lean-4
1 article tagged with lean-4
June 18, 2026
model releaseMistral AI
Mistral releases Leanstral, open-source 6B-parameter proof assistant for Lean 4 under Apache 2.0
Mistral AI has released Leanstral, a sparse 120B model with 6B active parameters designed specifically for the Lean 4 proof assistant. The model is available under Apache 2.0 license with free API access and achieves a 26.3 FLTEval score at pass@2, outperforming Claude Sonnet 4.6 while costing $36 versus $549.