Assistant Professor at CMU. Marathoner, @thesisreview.

Joined April 2011
That’s a great benchmark to look at
1/5 Verification has become the bottleneck as LLMs start proving conjectures at scale! No worries, Lean can help. But how well can AI agents solve open problems formalized in Lean, end to end? Introducing reuF2F: 244 open math problems from Research Experiences for Undergraduates (REU) programs, spanning a broad range of math areas, formalized by experts in Lean. We also build Leanimum-agent, a minimal coding agent for Lean, so every model is compared under the same harness. Even the best-performing model resolves only 109 out of 244 problems. More below 🧵
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If you've noticed a distinct dialect emerging in frontier AI models and struggled to understand what they're talking about, you're not crazy! We turned to psycholinguistics to investigate what makes the writing style so weird, and why this might be happening 🚨New preprint! 🧵
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Sean Welleck retweeted
AI agents can't yet carry out open scientific research Into the Unknown benchmarks 9 frontier agents on 15 unsolved research directions curated by DOE scientists. None of the 135 submissions meets the scientist's bar, and 114 fail an integrity check for fabricated or inconsistent results.
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REUF2F: Benchmarking coding agents on formalized undergraduate research problems. ~ Zeyu Zheng et al. zeyu-zheng.github.io/reuF2F.… #AI4Math
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Sean Welleck retweeted
Happy to see mini-Lean-agent style harnesses becoming popular! Systems that require complex lean search tools and other scaffolding might be overkill nowadays. Modern models can perform very well with just access to bash!
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reuF2F is now on arxiv 🎉 arxiv.org/abs/2610.27046
New benchmark: reuF2F 244 open math problems from Research Experiences for Undergraduates (REU) programs, formalized in Lean. Agents are given the Lean statement of an open problem, and produce formal proofs that are checked by Lean. Paper: zeyu-zheng.github.io/reuF2F.… (1/n)
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Sean Welleck retweeted
Now it's on arXiv! arxiv.org/abs/2610.27046
1/5 Verification has become the bottleneck as LLMs start proving conjectures at scale! No worries, Lean can help. But how well can AI agents solve open problems formalized in Lean, end to end? Introducing reuF2F: 244 open math problems from Research Experiences for Undergraduates (REU) programs, spanning a broad range of math areas, formalized by experts in Lean. We also build Leanimum-agent, a minimal coding agent for Lean, so every model is compared under the same harness. Even the best-performing model resolves only 109 out of 244 problems. More below 🧵
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What is TMLR doing under a 300% increase in submissions? - Suspensions of >150 authors - Publicly naming major violations - Submission quotas distinguishing slop patterns - Desk rejections 6% → 53%; focus on clarity - AI reviews evaluating soundness blog.tmlr.org/2026/adapting-…
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Amazing work and collaborative effort led by Zeyu Zheng (@regunivers)! Paper: zeyu-zheng.github.io/reuF2F.… Benchmark: github.com/cmu-l3/reuF2F Leanimum Agent: github.com/cmu-l3/Leanimum-a… (7/7)
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New benchmark: reuF2F 244 open math problems from Research Experiences for Undergraduates (REU) programs, formalized in Lean. Agents are given the Lean statement of an open problem, and produce formal proofs that are checked by Lean. Paper: zeyu-zheng.github.io/reuF2F.… (1/n)
1/5 Verification has become the bottleneck as LLMs start proving conjectures at scale! No worries, Lean can help. But how well can AI agents solve open problems formalized in Lean, end to end? Introducing reuF2F: 244 open math problems from Research Experiences for Undergraduates (REU) programs, spanning a broad range of math areas, formalized by experts in Lean. We also build Leanimum-agent, a minimal coding agent for Lean, so every model is compared under the same harness. Even the best-performing model resolves only 109 out of 244 problems. More below 🧵
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An important feature is that models can either prove or disprove the statement of a problem (5/n)
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Note that in total we resolved more than 100 open problems out of the 244, but we are not planning to release the proofs 😅. (It is a good practice to not release solutions to benchmarks in order to mitigate contamination) (6/n)
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Sean Welleck retweeted
1/5 Verification has become the bottleneck as LLMs start proving conjectures at scale! No worries, Lean can help. But how well can AI agents solve open problems formalized in Lean, end to end? Introducing reuF2F: 244 open math problems from Research Experiences for Undergraduates (REU) programs, spanning a broad range of math areas, formalized by experts in Lean. We also build Leanimum-agent, a minimal coding agent for Lean, so every model is compared under the same harness. Even the best-performing model resolves only 109 out of 244 problems. More below 🧵
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New paper led by @seungonekim: "Into the Unknown: Benchmarking AI agents on open scientific research problems" arxiv.org/abs/2610.19159 Given a paper and research direction, agents carry out research and write a follow-up paper. We worked with scientists from US national labs to create follow-up directions and evaluation rubrics, from areas such as plasma physics and materials science. None of the agents that we tested produced a paper that passed all of the rubric items. It will be exciting to see future systems that tackle these kinds of tasks!
🧪Can AI agents take a scientific paper and write a meaningful follow-up to it? We introduce Into the Unknown, an AI agent benchmark of 15 open scientific research problems. Each problem comes from a scientist currently or formerly at US DOE National Labs: @LosAlamosNatLab @SandiaLabs @BerkeleyLab @AmesNatLab @PPPLab @Livermore_Lab
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Sean Welleck retweeted
🧪Can AI agents take a scientific paper and write a meaningful follow-up to it? We introduce Into the Unknown, an AI agent benchmark of 15 open scientific research problems. Each problem comes from a scientist currently or formerly at US DOE National Labs: @LosAlamosNatLab @SandiaLabs @BerkeleyLab @AmesNatLab @PPPLab @Livermore_Lab
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This new benchmark evaluates nine frontier agents on 15 open scientific follow-up problems developed with domain scientists, producing 135 research papers. Most of the papers fail integrity checks, including discrepancies between claimed work and supporting execution evidence.
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