(defmacro ! (&rest l) `(bang ',l))


(defmacro bang (l)
  (let ((l1 (mapcar #'bang1 l)))
  `,l1))

(defun bang1 (x)
  (cond ((var? x) `(gensym "?"))
	((atom x) `',x)
	(t  `(list `,@(mapcar #'bang1 x)))))

(defun var? (x)
  (and (symbolp x)
       (eql (char (symbol-name x) 0) #\?)))