> Full-text translation from Chinese. The original remains authoritative for its research claims; this translation is not independent mathematical verification.

# TCDC-06
## Strict-Pressure Extra-Cost Ledger / Branch-Neutral Two-Sink Closure
### Generalized Half-Weight, Coarse-Cutoff Optimization, Prime Strictness Tax, Separate-Upper No-Go, and TCDC Branch-Neutral Capacity Reformulation

**Parent methodology:** TCDC — Target–Condition Dual Closure  
**Linked research lines:** RG-SCP / SRBRD  
**Round:** TCDC-06  
**Date:** 2026-10-02  
**Version:** v0.1  
**Authors:** Neo.K; Aletheia (GPT-5.6 Sol)  
**Nature:** Weighted-Sieve Optimization / Parity-Tax Audit / Failure-Capacity Reformulation  
**Prerequisites:** TCDC-00 through TCDC-05; SRBRD-00 through SRBRD-26  
**Status:** Generalizes the TCDC-05 half-weight to any coarse cutoff $w<z$; proves that quarter root is not a combinatorial necessity; under the current $3/5$ sieve, the pre-extra-cost margin is numerically maximal near $u\approx7.8$ at approximately $0.4067$; the standard separate prime upper bound remains too loose; proposes branch-neutral $P_2$ mass + dual-sink TCDC capacity as the main alternative to the strict parity tax; Goldbach remains unproved

---

# 0. This Round First Corrects the TCDC-05 Cutoff Interpretation

TCDC-05 fixes:

$$
w=X^{1/4},
$$

The principal reason is:

$$
\operatorname{RootRough}_w(y)
\Longrightarrow
y\in P_1\cup P_2\cup P_3.
$$

This makes the pointwise state table finite and simple.

However, on closer inspection,

what the strict-semiprime half-weight actually needs is not:

$$
\Omega(y)\le3.
$$

It needs only:

> Any composite coarse survivor,
> unless it is the desired:
> $$
> P_2
> \text{ with all factors }>z,
> $$
> has at least one prime factor in:
> $$
> (w,z].
> $$

This uses only:

$$
z^3\ge X.
$$

Thus, quarter root is not necessary for the validity of the pointwise weight.

---

# 1. General Coarse Cutoff

Take:

$$
\boxed{
2\le w<z,
}
$$

and:

$$
\boxed{
z^3\ge X.
}
$$

We do not require:

$$
w^4\ge X.
$$

Define:

$$
\boxed{
\nu_{w,z}(y)
=
\sum_{\substack{
\ell\in\mathbb P\\
w<\ell\le z
}}
v_\ell(y).
}
$$

and:

$$
\boxed{
E_1(y)
=
\mathbf1_{\{
y\text{ composite},
\operatorname{RootRough}_w(y),
\nu_{w,z}(y)=1
\}}.
}
$$

---

# 2. General Bad-Composite Lemma

## Theorem TCDC-06-T01

Suppose:

$$
3\le y\le X,
$$

and:

$$
\operatorname{RootRough}_w(y).
$$

If:

$$
y
$$

is composite,

but is not:

$$
\boxed{
y=q_1q_2,
\qquad
z<q_1\le q_2,
}
$$

then:

$$
\boxed{
\nu_{w,z}(y)\ge1.
}
$$

---

# 3. Proof of T01

Suppose, to the contrary:

$$
\nu_{w,z}(y)=0.
$$

Since:

$$
y
$$

is RootRough$_w$,

all prime factors are:

$$
>w.
$$

Also, no factor lies in:

$$
(w,z],
$$

so all prime factors are actually:

$$
>z.
$$

If:

$$
y
$$

has only two prime factors,

then it is precisely the desired:

$$
P_2^{>z},
$$

contradicting the assumption.

If it has at least three prime factors,

then:

$$
y>z^3\ge X,
$$

again contradicting:

$$
y\le X
$$

as displayed above.

Thus:

$$
\nu_{w,z}(y)\ge1.
$$

This completes the proof.

---

# 4. General Strict-Semiprime Half-Weight

Define:

$$
\boxed{
\omega_{w,z}^{strict}(y)
=
\mathbf1_{\operatorname{RootRough}_w(y)}
\left[
1
-
\mathbf1_{\mathbb P}(y)
-
\frac12\nu_{w,z}(y)
-
\frac12E_1(y)
\right].
}
$$

Desired indicator:

$$
\boxed{
H_z(y)
=
\mathbf1_{\{
y\text{ semiprime},
\operatorname{RootRough}_z(y)
\}}.
}
$$

---

# 5. Generalized Pointwise Theorem

## Theorem TCDC-06-T02

for all:

$$
3\le y\le X,
$$

$$
\boxed{
\omega_{w,z}^{strict}(y)
\le
H_z(y).
}
$$

This holds for any:

$$
2\le w<z,
$$

$$
z^3\ge X
$$

as displayed above.

Thus, the quarter-root theorem of TCDC-05 is merely the special case:

$$
w=X^{1/4}
$$

as displayed above.

---

# 6. Proof Sketch of T02

### Prime

$$
H_z=0.
$$

Meanwhile:

$$
1-\mathbf1_{\mathbb P}=0,
$$

the remaining medium term is nonpositive.

