最近在尝试把 Lean4 跑到浏览器里, 于是做了 Lean4.js ，欢迎需要的朋友使用和建议 github: https://github.com/timqian/lean4.jsplayground: https://timqian.com/lean4.js/discussion: https://leanprover.zulipchat.com/#narrow/channel/113488-general/topic/what.20is.20lean.2Ejs
