anchor.diff:  
   (defconstant +define-window-threshold+ 4)
   
  +(defun initialize-timestamp (state initial-priority string start end)
  +  (cond
  +    ((eq initial-priority :lookahead)
  +     (let ((priority-array (make-array '(8) :element-type 'fixnum :initial-element 0)))
  +       (declare (type (simple-array fixnum (8)) priority-array)
  +		(dynamic-extent priority-array))
  +       (loop for i of-type fixnum from start below end
  +	  as w = (find-suitable-dynamic-window state (char-code (char string i)))
  +	  when w do (incf (aref priority-array w)))
  +       (initialize-timestamp state priority-array nil nil nil)))
  +    ((eq initial-priority nil)
  +       (loop for w of-type fixnum from 0 below +window-count+
  +	  do (setf (scsu-state-timestamp state w) (- (random 100)))))
  +    ((typep initial-priority 'array)
  +     (let ((max (loop for i across initial-priority maximize i)))
  +       (loop for w of-type fixnum from 0 below +window-count+
  +	  do (setf (scsu-state-timestamp state w)
  +		   (- (aref initial-priority w) max)))))
  +    (t
  +     (error "message is unser construction")))) ; TODO
  +
   (defun encode-from-string (string
   			   &key (start1 0) (end1 (length string))
   			     (bytes (make-array (length string) ; no way to expect length..
   						:fill-pointer 0 :adjustable t
   						:element-type '(unsigned-byte 8)))
   			     (start2 0) (end2 (length bytes))
  +			     (initial-priority :lookahead)
   			     (state-initargs nil)
   			     (state (apply 'make-instance 'scsu-state state-initargs)))
     (declare (type string string)
   	   (type (array (unsigned-byte 8) *) bytes)	   
   	   (type fixnum start1 end1 start2 end2))
  +  (initialize-timestamp state initial-priority string start1 end1)
     (with-buffer-accessor (:writer put-byte :current dst-current)
         (bytes start2 end2 :element-type (unsigned-byte 8))
       (loop for src-current of-type fixnum from start1 below end1
  
positive.code: 		   :accessor scsu-state-dynamic-window)
     (active-window-index :initform 0 :accessor scsu-state-active-window-index)
     (timestamp-vector :initform (make-array +window-count+ :element-type 'fixnum
  					   :initial-element 0)
  		     :accessor scsu-state-timestamp-vector)
     (current-timestamp :initform 0 :accessor scsu-state-current-timestamp :type fixnum)
     (fix-dynamic-window :initarg :fixed-window :initform *scsu-state-default-fix-dynamic-window*
  
negative.code:   (and (compressible-code-point-p code-point)
         (not (scsu-state-fix-dynamic-window state))
         (same-window-p code-point next-code-point) ; next is in same window
         #+()				; TODO: consider..
         (funcall lookahead-func code-point))) 
  
  (defun find-LRU-dynamic-window (state)
    (loop with ret of-type fixnum = 0
  