A GitHub repository reports that a complete optimality proof for packing 11 squares has passed Lean verification: an EvolvingPrograms verification run accepted all 7,920 local Lean modules with a final audit reporting zero admissions. The project pins Lean 4.34.1 and a fixed Mathlib revision, and gives the optimal side length as T=(6u+4)/(1+2u−u²), where u is the unique root in (9/25,37/100) of a stated degree-eight polynomial, with the construction attaining about 3.8770835900228141773. Some expensive exact numerical certificate checks use native_decide, so the final theorem trusts Lean's kernel and native compiler rather than claiming kernel-only verification.

Lean·Mathlib·EvolvingPrograms