### Desired $P_2^{>z}$

$$
\nu=0,
$$

$$
E_1=0,
$$

Thus:

$$
\omega=1=H_z.
$$

### Any Other Composite

By T01:

$$
\nu\ge1.
$$

If:

$$
\nu=1,
$$

then:

$$
E_1=1,
$$

Thus:

$$
\omega=0.
$$

If:

$$
\nu\ge2,
$$

then:

$$
1-\frac12\nu\le0.
$$

This completes the proof.

---

# 7. Branch-Neutral Cube-Root Target

Define:

$$
\boxed{
G_z(y)
=
\mathbf1_{\operatorname{RootRough}_z(y)}.
}
$$

Since:

$$
z^3\ge X,
$$

For:

$$
3\le y\le X,
$$

we have:

$$
\boxed{
G_z(y)
=
\mathbf1_{\mathbb P}(y)
+
H_z(y).
}
$$

Thus:

# Branch-Neutral $P_2$ Mass

is:

$$
\boxed{
\text{prime branch}
+
\text{strict semiprime branch}.
}
$$

---

# 8. General Branch-Neutral Half-Weight

Define:

$$
\boxed{
\omega_{w,z}^{neutral}(y)
=
\mathbf1_{\operatorname{RootRough}_w(y)}
\left[
1
-
\frac12\nu_{w,z}(y)
-
\frac12E_1(y)
\right].
}
$$

---

# 9. Branch-Neutral Pointwise Theorem

## Theorem TCDC-06-T03

$$
\boxed{
\omega_{w,z}^{neutral}(y)
\le
G_z(y).
}
$$

The proof is the same as T02,

except that a prime is no longer treated as a bad branch.

For a prime:

- target:
  $$
  G_z=1;
  $$
- weight:
  $$
  1-\nu/2
  \le1.
  $$

Thus, it is admissible.

---

# 10. Strict Weight = Neutral Weight − Prime Tax

Exactly:

## Theorem TCDC-06-T04

$$
\boxed{
\omega_{w,z}^{strict}(y)
=
\omega_{w,z}^{neutral}(y)
-
\mathbf1_{\operatorname{RootRough}_w(y)}
\mathbf1_{\mathbb P}(y).
}
$$

But primes are always RootRough$_w$,

Thus:

$$
\boxed{
\omega_{w,z}^{strict}
=
\omega_{w,z}^{neutral}
-
\mathbf1_{\mathbb P}.
}
$$

This fully isolates the strictness cost as:

# Prime Tax

---

# 11. Prime-Tax Coefficient Is Unavoidable Locally

Consider any local weight:

$$
\boxed{
\mathbf1_{\operatorname{RootRough}_w}
\left[
1
-
c_P\mathbf1_{\mathbb P}
-
\text{other nonnegative penalties}
\right]
}
$$

where, for a prime:

$$
y>z,
$$

all other medium penalties are:

$$
0.
$$

To lower-bound the strict semiprime indicator pointwise:

$$
H_z(y)=0,
$$

one must have:

## Theorem TCDC-06-T05

$$
\boxed{
c_P\ge1.
}
$$

Thus:

$$
\boxed{
\text{A strict-semiprime local selector must pay the full prime-branch coefficient }1.
}
$$

This is the:

# Local Strictness Tax

---

# 12. Sum-Level Notation

On the high-suffix base:

$$
\mathcal A_\lambda,
$$

Define:

$$
A_1(w)
=
\#\{
(r,p)\in\mathcal A_\lambda:
\operatorname{RootRough}_w(y)
\}.
$$

Medium multiplicity:

$$
A_2(w,z)
=
\sum_{\substack{
(r,p)\in\mathcal A_\lambda\\
\operatorname{RootRough}_w(y)
}}
\nu_{w,z}(y).
$$

Exactly-one correction:

$$
E(w,z)
=
\sum
E_1(y).
$$

Prime branch:

$$
A_P=P_\lambda.
$$

---

# 13. Neutral Weighted Lower

Summing T03:

## Theorem TCDC-06-T06

$$
\boxed{
S_\lambda(z)
\ge
A_1
-
\frac12A_2
-
\frac12E.
}
$$

This lower-bounds:

$$
\boxed{
P_\lambda+\Pi_\lambda.
}
$$

There is no need to distinguish the parity branches within the sieve.

---

# 14. Strict Weighted Lower

Summing T02:

## Theorem TCDC-06-T07

$$
\boxed{
\Pi_\lambda
\ge
A_1
-
A_P
-
\frac12A_2
-
\frac12E.
}
$$

Thus:

$$
\boxed{
\text{strict route}
=
\text{neutral route}
-
A_P.
}
$$

---

# 15. Parameterize the Coarse Cutoff

Let:

$$
\boxed{
w=X^{1/u},
}
$$

where:

$$
u>3.
$$

Current distribution benchmark:

$$
\boxed{
\theta=3/5.
}
$$

Coarse lower-sieve parameter:

$$
\boxed{
s_0=u\theta=\frac{3u}{5}.
}
$$

A positive lower linear sieve requires:

$$
s_0>2,
$$

That is:

$$
\boxed{
u>10/3.
}
$$

---

# 16. Medium Upper-Sieve Endpoint Condition

Medium prime:

$$
\ell=X^v,
$$

$$
1/u\le v\le1/3.
$$

Remaining distribution level:

$$
D/\ell.
$$

Relative to:

$$
w=X^{1/u},
$$

Upper-sieve parameter:

$$
\boxed{
s_\ell
=
u(\theta-v).
}
$$

The minimum occurs at:

$$
v=1/3.
$$

Thus:

$$
s_\ell>1
$$

throughout the full medium interval requires:

## Theorem TCDC-06-T08

$$
\boxed{
u>\frac{15}{4}.
}
$$

This matches the sign threshold of TCDC-05 exactly.

