Lists for REST, OPTIONAL and AUX look nice

[Richard M. Stallman <RMS at MIT-AI>]

I agree that &OPTIONAL, &REST, &KEY and &AUX are different
 from the other lambda-list keywords, but it does not follow
that a Lispy syntax for them is ugly.  This example

(defun foo (a b c d
            (optional x y z
		      (default xxx t)
		      (default yyy 69))
	    (rest rest-arg)
	    (key parm1
		 parm2
		 (default parm3 t)
		 parm4)
	    (aux tem1 tem2))
  ...)

seems clear enough.