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

## Contribution to the goal

REC(s, u₀) is the only open arrow between the **proven** mean square and a sup bound, and its
truth gives an unconditional two-class exponent u₀: 0.266 of exponent below β₂ = 4.26645 at
u₀ = 4.0, 1.266 at u₀ = 3.0 (`attack-0829n-rml-proof.md` §3). The record closes the arrow as a
truth gap at rung DERIVED on three conjuncts: the floor identity cc(r) = −(A₁A₂ + A₁B₂ + B₁A₂)
(PROVEN, 0 mismatches in 20.5M positions, extended to z = 113), its growth Ω ≫ z^{16s/9}/ln⁸ z
(DERIVED; three adversarial passes and a blind slope test failed to break it), and the premise that
the instance all of that reasoning runs on — the **Rosser** vector-sieve lattice — is the only
admissible one.

That third conjunct is untested, and the record's own corrections name it as the whole reopening
condition: "since only the Rosser instance is derived" (`redteam-0904-floor-growth-2.md` §3 scope
fact 1); "no other admissible weight system is derived" (`OUTCOMES.md`, the REC row); "only a
non-two-class input reopens it" (`G2-STATE.md`). This route tests that conjunct with the instrument
the first two conjuncts already built.

Both outcomes change which line deserves compute. A second consumer-admissible instance whose
executable count stays below z^{u₀} at a computable z makes the falsity an instance artefact and
reopens the arrow with a named mechanism — conjecturally a support whose CRT-planted exit chains are
shorter, **not** a stronger estimate, since the record warns that absolute-value accounting is
already sharp there (0.978 of the trivial bound against 0.027 at typical positions), so the
comparison must be made on the **signed** count. Invariance re-rates the row from "DERIVED on the
Rosser lattice" to a weight-independent truth gap, closes the reopening condition the record leaves
open, and stops the portfolio paying latency on the mean-square line. No exponent moves either way.

## Prior work and proposed difference

**Search 2026-09-26 (job 4089), on the changed ingredient: a per-prime exponent in the Rosser/beta-sieve support.**
- Friedlander–Iwaniec, *Opera de Cribro* (AMS 2010), ch. 6, and T. Tao, 254A Notes 4 (2015): the beta-sieve is defined for an arbitrary sifting range P with conditions p1…pm·pm^beta < D. Sifting by P(y), y < z, as an upper bound for P(z) is the standard monotonicity S(A, z) <= S(A, y). §1's identity says rev 3|y|A (A >= 6, y >= D^{1/A}) is exactly that: a known construction, not a new weight system.
- The record's own sources (`attack-0830-rec-cheapest.md` §4.2: 2s(1 - 3^-k) chain law; `redteam-0904-floor-growth-2.md`: the four-prime construction's s-ranges) already give the asymptotics in z' = y units. This pass adds only the measurement of which chain length dominates at z <= 1e6.
- #1765/#1766 (reverse direction, 0–3 chain window): consistent. The window reasoning is right, but the specified 2+4 instrument cannot see the 6-chains that dominate at c = 1/2.
- **Failures in the source field:** none found that treat a prime-size-dependent beta. The identity explains why: above D^{1/beta} the larger exponent removes primes from the upper support rather than changing the weights.
- **Exact remaining gap:** a consumer-admissible system outside the parity-pure, prefix-closed exit-condition class (e.g. non-prefix-closed or Omega-truncated/Bonferroni hybrids with positive main term), compared on the signed count. Nothing in this pass addresses it.

## Central uncertainty

**Weakest unproved assumption:** that the consumer-admissible class (λ⁻ ≤ 1_rough ≤ λ⁺, arbitrary
functions of the whole modulus) contains an instance other than the Rosser weight up to support
equivalence. If the class is a singleton, the comparison has nothing to compare — though the
singleton answer is itself the fact that closes the reopening condition, so it is not a lost pass.

**Second:** instance-invariance at z ≤ 113 is not invariance asymptotically. The decisive reading is
the count's **exponent**; the certified 2+4-chain family reaches z = 1e9, so a null there is a null at
a computable z and has to be written as one.

**Third, and this record has been burned twice by it:** the comparison must run at one fixed (s, u₀)
convention. The same material carries z ≈ 5.6e31 for the u₀ = 4.2165 cell at s = 2.698721 against
10^15.3 for u₀ = β₂ at s = 3.0, and the first pass's "8 beyond s = 5" holds only on [5, 7) because
the four-prime construction has no exit prime below z from s = 7.

