Thomas Bloom stops marking Erdős problems open or solved as AI-written proofs multiply
Mathematician Thomas Bloom stopped tagging Erdős problems as open or solved before OpenAI posted 722 AI-produced manuscripts. A DeepMind paper in Science shows the documented, human-vetted alternative: 9 of 353 open problems solved.
The Scientist · Science desk

Key figures: AlphaProof Nexus solved 9 Erdős problems, out of a collection of 353 open Erdős problems the DeepMind team tackled. Thomas Bloom's website tracks more than 1,000 Erdős problems.
| Figure | Value | Note | Claim |
|---|---|---|---|
| Erdős problems solved by AlphaProof Nexus | 9 problems | 6 | |
| Open problems tackled | 353 problems | 7 | |
| Tracked on Bloom's site | 1,000 problems, over | 2 |
What happened
- Bloom, at the University of Manchester, runs a site that tracks more than 1,000 problems originally posed and collected by Paul Erdős.
- Visitors who once discussed open problems together increasingly competed to close them with AI proofs they often did not understand.
- DeepMind's Gemini-powered agents could call AlphaProof for hard steps, shared promising attempts, discarded weak ones, and used Lean to check their logic.
Why it matters
- What it limits constraint With tags gone and comments closed, the site no longer tells a reader which of its problems are open, and it no longer hosts discussion of them.
- What's now possible capability The team did not test whether the simple setup generalises; if it does, producing a proof needs little machinery while vetting it still needs a mathematician.
- Who's exposed exposure A Lean-verified proof does not automatically validate the paper around it, so anyone building on an AI-generated result inherits the risk of a mistranslated statement.
- What it sets up precedent Bloom's comparison gives mathematicians a yardstick for AI math claims: whether the method is described in detail and whether humans vetted the proofs.
Bloom's decision came first. "Exponentially exploding," Bloom told Science News by phone, describing the flood of new results [14]. Soon after that call he posted that he would no longer tag problems as open or solved and closed comments, before he knew OpenAI would announce anything [4]. The 722 manuscripts landed hours after the call [1], on a site where visitors had already shifted from discussing problems to racing to close them [3].
His stated reason is workload: according to Science News, he does not want to spend his days refereeing AI-generated work [5]. Science News goes further in its own voice, arguing that competition among AI companies threatens to overwhelm human collaboration and understanding [18]. The support it gives is that those companies typically do not disclose their methods and data [17], plus one website's change in visitor behavior.
The DeepMind paper offers a denominator. AlphaProof Nexus solved 9 of the 353 open Erdős problems it tackled, reported October 8 in Science [6][7]. That is about 2.5 percent [15], and it measures one system on one list of open problems.
The sharper experiment is the control. The team ran a simpler setup of independent Gemini agents using Lean feedback, with no sharing of attempts and no AlphaProof, on the nine problems the full system had solved [8]. It solved all nine. It used fewer computing resources on the easy problems and more on the two toughest [8]. Chaudhuri was surprised, and Science News says the result suggests capable language models can tackle research mathematics with relatively simple checking tools [10].
What that design rules out is a need for the multi-agent machinery on these nine. It cannot rule out that the machinery matters elsewhere, because the simpler setup was only tried where the full system had already succeeded, and the team did not establish whether it would solve any problem the full system missed [9].
Lean is the check in both setups. It verifies only the statement it is given, as written in its code, and a statement can be mistranslated into or out of Lean [11]. An October 6 preprint found mismatches between parts of OpenAI's written Navier-Stokes proof and its Lean counterpart [12]. The authors write that this does not mean the written proof is wrong, but that a valid Lean proof does not automatically validate an AI-generated math paper [12].
DeepMind's report describes in detail how its results were obtained, and human mathematicians vetted many of the proofs [16]. Bloom said that is "quite different" from how OpenAI and Anthropic are handling their math results [16]. "The human mathematician has to really think through the problem and set goals for the system," Chaudhuri said [13].
In our view, the evidence supports a narrower claim than the threat Science News describes. The scarce step is checking. Lean confirms a statement, and a person has to confirm it is the statement the problem posed [11][13]. That holds for problems that can be formalized in Lean. Nobody yet knows how many of the 722 manuscripts are correct.
What to watch
- Whether OpenAI publishes its methods or Lean checks for the 722 manuscripts, and whether the Navier-Stokes mismatches get resolved.
- Whether DeepMind or others run the simpler Gemini setup on the problems the full system missed.
- Whether Bloom restores problem tags or reopens comments on the Erdős site, and under what vetting rule.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence62
- Adoption
- Not scored
- Hype gap+20
- Incentives55
- Confidence64
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Hours after Bloom spoke with the reporter by phone, OpenAI posted 722 mathematical manuscripts that an unreleased AI model had produced.
- [2]
Thomas Bloom, a mathematician at the University of Manchester in England, runs a website that tracks progress on more than 1,000 problems originally posed and collected by Paul Erdős.
- [3]
On Bloom's site people used to collaborate to discuss open problems, but increasingly visitors were competing to close open problems with AI proofs that they often did not understand.
- [4]
Soon after speaking with the reporter, and before he knew OpenAI would announce its latest results, Bloom posted that he would no longer tag problems as open or solved, and he also closed comments.
- [5]
Bloom does not want to spend his days refereeing AI-generated work.
- [6]
The system called AlphaProof Nexus solved 9 Erdős problems and made a number of other mathematical advances, researchers report October 8 in Science; the peer-reviewed edition became public two days after OpenAI's release.
- [7]
To tackle a collection of 353 open Erdős problems, the DeepMind team used multiple agents powered by the Gemini language model, which could call on AlphaProof for difficult steps and used Lean to check their logic; the agents shared work, circulating promising proof attempts and discarding ones that were not going well.
- [8]
A simpler setup of independent Gemini agents using Lean feedback, without sharing attempts or consulting AlphaProof, was tested on the nine problems the full system solved and solved all nine; it used fewer computing resources than the full system on easy problems and more on the two toughest ones.
- [9]
The team did not establish whether the simpler setup would solve any of the problems the full system had missed.
- [10]
The simpler setup matching the full system surprised Swarat Chaudhuri of Google DeepMind, and it suggests that increasingly capable language models can tackle research mathematics with relatively simple checking tools.
- [11]
Lean checks only the statement it is given, as written in its code, and a mathematical statement may be incorrectly translated to or from Lean code.
- [12]
An October 6 preprint pinpoints mismatches between parts of OpenAI's written Navier-Stokes proof and its Lean counterpart; the researchers write that the mismatches do not mean the written proof is wrong, but that a valid Lean proof does not automatically validate an AI-generated math paper.
- [13]
'The human mathematician has to really think through the problem and set goals for the system,' Chaudhuri says.
- [14]
'Exponentially exploding,' Thomas Bloom told the reporter by phone, describing the flood of new results in his field.
- [15]
Nine solved of 353 open Erdős problems is about 2.5 percent.
- [16]
The DeepMind report includes a detailed description of how the results were obtained and human mathematicians vetted many of the proofs; Bloom says that is 'quite different' from how OpenAI and Anthropic are handling their math results.
- [17]
In their race for headline-grabbing breakthroughs, AI companies typically do not disclose their methods and data.
- [18]
Science News writes that competition among AI companies threatens to overwhelm human collaboration and understanding.
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Sources
2 independent publishers whose own reporting we read for this story.
- sciencenews.orgCan math stay human in the age of AI?
1 article · October 14, 2026
- scientificamerican.comCan AI break encryption? OpenAI’s new math has cryptographers divided
1 article · October 15, 2026
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