riemann

The validated symbol β_a and the ground-state level split — DIAGNOSTIC

Correction notice (2026-09-22, after the adversarial audit audits/circle-symbol-lane-2026-09-22-v2.html (NS-31, PR #16); originals retained below). What stands: the symbol β_a is the right object with the (−1)^n basis sign (independent mpmath quadrature confirms even and odd entries at λ=4; the “no odd tail” of §10 means omitted as O(log X/X³), not zero); the deep-block cancellation pattern at finite head in both parities (counts below 1e-8/1e-16/1e-30 survive a 120/180-digit replay; the N=96 values of order −1e-116 at λ ≥ 6 were arithmetic-floor artefacts and are positive at 180 digits); the close alignment of the ground pencil direction with the certified λ=3 source (overlap 0.99999998, not 1; the √2 factor comes from combining the ±n complex modes, not from an unnormalized constant mode; nothing is measured at other windows). What is withdrawn: (§5) “no λ-independent limiting picture” and “self-similar argument has nothing to act on” — four shapes differ, which is all that was measured; (§6) “the lobe deepens like a” — a measured sequence 0.67/0.55/1.44/2.13, not a local asymptotic; (§7) the blanket “six relative digits however small” — the correct first-order statement is δν/ν = −v*(δW⁻)v under relative form control of W⁻, which entry spot checks and the two-entry tail script do not supply; W in the solve is a midpoint at dps−5, so nothing below the arithmetic floor is meaningful; “the block is converged at λ=4” (12 → 13 from N=48 to 96); (§8) η_a^op → ∞ and “the unweighted layer-cake form does not give a uniform floor” as conclusions — the ratios 0.36/0.35/0.34/0.34 are four full-head, ξ ≤ 800 observations whose inequality direction against the source-compressed complete η is not established; (§10) “the same count” (6/4/1 vs 5/3/1; 12/10/7 vs 12/9/6) and “three to four decades” (matched N=48: 3.6 decades; the 1e-75 comparison mixed cutoffs); throughout, “nothing beyond”, “no mass”, “all energy at ξ<20”, “c = 0” mean below printed resolution, not exact.

Status: diagnostic, not a certificate. This is the correct version of the experiment retracted in evidence/diag_circle_split/results.md. The object is now the manuscript’s own symbol (eq:v130-r-symbol, eq:v130-beta):

β_a(ξ) = Re ψ(5/4 + iξ/2) − log π − r_a(ξ),
r_a(ξ) = 2 Σ_{1<m<e^{2a}} Λ(m)/√m · cos(ξ log m) − 2 ∫_0^{2a} e^{t/2} cos(ξt) dt,
q_a[f] = ∫_ℝ β_a(ξ) |F f̃(ξ)|² dξ     (unitary F of the zero extension; prop:v130-remainder / prop:v135-both-parities)

1. Validation against the assembled matrix (beta_check2.py, λ=3)

Quadrature of β_a · Fe_n · Fe_m over ℝ (step 0.01 to ξ=3000 plus an averaged analytic tail) against assembly_general.block():

entry block() (−1)^{n+m} × quadrature rel. err
W[0,0] +0.04085520 +0.04085521 2.5e-7
W[1,1] +0.08283138 +0.08283140 2.4e-7
W[0,1] +0.05817114 +0.05817115 2.5e-7
W[1,2] +0.08464430 +0.08464432 2.2e-7
W[0,2] +0.05943220 +0.05943222 2.3e-7
W[1,3] +0.08816769 +0.08816771 1.9e-7

So β_a is the exact symbol of the assembled operator, and block()’s basis carries a (−1)^n relative to the centered cosine transform (window [0,L] vs [−L/2, L/2]). Both facts must be used when moving a vector between the matrix and the transform; the earlier diagnostics used neither.

