))
  +                                (0 (setf (process kell) null-process))
  +                                (1 (setf (process kell) (car (map-parallel-composition #'identity
  +                                                                                          (process kell))))))))
         (warn "The process ~a is not contained in ~a, and thus can not be removed."
               process (process kell))))
     (:method ((process kell) kell)
  
positive.code:         (process-variable (setf (process trigger) null-process))
          (parallel-composition (setf (process-variables (process trigger))
                                      (delete process
                                              (process-variables (process trigger))))))
        (warn "The process ~a is not contained in ~a, and thus can not be removed."
              process (process trigger))))
    (:method ((process message) kell)
  
negative.code:                               (setf (parent proc) value))
                              process))
  
  (defgeneric remove-process-from (process kell)
    (:method (process kell)
      (warn "The process ~a is not contained in ~a, and thus can not be removed."
  