;; Author: jka@ece.cmu.edu (Jay K. Adams)
;; Keywords: data
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to
+;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
;;; Commentary:
;;; This package implements low-level support for reading, writing,
(apply operation args)))
;;;###autoload
-(defun auto-compression-mode (arg)
+(defun auto-compression-mode (&optional arg)
"Toggle automatic file compression and uncompression.
With prefix argument ARG, turn auto compression on if positive, else off.
Returns the new status of auto compression (non-nil means on)."