Issue: LAMBDA-LIST-DUPLICATES (Version 1)

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

I oppose LAMBDA-LIST-DUPLICATES:ALLOW-SEQUENTIAL-NON-ITERATIVE; I think
Common Lisp should continue to forbid binding the same variable more
than once in the same binding form.  I have two reasons:

1. This is an unnecessary complication of the language rules.  Allowing
duplicated variable names doesn't make it possible to write programs
that you couldn't write before, it just allows the programs to be
written in a more obscure way.

2. This would result in an unnecessary complication of the scoping rules
for DECLARE.  Common Lisp would have to define what happens when a
DECLARE of a variable is attached to a form that binds more than one
variable with the declared name.