anchor.diff:  (defun split-window-after (current-window new-window split-type)
     (assert (not (eq current-window new-window)))
     (window-set-size current-window
  -                   (window-%width current-window)
  +                   (window-width current-window)
                      (window-%height current-window))
     (move-point (window-view-point new-window)
                 (window-view-point current-window))
  
positive.code:    (width
      :initarg :width
      :reader window-width
      :accessor window-%width
      :type fixnum)
     (height
      :initarg :height
  
negative.code:                                  (window-x win)
                                   (window-y deleted-window))
                   (window-set-size win
                                    (window-width win)
                                    (+ (window-%height deleted-window)
                                       (window-%height win)))))
                (t
                 (dolist (win (lem-utils:max-if #'window-y window-list))
                   (window-set-size win
                                    (window-width win)
                                    (+ (window-%height deleted-window)
                                       (window-%height win)))))))))
  
  