Issue: LISP-SYMBOL-REDEFINITION

[Masinter.pa@Xerox.COM]

The mail I sent to Dabrowski@ICST-ECF.ARPA on this issue was returned as
undeliverable.

I think perhaps this issue deserves a writeup (merging it with
SPECIAL-FORM-SHADOW). 

There was one proposal mentioned to bring into the standard some
facilities for declaring that certain symbols were "locked" and not
subject to redefinition (local or global).

My belief is that without a new macro expansion mechanism, there is no
way that we can ensure portability without severe restrictions on
implementations. Given: 

(flet ((open  ))
   (with-open-file ...))

will the expansion of with-open-file use OPEN or SI::OPEN? 

There is a small interaction with CLOS in the sense that adding new
methods for a generic function "redefines" the generic function in some
(explicitly allowed) ways.

On the other hand, this may be beyond the scope of the cleanup
committee. 

I will leave this issue marked as Need Volunteer unless I hear
otherwise.