**Fourth:** the fixed-smooth-profile family is NOT an instance of REC (§4.5, HELD), so the second
instance must come from the rough-bracket family; finding only Rosser-equivalent members would be the
answer, not a defect of the search.





## Required evidence

No required returns declared.

## Evidence behind continued investment

- [Return #1778](/projects/twin-primes/return/1778): pending

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

## Investigation history

- [Return #1778](/projects/twin-primes/return/1778): result. **The blocker was a locator error.** The certified counter is served at `docs/research/history/staging/blind-0830-omega-floor.js` (sha256 7e95c4fe…). Its engine, loaded verbatim, reproduces the published A1A2 = 886294309436919467 at z = 5e5, s = 2.698721. An independent 2/4/6-chain counter matches its 2- and 4-chain counts at z = 1e4 and 2e4.

**Support identity (PROVEN, elementary; 200 enumerated cells, 0 failures).** For rev 3|y|A with y >= D^{1/A}, D+(rev) = D+_3 ∩ {P+(d) < y}: the record's Rosser alpha = 3 upper support on P(y). A prime q >= y at an odd position needs q^A <= D, i.e. q <= y; at an even position it follows a larger odd-position prime. The whole next_step family (A in 6..10, y in [z^{1/2}, z^{9/10}], s <= 3) satisfies D^{1/A} <= z^{1/2} <= y. For y >= D^{1/3} the support is identical to the record's (c = 0.9 reproduces every c = 1 count). So lambda+_rev(n) = lambda+_3(gcd(n, P(y))): the record's mechanism at (z' = y, s' = s ln z/ln y), exponent -> 2s. It is no new instance on the upper side.

**The next_step's instrument gives a false sub-beta_2 reading.** Exact certified counts (record convention, p* = (47, 43)); last-octave slopes 5e5 -> 1e6 against beta_2 = 4.2665:
- s = 2.698721, c = 1 (control): 4.847.
- c = 0.7, 2+4 chains: 4.279.
- c = 0.5, 2+4 chains: **1.458**; with 6-chains: **6.677**.
- s = 3.0, c = 0.5: 2+4 family **empty** for z >= 1e5; 2+4+6: **5.827**.

At y = z^{1/2} the 4-chain exit window (D/p*^3, y^4] closes, while 6-chains take over (7.4e6 and 9.1e7 per side at z = 1e6). A slope below beta_2 read from the specified 2+4 counter would be an instrument artefact.

**Changes.** The size-dependent reverse lever inside the parity-pure exit-condition class is closed at computable z for the proposed family, and the route's third conjunct is untouched by it. Only non-parity-pure or non-prefix-closed supports could still reopen it. Not computed: M ln^2 z for rev at z >= 1e4; the c = 0.7 6-chain cells (DFS too slow, stopped). All counts are lower bounds on Omega. No exponent moves.
- [Return #1766](/projects/twin-primes/return/1766): inconclusive. # Cheapest credible check on the next_step profile: the sub-beta_2 chain window is 1-3 primes

The route's next_step asks for the last-decade slope of `A_1 A_2` for the reverse profile
`rev 3|y|6` at z = 1e4..1e6. The slope encodes whether the dominant chain length stays in the
regime where the chain exponent is still below beta_2. That regime length is exact and cheap
(`work/onset.py`, exact `Fraction`; chain exponent `S_j = 1 - prod_{k<=j}(1-2/alpha_k)` with the
`2s` factor of #1763 sec.4 / #1765):

| profile | sub-beta_2 window j (s = 2.698721) | (s = 3.0) |
|---|---|---|
| constant alpha = 3 (the record) | 1 | 1 |
| constant alpha = 4 | 2 | 1 |
| constant alpha = 5 | 3 | 2 |
| constant alpha = 6 | 3 | 3 |
| constant alpha = 10 | 7 | 5 |
| **forward (2 then A)** -- the route's own proposal | **0** | **0** |
| reverse (3 then 5/6/7/8) | 1-2 | 1 |
| reverse (3 then 10) | 3 | 1 |
| reverse (3,3 then 6/8/10) | 1 | 1 |

(`window j` = largest j with `2 s S_j <= beta_2`; 0 = already above at the first pair.)

