anchor.diff:                   :use-modeline-p use-modeline-p))
   
   (defun clear-screens-of-window-list ()
  -  (dolist (window (window-list))
  -    (screen-clear (window-screen window))))
  +  (flet ((clear-screen (window)
  +           (screen-clear (window-screen window))))
  +    (mapc #'clear-screen (window-list))
  +    (mapc #'clear-screen (frame-floating-windows (current-frame)))))
   
   (defgeneric %delete-window (window))
   (defgeneric window-redraw (window force)
  
positive.code:     (setf (frame-window-tree frame) window)))
  
  (defun teardown-windows (frame)
    (mapc #'%free-window (window-list frame)))
  
  (defun window-recenter (window)
    (line-start
  
negative.code:                (window-tree-parent (window-node-cdr tree) node))))))
  
  (defun window-list (&optional (frame (current-frame)))
    (window-tree-flatten (frame-window-tree frame)))
  
  (defun one-window-p ()
    (window-tree-leaf-p (window-tree)))
  