arXiv Machine Learning

LeanPolish: Verified Supervision for Lean Proof Compression

arXiv AI
Sep 2

RePro: Proof-Verified Benchmark Rewriting for Reliable Evaluation of LLM Mathematical Problem Solving

RePro is a framework that rewrites benchmark problems for large language models (LLMs) in mathematical problem solving, ensuring that the rewritten problems and their answers are valid and correct through Lean-verified proofs. It integrates Lean-oriented neural automated theorem provers (ATPs) to regenerate answers, achieving 100% well-definedness, feasibility, and answer correctness on GSM8K and MATH datasets. Experiments show that models’ performance drops on these proof‑verified rewritten benchmarks, indicating sensitivity to surface‑level and structural variations and potential memorization effects.

By Xiyuan Zhou, Zhuoqi Li, Xinlei Wang, Yirui He, Yuhao Wu, Yuheng Cheng, Yan Xu, Junhua Zhao, Jinjin Gu
arXiv Machine Learning
Oct 16

Learning Lean Feedback for Efficient Proof-Candidate Evaluation on GPUs

The paper presents a neural evaluator that predicts Lean 4 theorem‑proving verdicts and compiler feedback, trained on 4.84 million labelled programs. A two‑stage approach—first screening candidates with a validity classifier, then scoring positives with a feedback model—achieves 87.8 % accuracy on a 68,932‑program benchmark and processes 3.5 candidates per second on an H100 GPU, outperforming a 64‑worker Lean baseline. Integrating this evaluator into a hybrid reward system reduces GRPO training steps by about 31 % while maintaining comparable miniF2F pass rates.

By Lazar Milikic, Etienne Bamas, Emmanuel Abbe, Viktor Kun\v{c}ak
arXiv AI
Jun 12

Pythagoras-Prover: Advancing Efficient Formal Proving via Augmented Lean Formalisation

arXiv:2606. 12594v1 Announce Type: new Abstract: Modern Lean theorem provers achieve strong performance only with substantial training and inference compute, driven in part by scarce verified proof data and the long reasoning traces of formal proof search, making both supervised fine-tuning (SFT) and sampling expensive.

By Joshua Ong Jun Leang, Zheng Zhao, Mihaela C\u{a}t\u{a}lina Stoian, Qiyuan Xu, Haonan Li, Wenda Li, Shay B. Cohen, Eleonora Giunchiglia
arXiv AI
Aug 28

FaithSieve: Fine-Grained Evaluation of Math Proofs with Faithful Formal Evidence

FaithSieve is a Lean‑assisted framework that fine‑grains natural‑language mathematical proofs into local reasoning units, extracts typed proof obligations, and verifies them with formal evidence gated by semantic alignment. It introduces two expert‑verified datasets—ProofLoc‑Olympiad and ProofLoc‑University—to benchmark first‑error localization. On these benchmarks, FaithSieve outperforms direct‑judging baselines, achieving 81.43% and 84.5% exact first‑error accuracy respectively.

By Ziyu Wang, Qiming Dai, Yishan Wu, Zaiwen Wen
arXiv AI
Oct 9

NanoProof: Open and Efficient Automated Theorem Proving in Lean 4

NanoProof is the first factorized execution‑guided theorem prover in Lean 4 whose training data, tooling, pipeline, and weights are all publicly released, enabling end‑to‑end reproducibility with open‑source resources. The authors provide a dataset of structured proof trees and a programmatic interaction tool for Lean 4, emphasizing compute efficiency to make training and evaluation more accessible. NanoProof achieves a 50.8% pass@16 on MiniF2F‑Test, outperforming comparable systems while using far less compute, demonstrating that such provers can be rebuilt from scratch with modest resources.

By Mat\v{e}j Kripner, Milan Straka
arXiv AI
4d ago

Fix, Not Just Resample: Bounded Compiler-Guided Repair in Lean 4

The paper presents a bounded, online step-level repair module for Lean 4 that uses compiler error messages to fix rejected tactics instead of discarding them. By sampling up to $K$ candidate tactics and allowing at most $R$ repairs per step, the method improves solve rates over a sampling-only baseline, achieving up to a 32% relative gain and solving 82 additional theorems on a 1,990-theorem subset of the LeanDojo benchmark. The approach trades extra runtime for reachable proofs, with most benefit coming from early repair attempts and shallow tactic failures, and it successfully replicates on the Lean Workbook benchmark, nearly doubling its solve rate without regressions.

By Haotian Deng, Chris Farber, Sonal Narasimha, Samskrithi Sivakumar, Yexiang Xue