Erdős Problem #106
Erdős problem #106 · erdosproblems.com/106
If is the maximum total side length of interior-disjoint squares packed in the unit square, is ? An exact rational configuration packs squares with total side length greater than , refuting the identity at .
- Result
- Disproved
- Status
- Resolved
- AI contribution
- AI-assisted
- Method
- Computation
- Field
- Discrete Geometry, Packing
- Posed by
- Paul Erdős
- Year posed
- 1932
- Years open
- 94y
- Solved
- 2026-07-29
- Model
- Claude Opus 5
- Vendor
- Anthropic
- Collaborators
- —
- Verification
- Lean-verified
- Publication
- Announced
- Significance
- 11 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What the AI did
The public Lean source credits Codex as formal author; The packing was discovered by Claude Opus 5 (Anthropic) against search infrastructure built and run by the submitter, and verified independently in exact rational arithmetic via separating-axis certificates.
Verification
A 613-line, placeholder-free Lean proof of the counterexample; the erdosproblems.com page has now the result and is showing the conjecture as disproved.
Sources
- CodeConstruction and verification code (GitHub)
- Problem recorderdosproblems.com/106