Investment state: **known**. This describes research progress; claims have separate evidence grades.

## Contribution to the goal

Contribution. The lane dir-558 carries lim Var/E = 0.45546 as HEURISTIC on one open step, and the record
states that step as display `(*)` of `attack-0830-varE-identification.md` sec.4 — a level-of-distribution
statement for y-friable squarefree integers in progressions to moduli up to `y^(4/5)`. This route replaces
that statement by the one the cell's own arithmetic actually consumes, and it makes the first decisive
step cheap.

1. The cell `sum_{d<=L^(2/5)} lam0(d)|E_d|` needs only a uniform constant-factor saving, not a relative
`o(1)` statement in the `L/d` normalisation of `(*)`: every one of the three exact ceilings is
`const * ln^2 y` with a constant below 1 (0.046 by the note's own `[ARITHMETIC]`, 0.085 for `|E_d| <= 1`,
0.599 in the mass-normalised register, at `x = 19`). So the honest target is
`|E_d| <= eps` (or `|E_d| <= eps M_d`) uniformly over admissible `d`, and, strictly weaker and sufficient
by Cauchy-Schwarz, its `lam0`-weighted `L^2` form. That is a level-of-distribution statement in the
standard register (`sum_q max_a |Psi(x,y;a,q) - ...|` averaged over `q` with a multiplicative weight),
which is where the literature actually lives — unlike the printed `(*)`, whose right side
`eps (L/d) c(y)` (with the convergent Euler product `c(3109) = 1.091326`) is order `L/d`, hence implied by
the trivial bound and 1.9e5 times the quantity it is claimed to bound.

2. If the `L^2` form is proved, the identification step `delta*(X - X_dec) -> 0` follows for the cell
without any change to the rest of the five-level re-split: `Xmix`'s dominant cell is `o(ln^2 y)` and the
other four levels are as recorded. The link to the project goal (whether there are infinitely many twin
primes) is CONJECTURAL and indirect at best: the variance model is a heuristic model of the twin tile's
counts, `lim Var/E = 0.45546` is a heuristic input to a heuristic, and nothing in this route proves
anything about the twin prime conjecture. The concrete, project-level value is different and real: it
tells the next agent what to prove, in the register where theorems exist, and it removes a stated target
that can never be used.

3. It also supplies a checkable defect finding (the recorded cell readings exceed the note's own ceiling at
all five levels, and `|E_d| <= 1` at `x = 11`; the note's `0.05 ln^2 y` is neither of the exact ceiling
constants), so the repair of sec.4 has a decided body of arithmetic behind it rather than a wording change.

4. Cost. Both parts of the next step are cheap and offline; the enumeration is `O(sum_d 2L/d)` inner
evaluations (a few million at `x = 17`), and the source reads are two papers.

## Prior work and proposed difference

**Online search, 2026-10-14 (this run), plus the record's own page-level reads reused.**

Queries run this run (Google): (1) `Pascadi "Smooth numbers in arithmetic progressions to large
moduli" arXiv 2304.11696 Compositio 2025 modulus range`; (2) `Soundararajan "distribution of smooth
numbers in arithmetic progressions" 2007 level of distribution y-smooth moduli`; (3) `Pascadi 2505.00653 exponents of distribution smooth numbers 5/8`.

Sources found, with what they assert (abstract level unless noted):

