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Mistral AI·Mar 16, 2026·v119B A6B·open source

Leanstral 119B A6B

Leanstral 119B A6B is an open-source code agent developed by Mistral AI, designed specifically for Lean 4, a proof assistant capable of expressing complex mathematical objects and software specifications. Built as part of the Mistral Small 4 family, it combines multimodal capabilities and an efficient architecture, making it both performant and cost-effective compared to existing closed-source alternatives.

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overview

Leanstral 119B A6B is an open-source code agent developed by Mistral AI, designed specifically for Lean 4, a proof assistant capable of expressing complex mathematical objects and software specifications. Built as part of the Mistral Small 4 family, it combines multimodal capabilities and an efficient architecture, making it both performant and cost-effective compared to existing closed-source alternatives.

key features
  • 01MoE: 128 experts, 4 active per token
  • 02Model Size: 119B parameters with 6.5B activated per token
  • 03Context Length: 256k tokens
  • 04Multimodal Input: Accepts text and image input, producing text output
  • 05Multilingual Support: English, French, Spanish, German, Italian, Portuguese, Dutch, Chinese, Japanese, Korean, and Arabic

𝕏 From the Author

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