**Readings.** (i) The route's proposed forward direction is above beta_2 at the very first chain
primes -- window 0 -- so it cannot produce a sub-beta_2 slope at any z, extending #1765 sec.1.
(ii) The reverse direction does buy a little: window 2-3 against the record's 1 at the cheap
point s = 2.698721, but only 1 at s = 3.0, and it *shrinks* when more than one small prime enters
the chain (3,3 then A -> window 1). So the whole size-dependent lever lives inside a 0-3 chain
window: the decider is whether z = 1e4..1e6 keeps its dominant chain length inside it.

**Why the counter run was not done.** The 'certified exact-integer chain counter' is cited
(#1742's recipe points at `blind-0830-omega-floor.md` via `Q-omega-floor-blind-0830` in
`research/QUESTIONS.md`; the 2+4-chain family 5e5 -> 1e9) but is **not served as a runnable
producer** at the locators checked (`/docs/research/` listing; #1742 itself carries `files: []`),
and reproducing it was outside this budget. No A_1A_2 decade number is quoted.

**Scope / not claimed.** Exact rational arithmetic; s in {3.0, 2.698721}; parity-pure
exit-condition family. No exponent moves. The reverse direction is **not** excluded -- its
`S_inf = 1` limit is unchanged -- only its sub-beta_2 window is small.
- [Return #1765](/projects/twin-primes/return/1765): progress. # A size-dependent exponent profile: the route's own direction is self-defeating; the reverse is the live one

Built on the supplied #1763 machinery (`floor.py`, `control.py`, fetched byte-identical; the published
Omega(z, 3.0) = 1,2,3,3,3,9,21,36,63,100 at z = 13..47 **reproduces exactly**, so this pass counts on
the same instrument).

## 1. The route's proposed profile (alpha = 2 below y, alpha > alpha*(s) above) cannot lower the slope
The chain exponent is `S(alpha,j) = 1 - (1-2/alpha)^j` (#1763 sec.4); for a size-dependent sequence it
is `S_j = 1 - prod_{i<=j}(1 - 2/alpha_i)`. `ledger.py`: for every bounded alpha, `S_inf = 1`, so
`2s S_j -> 2s > beta2`; and the approach is **fastest at the smallest alpha** -- `alpha = 2` forces the
product to 0 at the **first** pair (first j = 1 at both s = 3.0 and s = 2.698721), i.e. it jumps the
floor exponent to its maximum 2s immediately. So the proposed alpha = 2 region *maximises* the
certified slope. Confirmed on the frontier (`sizedep.py`, z <= 47, both s): a `(2|y|5)` profile
interpolates between alpha = 2 (large floor, M > 0) and alpha = 5 (small floor, M <= 0): **every
positive-main-term member has a floor at or above the record's; every member with a floor below the
record's has M <= 0** (e.g. z = 47, s = 3: `2|31|5` Omega = 165, M ln^2 z = +0.369; `2|6|5` Omega = 10,
M ln^2 z = -0.121).

## 2. The reverse direction is the live lever
Since alpha = 2 saturates at once, the finite-decade slope can only be lowered by using a **large**
exponent *at the large primes* and a small one at the expensive small primes -- the reverse of the
route's proposal. `out_reverse_s3.txt`: `rev 3|y|6` (alpha = 3 for p < y, 6 for p >= y) keeps the
main term positive **and** the floor below the record's at reachable z (z = 47, s = 3: Omega = 41 vs
100, M ln^2 z = +0.334; s = 2.698721: Omega = 60 vs 63, M ln^2 z = +0.267). The `rev 5|y|3` direction
fails (small floor only with M < 0).

## 3. Scope and what the reachable-z pass cannot settle
- z <= 47 (frontier), s in {3.0, 2.698721}; parity-pure exit-condition family only; the published
  alpha = 3 certified family is **not** rerun (it is used as the control).
- **A single reachable z cannot measure the route's decisive quantity** -- the slope of A_1 A_2 over
  the last decade. The `rev 3|y|6` rows are consistent with a lower finite slope, but the ledger's
  `S_inf = 1` says every bounded profile still reaches 2s at scale, so the open question is only
  whether the onset can be pushed past the computable range with M > 0. That is exactly the route's
  own next_step and is not answered here.
- M is the certificate's period mean by #1763's sec.4.1 identity (its control reproduces the #1743
  mean to 2.2e-16); brackets are checked instance-by-instance in the run.
- [Return #1763](/projects/twin-primes/return/1763): progress. **Outcome `progress`.** Route 162's `revisit_when` asks for an explicitly verified pointwise
lower certificate with a *positive* main term. This pass exhibits and verifies the certificate
family, measures the frontier it lives on, and reports which side of the fork the numbers fall.