2. The negative set of the true symbol (true_scan.py, ξ ∈ [0, 400])

λ L min β_a at ξ negative measure (2-sided) lobes naive (L/2π)·|neg|
3 2.197 −2.38 35.5 70.5 33 24.6
4 2.773 −3.37 39.3 115.9 67 51.1
6 3.584 −5.54 296.7 173.0 118 98.6
8 4.159 −6.22 362.3 212.4 161 140.6

The negative set is large and its deep part is at high frequency; the lobes recur at the window’s own resolution period 2π/L. The last column is what a Kac–Murdock–Szegő count would give against a certified 0 negative eigenvalues; it is reported for the record only — KMS’s hypotheses (a fixed symbol as L → ∞) do not hold, because the symbol’s oscillation scale is tied to L.

3. Level split of the λ=3 ground state (ground_true.py, levels_true.py)

Ground vector of the N=120 even compression by a full eigensolve (1024-bit assembly, 220 digits; ε_N = 2.954e-38, tail components ~1e-20 by n=60).

quantity value
Plancherel ∫\|Ff\|² 1.000000
q_neg = ∫_{β<0} β\|Ff\|² −0.089782
q_pos = ∫_{β>0} β\|Ff\|² +0.089782
q_neg + q_pos +1.4e-16 (true ε_N = 2.95e-38; quadrature-limited)
mass of \|Ff\|² on {β_a<0} 0.4991

By frequency band (negative / positive level energy): [0,5): −0.0828 / +0.0729; [5,10): −0.0069 / +0.0167; [10,20): −0.0001 / +0.0002; nothing beyond.

Reading. The identity q = ∫β_a|Ff|² is verified on the ground state to 16 digits. The ground state is a low-frequency object (ξ ≲ 10) sitting half on the first few negative lobes of β_a and half on the positive crests between them, with energies ∓0.0898 cancelling to 10^-38. It puts no mass where β_a is deeply negative (ξ ≈ 35, −2.4). Hence any bound that sees only inf β_a (the pointwise criterion eq:v130-pointwise) is pessimistic by −2.4 against a truth of 0; the weighted concentration criterion (eq:v131-weighted-concentration) must certify that the positive-level mass of every admissible f ⊥ u_a covers its negative-level mass — at the ground state that is an equality at scale 0.09. This is the number the live mechanism has to control, on the right object. Nothing here is a bound.

4. The same split at the certified window λ=4 (levels_l4.py)

Ground of the N=120 even compression (ε_N = 3.743e-75; certified complete μ0 < 2.454e-75, prop:v140-ground4).

quantity λ=3 λ=4
Plancherel 1.000000 1.000000
q_neg −0.089782 −0.225661
q_pos +0.089782 +0.225661
q_neg + q_pos (true) +1.4e-16 (2.95e-38) −8.3e-17 (3.74e-75)
mass on {β_a<0} 0.4991 0.5011
energy in [0,5) neg / pos −0.083 / +0.073 −0.185 / +0.204
energy in [5,10) −0.007 / +0.017 −0.039 / +0.021
energy in [10,20) −0.0001 / +0.0002 −0.0008 / +0.0003
beyond 20 0 0

The cancellation scale grows with the window (0.090 → 0.226) while the structure is unchanged: half the Fourier mass on the negative set, everything below ξ ≈ 10–20, nothing at the deep high-frequency negativity. The next step in this lane (NS-16) is the same split over the source-orthogonal complement f ⊥ u_a — the class the weighted criterion actually quantifies over — rather than the ground alone.

5. The ground in lattice units across λ (selfsim.py → selfsim_output.txt; N=120 even, midpoint eigensolve)

Question: does the ground state have a limiting shape in the window’s own frequency units u = ξL/2π (one unit = one resolution cell = one lattice mode)? Answer: no. Both the ground and the symbol change with λ in those units, in opposite directions.

