anchor.diff:                 (when new
                    (pushnew target changed)))))))
        (unless changed (return))
  -     (psetq previously-changed changed
  -            changed '())))
  +     (psetq previously-changed changed changed '()
  +            propagate-only t)))
     kernels)
   
   (defun print-states (kernels lookaheads &optional (stream *standard-output*))
  
positive.code:         (map-lr1-collection
           #'(lambda (item)
               (declare (type lr1-item item))
               (unless (item-dot-right-p item)
                 (push (cons i (lr1-item-shift item)) res)))
           j)))
      res))
  
negative.code: 
  ;;; Lookaheads
  
  (defun compute-lookaheads (kernel grammar &optional propagate-only)
    "Compute the LR(1) lookaheads for all items in KERNEL.
  If PROPAGATE-ONLY is true, ignore spontaneous generation."
    (declare (type kernel kernel) (type grammar grammar))
    (let ((res '()))
      (declare (optimize (speed 3) (space 0)))
  