---

# 17. Explicit Constant Window

When:

$$
\boxed{
15/4<u\le20/3,
}
$$

we have:

$$
2<s_0\le4,
$$

and:

$$
1<s_\ell\le3.
$$

Thus, the explicit standard linear-sieve formulas can be used:

$$
f_1(s)
=
\frac{
2e^\gamma
}{s}
\log(s-1),
$$

$$
F_1(s)
=
\frac{
2e^\gamma
}{s}.
$$

---

# 18. Coarse Lower Constant

In the standard normalization:

## Theorem TCDC-06-T09

$$
\boxed{
C_0(u)
=
f_1(3u/5)
=
\frac{
10e^\gamma
}{
3u
}
\log
\left(
\frac{
3u-5
}{5}
\right).
}
$$

---

# 19. Medium First-Order Constant

Medium multiplicity upper bound:

$$
\boxed{
C_{\mathrm{med}}(u)
=
\int_{1/u}^{1/3}
F_1
\left(
u(3/5-v)
\right)
\frac{dv}{v}.
}
$$

Direct integration gives:

## Theorem TCDC-06-T10

$$
\boxed{
C_{\mathrm{med}}(u)
=
\frac{
10e^\gamma
}{
3u
}
\log
\left(
\frac{
3u-5
}{4}
\right).
}
$$

---

# 20. Neutral Core Margin

Before the exactly-one correction:

$$
\boxed{
C_{\mathrm{core}}(u)
=
C_0(u)
-
\frac12C_{\mathrm{med}}(u).
}
$$

Thus:

## Theorem TCDC-06-T11

$$
\boxed{
C_{\mathrm{core}}(u)
=
\frac{
5e^\gamma
}{
3u
}
\log
\left(
\frac{
4(3u-5)
}{
25
}
\right).
}
$$

---

# 21. Exact Positivity Threshold

T11：

$$
C_{\mathrm{core}}(u)>0
$$

iff:

$$
\frac{
4(3u-5)
}{
25
}
>1.
$$

Thus:

## Corollary TCDC-06-C01

$$
\boxed{
C_{\mathrm{core}}(u)>0
\iff
u>15/4
}
$$

inside the explicit window.

This is exactly the same as T08.

Thus:

> When the upper-sieve endpoint first enters the admissible regime,
> the half-weight core also turns positive.

---

# 22. Explicit Constant Table

| $u$ | $C_0(u)$ | $C_{\mathrm{med}}(u)$ | $C_{\mathrm{core}}(u)$ |
|---:|---:|---:|---:|
| $4$ | $0.499401$ | $0.830597$ | $0.084103$ |
| $5$ | $0.823030$ | $1.087987$ | $0.279037$ |
| $20/3$ | $0.978354$ | $1.177071$ | $0.389818$ |

Thus:

$$
\boxed{
\text{quarter-root }u=4
\text{ is far from optimal even before extra costs}.
}
$$

---

# 23. Monotonicity on the Explicit Window

The derivative sign in T11 is controlled by:

$$
\frac{
3u
}{
3u-5
}
-
\log
\left(
\frac{
4(3u-5)
}{
25
}
\right)
$$

as displayed above.

This quantity, on:

$$
[15/4,20/3]
$$

decreases monotonically,

and at:

$$
u=20/3
$$

is still positive.

Thus:

## Theorem TCDC-06-T12

$$
\boxed{
C_{\mathrm{core}}(u)
\text{ strictly increases on }
(15/4,20/3].
}
$$

---

# 24. Beyond $u=20/3$

When:

$$
u>20/3,
$$

The linear-sieve functions enter subsequent delay-differential segments.

The pointwise T03 remains fully admissible;

only:

$$
F_1,
\quad
f_1
$$

are no longer represented by the elementary closed forms of the first two segments.

Numerical evaluation using the classical delay-differential equations gives:

as follows:

## Computational Diagnostic TCDC-06-D01

$$
\boxed{
C_{\mathrm{core}}(u)
}
$$

near:

$$
u\approx7.806
$$

attains approximately:

$$
\boxed{
0.406677.
}
$$

---

# 25. The $u=8$ Benchmark

Take:

$$
\boxed{
u=8,
\qquad
w=X^{1/8}.
}
$$

Standard linear-sieve numerical values:

$$
\boxed{
C_0(8)
\approx
0.997028,
}
$$

$$
\boxed{
C_{\mathrm{med}}(8)
\approx
1.181542,
}
$$

Thus:

## Diagnostic TCDC-06-D02

$$
\boxed{
C_{\mathrm{core}}(8)
\approx
0.406257.
}
$$

This is very close to the D01 optimum.

---

# 26. Relation to Classical Chen's $x^{1/8}$ Cutoff

Classical expositions of Chen often choose:

$$
z_{\mathrm{Chen}}
=
x^{1/8}.
$$

This round does not directly copy Chen's cutoff:

$$
1/8.
$$

Instead, after re-optimizing the cutoff using:

- the current:
  $$
  \theta=3/5;
  $$
- generalized strict / neutral half-weight;
- standard linear-sieve functions;

as listed above,

the numerical optimum naturally lies at:

$$
\boxed{
u\approx7.8,
}
$$

that is, very close to the exponent:

$$
1/8
$$

as displayed above.

