Comment by mejutoco

2 days ago

I dont think mathlib is mandatory to use lean.

It isn’t but the borrow checker has a formal proof that does need mathlib.

  • > having a mathlib dependency just to build a programming language is a big ask for people.

    This is an implementation choice you did when implementing your programming language, if I understand correctly.

    I thought of it because writing some lean lang I also had the option of adding Mathlib or keep it "bare".

  • Publishing the proof is good, but why do you need it to build the language?

    You can have one piece of software that does things, and a separate piece that proves that the things the first piece does are correct.