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A Presentation of the Absolute Galois Group of Q₂

Field Number theory
Researcher David Roe / David Turturean
Model GPT-5.5 Pro
Date Jun 24, 2026; manuscript and formalization record Jul 26, 2026
Status Very strong; public FrontierMath prompt, detailed development record, and two Lean formalizations
Prompt prompt.md

Result

The prompt asks for an explicit profinite presentation of the absolute Galois group of the 2-adic numbers. The public record reports an explicit presentation with four generators and two relations, followed by independent Lean formalizations and finite-quotient verification.

Provenance and verification

The Lean checks are kernel-checked subject to their stated axioms. The finite quotient verifier is strong supporting evidence, not by itself a proof of all finite quotients.

Prompt techniques

The prompt fixes a strict output grammar, supplies useful pro-2 background, and gives an analogous p=3 presentation. This makes the task machine-checkable while leaving the central construction open.