Ground-state Fourier mass per lattice cell (2∫|Ff|² over the cell; rows sum to 1):

λ [0,½) [½,1½) [1½,2½) [2½,3½) [3½,4½) [4½,6½) [6½,10½)
3 0.326 0.471 0.173 0.029 0.002 0.000 0.000
4 0.267 0.429 0.221 0.070 0.013 0.001 0.000
6 0.212 0.369 0.244 0.120 0.043 0.012 0.000
8 0.186 0.335 0.243 0.141 0.065 0.029 0.001

Lattice-mode coefficients |v_0..v_5| tell the same story (λ=3: 0.58, 0.69, 0.41, 0.16, 0.03, 0.00; λ=8: 0.43, 0.58, 0.49, 0.37, 0.25, 0.15). The ground delocalizes outward in lattice units as the window grows, even though it contracts in physical frequency (§3–4: everything below ξ ≈ 10–20).

The validated symbol at fixed u:

λ u=¼ u=½ u=¾ u=1 u=1¼ u=1½ u=2 u=2½ u=3 u=4
3 −0.001 −0.285 +0.005 +0.284 −0.012 −0.279 +0.272 −0.259 +0.238 +0.119
4 −0.000 −0.687 +0.001 +0.695 −0.001 −0.708 +0.728 −0.757 +0.797 +0.935
6 −0.010 −0.509 +0.029 +0.512 −0.049 −0.515 +0.520 −0.527 +0.536 +0.562
8 +0.000 −0.131 −0.001 +0.132 +0.002 −0.134 +0.138 −0.142 +0.148 +0.166

At low frequency β_a resembles an alternating train in the window’s own units, but the displayed quarter-point samples are not exactly zero and the integer crests are not equal. NS-26 gives the exact varying cosine and sine envelopes in prop:v146-beta-explicit and eq:v146-lattice; see evidence/diag_beta_lattice_identity/results.md. The representative crest scale is not monotone in λ (0.28, 0.70, 0.51, 0.13). The train comes from the −r_a term, whose low-frequency size is the weighted Chebyshev remainder

r_a(0) = 2 [ Σ_{1<m<λ²} Λ(m)/√m − 2(λ−1) ]  =  −1.66, −2.06, −1.88, −1.50   (λ = 3, 4, 6, 8),

which orders the four windows the same way as the crest amplitude (4 > 6 > 3 > 8). The remainder is the whole explanation of the ordering, not a formula for the amplitude (the constant Re ψ(5/4) − log π ≈ −1.372183419 and the ξ-dependence of the continuum term also enter). Earlier wording that attributed this to ψ(λ²) − λ² was loose; the relevant object is the 1/√m-weighted sum.

Reading. In lattice units the ground state’s energy budget is a window-by-window arithmetic quantity: the ground samples a ± train whose amplitude is set by the prime-power remainder at the cutoff λ², spreading over more cells as the window grows. There is no λ-independent limiting picture in these units, so a self-similar (renormalization-style) argument for the ground alone has nothing to act on. Nothing here is a bound.

6. The negative lobe nearest the first zeta ordinate (nearzero.py → nearzero_output.txt)

γ₁ = 14.1347. For each λ, the negative interval of β_a nearest γ₁ (not a lobe centred on γ₁: at λ=3 it lies below, at λ ≥ 4 above), its depth and width, and the ground’s mass and negative-level energy there.

λ L ε_N lobe centre depth width width·L/2π mass in \|ξ−γ₁\|<1 mass in lobe E_neg in lobe mass ξ>10
3 2.197 3.0e-38 12.289 −0.668 1.258 0.440 3.9e-6 1.5e-4 −5.6e-5 1.7e-3
4 2.773 3.7e-75 15.613 −0.550 0.988 0.436 2.7e-6 1.1e-6 −3.7e-7 1.4e-3
6 3.584 3.1e-150 15.293 −1.442 0.804 0.459 2.0e-6 5.5e-7 −5.1e-7 1.1e-3
8 4.159 7.5e-190 15.241 −2.130 0.764 0.506 1.4e-6 3.5e-7 −4.8e-7 9.4e-4

(ε_N at λ=6, 8 is the N=120 midpoint value at 2048 bits, cutoff-limited; the certified values are in evidence/v138/.)

