anchor.diff:  (define-command other-window-or-split-window (&optional (n 1)) ("p")
     (when (one-window-p)
       (split-window-sensibly (current-window))
  -    (when *balance-after-split-window*
  -      (balance-windows)))
  +    (maybe-balance-windows))
     (other-window n))
   
   (define-command switch-to-last-focused-window () ()
  
positive.code: (define-command split-active-window-vertically (&optional n) ("P")
    (split-window-vertically (current-window) n)
    (unless n
      (when *balance-after-split-window*
        (balance-windows))))
  
  (define-key *global-keymap* "C-x 3" 'split-active-window-horizontally)
  (define-command split-active-window-horizontally (&optional n) ("P")
    (split-window-horizontally (current-window) n)
    (unless n
      (when *balance-after-split-window*
        (balance-windows))))
  
  (defvar *last-focused-window-id* nil)
  
  
negative.code:              (arg) (,prompt)
             (when (one-window-p)
               (split-window-sensibly (current-window))
               (maybe-balance-windows))
             (other-window)
             (,command arg))
          (warn "command ~a is not defined." command)))
  