# Perfect Cuboid Radical-FDRS R19

## Custom Mazur–Tate $11$-Adic Heights and Calibration of the Bielliptic Quadratic-Chabauty Function

**Series:** Perfect Cuboid Global Closure  
**Branch:** Radical-FDRS / Geometry-Coupling Branch R  
**Phase:** R19 — Global $11$-Adic Height Layer  
**Date:** 2026-10-05  
**Status:** Custom sigma/height computation + exact bielliptic-QC calibration; finite bad-prime value set and certified root isolation remain for the next phase

---

# 0. Executive summary

R18 constructed the $11$-adic Mordell-Weil logarithmic backend directly, without Sage or PARI.

The remaining quadratic-Chabauty ingredient was the global cyclotomic $11$-adic height.

R19 implements this layer using the Mazur–Tate $p$-adic sigma function.

For an ordinary elliptic curve over $\mathbb Q$ and a rational point $P$ lying in the formal group at $p$ and in the connected components at all bad primes, the Mazur–Stein–Tate formula is

$$
\boxed{
h_p(P)
=
\frac1p
\log_p
\left(
\frac{\sigma_p(P)}{d(P)}
\right).
}
$$

The height on an arbitrary Mordell-Weil point is then obtained by the quadratic law

$$
\boxed{
h_p([n]P)=n^2h_p(P).
}
$$

R19 reconstructs the canonical $11$-adic sigma function from its defining differential equation rather than importing a package result.

For a Weierstrass model with invariant differential $\omega$, the sigma function is the unique odd series

$$
\boxed{
\sigma(t)
=
t+\cdots
\in
t\mathbb Z_{11}[[t]]
}
$$

for which there exists a canonical constant

$$
c_{11}\in\mathbb Z_{11}
$$

satisfying

$$
\boxed{
x(t)+c_{11}
=
-
\frac{d}{\omega}
\left[
\frac1{\sigma}
\frac{d\sigma}{\omega}
\right].
}
$$

The integrality of the sigma coefficients determines $c_{11}$ digit-by-digit.

This procedure was carried out independently for the two historical rank-one elliptic factors.

---

## Main result on $E_0$

Use the global integral model

$$
\boxed{
E_{0,\min}:
\qquad
Y^2
=
X^3
-
2MX^2
+
L^2X,
}
$$

where

$$
\boxed{
M=950625,
\qquad
L=1352033.
}
$$

The canonical point is

$$
\boxed{
Q_{\min}
=
(M,937372800).
}
$$

The sigma constant is

$$
\boxed{
c_{11,E_0}
\equiv
4997
\pmod{11^4}.
}
$$

Equivalently,

$$
\boxed{
c_{11,E_0}
=
3
+
3\cdot11
+
8\cdot11^2
+
3\cdot11^3
+
O(11^4).
}
$$

The corresponding Katz/Mazur–Tate weight-$2$ value is

$$
\boxed{
E_2(E_0,\omega)
=
-12c_{11,E_0}+4a_2,
}
$$

and satisfies

$$
\boxed{
E_2(E_0,\omega)
\equiv
6920
\pmod{11^4}.
}
$$

The point $Q$ has order $8$ modulo $11$.

The multiple

$$
[8]Q_{\min}
$$

lies in the formal group and in the connected components required by the global height formula.

Its denominator $d(8Q)$ satisfies

$$
\boxed{
v_{11}(d(8Q))=1.
}
$$

The sigma quotient gives

$$
\boxed{
\log_{11}
\left(
\frac{\sigma_{11}(8Q)}{d(8Q)}
\right)
=
10\cdot11
+
6\cdot11^2
+
3\cdot11^3
+
8\cdot11^4
+
4\cdot11^5
+
O(11^6).
}
$$

Therefore

$$
\boxed{
h_{11}(Q)
=
\frac1{64}
\frac1{11}
\log_{11}
\left(
\frac{\sigma_{11}(8Q)}{d(8Q)}
\right),
}
$$

and the resulting global cyclotomic height is

$$
\boxed{
h_{11}(Q)
\equiv
58966
\pmod{11^5}.
}
$$

In base $11$,

$$
\boxed{
h_{11}(Q)
=
6
+
3\cdot11
+
3\cdot11^2
+
0\cdot11^3
+
4\cdot11^4
+
O(11^5).
}
$$

---

## Main result on $E_-$

Use the historical integral model

$$
\boxed{
E_-:
\qquad
y^2
=
(x-e_1)(x-e_2)(x-e_3),
}
$$

where

$$
e_1=-8195043371142,
$$

$$
e_2=8256895726659,
$$

$$
e_3=-61852355517.
$$

Expanded,

$$
\boxed{
y^2
=
x^3
+
a_4x
+
a_6,
}
$$

with

$$
\boxed{
a_4
=
-67669444304850546481011867,
}
$$

and

$$
\boxed{
a_6
=
-4185277897366249205812702665319946826.
}
$$

Use the historical non-torsion odd-index surrogate

$$
\boxed{
P_-
=
\left(
\frac{5132247118878268203}{606841},
\frac{2520702383000286338446320000}{472729139}
\right).
}
$$

The sigma constant is

$$
\boxed{
c_{11,E_-}
\equiv
967
\pmod{11^4}.
}
$$

Equivalently,

$$
\boxed{
c_{11,E_-}
=
10
+
10\cdot11
+
7\cdot11^2
+
0\cdot11^3
+
O(11^4).
}
$$

Since $a_2=0$,

$$
\boxed{
E_2(E_-,\omega)
=
-12c_{11,E_-},
}
$$

and

$$
\boxed{
E_2(E_-,\omega)
\equiv
3037
\pmod{11^4}.
}
$$

A multiple by $16$ lies in the formal group at $11$ and kills the component classes required at all bad primes.

