https://www.reddit.com/r/emacs/comments/1558hok/silly_question_how_can_i_add_both_vertical_and/jst4ztn/?utm_source=share&utm_medium=ios_app&utm_name=ioscss&utm_content=1&utm_term=1&context=3
你可能想要这个
行号可以用在org-mode文档里辅助判断折叠情况