anchor.diff:  (define-command split-active-window-horizontally (&optional n) ("P")
     (split-window-horizontally (current-window) n))
   
  +(defvar *last-focused-window-id* nil)
  +
  +(defun update-last-focused-window ()
  +  (setf *last-focused-window-id* (window-id (current-window))))
  +
   (define-key *global-keymap* "C-x o" 'other-window)
   (define-command other-window (&optional (n 1)) ("p")
     (let ((window-list
  
positive.code:   (when (one-window-p)
      (split-window-sensibly (current-window)))
    (other-window n))
  
  (define-command window-move-down () ()
    (alexandria:when-let ((window (down-window (current-window))))
  
negative.code:           scroll-up
            find-file-other-window
            read-file-other-window
            select-buffer-other-window
            switch-to-last-focused-window))
  
  (eval-when (:compile-toplevel :load-toplevel)
    (defmacro define-other-window-command (command prompt)
  