anchor.diff:  			   (declare (type window-index i))
   			   (lookup-dynamic-window state i))))
   
  -(defun use-define-window-p (state code-point &optional next-code-point lookahead-func)
  -  (declare (type unicode-code-point code-point next-code-point)
  -	   (type lookahead-func-type lookahead-func))
  +(defun use-define-window-p (state code-point &optional next-code-point)
  +  (declare (type unicode-code-point code-point next-code-point))
     (and (not (scsu-state-fix-dynamic-window state))
          (not (standalone-character-p code-point))
          (let ((offset (codepoint-to-window-offset code-point)))
  
positive.code: 	       (setf (scsu-state-mode state) :single-byte-mode)
  	       (scsu-change-to-window state dwindow)
  	       (funcall write-func (+ +UC0+ dwindow))
  	       (encode-unit* state code-point next-code-point write-func lookahead-func)))))
  	((use-define-window-p state code-point next-code-point) ; define window
  	 (setf (scsu-state-mode state) :single-byte-mode)
  	 (encode-define-window state (or (find-common-window code-point next-code-point)
  					 (codepoint-to-window-offset code-point))
  			       write-func +UD0+ +UDX+)
  	 (encode-unit* state code-point next-code-point write-func lookahead-func))
  	((> code-point #xFFFF)		; use surrogate pair
  	 (encode-SMP-as-surrogate-pair state code-point next-code-point write-func lookahead-func))
  	(t
  	 (when (<= #xE000 code-point #xF2FF)
  	   (funcall write-func +UQU+))
  	 (funcall write-func (ldb (byte 8 8) code-point))
  	 (funcall write-func (ldb (byte 8 0) code-point)))))
  
  (defun encode-unit* (state code-point next-code-point write-func lookahead-func)
    (declare (type unicode-code-point code-point next-code-point)
  	   (type write-func-type write-func))
    (ecase (scsu-state-mode state)
      (:single-byte-mode
       (encode-unit*/single-byte-mode state code-point next-code-point write-func lookahead-func))
      (:unicode-mode
       (encode-unit*/unicode-mode state code-point next-code-point write-func lookahead-func))))
  
  (defconstant +define-window-threshold+ 4)
  
  (defun initialize-timestamp (state initial-priority string start end)
    (cond
  
negative.code: (deftype write-func-type ()
    '(function ((unsigned-byte 8)) t))
  
  (defun in-window-p (offset code-point)
    (declare (type unicode-code-point offset code-point))
    (<= offset code-point (+ offset #x7f)))
  