This is a strong structural-consistency signal,

not a theorem identification.

---

# 27. Prime Branch: Standard Separate Upper

The strict route requires an upper bound on:

$$
A_P
$$

as displayed above.

If the same level:

$$
D=X^{3/5}
$$

is used,

then, to isolate a prime complement:

$$
y\le X,
$$

one can apply the upper sieve up to:

$$
\boxed{
Z_P=X^{1/2}.
}
$$

because every composite:

$$
y\le X
$$

has a prime divisor:

$$
\le\sqrt X.
$$

---

# 28. Prime Upper Sieve Parameter

$$
\boxed{
s_P
=
\frac{
\log D
}{
\log Z_P
}
=
\frac{
3/5
}{
1/2
}
=
\frac65.
}
$$

Thus:

$$
\boxed{
F_1(6/5)
=
\frac{
5e^\gamma
}{3}
\approx
2.968454.
}
$$

---

# 29. Euler-Product Ratio

Relative to the coarse cutoff:

$$
w=X^{1/u},
$$

the dimension-1 Euler product obeys:

$$
W(t)
\asymp
C/\log t.
$$

Thus:

## Diagnostic TCDC-06-D03

$$
\boxed{
\frac{
W(X^{1/2})
}{
W(X^{1/u})
}
\to
\frac{
2
}{u}.
}
$$

---

# 30. Standard Separate Prime-Cost Constant

Thus, the normalized main coefficient of the standard separate prime upper bound:

## Diagnostic TCDC-06-D04

$$
\boxed{
C_P^{\mathrm{std}}(u)
=
\frac{
2
}{u}
F_1(6/5)
=
\frac{
10e^\gamma
}{
3u
}.
}
$$

at:

$$
u=8,
$$

$$
\boxed{
C_P^{\mathrm{std}}(8)
\approx
0.742114.
}
$$

---

# 31. Standard Separate-Upper No-Go at $u=8$

Branch-neutral core:

$$
\boxed{
C_{\mathrm{core}}(8)
\approx0.406257.
}
$$

Standard prime upper bound:

$$
\boxed{
C_P^{\mathrm{std}}(8)
\approx0.742114.
}
$$

Thus:

## Diagnostic TCDC-06-D05

$$
\boxed{
C_{\mathrm{core}}(8)
-
C_P^{\mathrm{std}}(8)
\approx
-0.335857.
}
$$

This has not paid anything at all for:

$$
E_1.
$$

Therefore:

## Provider No-Go TCDC-06-N01

$$
\boxed{
\text{generalized half-weight}
+
\text{standard separate linear-sieve prime upper}
}
$$

cannot close strict pressure at:

$$
u=8.
$$

This is not a mathematical impossibility theorem;

it rejects this specific provider stack.

---

# 32. Ideal Prime Density Is Much Smaller Than the Standard Upper

If the prime branch had precisely the ideal sieve multiplier:

$$
1
$$

rather than:

$$
F_1(6/5),
$$

its normalized density ratio would be only approximately:

$$
\boxed{
C_P^{\mathrm{ideal}}(u)
=
2/u.
}
$$

at:

$$
u=8:
$$

$$
\boxed{
C_P^{\mathrm{ideal}}(8)
=
1/4.
}
$$

Thus:

$$
\boxed{
C_{\mathrm{core}}(8)
-
C_P^{\mathrm{ideal}}(8)
\approx
0.156257.
}
$$

before:

$$
E_1.
$$

---

# 33. Interpretation

The strict route is not purely combinatorially impossible.

The actual problem:

$$
\boxed{
\text{available / standard prime upper multiplier is far above ideal}.
}
$$

Thus, for the strict route to remain viable,

it needs:

- a near-asymptotic upper bound for balanced prime product + prime;
- a transport-assisted prime cost;
- or a different treatment of the branches.

---

# 34. Classical Chen Triple Benchmark

The triple-factor term of the classical Chen $x^{1/8}$ treatment has a normalized integral constant of approximately:

$$
0.363
$$

in Tao's exposition.

If, very crudely, one takes:

$$
\frac12\times0.363
\approx0.1815
$$

as an architectural benchmark,

then even the ideal:

$$
u=8
$$

window after the prime tax:

$$
0.1563
$$

may be insufficient.

However:

## Research Firewall TCDC-06-R01

$$
\boxed{
\text{classical Chen triple constant is not automatically the TCDC high-suffix }E_1\text{ constant}.
}
$$

The base sequences differ:

- classical Chen:
  prime + complement;
- here:
  balanced prime product + complement.

Thus, this serves only as a warning,

not as a no-go theorem.

---

# 35. Strict Local Route Is Parity-Taxed

T05 shows that the prime coefficient:

$$
1
$$

is unavoidable.

Meanwhile:

$$
P_\lambda
$$

and:

$$
\Pi_\lambda
$$

are precisely the cube-root RootRough boundary's:

- odd-parity branch;
- even-parity branch.

Thus:

$$
\boxed{
\text{The strict local pressure selector explicitly puts the parity split back into the proof ledger}.
}
$$

This is the essence of the prime tax.

