axiom
Q2Presentation.Induction.q2_trivialCoeff_h2_line
{GQ2Profinite : ProfiniteGrp.{0}}
:
IotaToken GQ2Profinite
H²(G_{ℚ₂}, ℤ/2) is a line — the trivial-coefficient degree-two
cohomology of the absolute local Galois group at the single copy of ℤ/2
has dimension exactly 1, consumed here in the strictly weaker
cocycle-level token form (dim ≤ 1): two non-cobounding normalized
continuous 2-cocycles sum to a cobounding one.
EXACT-CITABLE (audit/CITABILITY_AUDIT_20260708.md §H, verified verbatim
against NSW 2nd ed. v2.3, errata clean):
- NSW (7.1.8)(ii):
H²(k, μ_n) ≅ (1/n)ℤ/ℤ— atn = 2, withμ₂ = {±1} ⊆ ℚ₂ˣcarrying the TRIVIAL action (soμ₂ ≅ ℤ/2asG_{ℚ₂}-modules), this is the direct numbered statementh² = 1. - NSW (7.2.6) at
A = ℤ/2,i = 0(concordant second anchor):H²(k, ℤ/2) ≅ H⁰(k, ℤ/2)* = ℤ/2. The solvability dictionary (CochainSolvable= existence of a locally-constant — equivalently continuous into discreteℤ/2— cobounding 1-cochain) is the DEFINITION of continuous-cochainH²at this carrier; the token assertsdim ≤ 1, strictly weaker than the citation's= 1.
LOAD-BEARING GUARDS (§H): SINGLE copy of ℤ/2 only — the token is FALSE
already at untwisted (ℤ/2)² coefficients (h² = 2); normalized-cocycle
law and local constancy on the Fᵢ are required; Γ is pinned to
GQ2Profinite (no open-subgroup or twisted-module quantifier).