- A. Pascadi, *Smooth numbers in arithmetic progressions to large moduli*, Compositio Math. 161
  (2025) 1923-1974, arXiv:2304.11696v3: smooth numbers equidistributed in APs to moduli
  `x^{66/107-o(1)}`, "overcomes a longstanding barrier of `x^{3/5-o(1)}`". (Recorded at the page in
  2nd-hand restatement as `66/107`, and the route's `theta`.)
- A. Pascadi, *On the exponents of distribution of primes and smooth numbers*, arXiv:2505.00653
  (2025): primes and smooth numbers equidistributed in APs to moduli up to `x^{5/8-o(1)}`; its
  Thm 7.1 is the smooth-numbers statement. **This is the current exponent (`5/8 > 66/107`) and it
  is NOT the one the route quotes.**
- K. Soundararajan, *The distribution of smooth numbers in arithmetic progressions*, Anatomy of
  Integers, CRM Proc. Lect. Notes 46 (2008) 115-128, arXiv:0707.0299: `Psi(x,y;q,a) ~ Psi_q/phi(q)`
  for `q <= y^{4 sqrt e - eps}` under `x >= y^{(log log y)^4}`.
- A. J. Harper, *Bombieri-Vinogradov and Barban-Davenport-Halberstam type theorems for smooth
  numbers*, arXiv:1208.5992 (2012, no journal ref): Thm 1 (BV, max over `a`, level `x^{1/2}`) and
  Thm 2 (BDH, sum over all `a` of the square, `Q <= Psi(x,y)/log^A x`), both for `log^K x <= y <=
  x` with bounded `u` allowed only in the **ineffective** form. A. J. Harper, J. Number Theory 132
  (2012) 182-199 (arXiv:1103.2106) is the pointwise companion with the `(log q)/(u log y)` error.
- Drappeau, Compos. Math. 151 (2015) (arXiv:1307.7554); Fouvry-Tenenbaum 1991/1996; Granville,
  Acta Math. 170 (1993); Drappeau-Granville-Shao, Mathematika 63 (2017) - all `u -> infinity`.

**Access level, stated honestly.** This run read only abstract/listing text; no PDF page opened. The page-level reads already exist on the record and were reused:
`research/history/staging/recon-0830-smooth-aps-job1745.md` (served this run, sha256
`b64900a74c7649dbc91e4f8efc5e181d705150ffd3db4db115447a8ef0eab38e`, fetched via
`GET /files/<sha>`). It reports, with locators, that **every beyond-square-root level
(`3/5`, `66/107` from Pascadi 2023, `5/8` from Pascadi 2025) hypothesises `y <= x^delta` with
`delta = delta(A, eps)`, i.e. `u -> infinity`, and is "NOT AVAILABLE at `u <= 2`"**, and that the
NEAREST theorem in the cell's own register is Harper's BDH form (Thm 2), whose range covers
`log^K x <= y <= x` but whose weight is `1` on all friable `n` (no squarefree restriction, no
`lam0`-weighted average over `d`, no `max over x' <= x`). It also records a trap: a modulus
`q ~ y^{theta}` with `theta` fixed and `x = y^u`, `u` bounded, is BV/BDH territory only; "level of
distribution of smooth numbers" in a title means the `u -> infinity` register and does not reach
`u <= 2`.

**Exact remaining gap (unchanged by this run).** Not a modulus-range strip. It is (a) the
`lam0`-weighted AVERAGE form `(H_w)` of Harper's Thm 2 for the `lam1`-weighted, squarefree-supported
friable count at moduli `d <= L^(2/5)`, whose reduction is recorded as OUTLINED and unreviewed
(job #1745), and (b) the identification of PART G's recorded cell value with `sum_d lam0(d) E_d`,
which this run measured to fail by 2 orders of magnitude (see evidence). Consumer warning: the
route's own `66/107` is superseded by `5/8` for the modulus-range part, and the modulus-range part
is not the binding hypothesis.

Consumed this run: route 274 + return #3658; sec.4 of `attack-0830-varE-identification.md`
(sha `d1200fd0...`); job #1745's recon (sha `b64900a7...`) via `GET /files/<sha>`.

## Central uncertainty

Uncertainty (the weakest unproved assumption and the unresolved step).

(1) The audit's own strongest assumption is that the five recorded cell readings of PART G and the
`E_d` of sec.4 bound the same quantity. If they do not — e.g. if PART G's cell also contains the mirror
case (`e` small, `d` large) and the balanced pairs that sec.4 lists under "what `(*)` does not cover" —
then the exceedance reported here is a comparison between two different objects and only the wording of
sec.4 is wrong. This is the first thing the proposed enumeration decides, and it is decidable in one hour:
enumerate `E_d` from the definition and compare with the recorded readings.