Three things are happening at once near γ₁:

  1. the nearest lobe deepens (−0.55 → −2.13 from λ=4 to 8), consistent with the unconditional inf β_a → −∞ of cor:v137-scalar-no-go;
  2. it narrows in physical frequency but stays about half a resolution cell wide (0.44–0.51 of 2π/L), so the window cannot resolve it;
  3. the ground’s mass in it shrinks (1.5e-4 → 3.5e-7 from λ=3 to 8) and its negative-level energy there stays at the 1e-7 scale — five to six orders below the ∓0.09 / ∓0.23 cancellation budget of §3–4.

In lattice units γ₁ sits at u = γ₁L/2π = 4.9, 6.2, 8.1, 9.4, at the outer edge of the ground’s support (§5: 1e-3 of the mass in [6.5,10.5) at λ=8). Both the ground’s spread and u(γ₁) grow with L; whether the ground’s mass at u(γ₁) stays negligible as a → ∞ is the local, quantitative form of the open question, and two more windows would not settle it (prop:v121-cofinal-rh). The frontier this lane leaves is therefore: the ground’s energy near the first zeta ordinate is a race between a lobe that deepens like a (cor:v137-scalar-no-go) and half a cell wide, and a ground whose mass there is currently 1e-6 and falling. Nothing here is a bound.

7. The level pencil: is the cancellation one direction or a block? (pencil.py → pencil_output.txt, pencil_N96_output.txt)

Question left by §3–6: the ground state cancels ∓0.09 (λ=3) / ∓0.23 (λ=4) of negative- and positive-level energy to 1e-38 / 1e-75. Is that a single critical direction, with the rest of the head comfortably positive, or is the whole deep block a cancellation? The weighted criterion (eq:v131-weighted-concentration) quantifies over every admissible f, so the answer decides whether G2 at a window is a one-dimensional problem.

Method. W = block() (Arb, exact), W⁻ = ∫ β_a⁻ |Fe|² (negative level, float quadrature over the bounded negative set; the part beyond the grid is ≤ 3e-4 relative, wminus_tail.py), W⁺ = W + W⁻. The pencil W v = ν W⁺ v gives ν_k = q[v_k]/q⁺[v_k], the fraction of positive-level energy that survives in direction k; ν ≥ 0 in every direction is positivity, and 1−ν_k = μ_k is the negative-to-positive ratio. The numerator is exact and the denominator is accurate to ~1e-6 (the full-symbol quadrature reproduces block() to 7e-5 on every head entry with |W| > 1e-2, 2e-6 on the low block), so each ν_k carries about six relative digits however small it is. Solved in mpmath at 120 digits.

Even head N=48 (e_k = eigenvalues of W itself, for comparison):

λ ν_0 ν_1 ν_2 ν_3 … first ν > 1e-2 at k e_k/ν_k over the deep block #ν < 1e-8 #ν < 1e-16 #ν < 1e-30
3 4.7e-37 3.5e-30 4.7e-24 6.2e-19 … 7 (0.011) 0.09 – 0.50 6 4 1
4 2.9e-65 2.7e-58 5.2e-52 5.3e-46 … 14 0.23 – 0.69 12 10 7
6 6.3e-92 5.5e-85 1.3e-78 9.7e-73 … >14 0.17 – 0.53 21 18 13
8 1.5e-105 1.0e-98 1.6e-92 9.8e-87 … >14 0.04 – 0.41 26 22 17

Cutoff dependence of the counts (#ν < 1e-8 / 1e-16 / 1e-30):

λ N=24 N=48 N=96
3 6 / 4 / 1 6 / 4 / 1 —
4 9 / 7 / 3 12 / 10 / 7 13 / 10 / 7
6 — 21 / 18 / 13 30 / 26 / 22
8 — 26 / 22 / 17 41 / 37 / 31

