The Deterministic Horizon: When Extended Reasoning Fails and Tool Delegation Becomes Necessary
On the map: LLM reasoning → Prompting and chain-of-thought reasoning
Abstract (arXiv)
Extended chain-of-thought reasoning can degrade performance on deterministic state-tracking tasks, not solely because of preference biases but, on the evidence we present, because of information-theoretic limits in the capacity of decoder-only attention. We present: (1) an Attention Bottleneck analysis providing evidence that total state-tracking capacity in bits is bounded in terms of head count, head dimension, and context length under stated modeling assumptions, and that total capacity is not the binding constraint; (2) a context-dependent error model with a depth-dependent quadratic term in the error exponent; (3) the State-Space Jaccard metric measuring state drift; and (4) a Deterministic Horizon d^* ∈ [19, 31] (at α = 0.5) marking the depth at which unaided accuracy crosses 50%. Across twelve models and eight task domains (including SWE-Bench, WebArena, and SQL-Multi), tool-integrated reasoning reaches 76-94% accuracy versus 17-42% for neural chain-of-thought on PermutationProbe. Fine-tuning on optimal-length traces yields <3 percentage-point improvement, supporting an architectural ceiling.
Key facts. Cited by 1 paper in the map (data through 7 Oct 2026). Placed in Prompting and chain-of-thought reasoning, one of 17 directions in LLM reasoning. Builds on 59 of its 77 references that are in the map. First posted on arXiv 29 May 2026.
Builds on
59 of 77 references.
Closest ancestors · 9
Same direction, newest first
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- 2022Program of Thoughts Prompting: Disentangling Computation from Reasoning for Numerical Reasoning Tasks22 Nov
- 2022Large Language Models are Zero-Shot Reasoners24 May
- 2022Self-Consistency Improves Chain of Thought Reasoning in Language Models21 Mar
- 2022Chain-of-Thought Prompting Elicits Reasoning in Large Language Models28 Jan
Other references · 50
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