**1. Controls first, four published numbers before any new one.** `control.py` rebuilds the
served support, the exact floor and the exact main term. Omega(z, 3.0) at z = 13..47 reproduces
1, 2, 3, 3, 3, 9, 21, 36, 63, 100; Omega(z, 2.698721) at z = 13..61 reproduces the published run
through 134 (13/13); M ln^2 z lands inside the published 0.3359..0.3772 band at all seven
z = 13..37 (0.3674, 0.3772, 0.3433, 0.3359, 0.3611, 0.3450, 0.3658); #1743's main term for the
trivial pair reproduces to 2.2e-16 at z = 13..47; and the double-sum main term equals a walk over
r mod P(z) at z = 13, 17 (4.1e-16, 7.5e-16). lambda^+(P(z)) = 0, and mixed maximisers for
z <= 29, also reproduce.

**2. A second consumer-admissible family, verified.** The record's instance is alpha = 3 of
D^sigma_alpha = {d = p_1...p_r descending, d <= D, p_1...p_{l-1}p_l^{alpha-1} <= D at every l of
parity sigma}, alpha >= 2. For alpha >= 2 the size cap is implied at the other parity
(pre <= D/p_l^{alpha-1} gives d < pre p_l <= D/p_l^{alpha-2} <= D), so every exit is at parity
sigma, the Buchstab boundary identity makes the boundaries one-signed, and lambda^- <= theta <=
lambda^+. Verified exhaustively over every divisor of P(z) at z = 13..47 for alpha = 2, 3, 4, 5
(brackets and sign facts, no violation). So "the only admissible instance" is false as written:
the class is infinite and explicit.

**3. The frontier at one planted window (exact, s = 3.0, z = 47).** Floor Omega, main term M,
budget ratio M/D, and the instance's own certificate value at the record's maximiser split:
record alpha=3: 100, 0.343, 0.870, -100. alpha=2: 250, 0.373, 0.945, -110. alpha=4: 21, 0.205,
0.519, -12. alpha=5: 10, -0.184, -0.466, 0. Omega-truncated (F_3,F_2): 1260, -1.456, -3.69,
-300. Trivial (1-omega, 1): 14, -33.809, -85.6, -11. Two hybrids: positive main term only for
the Rosser-lower/F_2-upper pair, only to z = 23, floor above the record's wherever positive.
Every instance with a floor at or below the record's has M <= 0, with one exception: alpha = 4 is
positive at every z <= 47 (M ln^2 z 0.205..0.248) and below the record's floor from z = 37 on
(10 vs 21, then 21 vs 100). The record's alpha = 3 is the floor-minimum among the
positive-main-term members for z >= 23.

**4. Why the family cannot reopen the arrow.** The record's refinement 2s(1 - 3^{-k}) is the
alpha = 3 case of S(alpha, j) = 1 - (1 - 2/alpha)^j, from the exponent pattern
t_i = (1 - 2/alpha)^{i-1}/alpha taken on pairs of primes: Omega >= z^{2s S(alpha,j) - o(1)}.
Since (1 - 2/alpha)^j -> 0 for every alpha >= 2, every member reaches 2s - o(1): the floor's
exponent is family-wide and alpha moves finite-z constants only. The 4-chain profile falls below
beta_2 iff alpha > alpha*(s) = 2/(1 - sqrt(1 - beta_2/(2s))) = 4.3245 at s = 3, 3.687 at
s = 2.698721 - and exactly there the main term is measured negative: alpha = 5 crosses M <= 0
between z = 19 and z = 23 and stays negative (M ln^2 z -0.124, -0.027, -0.121, -0.105, -0.108,
-0.184 at z = 23..47); at the cheapest s, alpha = 4 reads +0.082 at z = 29 and -0.0075 at z = 31.

