Mistral AI·· 2026-07-02
Leanstral 1.5: Proof Abundance for All
Leanstral 1.5: Proof Abundance for All
AI summary
Mistral released Leanstral 1.5 under Apache-2.0, with 119B total and 6B active parameters and major formal verification improvements. It achieves 100% on miniF2F, solves 587 of 672 PutnamBench problems, and sets current best results of 87% on FATE-H and 34% on FATE-X.
Selection record
Threshold 60Official, first-handFirst 62Second 62
AdmittedSum of both 124 ≥ twice the threshold 120
- Source tier
- Official, first-hand; this tier's threshold is 60
- Pre-filter
- passed：Mistral发布AI模型Leanstral 1.5，含训练与评测
- Why it was chosen
- Benchmark results and open-source access support assessment of Leanstral 1.5 for proof engineering.
A model scores each item twice, independently, against one written standard, out of 100. An item is admitted only when the two scores add up to twice the threshold. The threshold is set per source tier.
Source: Mistral AI · mistral.ai