---

# 36. TCDC Allows a Different Strategy

TCDC failure geometry does not require the sieve itself to distinguish:

$$
P_\lambda
\text{ vs }
\Pi_\lambda.
$$

We can let the sieve prove only that:

$$
\boxed{
S_\lambda(z)
=
P_\lambda+\Pi_\lambda
}
$$

is large.

Then failure transport determines:

- where the prime branch can flow;
- where the semiprime branch can flow.

This is:

# Branch-Neutral Sieve + Branch-Sensitive Capacity

---

# 37. Two Sink Channels

For the high suffix:

### Prime Branch

$$
P_\lambda
$$

flows into:

$$
\boxed{
\text{prime sink}.
}
$$

### Semiprime Branch

$$
\Pi_\lambda
$$

flows into:

$$
\boxed{
\text{mirror semiprime receiver}.
}
$$

Therefore:

$$
S_\lambda=P_\lambda+\Pi_\lambda
$$

is the total sender mass.

---

# 38. Prime-Sink Capacity

Let:

$$
\boxed{
C_P^{fail}(\lambda)
}
$$

to be any proof-admissible failure upper bound satisfying:

$$
\boxed{
P_\lambda
\le
C_P^{fail}(\lambda).
}
$$

It may come from:

- row mixed capacities:
  $$
  \sum_{r\in B_\lambda}U_r^P;
  $$
- prime-sink saturation cuts;
- center-divisor locks;
- balanced-convolution upper bounds;
- an LP-dual combination.

---

# 39. Mirror-Sink Capacity

TCDC-02 defines:

$$
\boxed{
C_{\mathrm{mir}}^{fail}(\lambda)
}
$$

such that:

$$
\boxed{
\Pi_\lambda
\le
C_{\mathrm{mir}}^{fail}(\lambda)
}
$$

under failure.

Sources:

- a mirror-prefix receiver;
- cross-cell capacities;
- prime usage in the prefix;
- recursion;
- MRC analytic compression.

---

# 40. Two-Sink Failure Inequality

Since:

$$
S_\lambda
=
P_\lambda+\Pi_\lambda,
$$

failure must satisfy:

## Theorem TCDC-06-T13

$$
\boxed{
S_\lambda(z)
\le
C_P^{fail}(\lambda)
+
C_{\mathrm{mir}}^{fail}(\lambda).
}
$$

This is an exact branch-capacity consequence.

---

# 41. Branch-Neutral Closure Theorem

Suppose there is a branch-neutral lower bound:

$$
\boxed{
L_{P_2}(\lambda)
\le
S_\lambda(z).
}
$$

If:

$$
\boxed{
L_{P_2}(\lambda)
>
C_P^{fail}(\lambda)
+
C_{\mathrm{mir}}^{fail}(\lambda),
}
$$

then:

## Theorem TCDC-06-T14

$$
\boxed{
\text{Goldbach failure impossible}.
}
$$

Thus:

$$
\boxed{
M_{PP}>0.
}
$$

---

# 42. Two-Sink Deficit

Define:

$$
\boxed{
\Delta_{2S}(\lambda)
=
L_{P_2}(\lambda)
-
C_P^{fail}(\lambda)
-
C_{\mathrm{mir}}^{fail}(\lambda).
}
$$

If:

$$
\boxed{
\Delta_{2S}(\lambda)>0,
}
$$

then the failure polytope is empty.

This is a:

# Branch-Neutral TCDC Certificate

---

# 43. Why This Is Not Just Moving Terms Around

Strict weighted route:

$$
\Pi
\ge
L_{P_2}-U_P.
$$

It requires:

$$
U_P
$$

as an isolated analytic upper bound,

directly consuming the sieve margin.

The two-sink TCDC route instead allows:

$$
C_P^{fail}
$$

to be obtained jointly from:

- multiple row constraints;
- global prime-sink saturation;
- the transport dual;
- center locks;

as listed above.

Thus:

$$
\boxed{
C_P^{fail}
}
$$

need not equal an independent analytic upper bound.

This is the additional freedom genuinely provided by the failure-polytope method.

---

# 44. LP-Dual Interpretation

In the TCDC-01 failure LP:

- mixed edges:
  $$
  M_{r,0};
  $$
- internal edges:
  $$
  M_{r,s}.
  $$

A branch-neutral lower bound:

$$
S_\lambda
$$

merely adds a lower-mass constraint to selected sender rows.

The LP dual can automatically supply:

- a prime-sink price;
- a mirror-sink price;
- a row price.

Thus:

$$
\boxed{
\text{branch-neutral weighted sieve}
+
\text{LP dual transport}
}
$$

is a natural combined proof architecture.

---

# 45. A Parametric Branch Price

More generally,

Take:

$$
0\le\eta\le1.
$$

Define:

$$
\boxed{
S_{\lambda,\eta}
=
\Pi_\lambda
+
\eta P_\lambda.
}
$$

Pointwise weight:

$$
\boxed{
\omega_{\eta}
=
\omega_{neutral}
-
(1-\eta)\mathbf1_{\mathbb P}.
}
$$

Thus:

## Theorem TCDC-06-T15

$$
\boxed{
S_{\lambda,\eta}
\ge
A_1
-
(1-\eta)A_P
-
\frac12A_2
-
\frac12E.
}
$$

---

# 46. Dual Capacity for Branch Price

Under failure:

$$
\Pi_\lambda
\le
C_{\mathrm{mir}},
$$

$$
P_\lambda
\le
C_P.
$$

Thus:

## Theorem TCDC-06-T16

$$
\boxed{
S_{\lambda,\eta}
\le
C_{\mathrm{mir}}
+
\eta C_P.
}
$$

If the lower bound exceeds the right side,

failure is impossible.

