Mistral Releases Leanstral 1.5: Open-Source Lean 4 Agent on Apache
sophiamyang · x · 2026-07-04
Mistral AI has released Leanstral 1.5, an open-source Lean 4 code agent model based on the Apache-2.0 license. On the PutnamBench math competition benchmark, the model successfully solved 587 out of 672 problems, demonstrating exceptional formal mathematical proof capabilities. Tailored for mathematical theorem proving and formal verification, this specialized AI model marks a significant milestone for Mistral in the field of mathematical reasoning.
Related event: Mistral Releases Open-Source Lean 4 Proving Agent Leanstral 1.5(5 posts)→
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