Ticket: P-16d6 (docs/p16-ticket-split.md). Prove GQ2.SectionEight.prop_8_9
(SectionEight.lean:2143, currently sorry at 2151): for both sources B.bA (Γ_A = GammaA) and
B.bF (G_ℚ₂ = AbsGalQ2), a shared witness (μ, G0, DT, phase) and ClosedRecursion each.
Owner Opus, 2026-07-06.
prop_8_9_aux (SectionEight.lean:2002, proved) turns a per-source RecursionInputs bundle
(stageR136 + half139 + phase140; (137)/(138) are discharged inside from partition137_of
lemma_8_3) intoClosedRecursion. Soprop_8_9= witness + twoRecursionInputs+ per-sourcehfg/hscalar/hhead.
- ✅
prop_8_9_of(std-3, sorry-free) — the splice backbone: reducesprop_8_9's conclusion to the witness + twoRecursionInputs+hfg/hheadper source, viaprop_8_9_aux×2.hscalardischarged internally (lemma_8_2_gammaA/lemma_8_2_local, both proved). Instance args[CompactSpace/TotallyDisconnected/IsTopologicalGroup]forGammaA/AbsGalQ2(these are per-decl instances, not global —prop_8_9's section supplies them, so the final splice will too). - ✅
half139_via_radData(std-3, sorry-free) — strips the P-16d3 bridge plumbing (centralOver_equiv/liftsOver_equivoverEn.radData l h) offhalf139, reducing it (BOTH sources) to the two pureMLifts-level source facts forρ' = rhoPrime …:hlem86M : 2·#{central M-lifts} = #(M-lifts)andhMcountM : #(M-lifts) = |M_B|². - ✅
phase140_ofPhaseData(std-3, sorry-free) — the (140) reducer, thelemma_8_5/8.7 analog ofstageR136_of: reduces the (140) display to the two-count phase datumhfib : zBC = μ·M(the μ-fibration) +hgauss : 2|D_T|·M = |V|·e_Γ(C) + G0·Σ_ζ(2·nPhase(phase ζ) − e_Γ(C))(lemma_8_5aggregated), by pure algebra (linear_combination). So all three displays (136)/(139)/(140) now have clean reducers; only the concrete data remains. - ✅
zBC_eq_sum_centralOver(std-3, sorry-free) — thezBCfibrationzBC = Σᶠ_ρ #CentralOver(ρ)(extracted fromhalf139_of), the shared first step of both (139) and (140). Discharges level 1 of the phase-module'shfib:zBC = Σ_ρ #CentralOver = Σ_ρ μ·M_ρ = μ·M. - ✅
central_card_eq_reductions_mul_tcocycle(std-3, sorry-free) —hfiblevel 2, the per-ρ μ-partition at theMLiftslevel:#{central M-lifts of ρ} = M_ρ · #Z¹(T), whereM_ρ = #(achievable centralT-reductions). Proof: corestrictredTto its finite range,Equiv.sigmaFiberEquiv+Nat.card_sigma, each fibre= #Z¹(T)bylemma_8_7_count(viasubtypeSubtypeEquivSubtypeInter), sum the constant. The fibre-bundle-with-central-basepoint count — done. - ✅
centralOver_card_eq_reductions_mul_tcocycle(std-3, sorry-free) — the same in bridge vocabulary, transported throughcentralOver_equiv:#CentralOver(ρ) = M_ρ · #Z¹(T)forρ' = rhoPrime …. - ✅
zBC_eq_mu_mul_reductionCount(std-3, sorry-free) — the (140)hfibdatum, reduced to μ-independence: summing the per-ρ partition over theC-image and factoring outμgiveszBC = μ · (Σ_ρ M_ρ)from the single hypothesishμ : ∀ ρ, #Z¹(T)_{ρ'} = μ. This IS thehfibargument ofphase140_ofPhaseData. - ✅
lemma_8_5_aggregated(std-3, sorry-free) — the hgauss aggregation: sums the proved Gauss enginelemma_8_5over the finite ρ-family and swaps the double sum, giving2·|E^∨|·Σ_ρ N(κ_ρ,ε_ρ) = |I|·|W| + G(Q)·Σ_χ Σ_ρ (−1)^{χκ_ρ+ε_ρ+Q(a_χ)}. Pure 𝔽₂ algebra. - ✅
phase140_of_gaussCorrespondence(std-3, sorry-free) — the capstone (140) reducer (the analog ofstageR136_ofRObstructionData): derives the wholephase140field fromzBC_eq_mu_mul_reductionCount+lemma_8_5_aggregated+phase140_ofPhaseData, isolating the concrete Prop-8.8 fieldshM/hphase/hμ+ the matcheshDT/hWV/hG0. (140) is now a complete reducer down to its concrete residues. - ✅
polarInverseL/polarInverseL_spec/phase140_of_nonsingular(std-3, sorry-free) — discharge the (140) engine's polar dataa_χ/hafrom nonsingularity (provedexists_polar_inverse). SinceEnrichmentcarriesqbar/hquad/hns, the (140) reducer now takes exactly whatEnsupplies;a_χ = polarInverseL (En.qbar) (En.hquad) (En.hns) Lis canonical, sohphaseis phrased against it. Key finding:Enrichmentalready carriesVmod/qbar/hns/dat— the (140) engine + witness are constructible fromEn, not blocked. - ✅
enrichment_card_Vmod(std-3, sorry-free) — thehWVmatch|V| = |M_B|/|T_B|, fromEn.descend(surjective,ker = T_B) by the first isomorphism theorem. So of the (140) engine data,Ennow supplies all ofQ = qbar,hquad,hns,a_χ(polarInverseL),G0 = gaussSum qbar(definitional), and|V| = |M_B|/|T_B|(this). WithDT := V^∨givinghDTbyrfl, the (140) residual is exactly the three deep factshM/hphase/hμ+ the witness(μ, G0, phase)l-independence.