---

# 47. $\eta$ Is a TCDC Dual Variable

### $\eta=0$

Strict semiprime pressure route.

### $\eta=1$

Fully branch-neutral $P_2$ route.

### Intermediate

The prime branch receives partial credit.

Thus:

$$
\boxed{
\eta
}
$$

can be jointly optimized using:

- analytic prime-upper quality;
- transport prime-sink capacity;
- mirror capacity;

as listed above.

This is not merely a sieve parameter,

but a:

# Failure-Polytope Dual Price

---

# 48. Relation to Classical Chen

Classical Chen target:

$$
P_2
$$

naturally corresponds to:

$$
\boxed{
\eta=1.
}
$$

because primes and semiprimes are both acceptable.

Goldbach strict pressure:

$$
\boxed{
\eta=0.
}
$$

TCDC instead allows:

$$
\boxed{
0<\eta<1
}
$$

because, although the prime branch is not the pressure target,

it still consumes failure-transport capacity.

This is a new degree of freedom of this framework relative to classical Chen.

---

# 49. Remaining Medium-$P_2$ Cost

The branch-neutral choice:

$$
\eta=1
$$

eliminates the prime tax,

but:

$$
E
=
A_{2,1}
+
A_{3,1}
+\text{higher-factor }\nu=1\text{ states}
$$

still exists.

The target still requires:

$$
\operatorname{RootRough}_z.
$$

A medium semiprime:

$$
\ell q,
\quad
w<\ell\le z,
$$

does not belong to the cube-root transport boundary.

Thus:

$$
\boxed{
\text{medium-}P_2\text{ cost remains a genuine cutoff-descent cost}.
}
$$

---

# 50. Lowering $w$ Increases $E_1$ Complexity

The generalized T02 permits:

$$
u>4,
$$

but coarse RootRough$_w$ may contain:

$$
P_4,P_5,\ldots
$$

Although the pointwise weight remains admissible,

$$
E_1
$$

includes:

> exactly one medium factor,
> plus multiple factors $>z$.

However, if:

$$
z^3\ge X,
$$

after exactly one medium factor, there cannot be three additional factors:

$$
>z.
$$

Since:

$$
w\cdot z^3>X
$$

for any:

$$
w>1.
$$

Thus:

## Theorem TCDC-06-T17

$$
\boxed{
E_1
}
$$

still contains only:

- medium $P_2$;
- medium $P_3$.

even if:

$$
w
$$

is far below quarter root.

This is an important reason why the generalized cutoff remains analytically manageable.

---

# 51. Proof of T17

If:

$$
\nu=1,
$$

there is a unique medium prime factor:

$$
\ell>w.
$$

All other prime factors are:

$$
>z.
$$

If there are at least three other factors,

then:

$$
y>\ell z^3>wX>X,
$$

a contradiction.

Thus, there are at most two other prime factors.

It is composite and has at least one other factor,

Hence:

- one other:
  $$
  P_2;
  $$
- two others:
  $$
  P_3.
  $$

This completes the proof.

---

# 52. Why $u\approx8$ Is Especially Attractive

at:

$$
u=8,
$$

we simultaneously obtain:

1. a coarse lower multiplier almost equal to:
   $$
   1;
   $$
2. the half-medium core:
   $$
   \approx0.406;
   $$
3. an exactly-one correction still requiring only:
   - medium $P_2$;
   - medium $P_3$;
4. a cutoff at the same scale as classical Chen:
   $$
   x^{1/8}
   $$
   as displayed above.

Thus:

$$
\boxed{
u=8
}
$$

becomes a more natural TCDC-06 baseline than:

$$
u=4
$$

as displayed above.

---

# 53. Updated Strict Extra-Cost Gate at $u=8$

Strict route:

$$
\Pi
\ge
\text{core}
-
A_P
-
\frac12E.
$$

Normalized:

$$
\boxed{
C_P
+
\frac12C_E
<
0.406257
}
$$

is required for positive pressure.

This is much larger than TCDC-05's:

$$
0.0841
$$

as displayed above.

However, the standard separate prime upper bound:

$$
C_P^{std}
\approx0.7421
$$

already exceeds the budget.

---

# 54. Updated Neutral Gate at $u=8$

Branch-neutral route:

$$
S_z
\ge
\text{core}
-
\frac12E.
$$

Thus, one needs only:

$$
\boxed{
\frac12C_E
<
0.406257
}
$$

for positive $P_2$ mass.

Then leave branch allocation to the two-sink capacity.

This is clearly more consistent with classical Chen polarity.

---

# 55. Provider Priorities After This Round

The priority is no longer:

> sharply upper-bound $A_P$, then subtract it outright from the strict weight.

