Re: New argument-list syntax proposal.

[ACW at MIT-AI (Allan C. Wechsler)]

OK.  Look at this, folks.

(DEFUN FOO ((OPTIONAL X) Y) ... )

So the first argument is optional, right?  And the second argument
is mandatory, right?  Are your brains all broken?  WHAT DOES THIS
FUNCTION DO WHEN IT GETS ONE ARGUMENT?  Is it an error because the
second (mandatory) argument is missing?  What weird heuristics will
you use to disambiguate an arglist like:

(X Y (OPTIONAL Z W) Q R)

You may say, "Well, we'll make it illegal to precede mandatory
arguments by optional arguments."  But if we do that sane thing, 
then we are burdened by zillions of (OPTIONAL ...)s at the end
of the arglist.  So we factor out the OPTIONALs ... and end up
with a notation a lot like the present one.

   ---Wechsler