> For the complete documentation index, see [llms.txt](https://www.oulan.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.oulan.com/2020/05/02.md).

# 02

过去可知不可控，未来可控不可知。---香农

![](/files/77Muv62H94EwqvRmjaQ0)