Instead:

### Priority 1

lower-bound the branch-neutral:

$$
S_\lambda(z).
$$

### Priority 2

upper-bound / dual-certify:

$$
C_P^{fail}+C_{\mathrm{mir}}^{fail}.
$$

### Priority 3

optimize:

$$
\eta.
$$

### Priority 4

only if needed,
return to strict:

$$
\eta=0.
$$

---

# 56. Formal Theorem Queue

```yaml
TCDC_06:

  T01:
    generalized_bad_composite_has_medium_factor

  T02:
    generalized_strict_half_weight

  T03:
    generalized_branch_neutral_half_weight

  T04:
    strict_equals_neutral_minus_prime

  T05:
    local_prime_tax_coefficient_at_least_one

  T06:
    summed_neutral_lower

  T07:
    summed_strict_lower

  T08:
    full_medium_upper_legal_requires_u_gt_15_4

  T09:
    explicit_coarse_lower_constant

  T10:
    explicit_medium_integral

  T11:
    explicit_half_core_constant

  T12:
    core_monotone_on_closed_form_window

  T13:
    two_sink_failure_inequality

  T14:
    branch_neutral_failure_closure

  T15:
    eta_weighted_lower

  T16:
    eta_dual_capacity_upper

  T17:
    exactly_one_medium_remains_only_P2_or_P3
```

---

# 57. Diagnostic Queue

```yaml
TCDC_06_Diagnostics:

  quarter_root:
    u:
      4
    core:
      0.084102748153

  u_5:
    core:
      0.279036833468

  closed_form_endpoint:
    u:
      20/3
    core:
      0.389818305228

  numerical_optimum:
    u:
      7.805950
    core:
      0.406676567891

  u_8:
    coarse:
      0.997027667435
    medium:
      1.181541540743
    core:
      0.406256897064

    standard_prime_upper:
      0.742113507496

    ideal_prime_density:
      0.250000000000
```

---

# 58. Barrier Queue

```yaml
TCDC_06_Barriers:

  B01:
    strict_local_prime_tax:
      coefficient_at_least_one

  B02:
    standard_prime_upper_multiplier_too_large

  B03:
    exact_one_medium_cost_not_closed

  B04:
    branch_neutral_prime_sink_capacity_not_closed

  B05:
    mirror_capacity_not_closed

  B06:
    eta_dual_optimization_not_done

  B07:
    no_positive_two_sink_deficit_yet
```

---

# 59. Acceptance Gate

Before the TCDC-06 formal core, the following are required:

1. a generalized pointwise theorem independent of the factor-depth cutoff;
2. the desired $P_2$ branch exact;
3. a lower bound on the prime coefficient;
4. the $u$ parameter domain;
5. lower / upper sieve parameters separated;
6. closed-form constants used only within their valid $s$ ranges;
7. $u\approx7.8$ labeled a numerical diagnostic;
8. the classical $1/8$ comparison labeled structural, not a derivational identity;
9. the standard prime-upper no-go labeled a provider-stack no-go;
10. ideal prime density labeled diagnostic;
11. the branch-neutral two-sink theorem exact;
12. the $\eta$ dual price exact;
13. no positive two-sink-deficit claim;
14. no Goldbach-proof claim.

---

# 60. Verdict

This round can formally give:

$$
\boxed{
\mathrm{TCDC\mbox{-}06\ BRANCH\mbox{-}NEUTRAL\ DUAL\mbox{-}SINK\ KERNEL\ PASS}.
}
$$

The greatest combinatorial improvement:

$$
\boxed{
\text{TCDC-05 half-weight does not require }w=X^{1/4}.
}
$$

It holds for any:

$$
w<z,
\qquad
z^3\ge X
$$

as displayed above.

Thus, the cutoff can be optimized.

Under the current:

$$
\theta=3/5
$$

as displayed above,

$$
u=4
$$

core:

$$
\boxed{
0.0841,
}
$$

while the numerical optimum:

$$
u\approx7.806
$$

raises this to:

$$
\boxed{
0.4067.
}
$$

$$
u=8
$$

is already nearly optimal:

$$
\boxed{
C_{\mathrm{core}}(8)
\approx0.4063.
}
$$

However, the standard separate prime upper bound on the same scale is still approximately:

$$
\boxed{
0.7421,
}
$$

Thus:

$$
\boxed{
\text{The strict local route + standard prime upper bound still cannot close}.
}
$$

This identifies prime subtraction as a:

# Parity / Strictness Tax

The principal TCDC alternative:

$$
\boxed{
S_\lambda(z)
=
P_\lambda+\Pi_\lambda
}
$$

is first lower-bounded by a Chen-type branch-neutral weighted sieve,

then uses failure transport:

$$
\boxed{
S_\lambda(z)
\le
C_P^{fail}(\lambda)
+
C_{\mathrm{mir}}^{fail}(\lambda).
}
$$

Thus, the actual closure target becomes:

$$
\boxed{
\Delta_{2S}(\lambda)
=
L_{P_2}
-
C_P^{fail}
-
C_{\mathrm{mir}}^{fail}
>0.
}
$$

This avoids requiring the sieve itself to cross the prime / semiprime parity split.

More generally, there is also:

$$
\boxed{
\eta\in[0,1]
}
$$

as a prime-branch dual price,

connecting classical Chen:

$$
\eta=1
$$

and strict pressure:

$$
\eta=0
$$

into a single family of TCDC certificates.

However, currently:

$$
\boxed{
\mathrm{NO\ POSITIVE\ TWO\mbox{-}SINK\ DEFICIT\ YET}.
}
$$

Therefore:

$$
\boxed{
\mathrm{GOLDBACH\ STILL\ OPEN}.
}
$$

---

# 61. Recommendations for the Next Round

# TCDC-07
## Two-Sink Capacity Ledger / $\eta$-Dual Optimization Closure

The next round should no longer attempt a separate analytic subtraction of the prime branch.