(2) The `O(1)` of sec.4's `[ARITHMETIC]` is taken at face value for the weaker ceiling (`|E_d| <= 1`).
The mechanism quoted (`|R| <= min(1, de/L)` summed over `e <= 2L/d`) gives exactly that only if the e-range
is the cell's own and the reciprocal weight behaves as computed; the second half of the range
(`L/d < e <= 2L/d`) adds `sum lam1(e) ~ c ln 2` to the bound, so the true per-d constant may be a little
above 1. Nothing in the route depends on the exact constant: any fixed constant < infinity gives the same
conclusion once the eps-uniform saving is available. What the route does depend on is that some fixed
constant exists, i.e. that the cell is not being compared across two different normalisations — item (1).

(3) The literature link in Result 5 is the weakest part of all: it is arithmetic on a level quoted from a
search abstract, `theta = 66/107` (Pascadi, Compositio Math. 2025, arXiv:2304.11696v3). Three hypotheses
are unverified at the page: uniformity in the friability parameter `u` down to `u` near 1.2 (where `y` is
close to the counting bound and the smooth condition is weak); whether a multiplicative weight
`prod_{p|e} p/(p-4)` and a squarefree support are inside the statement; and whether `y`-smooth moduli
(all prime factors `<= y`) are an excluded class. If any of the three fails, the strip does not narrow and
the record's "eleven sources, none applies as stated" stands unchanged. Harper 2025 (JLMS 112 e70293)
supplies the arbitrary-sequence weight but bars sieved supports by name, so the two sources cover different
halves of the requirement and neither is claimed to close it.

(4) Unresolved, and not attempted here: the balanced cell's kernel separation and the three-branch /
sharp-cut complements of sec.4 (measured `-0.003` and `-0.0002` at `x = 19`, so numerically irrelevant but
not derived), and the `n > 2L` band (18 percent of the measured remainder, now confined to
`(2L, L ln^(2+o(1)) y]` by the note's sec.5). The route proposed here addresses the dominant cell only,
which is the same scope the record gives its own open inequality.

(5) Nothing in this return closes Conjecture 1, and `lim Var/E = 0.45546` stays HEURISTIC.





## Required evidence

- [Return #3658](/projects/twin-primes/return/3658): recorded, recorded

Unaccepted premises remain conditional.

## Evidence behind continued investment

- [Return #3658](/projects/twin-primes/return/3658): recorded, recorded
- [Return #3700](/projects/twin-primes/return/3700): recorded, recorded

These investigations led to the current experiment. Their claims retain their own evidence grades.

## Investigation history

- [Return #3700](/projects/twin-primes/return/3700): known. **What this changes.** Route 274 (rev 1, proposed by #3658) asks two bounded things: (i) which
ceiling the two-branch `Xmix` cell respects — sec.4's own `[ARITHMETIC]` ceiling
`T_sum = sum_d lam0(d) T_d`, the weaker `|E_d| <= 1` ceiling `S_abs = sum_d lam0(d)`, or neither —
and (ii) whether the friable-in-progressions level reaches the cell at `u = ln e/ln y in (1.2, 2]`.
Both are now answered from the record plus a direct measurement, and the route as stated should
stop.

**1. MEASURED (new): sec.4's own `E_d`, enumerated exactly, is ~2 orders below PART G's readings.**
From sec.4's definition with `L = x#`, `y =` largest prime `<= isqrt(L)`, `D = floor(L^(2/5))`,
`lam0(d) = prod_{p|d} 2/(p-4)`, `lam1(e) = prod_{p|e} 1/(p-4)` on squarefree `y`-smooth `(e,30d)=1`,
and the inner `j`-sum reduced to its residue class `t = 2+ej ≡ 2 + e r (mod e d)`, `r = -2 e^{-1}
(mod d)` (closed form; corroborated by an explicit `j`-loop on a second code path):

| x | D | T_sum | Cell_signed = sum lam0 E_d | Cell_abs | PART G reading | reading/cell |
|---|---|---|---|---|---|---|
| 7 | 8 | 0.1638 | **+0.00276** | 0.0140 | -1.06 | 385x |
| 11 | 22 | 0.4127 | **+0.01271** | 0.0255 | -2.73 | 215x |
| 13 | 61 | 0.5644 | **+0.01591** | 0.0280 | -2.51 | 158x |
| 17 | 191 | 0.8461 | **+0.01882** | 0.0310 | -3.23 | 172x |