hfib is now fully reduced to μ-independence (zBC_eq_mu_mul_reductionCount). With the
whole reducer layer complete, closing (140) needs (for the concrete frame, descent case
Descent (En.radData l h)):
- μ-independence
hμ : ∀ ρ, #(TCocycle D ρ') = μ— the source 5.15/5.16 fact that the crossedZ¹_{Γ,ρ}(T)count is the same for every lower mapρ(the ρ-twisted conjugation actions onTall give the same cohomology count). Genuinely a source input — theredT-fibre count#Z¹(T)isρ-dependent a priori. hgauss—lemma_8_5onW =theV-lift space,Q = En.qbar,a_χfromexists_polar_inverse, plus the phase-cover↔character reindexΣ_χ sign(…) = Σ_ζ(2·nPhase − e)— the sameΔ/phasethat defines the witness(μ,G0,DT,phase). HereM = Σ_ρ M_ρ(the reduction count ofzBC_eq_mu_mul_reductionCount) is the constrained quadratic count and#{central-liftable T-reductions} = N(κ_ρ,ε_ρ)is the (135)/Prop 8.8 identity.
hgauss + the witness are one build (source/concrete-coupled); μ-independence is a source fact.
These are the genuinely deep O-half (not clean reducers) — a dedicated (140) phase-module pass.
UPDATE — the (140) reducer is now COMPLETE. phase140_of_gaussCorrespondence (std-3,
sorry-free) derives the entire phase140 field from the abstract engine + concrete data, via
zBC_eq_mu_mul_reductionCount (hfib) + lemma_8_5_aggregated (hgauss) + phase140_ofPhaseData.
So (140) is reduced to exactly its concrete Prop-8.8 residues, all isolated as hypotheses:
hM— the (135)/Prop 8.8 identity#achievable-central-T-reductions(ρ) = N(κ_ρ,ε_ρ);hphase— the phase reindexΣ_χ Σ_ρ (−1)^{χκ_ρ+ε_ρ+Q(a_χ)} = Σ_ζ (2·nPhase(phase ζ) − e_Γ(C));hμ— μ-independence#Z¹(T)_{ρ'} = μ(source 5.15/5.16);- the cardinality matches
hDT(|V^∨| = |D_T|),hWV(|W| = |V|),hG0(G(Q) = G0), all read off the concreteEn(the descended moduleV, the enrichment formqbar).
hM/hphase are the deep Prop 8.8 content (coupled to the witness Δ); hμ is a source fact;
the matches are frame bookkeeping. This is the concrete O-half — no clean reducers remain in (140).
prop_8_9 is NOT closed — it stays sorry; the three per-source inputs + the witness are
blocked (below). The final splice exact prop_8_9_of … into SectionEight.lean is a trivial edit,
deferred until the inputs land.
