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Featured in Domain Arrivals · 2026-08-11

LeanArena Makes Language Models Prove Theorems Cold

leanarena.com ↗ · Developer Corner · score 84.0
Open: public page gives enough substance to understand the site $Paid: pricing, booking, ecommerce, subscription, or paid access is visible ADAds: visible ad load or ad-supported content Pretty: notable design, copy, craft, or presentation Pro: polished, finished-feeling, serious, or operationally mature Niche: specific audience, workflow, or unusually focused use case Human: personal, local, community, civic, handmade, or real-person signal !Suspicious: scammy, spammy, trust theater, finance fog, or credibility concern

A public benchmark of Lean 4 problems written and solved by language models, with every admitted proof checked by the Lean kernel.

Why it surfaced

A problem enters the arena only after a fresh session proves it from the statement alone, without access to the model's original attempt. The six listed challenges span number theory, real analysis, algebra, and combinatorics—and the proofs themselves remain unpublished so others can try.

Lunch Through the Bee Veil

August 11’s newborn domains include a bee veil with a lockable lunch flap, a book designed to unfold over ten years, a Colombian missing-person and aid board, and a brick studio made by a dad and his 10-year-old co-founder.

This is one of 1,000 discoveries in the 2026-08-11 Domain Arrivals issue.