the funny thing about my Lean posting is i remember some people were like Haskell posting or PureScript posting or whatever in 2013 and i was like ahhh i don't have patience to learn a pure functional thing, what's the point. and here i am
the "old" Lean reference is very good. i don't understand why it was replaced by an incredibly dry "new" reference (which i personally find mostly unsuitable for learning the language). but i'm glad this is still up: [sebasti.a.nullri.ch/lean4/doc/](https://sebasti.a.nullri.ch/lean4/doc/ )
[What is Lean - Lean Manual](https://sebasti.a.nullri.ch/lean4/doc/ )