20 rules to structure knowledge

I want to explain all rules, but if I do it in the paper book, it consumes 22 pages, one chapter. Original documents: https://www.supermemo.com/en/articles/20rules

--- This page is auto-translated from [/nishio/20 rules to structure knowledge](https://scrapbox.io/nishio/20 rules to structure knowledge) using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at [@nishio_en](https://twitter.com/nishio_en). I'm very happy to spread my thought to non-Japanese readers.