DeepSeek-Prover-V1.5 combines proof-assistant feedback, reinforcement learning and tree search

The model was specialized for Lean 4 formal mathematics, refined with reinforcement learning from Lean feedback and paired with an intrinsic-reward Monte Carlo tree-search variant to explore diverse proof paths. DeepSeek released model weights and code for reproducing the proof-search setup.

What happened?

DeepSeek-Prover-V1.5 reported 63.5% success on miniF2F-test and 25.3% on ProofNet using reinforcement learning from proof-assistant feedback plus RMaxTS proof search, improving on the earlier DeepSeek-Prover line.

Why it matters

The system is a clear bridge from static proof generation toward learned agents that train and search against a formal verifier, while remaining small enough and open enough to become a widely reusable research baseline.

Significance rationale: DeepSeek-Prover-V1.5 made proof-assistant feedback a training signal through reinforcement learning and combined it with Monte Carlo tree search, while releasing the 7B model and proof-search implementation openly.

Historical context

Primary evidence

Evidence & status at a glance

Significance
H2 · Field milestone
Verification
Paper released
Evidence level
E3 · Inspectable artifact
AI role
AI primary, human verified
Formal assurance
Machine-checked

How should these labels be read? →

Contribution & verification

Mathematical novelty
Benchmark result
Interface
Formal, Symbolic
AI contribution
The language model generated Lean proofs and tree-search actions, while Lean supplied correctness feedback for both training and inference-time verification.
Human contribution
Researchers assembled formal training data, designed reinforcement-learning and RMaxTS procedures, trained the models and selected benchmark protocols.
Verification
Paper released · E3 · Inspectable artifact · Machine-checked
Last reviewed
2026-09-11

Technical details

Systems
deepseek-prover-v1-5, lean
Organizations
deepseek-ai
Problems
minif2f, proofnet
Methods
reinforcement-learning-from-proof-feedback, monte-carlo-tree-search, formal-theorem-proving, proof-search

Sources & artifacts

Verification history

  • 2024-08-15 · Paper released · E2 · Research record

    The paper reported the training method and benchmark results.

  • 2024-08-15 · Paper released · E3 · Inspectable artifact

    Model weights, Lean integration and proof-search code were released publicly.

Corrections

No corrections recorded.