Leanstral 1.5: Proof Abundance for All
Summary
Mistral AI has released Leanstral 1.5, an open source AI model that performs formal verification and mathematical proof in a Lean 4 environment.
Key Points
- Leanstral 1.5 is a free Apache-2.0 licensed model with only 6B of the total 119B parameters enabled.
- It shows excellent performance in various math and algebra benchmarks (miniF2F, PutnamBench, FATE, etc.) and found 5 unknown bugs in practical code verification.
- It was trained through two reinforcement learning (RL) environments utilizing intermediate training, supervised fine tuning, and feedback loops.
Notable Quotes & Details
Notable Data / Quotes
- 119B total
- 6B active parameters
- 587/672 PutnamBench problems
- 87% on FATE-H
- 34% on FATE-X
- 5 previously unknown bugs across 57 repositories
Intended Audience
AI researcher and software engineer working on formal verification and Lean 4 mathematical proofs