anchor.diff:                                       'cursor
                                        (count-lines view-point point)
                                        charpos
  -                                     (1+ charpos)))))
  +                                     (1+ charpos)
  +                                     :transparency nil))))
   
   (defun reset-screen-lines (screen view-point)
     (with-point ((point view-point))
  
positive.code: 
  
  #+(or)
  (progn
    (defun overlay-line (elements start end attribute)
      (declare (optimize (speed 3) (safety 0) (debug 0)))
      (declare (type fixnum start end))
      (let ((acc '()))
        (flet ((add (start end attribute)
                 (when (< start end)
                   (push (list start end attribute) acc))))
          (if (null elements)
              (add start end attribute)
              (loop :for rest :on elements
                    :for firstp := t :then nil
                    :for prev := nil :then e
                    :for (s e value) :of-type (fixnum fixnum t) :in elements
                    :if firstp :do (add start (the fixnum (+ start s)) attribute)
                    :if (and prev) :do (add (the fixnum (+ start (the fixnum prev)))
                                            (the fixnum (+ start s))
                                            attribute)
                    :do (let ((src-attribute (ensure-attribute value nil)))
                          (add (the fixnum (+ start s))
                               (the fixnum (+ start e))
                               (merge-attribute src-attribute attribute)))
                    :if (null (cdr rest)) :do (add (the fixnum (+ start e)) end attribute))))
        acc))
  
    (defun draw-attribute-to-screen-line (screen attribute screen-row start-charpos end-charpos)
      (when (and (<= 0 screen-row)
                 (< screen-row (screen-height screen))
                 (not (null (aref (screen-lines screen) screen-row)))
                 (or (null end-charpos)
                     (< start-charpos end-charpos)))
        (destructuring-bind (string . attributes)
            (aref (screen-lines screen) screen-row)
          (declare (ignore string))
          (let ((end-charpos (or end-charpos (screen-width screen))))
            (let* ((range-elements
                     (lem-base::subseq-elements attributes
                                                start-charpos
                                                end-charpos)))
              #+(or)
              (when (< (length string) end-charpos)
                (setf (car (aref (screen-lines screen) screen-row))
                      (concatenate 'string
                                   string
                                   (make-string (1- (- end-charpos (length string)))
                                                :initial-element #\space))))
              (setf (cdr (aref (screen-lines screen) screen-row))
                    (lem-base::normalization-elements
                     (nconc (overlay-line range-elements
                                          start-charpos
                                          end-charpos
                                          attribute)
                            (lem-base::remove-elements attributes
                                                       start-charpos
                                                       end-charpos)))))))))
    )
  
  (defun draw-attribute-to-screen-line (screen attribute screen-row start-charpos end-charpos)
    (when (and (<= 0 screen-row)
               (< screen-row (screen-height screen))
               (not (null (aref (screen-lines screen) screen-row)))
  
negative.code:                            (make-string (- end-charpos (length string))
                                          :initial-element #\space))))
        (setf (cdr (aref (screen-lines screen) screen-row))
              (if transparency
                  (overlay-attributes attributes
                                      start-charpos
                                      (or end-charpos (length string))
                                      attribute)
                  (lem-base/line::put-elements attributes
                                               start-charpos
                                               (or end-charpos (length string))
                                               attribute))))))
  
  (defun draw-attribute-to-screen-region (screen attribute screen-row start end)
    (flet ((draw-line (row start-charpos &optional end-charpos)
  