Process-Verified Reinforcement Learning for Theorem Proving via Lean
Researchers demonstrate that the Lean proof assistant can provide fine-grained, process-level feedback during reinforcement learning training for theorem proving, beyond simple binary verification signals. By parsing proof attempts into tactic sequences and leveraging Lean's elaboration system, the approach delivers dense, verified credit signals grounded in type theory, showing improvements over outcome-only baselines on benchmarks like MiniF2F and ProofNet.