Geoffrey Irving fails to prove Lean kernel correct after weeks of attempts

geoffreyirving · x · 2026-09-11

Geoffrey Irving shared a failed attempt: after several weeks of work, he could not prove a full Lean kernel correct, in the spirit of publicizing negative results.

He had earlier predicted 80% odds that Lean's type theory difficulties are resolved within a month and 40% within a week — the failure suggests the problem is harder than expected.

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