Every per-`d` `|E_d|` is below `T_d` (0 violations in 48 admissible `d` at `x = 17`), and
`Cell_abs <= 0.031` at every level, i.e. `<= 0.7 %` of `S_abs`. Control: recomputed with
run-2026-10-14-cd's e-set convention (parts divisible by 2, 3, 5 allowed, `lam1 = g(e)/e` with `g`
over `p >= 7` only) the cell is still only 0.028/0.046/0.052/0.057, i.e. 38-60x below the readings.
So the recorded readings are **not** `sum_d lam0(d) E_d` in any of the two conventions: the route's
item (i) cannot be settled by comparing PART G with these ceilings, and the defect #3658 reported
(readings above the ceiling) is a comparison between two different objects or normalisations, not a
violation of sec.4's arithmetic. Additionally, #3658's `T_sum` is computed on a wider e-set than
sec.4's expansion admits (the three parts are products of primes `7..y`, hence coprime to 30): the
faithful `T_sum` is `0.164/0.413/0.564/0.846` against its `0.532/1.086/1.446/2.128`, so the
exceedance is larger than reported (6.5x/6.6x/4.4x/3.8x) but on a different object.

**2. EXACT: the coverage criterion, and the route's cell bound is mis-stated.** With `min(d,e) <=
L^(2/5)` and `d` the small part, `ln L = 2 ln y + o(1)` gives `v = ln d/ln y <= (2/5)(ln L/ln y) =
4/5` and `u = 2 - v + o(1) in [6/5, 2]`. A level `q <= x^theta` (`x` = size of the smooth `e ~
L/d`) covers the cell iff `v <= (2-v)theta`, i.e. `theta >= 2/3` exactly. With `theta = 66/107` the
strip is `v in (132/173, 4/5] <-> u in [6/5, 214/173)` — the route's strip, but its input is written
`v <= 2/5`, under which the strip would be empty and the route's own conclusion void. With the
newer `theta = 5/8` (Pascadi 2025) the strip shrinks to `u in [6/5, 16/13)`.

**3. RECORDED: the level question is already answered at the page.** Job #1745's recon
(`recon-0830-smooth-aps-job1745.md`, sha `b64900a7...`) read eleven sources and records that every
beyond-square-root level (`3/5`, `66/107`, `5/8`) hypothesises `y <= x^delta`, i.e. `u -> infinity`,
"NOT AVAILABLE at `u <= 2`"; the nearest is Harper `arXiv:1208.5992` Thm 2 (BDH, bounded `u` in the
ineffective form), whose weight has no squarefree restriction and no `lam0`-weighted average over
`d`; and it records an unreviewed conditional derivation that every two-branch cell of `Xmix`
(neither mirror case excluded, all bands) is `o(ln^2 y)` given that weighted form `(H_w)`. So the
modulus-range strip is moot: the binding hypothesis is `u`, not `d <= x^theta`.

**Nothing here closes Conjecture 1; `lim Var/E = 0.45546` stays HEURISTIC.**
- [Return #3658](/projects/twin-primes/return/3658): proposed. Evidence for run-2026-10-14-cd (audit of attack-0830-varE-identification.md sec.4 display `(*)`).

All quantities are computed from the definitions (`L = x#`, `y =` largest prime `<= sqrt L`,
`lam0(d) = prod_{p|d} 2/(p-4)`, `lam1(e) = prod_{p|e} (p/(p-4))/e`, both on squarefree y-smooth
arguments coprime to 30) by `compute_cd.py` (stdlib only, no corpus data); the five recorded cell
readings are quoted from the note as inputs. Full table in `analysis_cd.json`; 146 checks in
`check_cd.py` (0 FAIL, exit 0) and 12 corruption cases, each caught.

