anchor.diff:                    (%skip-list-backward point 0))
                    ((syntax-open-paren-char-p c)
                     nil)
  +                 ((multiple-value-setq (n pair) (syntax-end-block-string-p point))
  +                  (character-offset point (- n))
  +                  (if (search-backward point (car pair))
  +                      point
  +                      nil))
                    ((syntax-string-quote-char-p c)
                     (%skip-string-backward point))
                    ((syntax-fence-char-p c)
  
positive.code:             (when result
                (return (values result pair))))))))
  
    (defun syntax-start-block-comment-string-p (line-string pos)
      (syntax-start-block-syntax-string-p line-string
                                          pos
                                          (syntax-table-block-comment-pairs
                                           (current-syntax))))
  
    (defun syntax-end-block-comment-string-p (line-string pos)
      (syntax-end-block-syntax-string-p line-string
                                        pos
                                        (syntax-table-block-comment-pairs
                                         (current-syntax)))))
  
  (defun syntax-line-comment-p (point)
    (syntax-line-comment-string-p (line-string point)
                                  (point-charpos point)))
  
  (defun syntax-start-block-comment-p (point)
    (syntax-start-block-comment-string-p (line-string point)
                                         (point-charpos point)))
  
  (defun syntax-end-block-comment-p (point)
    (syntax-end-block-comment-string-p (line-string point)
                                       (point-charpos point)))
  
  
  
negative.code:   (syntax-skip-expr-prefix-forward point)
    (skip-chars-forward point #'syntax-expr-prefix-char-p)
    (unless (end-buffer-p point)
      (let ((c (character-at point))
            n pair)
        (cond ((or (syntax-symbol-char-p c)
                   (syntax-escape-char-p c))
               (%skip-symbol-forward point))
  