Leanstral 1.5: Proof Abundance for All
Leanstral 1.5, a free Apache-2.0 licensed model with 6B active parameters, delivers a major performance upgrade in formal verification, saturating miniF2F, solving 587/672 PutnamBench problems, and achieving state-of-the-art results on FATE-H (87%) and FATE-X.
- Why it matters
- This update may affect model choice, API planning, eval coverage, or migration timing. Its practical impact depends on the constraints, benchmark conditions, and rollout timing described in the source.
- Technical impact
- Technical impact depends on source details, integration surface, evaluation evidence, and operational constraints.
- Risk note
- Lower evidence risk: the item links to a primary source, but benchmark and vendor-performance claims still need context.