[plt-scheme] lambda argument lists that contain only a rest argument

> Why is this OK:
> (define (rest-only . r)
>   r)
>
> But this can't even be read into the interpreter:
> (define rest-only
>   (λ ( . r)
>     r))
>

(lambda args (do-something-to args))

ie, have your lonely rest var not in parens