(in-package :mma)
(defun parse-alternatives
    (end &aux (temp (parse-rule end)) res) ; E::=e1 \|  e2  n-ary  (Alternatives)

  (cond ((eolp end) temp)
	(temp
	 (cond ((guess-token '|\|| ) ;;check first to avoid consing
		(setq res (cons temp nil))
		(loop
		 (cond ((eolp end)(return(parse-nary1 res 'Alternatives)))
		       ((guess-token  '|\||)
			(rt)
			(setq res (cons (parse-rule end) res)))
		       (t (return(parse-nary1 res 'Alternatives)))
		       )))
	       (t temp)))
        (t nil) ; not an Alternatives-expression
	))


;;patched
(defun parse-replace( end &aux(temp(parse-alternatives end)))
  (cond (temp (parse-replace1 temp end))
	(t nil)))