anchor.diff:                   :height height
                    :%buffer buffer
                    :screen (make-screen x y width height use-modeline-p)
  -                 :view-point (copy-point (buffer-point buffer) :right-inserting)
  +                 :view-point (copy-point (buffer-point buffer) :right-inserting "view-point")
                    :use-modeline-p use-modeline-p
  -                 :point (copy-point (buffers-start buffer) :right-inserting)))
  +                 :point (copy-point (buffers-start buffer) :right-inserting "window-point")))
   
   (defun window-x (&optional (window (current-window)))
     (window-%x window))
  
positive.code:                     (copy-point (buffer-point (window-buffer (current-window))) :right-inserting)))))
      (set-window-buffer (current-window) buffer)
      (setf (current-buffer) buffer)
      (point-change-buffer (%window-point (current-window)) buffer)
      (point-change-buffer (window-view-point (current-window)) buffer)
      (cond ((buffer-keep-binfo buffer)
             (destructuring-bind (view-point cursor-point)
                 (buffer-keep-binfo buffer)
               (move-point (window-view-point (current-window)) view-point)
               (move-point (%window-point (current-window)) cursor-point)
               (move-point (window-point (current-window)) (buffer-point buffer))))
            (t
             (move-point (window-view-point (current-window)) (buffers-start buffer)))))
    (setf (window-parameter (current-window) 'change-buffer) t)
    buffer)
  
  
negative.code:     :type point)
     (point
      :initarg :point
      :accessor %window-point
      :type point)
     (delete-hook
      :initform nil
  