So the block is converged in N at λ=3 and λ=4 (a head of ~2λ² modes suffices) and still growing with the cutoff at λ=6 and 8: there the count is a finite-section quantity and the numbers above are lower bounds on the deep block of the complete operator. At N=96 and λ ≥ 6 the smallest ν_k sit below the 120-digit working precision (values of order ±1e-116 are numerical zero, not negative eigenvalues; the complete operator is certified nonnegative in evidence/v138/), which does not affect the counts at the 1e-30 threshold. The e_k are the compression’s eigenvalues, not the certified complete values (v138/, v140/), and are quoted only for the ratio; at λ=4, N=96, e_0 = 5.2e-75 sits above the certified complete μ0 < 2.454e-75 as it must. The validation line in pencil_N96_output.txt predates the tail-factor fix in pencil.py and reads a few percent; the pencil itself never uses that quadrature (W is exact from Arb), so the ν_k are unaffected; pencil_output.txt carries the corrected line (≤ 7e-5).

Reading.

  1. It is a block, not a direction. Every deep direction has ν_k ≈ e_k / q⁺ with q⁺ between 0.05 and 0.7: in each of them a positive-level energy of order 0.1–0.5 is cancelled by an equal negative-level energy down to e_k. The ground is only the tightest of these. The number of directions cancelled below 1e-8 grows with the window (6, 13, ≥30, ≥41 at λ = 3, 4, 6, 8), of the order of the deep-block size N ~ λ² (AGENTS.md §8), and the pencil spectrum decays super-exponentially with a step that shrinks as k grows (λ=8: 7, 7, 6, 6, 5, 5, 4 decades per step).
  2. What this rules out. Any argument that treats the ground state as the single delicate direction and bounds the rest of the head by a comfortable margin is wrong in its premise: at λ=8 the thirty-first direction is still cancelled to 1e-30. This is the finite-dimensional face of cor:v137-scalar-no-go and of the meta-obstructions of v1.39: arithmetic-blind bounds fail on the whole deep block, not at one vector.
  3. What this leaves — with a qualification (2026-09-21, after Astra’s translation of the criterion into these coordinates). The pencil vectors v_k order the head by q/q⁺, and for a source-admissible direction the minorant of eq:v131-step-minorant may lose at most ν_k q⁺[v_k] + η_a ‖v_k‖² there. At zero allowed error that is a relative loss of at most ν_k, i.e. down to 1e-100 at λ=8 in ~40 directions at once — the exact-positivity reading. But the target is the uniform finite floor of prop:v136-bounded-floor, which allows a finite η_a uniformly bounded in a; a finite η_a swamps every ν_k above, so the tiny values do not by themselves obstruct the weaker goal. Two further qualifications: this pencil is on the uncompressed even head, whereas the criterion acts on the source complement; and directional checks do not control mixtures (the cross-term rule of prop:v126-direction-complement). The directional test is a finite-window statement; using it for the live criterion still needs the full complement and uniform control along a cofinal family. Nothing here is a bound.

8. The layer-cake constant η_a^op on the even head (layercake.py → layercake_output.txt, layercake_N256_output.txt)

Follow-up to §7’s qualification: under the bounded-floor target (prop:v136-bounded-floor) the question is not the tiny ν_k but whether the concentration mechanism’s loss η_a can be kept bounded in a. The first form of the mechanism is the layer-cake bound eq:v131-layercake,

q[f] ≥ −η_a^op ‖f‖²,   η_a^op = ∫_0^{D_a} ‖C_a(E_a(t))‖ dt,   E_a(t) = {β_a < −t},

with D_a = ‖β_a⁻‖_∞. Here ‖C_a(E)‖ is the top eigenvalue of the concentration matrix ∫_E Fe_n Fe_m on the even head (source term omitted, so this is the norm on the full head: an upper bound for the complement and a lower bound for the complete operator; 80 levels of t; grid to ξ=800, so the deepest lobes beyond 800 at λ=6, 8 are missed and D_a there is the grid value, 5.54 / 6.22 against 5.81 / 7.82 on [0, 4000]).