Directly establish:

$$
\boxed{
\Delta_\eta
=
L_\eta
-
C_{\mathrm{mir}}
-
\eta C_P.
}
$$

### Part A — Weighted Lower

Using:

$$
u\approx8
$$

as a baseline,

establish:

$$
L_\eta.
$$

### Part B — Prime Sink

Do not use only single-row BT.

Combine:

- prime-sink saturation;
- center locks;
- suffix arithmetic progressions;
- the transport LP dual;

to form:

$$
C_P^{fail}.
$$

### Part C — Mirror Sink

Use TCDC-02 / MRC:

$$
C_{\mathrm{mir}}^{fail}.
$$

### Part D — Optimize $\eta$

Find:

$$
\boxed{
\sup_{0\le\eta\le1}
\Delta_\eta.
}
$$

If positive,

the failure polytope is immediately empty.

This will be the first genuine combination of:

# Chen Weighted Sieve

and:

# TCDC Failure Transport Dual

within one optimized certificate.

---

# Appendix A: Generalized Pointwise Weights

```yaml
strict:

  omega:
    RR_w * (
      1
      - prime
      - nu/2
      - E1/2
    )

  lower_bounds:
    strict_semiprime_lpf_gt_z

neutral:

  omega:
    RR_w * (
      1
      - nu/2
      - E1/2
    )

  lower_bounds:
    RootRough_z:
      prime_or_semiprime

conditions:
  w < z
  z^3 >= X
```

---

# Appendix B: Closed-Form $3/5$ Core

```yaml
u_range:
  15/4 < u <= 20/3

theta:
  3/5

C0:
  (10*exp(gamma)/(3u))
  * log((3u-5)/5)

Cmed:
  (10*exp(gamma)/(3u))
  * log((3u-5)/4)

Ccore:
  (5*exp(gamma)/(3u))
  * log(4*(3u-5)/25)

positive_iff:
  u > 15/4
```

---

# Appendix C: $u=8$ Diagnostic

```yaml
u:
  8

coarse:
  0.997027667435

medium:
  1.181541540743

half_core:
  0.406256897064

standard_separate_prime_upper:
  0.742113507496

ideal_prime_density:
  0.250000000000

strict_with_standard_prime_upper:
  negative_before_E1: true

neutral_before_E1:
  positive: true
```

---

# Appendix D: Two-Sink Closure

```yaml
sender:
  S_lambda:
    prime_branch + semiprime_branch

failure_sinks:

  prime:
    capacity:
      C_P_fail

  mirror_semiprime:
    capacity:
      C_mir_fail

failure_requires:
  S_lambda <= C_P_fail + C_mir_fail

if_lower:
  L_P2 > C_P_fail + C_mir_fail

then:
  failure_polytope_empty: true
  Goldbach_success: true
```

---

# Appendix E: $\eta$ Dual Price

```yaml
eta:
  range:
    0_to_1

weighted_sender:
  S_eta:
    Pi + eta*P

weighted_lower:
  A1
  -(1-eta)*A_P
  -A2/2
  -E/2

failure_capacity:
  C_mir + eta*C_P

special_cases:

  eta_0:
    strict_pressure

  eta_1:
    branch_neutral_P2
```

---

# Appendix F: Commit Decision

```yaml
research_round:
  TCDC-06

decision:

  half_weight_generalized:
    true

  quarter_root_necessity:
    false

  cutoff_optimization:
    true

  near_eighth_root_optimum:
    computationally_identified

  strict_prime_tax:
    formalized

  standard_separate_prime_upper_closure:
    false

  branch_neutral_two_sink_route:
    formalized

  eta_dual_price:
    formalized

  positive_two_sink_deficit:
    not_proved

  Goldbach_proved:
    false

next:
  TCDC-07_TwoSink_CapacityLedger_EtaDual_Optimization_Closure
```

---

# References / Audited External Sources

1. Terence Tao, **254A, Supplement 5: The linear sieve and Chen's theorem**, 2015.

   Relevant facts:
   - classical dimension-$1$ linear sieve functions and their delay-differential continuation;
   - Chen's proof uses a coarse cutoff $z=x^{1/8}$, half-weighting of medium divisors, and switching / triple-factor control;
   - Chen's target is $P_2$, hence branch-neutral with respect to prime versus semiprime.

2. James Maynard, **Primes in arithmetic progressions to large moduli II: Well-factorable estimates**, *Memoirs AMS* 306 (2025), no. 1543.

   Relevant benchmark:
   mean distribution with suitably well-factorable weights to level $x^{3/5-\varepsilon}$.

3. James Maynard, **Primes in arithmetic progressions to large moduli III: Uniform residue classes**, *Memoirs AMS* 306 (2025), no. 1544.

   Relevant as a possible source of sharper prime-sink / balanced-convolution upper estimates than the standard isolated linear-sieve prime upper.

4. Zhiyuan Yang, **Convolution-type Bombieri-Vinogradov theorem with well-factorable Weights, and its applications**, arXiv:2608.13299 (2026).

   Relevant as a modern convolution / well-factorable-weight technology source. No direct Goldbach-shift application is asserted here.
