From: Barry Margolin
Subject: Lexical scoping good, dynamic scoping bad
Date: 
Message-ID: <1pm8obINNdon@early-bird.think.com>
Just saw the following post in gnu.emacs.bugs.  If anyone is still confused
about why lexical scoping is better than dynamic scoping, I think this
should demonstrate the problem.

I also really liked his Subject line.

From: ·······@cs.uiuc.edu (Daniel LaLiberte)
Subject: arg !!
Date: 1 Apr 93 21:24:02 GMT
Organization: University of Illinois, Urbana-Champaign, Dept CS

In Emacs 18.59, if we set the global variable "arg" to some value, and
then check its value, the result is nil:

(setq arg 3)
=> 3
arg
=> nil

This is because several read-eval-print commands in lisp-mode.el have
an argument named "arg" which is visible during the evaluation.
-- 
Barry Margolin
System Manager, Thinking Machines Corp.

······@think.com          {uunet,harvard}!think!barmar