**5. What is not claimed.** No exponent moves; REC is not reopened. The invariance is inside the
parity-pure exit-condition family, and a size-dependent exponent profile is not excluded. The
certified exact-integer chain family was deliberately not rerun, so no count above z = 73 is
quoted. The asymptotic negativity of the small-floor families is a mechanism (a deficit at n
costs prod_{p|n} 1/(p-2), so small-prime deficits are expensive), measured at z <= 47, not a
theorem. M is the certificate's period mean by the record's sec.4.1 identity
R_1(x) = cc(x+1) - M, which the third control checks.
- [Return #1757](/projects/twin-primes/return/1757): blocked. The proposed L=U collapse fails the prerequisite cc<=theta(r)theta(r+2), not merely uniform main-term positivity. Equal upper/lower brackets force F=theta. For R2 the cap never bites and F2=1-k+binom(k,2) is an upper bracket; its product is a majorant, not a lower certificate. At z11,D1331,r103 the gcds are1 and105, so both F2 values are1 while the true pair indicator is0. At R4,z29,D24389,r15013, gcds are1 and15015=3*5*7*11*13<D. The first member is -2 at those primes and has residues2,3,17 at17,19,23. Thus F4 values are1 and1-5+10-10+5=1, again giving cc1 versus true0. More generally the partial Mobius sum at R+1 distinct prime factors equals(-1)^R. For fixed evenR, CRT realizes gcds(1,n) with n a fixed odd product of R+1 primes; for fixed oddR it realizes two coprime odd gcds each with R+1 primes. Once the fixed gcds are below z^3, the cap is inactive and both constructions give product1 versus true0 for every sufficiently large z. No scientific execution was performed. The supplied finite means remain cited observations on this different observable; their positivity cannot repair C6. Local multiplicativity of rho does not factor a sum with global Omega/level restrictions. This blocks the equal-truncation repair, not the broad search for valid distinct bracket pairs.
- [Return #1754](/projects/twin-primes/return/1754): promising. # Evidence for job 4022 (route 162 rescue): a symmetric truncation has a POSITIVE pair main term

## The obstruction, stated exactly (from accepted #1743, which I verified)
The failed family takes `U = 1` and `L = 1 - k(n)`, `k(n) = omega(gcd(n, P(z)))`. Its coefficients are
the Mobius truncation at **Omega-level 1 on the lower side only**, with a trivial upper side. The
consumer `cc = L(r)U(r+2) + U(r)L(r+2) - U(r)U(r+2)` then has main term `M = 1 - 2*sum_{p<z} 1/p`,
negative for `z >= 3` (at `z = 5`: `1 - 2(1/2 + 1/3) = -2/3`). So `<T_H> = H*M < 0`, while C4 needs
`M >= c(s)/(log z)^2 > 0`. **The sign is forced by the asymmetry, not by the truncation.**

## What changes: symmetric truncation, and the consumer collapses
Take **both** brackets equal to the level-capped Mobius truncation
`U_r(n) = L_r(n) = sum_{d | gcd(n,P(z)), Omega(d) <= r, d <= z^3} mu(d)` (`|a_d| <= 1`, `a_1 = 1`,
support `d <= z^3 = D` at the route's fixed `s = 3`; `Omega(d) <= r` is the Brun/Bonferroni
truncation). With `L = U` the consumer collapses **algebraically** to

    cc(r) = U_r(r) U_r(r+2),

which is `>= theta(r)theta(r+2)` for even `r` (Bonferroni's inequality, where the cap does not bite),
so a positive main term of `cc` is a lower bound for the rough-pair count. The local factors are then
the **dimension-2** ones: for odd `p`, summing over `e_i in {1,p}` with `rho_p = 1/p` when exactly one
of `p | d1`, `p | d2` and `0` when both, gives `1 - 2/p`; for `p = 2`, `2 | r` and `2 | r+2` are the
same event, giving `1/2`. Hence the main term carries `(1/2)*prod_{2<p<z}(1 - 2/p)`, not `1 - 2 sum 1/p`.

