AI Research Published on July 2, 2026
Mistral releases Leanstral 1.5, open-source formal verification model
Mistral released Leanstral 1.5 on July 2, 2026, under Apache 2.0.
The 119B-parameter MoE model is built for the Lean 4 proof assistant.
It reportedly scored 587/672 on PutnamBench and found five previously unknown bugs in open-source code.
The model is available as a free API endpoint and with weights on Hugging Face.
Source: Mistral AI