anchor.diff:      (defun add-cell ()
         (unless (processing-p)
   	(make-cell focused-cell)))
  -    
       
       ;; Remove a focused-cell and focus goes up
       ;; if there's only one cell do nothing
  
positive.code:       (setf focused-cell cell)
        (turn-on-border cell))
  
      ;; scroll to focused element to show up
      (defun auto-scroll ()
        (chain (getprop focused-cell 'div-outer) (scroll-into-view)))
  
      ;; notify at notice area
      (defun notify (message color-string)
        (setf (chain notice |innerHTML|) message)
        (setf (chain notice style color) color-string))
  
negative.code:     ;; ====================================================
      ;; misc.
      ;; ====================================================
      (defun search-cells-to-render (cellnos)
        (loop for cell in all-cells when (member (getprop cell 'no) cellnos)
  	 collect cell))
  
      (defun focus-to-next-cell (cell)
        (let ((cell-to-focus
  	     ;; if the given cell is the last cell and the content is empty
  