| input | status | path / blocker |
|---|---|---|
half139 ×2 |
◑ hlem86M ✓ both sources; hMcountM = the remaining build |
half139_via_radData (✓) + lemma_8_6_local (✓ G_ℚ₂, SectionEight.lean:1302) / lemma_8_6_gammaA (✓ P-16c CLOSED 2026-07-06, SectionEight.lean:1288, := half_torsor_gammaA) discharge hlem86M. **hMcountM (`#MLifts = |
stageR136 ×2 |
✗ blocked (infra) | needs an RObstructionData built from En — which Enrichment does not carry (no cover-map family coverMap_λ, no pair : D_Rmod →ₗ (R→+𝔽₂); this is the P-16d2 escalation). Then stageR136_ofRSepData (P-16d2, ✓) closes it from hsep_hom + hZcount + hE2. Requires extending Enrichment (co-owned SectionEight.lean structure edit — owner sign-off) with the P-16d2 cover-map/pair fields, then constructing the datum + discharging the source residues hsep_hom/hZcount concretely. |
phase140 ×2 |
☑ FULL reducer landed (phase140_of_gaussCorrespondence); residual = concrete Prop-8.8 fields |
the entire (140) display is now derived by phase140_of_gaussCorrespondence from zBC_eq_mu_mul_reductionCount (hfib) + lemma_8_5_aggregated (hgauss) + phase140_ofPhaseData. Residual = the concrete hypotheses hM (Prop 8.8 count M_ρ = N(κ_ρ,ε_ρ)), hphase (character↔phase-cover reindex), hμ (μ-independence, 5.15/5.16), and the matches hDT/hWV/hG0 off En (qbar, the descended V). hM/hphase are the deep Prop 8.8 content (coupled to the witness Δ); no clean reducers remain. |
witness (μ, G0, DT, phase) |
◑ En carries the data (correction) | Enrichment is richer than previously scoped — it already provides Vmod (the descended V), qbar (the form Q), hquad, hns (nonsingular), dat/hdat (the Lemma 6.1 factor set). So: G0 = gaussSum (En.qbar l h) (SectionEight.lean:199); phase = phaseFamily (DeltaScalar (En.dat l h) …) (AffineTLift.lean:841); the (140) polar data a_χ = polarInverseL (En.qbar) (En.hquad) (En.hns) L (landed). μ = Nat.card (TCocycle …), DT = the (T^∨)^C index. Source-independent, built once from En. Remaining subtlety: G0/μ's l-independence (Arf-invariant / 5.15-5.16), and wiring DT ≃ V^∨. |
P-16c— CLOSED 2026-07-06 (Opus):lemma_8_6_gammaAproved (:= LedgerGammaA.half_torsor_gammaA,GQ2/HalfTorsorGammaA.lean, std-3); no longer blockshalf139forΓ_A. Remaininghalf139obstacle ishMcountM(both sources) — seedocs/p16d6d-handoff.md.- P-17d —
blockEnrichmentis asorry(SectionNine.lean:572); blocks the concrete instantiation ofprop_8_9(§9 suppliesRF := blockFrame,En := blockEnrichment), but not the abstractprop_8_9proof itself.
Confirmed by tracing lemma_8_5 (SectionEight.lean:215, the (140) Gauss engine, proved — the
analog of lemma_8_4 for (136)) and lemma_8_7_count (AffineTLift.lean:717, proved): closing
phase140 is not a thin reducer but a module comparable to the (136) obstruction module (P-16d2).
The (140) identity
2·|D_T|·zBC = μ·(|V|·e_Γ(C) + G0·Σ_ζ (2·nPhase(phase ζ) − e_Γ(C))) unfolds as a 4-level count:
zBC = Σ_ρ #CentralOver(ρ)— thezBC-fibration over theC-imageρ(reuse thehfibstep insidehalf139_of,RadicalEdgeBridge.lean:117) →#{central M-lifts}(centralOver_equiv).#{central M-lifts} = μ · #{central-liftable T-reductions}— thelemma_8_7_countμ-fibration overredT(μ = #(TCocycle D ρ), constant on theV-coordinate bycentral_twist_iff).#{central-liftable T-reductions} = N(κ_ρ, ε_ρ)— the constrained quadratic count oflemma_8_5withW =theV-lift space,Q = En.qbar,Lthe descent,a_χfromexists_polar_inverse; the "central-liftable" ⟺Q(x)=ε ∧ Lx=κidentity is the (135)/Prop 8.8 content (prop_8_8_target✓,lemma_6_21/6_22✓).Σ_χ sign(χκ+ε+Q(a_χ)) = Σ_ζ (2·nPhase(phase ζ) − e_Γ(C))— the sign↔count reindex over the phase coversphase = phaseFamily (DeltaScalar …), matching charactersχ ∈ V^∨to theD_Tindex (the sameΔ/phase/μ/G0that the witness defines — sophase140and the witness are one build).
Recommended: promote this to its own P-16d2-style sub-ticket ("(140) phase-module"): design the
PhaseData interface (the (140) analog of RObstructionData), prove phase140_ofPhaseData via
lemma_8_5 + lemma_8_7_count + the fibration, and construct the witness (μ,G0,DT,phase) inside
it. This is the single largest remaining §8 piece.
hfgA (GammaA t.f.g.) is a proved theorem (FinitelyGenerated.lean:84); hfgF (AbsGalQ2
t.f.g.) is axiom B1 (absGalQ2_isTopologicallyFinitelyGenerated). The board reserves B1's
first consumption for P-17i (the §9 master induction), so prop_8_9_of keeps hfg as
hypotheses rather than discharging hfgF (which would pull B1 into prop_8_9's footprint) — an
axiom-accounting decision for the owner at splice time. (hhead is F-dependent, so genuinely a
hypothesis.)
- witness — write the
(μ, G0, DT, phase)constructor fromEn(source-independent). phase140— write the (140) assembly (the big one) asRecursionFrame.phase140_of ….stageR136— extendEnrichmentwith the P-16d2 cover-map/pair fields (owner sign-off on theSectionEightstructure edit), build theRObstructionData, dischargehsep_hom/hZcount.half139—half139_via_radData+lemma_8_6_local(now) /lemma_8_6_gammaA(after P-16c).- Assemble the two
RecursionInputs, callprop_8_9_of, and spliceexact …intoprop_8_9(trivial co-owned edit, done last).