λ a D_a (grid) η_a^op, head 48 η_a^op, head 256 η/D_a trace bound ‖C(E(0))‖ |E(0)|
3 1.099 2.378 0.862 0.862 0.36 1.99 0.63 81
4 1.386 3.419 1.200 1.206 0.35 3.11 0.81 146
6 1.792 5.537 1.30 (cut off) 1.886 0.34 4.58 0.72 251
8 2.079 6.221 1.37 (cut off) 2.128 0.34 5.45 0.80 331

Head 48 only reaches ξ < 2πN/L (84 at λ=6), below the deep lobes, which is why its λ=6, 8 values are too small; head 256 covers ξ < 449 / 387 and is converged at λ=3, 4 (identical to head 48 there). The norm profile is close to linear in the level: ‖C(E(t))‖ ≈ 0.6–0.8 · (1 − t/D_a).

Reading.

  1. The layer-cake loss is a fixed fraction of the depth, ~0.35 D_a. Since D_a → ∞ unconditionally (cor:v137-scalar-no-go, inf β_a → −∞), η_a^op → ∞ along with it: the unweighted layer-cake form of the mechanism does not give a uniform finite floor either. This is a statement about the bound, on the head; the true form is ≥ 0.
  2. The concentration norm never approaches 1, even for the whole negative set (0.63–0.81 at t = 0, with |E(0)| in the hundreds). Correction (v1.46, lem:v146-packet-concentration, eq:v146-halfcell-upper): these 0.6–0.8 values are for the entire negative set and must not be read as the concentration norm of a single half-cell trough, which the even trace bound caps below 0.509; the certified lower bounds for one cell / half-cell packet are 7/10 and 11/25 uncompressed, 3/5 and 3/8 after source projection. The negative set is a comb at the window’s own resolution (§5), and a comb of half-cells has concentration eigenvalues bounded away from 1 no matter how many teeth it has. That is the same fact as the pencil’s 50/50 level split, seen from the operator side. The trace bound eq:v131-trace-bound (min{1, tr}) is far weaker than the norm (1.99 vs 0.86 at λ=3) and is not the right tool here.
  3. What a bounded floor would need. A step minorant with finitely many weighted sets recovers at most the layer-cake profile unless the sets G_{a,j} follow the comb, i.e. unless the minorant tracks β_a at the cell scale. As J → ∞ the weighted form reproduces q exactly, so it is not a closure; but any bounded-complexity minorant that ignores the cell-scale structure loses ~0.35 D_a → ∞. The remaining question for the mechanism is therefore purely about that fine structure: whether a minorant with J growing with a can hold the loss bounded, which is the arithmetic-blind obstruction of v1.39 in operator form. Nothing here is a bound.
  4. Correction after NS-22 (evidence/diag_comb_minorant/): the binding direction of every step minorant is not the low-frequency train of §5 but a packet sitting at a deep trough at cell index 12–500, so the obstruction is the density of near-D_a troughs at moderate frequency. Item 3’s “cell-scale comb” wording pointed at the wrong part of the symbol; the level structure is what matters, and NS-22 measures it: η_a(J) ≈ 1.2 D_a / J for a J-level quantization of β_a.

