anchor.diff:  (define-key *dired-mode-keymap* "R" 'dired-rename-files)
   (define-key *dired-mode-keymap* "+" 'dired-mkdir)
   
  -(defun move-to-file-column ()
  -  (lem::line-start (current-marker)))
  -
  -(defun move-to-start-point ()
  -  (lem::line-offset (lem::buffer-start (current-marker))
  -                    (1- *start-line-number*)))
  +(defun dired-first-line-p (marker)
  +  (lem::same-line-p *start-marker* marker))
  +
  +(defun dired-last-line-p (marker)
  +  (lem::last-line-p marker))
   
   (define-command dired-update-buffer () ()
     (save-excursion
  
positive.code: 
  (define-command dired-next-line (n) ("p")
    (forward-line n)
    (when (> *start-line-number* (current-linum))
      (setf (current-linum) *start-line-number*))
    (when (last-line-p (current-marker))
      (forward-line -1))
    (move-to-file-column))
  
  (define-command dired-previous-line (n) ("p")
    (forward-line (- n))
    (setf (current-linum)
          (max *start-line-number* (current-linum)))
    (move-to-file-column))
  
  (define-command dired-next-directory-line (n) ("p")
    (let ((point (current-point)))
      (loop
        (unless (forward-line 1)
          (setf (current-point) point)
          (return))
        (when (and (eq :directory (get-property (current-point) 'type))
                   (>= 0 (decf n)))
          (move-to-file-column)
          (return)))))
  
  (define-command dired-previous-directory-line (n) ("p")
    (let ((point (current-point)))
      (loop
        (unless (forward-line -1)
          (setf (current-point) point)
          (return))
        (when (and (eq :directory (get-property (current-point) 'type))
                   (>= 0 (decf n)))
          (move-to-file-column)
          (return)))))
  
  (define-command dired-mark-and-next-line (n) ("p")
  
negative.code:       (funcall open-file file))))
  
  (defun mark-current-line (flag)
    (when (and (marker<= *start-marker* (current-marker))
               (not (last-line-p (current-marker))))
      (save-excursion
        (beginning-of-line)
  