The least distortion of embedding edit distance into l1
Let be the least distortion of an embedding into of the strings of length at most over an alphabet , with unit-cost edit distance (insertions, deletions, substitutions). Ostrovsky and Rabani (2007) embedded binary strings with distortion . Lower bounds rose from (Andoni-Deza-Gupta-Indyk-Raskhodnikova 2003) to (Khot-Naor 2006) and (Krauthgamer-Rabani 2009), leaving an exponential gap. What is the order of growth of ; in particular, is the Ostrovsky-Rabani bound optimal?
- Result
- Proved(see note)
- Status
- Candidate (review pending)
- AI contribution
- AI-discovered
- Method
- Argument
- Field
- Metric embeddings; edit distance
- Posed by
- Open since the Ostrovsky-Rabani upper bound (J. ACM 2007) and the Krauthgamer-Rabani lower bound (2009); the manuscripts cite no explicit statement of the question
- Year posed
- —
- Years open
- —
- Solved
- 2026-09-27
- Model
- Unreleased internal OpenAI model
- Vendor
- OpenAI
- Collaborators
- —
- Verification
- Lean-checked, statement unaudited
- Publication
- Announced
- Collection
- OpenAI math release (October 2026), version adc7f12
- Significance
- 32 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What was actually shown
Theorem 1.1: there are absolute and with for all and all finite , so the Ostrovsky-Rabani scale is sharp up to constants in the exponent. The upper bound is Ostrovsky-Rabani's method made uniform over alphabets and lengths; the new content is the matching lower bound, given by three constructions across the family. The constants are not determined, and nothing is said about computational efficiency.
What the AI did
The release README says every result in openai/math was produced by an unreleased internal OpenAI model with a fixed procedure, on average about three hours of ChatGPT Pro thinking compute per result. This result is not one of the README's two exceptions (the Hodge conjecture for CM abelian varieties and the Re(s) > 11/12 zero-free region). The manuscript is authored 'OpenAI' and names no human author. The family has two companion manuscripts of the same date giving independent finite-circle and tree constructions for the lower bound and a uniform histogram embedding for the upper bound.
Verification
No independent mathematician has checked this yet. Checked here: Theorem 1.1 was read against the question: absolute with for all large , uniformly over finite alphabets of size at least two, the lower bound witnessed by binary strings of one length. The challenge is not in lean/formalization.yaml; lean/ComparatorChallenges/EditDistance.json exists with solution_module OAI.Combinatorics.EditDistance.Main, whose file exists at the pinned commit. The statement EditDistance.lean was read here; not rebuilt here. It defines edit distance by unrestricted unit-step scripts with substitutions, distortion as the product of the two extreme ratios over injective maps into , and states the two-sided bounds for every finite alphabet type, the binary witness and the alphabet supremum. This states the headline. Permitted axioms: propext, Quot.sound, Classical.choice.
Sources
- PaperCompanion: Finite-Circle Obstructions, Binary Codes, and Histogram Embeddings for Edit DistanceCompanion: Tree Constructions for the l1 Distortion of Binary Edit Distance
- Lean proofLean proof (OAI.edit_distance_main)
- CodeOpenAI math release: Edit Distance in l1: Matching Bounds up to Constants in the Exponent