9. Are the pencil directions source-admissible? (source_overlap.py → source_overlap_output.txt)

v1.44 (prop:v144-pencil-concentration) points out that the criterion acts on the source complement E = H ∩ u_a^⊥, that the uncompressed pencil does not establish b_k = ⟨v_k, u_a⟩ = 0, and that projecting a raw pencil vector need not preserve its ratio. Checked here at the one window where the source is certified: λ=3, even head N=64, u = the certified projected source (evidence/v124/g2_source_certificate/source_polynomial_intervals.json, projected_positive_coefficients; its n=0 entry is stored against the unnormalized constant mode and must be divided by √2 — with that, the angle to the finite Weil ground is sin = 2.159e-4, matching the certificate’s < 2.16e-4 to four digits, which fixes the basis).

k ν_k (full head) |b_k| = |⟨v_k,u⟩| ν’_k (complement pencil)
0 4.06e-37 1.000000 —
1 2.88e-30 0.0141 2.884e-30
2 3.97e-24 0.0176 3.965e-24
3 5.54e-19 0.0051 5.538e-19
4 4.95e-14 0.0138 4.951e-14
5 1.08e-9 0.0084 1.076e-9
6 7.65e-6 0.0025 7.649e-6
7 9.74e-3 0.0012 9.741e-3
8 0.505 0.0013 0.5053

Rayleigh floor of W on u^⊥: 2.584e-31, equal to the second even eigenvalue; full ground 3.64e-38.

Reading.

  1. The ground pencil direction is the source. b_0 = 1 to six digits: the deepest cancellation of the whole head is the direction the criterion quantifies away from. This is the certified G1 fact (thm:v14-radical, angle sine < 2.16e-4) seen from the pencil side, and it means the 1e-37 (λ=3) / 1e-65 (λ=4) surplus of §7 is not a demand on the mechanism at all.
  2. Every other deep direction is source-admissible to ~1%, and the complement pencil reproduces the full-head values ν_{k+1} to four digits. So the source constraint removes exactly one direction and leaves the rest of the deep block untouched: the deepest admissible surplus at λ=3 is 2.9e-30, and the block structure of §7 (6 / 13 / ≥30 / ≥41 directions below 1e-8) loses one member per window.
  3. For v1.44’s quantifier. The directional budget eq:v144-direction-budget should be read on E with ν'_k, which here equals ν_{k+1}; the mixture condition eq:v144-pencil-matrix on ker b is, to the same 1%, the pencil on the complement. This is λ=3 only (the certified source exists at no other window); at λ=4 the analogous statement would need the v126 normalized source. Nothing here is a bound.

10. The odd sector (pencil_odd.py → pencil_odd_output.txt)

Everything above is even-sector. The bounded-floor corollary needs both parity blocks, and prop:v135-both-parities says the same symbol β_a drives the odd form. Checked: with odd modes e_n = √(2/L) sin(2πn x/L), n ≥ 1, the full-symbol grid quadrature reproduces block(…,'odd',…) to 2.3e-5 (λ=3) and 1.2e-4 (λ=4) on every head entry with |W| > 1e-2, with the same (−1)^n basis sign as the even sector and no high-frequency tail (odd transforms decay like 1/ξ², so |Fe_n|² is O(ξ⁻⁴)). The odd pencil, N=48:

  λ=3 even λ=3 odd λ=4 even λ=4 odd
ν_0 4.7e-37 1.7e-33 2.9e-65 1.2e-61
ν_1 3.5e-30 5.0e-27 2.7e-58 4.1e-55
ν_2 4.7e-24 2.1e-21 5.2e-52 5.8e-49
e_k/ν_k over the deep block 0.09–0.50 0.09–0.60 0.23–0.69 0.21–0.43
#ν < 1e-8 / 1e-16 / 1e-30 6 / 4 / 1 5 / 3 / 1 12 / 10 / 7 12 / 9 / 6

Reading. The odd block is the even block shifted up by three to four decades (its ground is 1e-34 / 1e-61 against 1e-38 / 1e-75, levels_true.py, evidence/v138/), with the same count of cancelled directions and the same 0.1–0.6 level energies per direction. There is no parity in which the deep block is absent, so nothing in §7–§9 is an even-sector artefact. The odd sector has no source constraint (the source is even), so all of its deep directions are admissible. Nothing here is a bound.