Home

Welcome to the yatima-lang wiki!

The end goal of this repository is to:

• Independently evaluate and typecheck Lean 4 programs with a kernel implemented both in Rust and Lean 4
• Content-address every Lean 4 environment, declaration, expression and universe level via using the IPLD data format, with a name-irrelevant representation similar to the Unison language
• Compile Lean programs to the Lurk zk-SNARK language, so that we can generate zero-knowledge proof, which can be verified in constant-time and space, that a Lean program f, with input x, evaluates to y
• Compile the Yatima typechecker itself to Lurk, so we can generate zero-knowledge proofs that our Lean typechecker, with inputs env : Yatima.Environment and const : Yatima.Constant, returns successfully without error. For example, we can produce a cryptographic witness that some definition def foo : M := N correctly typechecks, which can be validated without re-running the typechecker.

This will enable us to produce a succinct and efficiently verifiable correctness certificate for e.g. Lean's mathematical library (and for each of its declarations) once it's ported to Lean 4, which currently takes over 4 hours to be typechecked by the Lean 3 kernel (as of May '22).

The plan of action

Learning resources

• Created by the team

  • Yatima Presentation
  • A deep dive on inductive types in Lean 4
  • Universe levels in Lean 4
  • IPLD and CID
  • Zero knowledge proofs and zk-SNARKs
  • Extended Example: Content addressing Universes

• Official documentation

  • Lean 4
  • IPLD
  • Lurk

• Literature, books, repositories, videos, blogs

  • A presentation about Lurk
  • Type-Directed Partial Evaluation
  • Checking Dependent Types with Normalization by Evaluation: A Tutorial
  • pi-forall