-;; XEmacs - extra parameter
-(defun backward-word (arg &optional buffer)
- "Move backward until encountering the end of a word.
-With argument, do this that many times.
-In programs, it is faster to call `forward-word' with negative arg."
- (interactive "_p") ; XEmacs
- (forward-word (- arg) buffer))
-
-(defun mark-word (arg)
- "Set mark arg words away from point."
+(defun backward-word (&optional count buffer)
+ "Move point backward COUNT words (forward if COUNT is negative).
+Normally t is returned, but if an edge of the buffer is reached,
+point is left there and nil is returned.
+
+COUNT defaults to 1, and BUFFER defaults to the current buffer."
+ (interactive "_p")
+ (forward-word (- (or count 1)) buffer))
+
+(defun mark-word (&optional count)
+ "Mark the text from point until encountering the end of a word.
+With optional argument COUNT, mark COUNT words."