anchor.diff:                           ;; set action when click
                            (let ((frame frame))
                              (lambda ()
  -                             (setf (virtual-frame-current window) frame)
  -                             (setf (virtual-frame-changed window) t)))
  +                             (switch-current-frame virtual-frame frame)))
                            :attribute (if focusp
                                           'frame-multiplexer-active-frame-name-attribute
                                           'frame-multiplexer-frame-name-attribute))
  
positive.code:     (let ((frame (make-frame (current-frame))))
        (setup-frame frame (primordial-buffer))
        (allocate-frame vf frame)
        (switch-current-frame vf frame)
        (setf (virtual-frame-changed vf) t))))
  
  (define-key *global-keymap* "C-z d" 'frame-multiplexer-delete)
  (define-command frame-multiplexer-delete () ()
  
negative.code:          (frame (search-next-frame vf (virtual-frame-current vf))))
      (when frame
        (switch-current-frame vf frame))
      (lem::change-display-size-hook)))
  
  (define-command frame-multiplexer-test () ()
    (labels ((vf ()
  