anchor.diff:        (return t))))
   
   (defun sequence-derives-epsilon (sequence grammar)
  +  "Sequence version of DERIVES-EPSILON*."
     (declare (list sequence) (type grammar grammar))
     (every #'(lambda (s) (derives-epsilon s grammar)) sequence))
   
  
positive.code:      collection)))
  
  (defun lr1-add-collection (items collection)
    (declare (type lr1-collection items collection))
    (typecase items
      (list
  
negative.code:   (action (required-argument) :type simple-vector))
  
  (defun find-precedence (op precedence)
    "Return the tail of PRECEDENCE starting with the element containing OP.
  PRECEDENCE is a list of elements of the form (KEYWORD . (op...))."
    (cond
      ((null precedence) '())
      ((member op (cdar precedence)) precedence)
  