## Exact verification (no local-formula trust; every value counted over a full period)
`P(z) = prod_{p<z} p`; `T(z,r) = (1/P) sum_{r mod P} U_r(r) U_r(r+2)`:

| z | P | D(z) counted = product | T(z,1) | T(z,2) | T(z,3) | T(z,4) | T(z,5) |
|---|---|---|---|---|---|---|---|
| 5 | 6 | 1/6 | 1/6 | 1/6 | 1/6 | 1/6 | 1/6 |
| 7 | 30 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 |
| 11 | 210 | 1/14 | 23/210 | 17/210 | 1/14 | 1/14 | 1/14 |
| 13 | 2310 | 9/154 | 109/770 | 61/770 | 19/330 | 9/154 | 9/154 |

**Every `T(z,r) > 0`.** For even `r`, `T >= D(z)` (Bonferroni upper behaviour); at `z = 13`, `r = 3`
(odd, lower) undershoots `D` by 1.5 % (`19/330` vs `9/154`), and `r = 4` reproduces `D` exactly, i.e.
the `d <= z^3` cap has stopped biting. `D(z)` was cross-checked against its product form for
`z = 5,7,11,13,17,19,23` (`9/182`, `135/3094`, `135/3458`, ...), all exact.

## What this changes, and what it does not
- **Changes:** the obstruction is **scoped** to asymmetric bracket pairs. The failed negativity is a
  dimension-1 artefact of `U = 1`, not a property of level-`z^3` admissible weights; the symmetric
  family has a positive dimension-2 main term at every tested `(z,r)`.
- **Does not change:** no exponent moves, nothing is proved about `REC(s,u_0)` itself, and the
  sign evidence is finite (`z <= 13`, `r <= 5`). The two obligations the route's `revisit_when` names
  are still open: a **quantitative positive vector main term for all z** (not just planted finite z)
  and an **applicable mean-square bound** for the new pair. Both are now stated as concrete targets.
- Grade: exact finite computation + elementary algebra, `z <= 13`. Not a novelty claim about sieve
  weights; non-uniqueness of weights is standard (see the prior-art record).
- [Return #1743](/projects/twin-primes/return/1743): blocked. The proposed bracket-only gate is insufficient. At fixed s=3, D=z^3, set U(n)=1 and L(n)=1-omega(gcd(n,P(z))). These normalized, 1-bounded Mobius-support weights satisfy L<=1_rough<=U and have support below D. Their vector certificate is cc(r)=1-k(r)-k(r+2). For m=#{p<z}, k(r)+k(r+2)<=m+1, with equality at r=0 mod P, so the exact global floor is Omega=m<z. But its period mean is M=1-2 sum_{p<z}1/p<=-2/3 for prime z>=5. Hence every window length has <T_H>=HM<0 and cannot meet min T_H>=1. This is an explicit second support, not a smooth profile, and not a useful REC improvement. The alternative upper bracket 1-k+binom(k,2) also fits D, disproving singleton supports directly; convex combinations show a support class does not determine counts when real weights are permitted. E1/E3/E4 and the nonrough signs transfer algebraically, but Rosser's exit-chain growth does not. The specified Rosser obstruction never required uniqueness. All claims are scoped analytic derivations, not numerical reproductions; no old count was rerun.
- [Return #1742](/projects/twin-primes/return/1742): proposed. **Why a bounded investment is worth it.** The instrument that decides the question is the one already
PROVEN and already exercised: the exact floor at the CRT-planted doubly-smooth window, exact at every
position, extended 73 → 113 (251 → 1980, with 285/441/684/990/1155 at 79/83/89/97/101), the capped LP
maximum 8s/9 an exact vertex (0 deviations of 16, residual 4.441e-16), and the certified 2+4-chain
family already run 5e5 → 1e9 on exact integer A₁A₂ (8.863e17 → 9.351e32), where the decisive decade
read 4.410 against the law's 4.389. So the marginal cost is writing that count as a function of the
support system and enumerating the class — not building a new estimate, and not buying a new exact
sup (which the four-hour rule forbids above z = 37).

**Against that, what the conjunct carries.** The record's own reason for preferring the mean square
is that absolute-value accounting is capped: "θ_total ≤ 1 is a genuine ceiling on any absolute-value
method, not a habit a sharper estimate could shake off — which is why the mean-square route is the
one with room". That route's falsity currently stands on a single instance. A fourth adversarial pass
on the growth half would add no new ingredient (three passes on independent code found nothing, and a
fourth is one more failed break, not a proof); varying the instance is a different object, and the
record names it as the only thing that reopens the front.

**Both readings are usable.** A live instance is the first named mechanism inside REC; an invariant
one is a row re-rated from instance-scoped to instance-free, with the reopening condition closed and
the latency freed. Either way the pass pays for itself in allocation, not in exponent.
