Building a readable Lean 4 theorem ladder for statistical learning theory

Project

I’ve been building a Lean 4 project focused on formalizing parts of statistical learning theory:

FormalSLT repository

Current verified results include:

  • finite-class ERM bounds
  • Rademacher symmetrization
  • high-probability Rademacher bounds
  • Sauer–Shelah / VC-dimension bridge
  • finite scalar contraction
  • linear predictor bounds
  • finite PAC-Bayes bounds
  • algorithmic stability

The project currently has:

  • 45 Lean modules
  • ~19.5k lines
  • zero sorry
  • zero custom axioms

The main goal is not just theorem proving for its own sake, but trying to make statistical learning theory more explicit and auditable:

  • assumptions are attached directly to theorem signatures
  • constants are machine checked
  • proofs become buildable dependency chains instead of only textbook prose

I’m also trying to structure it pedagogically as a “theorem ladder”:
definitions → concentration → Rademacher → VC/PAC → stability → PAC-Bayes.

Compared to some existing Lean learning-theory work that focuses more on abstract probability infrastructure, this repo is currently more focused on readable finite-sample ML bounds and end-to-end theorem chains.

Would especially appreciate feedback from people interested in:

  • ML theory
  • theorem proving
  • formal methods
  • learning theory pedagogy

Posted May 8, 2026, 3:41 PM UTC

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