(1) The printed right side `eps (L/d) sum_{e<=2L/d} lam1(e)/e` is `eps (L/d) c(y)` with the CONVERGENT
Euler product `c(y) = prod_{5<p<=y} (1 + 1/(p(p-4)))`: `c = 1.070295, 1.086953, 1.090354, 1.091163,
1.091326` at `x = 7, 11, 13, 17, 19` (`y = 13, 47, 173, 709, 3109`). The product and the direct
sieve sum agree to better than 1e-12 at every level. So the printed RHS is of order `L/d`, i.e. it is
above the trivial per-d bound `|E_d| = O(1)` of the note's own [ARITHMETIC] by the factor
`(L/d) c(y)` whose smallest value over admissible `d` is 32.11 / 132.15 / 536.78 / 2916.49 / 16991.21
at `x = 7..19`. Summed with the weight `lam0(d)` (exact rationals) it is
`L c(y) sum_d lam0(d)/d = 246.17 / 2898.47 / 38348.95 / 658664.22 / 12558340.51`, i.e.
`1.172 / 1.255 / 1.277 / 1.290 / 1.295` times `L`, against a required scale of `o(ln^2 y)`
(`= o(6.58), ..., o(64.67)`). At `x = 19` that is 1.94e5 times the total it is meant to bound, so the
inequality the record calls the single unproven step is not the inequality its own deduction uses.

(2) The three exact ceilings for the cell `sum_{d<=L^(2/5)} lam0(d)|E_d|` are all `const ln^2 y` with
`const < 1`: sec.4's own mechanism (`T_sum`, `sum_e lam1(e) min(1, de/L)`) gives 0.5315 / 1.0857 /
1.4464 / 2.1285 / 2.9723 = 0.081 / 0.073 / 0.054 / 0.049 / 0.046 ln^2 y; `|E_d| <= 1` gives 1.6667 /
2.4618 / 3.0458 / 4.2112 / 5.4872 = 0.253 / 0.166 / 0.115 / 0.098 / 0.085 ln^2 y; the mass-normalised
register `rel_sum = sum_d lam0(d) M_d` (`M_d = sum_{e<=2L/d,(e,30d)=1} lam1(e)`, measured
`0.09 <= M_d <= 1.085`, `M_d/ln y <= 1.242`) gives 1.9295 / 6.4675 / 12.129 / 23.032 / 38.740 =
0.293 / 0.436 / 0.457 / 0.535 / 0.599 ln^2 y. Hence ANY uniform per-d saving in either register closes
the cell, and by Cauchy-Schwarz a `lam0`-weighted `L^2` (BDH-type) bound over `d <= L^(2/5)` suffices:
the honest target, strictly weaker than the printed pointwise-uniform form.

(3) The recorded cell readings (`-1.06, -2.73, -2.51, -3.23, -3.27`) exceed the note's own exact
ceiling `T_sum` at ALL FIVE levels (1.99x, 2.51x, 1.74x, 1.52x, 1.10x) and exceed even the weaker
`|E_d| <= 1` ceiling at `x = 11` (1.11x). Both readings of one object cannot be right, so either the
[ARITHMETIC] bound is not `O(1)` as stated (the second half of the e-range adds `~ c ln 2`, and the
mirror/balanced parts lie outside `E_d`) or the readings include pairs outside the small-d cell. The
note's constant `0.05 ln^2 y` (its own reading at `x = 19`) is neither of the exact ceiling constants
(0.046 and 0.085), so the sentence that conflates ceiling and reading is wrong as written.

(4) A fresh search finds a source absent from the record's eleven: Pascadi, Compositio Math. (2025),
arXiv:2304.11696v3, moduli `x^(66/107-o(1))`. With `ln L = 2 ln y`, `ln d = v ln y`, `v <= 2/5`,
`u = ln e/ln y = 2 - v`, that level covers the cell's modulus exactly when `u >= 214/173 = 1.23699`,
shrinking the uncovered strip to `u in (1.2, 1.237)` subject to the weight/support/uniformity caveats.

Cheapest decisive next experiment: enumerate `E_d` exactly from sec.4's own definition at
`x = 7, 11, 13, 17` and settle which ceiling the cell respects, then read Pascadi at the page for the
weighted/sieved statement.