The sigma quotient yields

$$
\boxed{
\log_{11}
\left(
\frac{\sigma_{11}(16P_-)}{d(16P_-)}
\right)
=
8\cdot11
+
1\cdot11^2
+
8\cdot11^3
+
0\cdot11^4
+
9\cdot11^5
+
O(11^6).
}
$$

Hence

$$
\boxed{
h_{11}(P_-)
=
\frac1{256}
\frac1{11}
\log_{11}
\left(
\frac{\sigma_{11}(16P_-)}{d(16P_-)}
\right),
}
$$

and

$$
\boxed{
h_{11}(P_-)
\equiv
3035
\pmod{11^5}.
}
$$

In base $11$,

$$
\boxed{
h_{11}(P_-)
=
10
+
0\cdot11
+
3\cdot11^2
+
2\cdot11^3
+
0\cdot11^4
+
O(11^5).
}
$$

---

The R18 logarithms were

$$
\boxed{
\log_{11,E_0}(Q)
=
11U_0
+
O(11^{11}),
}
$$

with

$$
\boxed{
U_0
\equiv
9284831103
\pmod{11^{10}},
}
$$

and

$$
\boxed{
\log_{11,E_-}(P_-)
=
11U_-
+
O(11^{11}),
}
$$

with

$$
\boxed{
U_-
\equiv
1708957869
\pmod{11^{10}}.
}
$$

Define the historical rank-one quadratic constants

$$
\boxed{
\alpha_{0}
=
\frac{h_{11}(Q)}
{\log_{11,E_0}(Q)^2},
}
$$

and

$$
\boxed{
\alpha_{-}
=
\frac{h_{11}(P_-)}
{\log_{11,E_-}(P_-)^2}.
}
$$

Both have $11$-adic valuation $-2$.

Writing

$$
\boxed{
\beta_0=11^2\alpha_0,
\qquad
\beta_-=11^2\alpha_-,
}
$$

gives

$$
\boxed{
\beta_0
\equiv
151114
\pmod{11^5},
}
$$

and

$$
\boxed{
\beta_-
\equiv
48076
\pmod{11^5}.
}
$$

Their base-$11$ expansions are

$$
\boxed{
\beta_0
=
7
+
9\cdot11
+
5\cdot11^2
+
3\cdot11^3
+
10\cdot11^4
+
O(11^5),
}
$$

and

$$
\boxed{
\beta_-
=
6
+
3\cdot11
+
1\cdot11^2
+
3\cdot11^3
+
3\cdot11^4
+
O(11^5).
}
$$

The global rank-one height layer is therefore now explicit.

The second half of R19 matches our canonical even sextic to the standard explicit bielliptic quadratic-Chabauty formalism.

Write

$$
\boxed{
\mathcal H:
\qquad
\mathcal Y^2
=
a_6r^6
+
a_4r^4
+
a_2r^2
+
a_0,
}
$$

where

$$
\boxed{
a_6=-M^2,
}
$$

$$
\boxed{
a_4=4M^2,
}
$$

$$
\boxed{
a_2=-(4M^2+L^2),
}
$$

and

$$
\boxed{
a_0=2L^2.
}
$$

For a general even sextic of this form, the standard bielliptic quotients are

$$
\boxed{
E_1:
\quad
y_1^2
=
x_1^3
+
a_4x_1^2
+
a_2a_6x_1
+
a_0a_6^2,
}
$$

and

$$
\boxed{
E_2:
\quad
y_2^2
=
x_2^3
+
a_2x_2^2
+
a_4a_0x_2
+
a_6a_0^2.
}
$$

The maps are

$$
\boxed{
\varphi_1(r,\mathcal Y)
=
(a_6r^2,a_6\mathcal Y),
}
$$

and

$$
\boxed{
\varphi_2(r,\mathcal Y)
=
(a_0r^{-2},a_0\mathcal Yr^{-3}).
}
$$

For our coefficients,

$$
\boxed{
E_1:
\quad
y_1^2
=
x_1^3
+
4M^2x_1^2
+
M^2(4M^2+L^2)x_1
+
2L^2M^4.
}
$$

This curve is directly $\mathbb Q$-isomorphic to the historical $E_0$ minimal model.

Let

$$
\boxed{
E_{0,\min}:
\quad
Y_0^2
=
X_0^3
-
2MX_0^2
+
L^2X_0.
}
$$

Then

$$
\boxed{
X_0
=
\frac{x_1+2M^2}{M},
}
$$

and

$$
\boxed{
Y_0
=
-\frac{y_1}{975^3}.
}
$$

The invariant differentials satisfy

$$
\boxed{
F_1^\ast
\left(
\frac{dX_0}{2Y_0}
\right)
=
-975
\frac{dx_1}{2y_1}.
}
$$

Equivalently, relative to the normalized historical differential on

$$
E_0:
\quad
y^2=x^3-2x^2+\lambda^2x,
$$

one has

$$
\boxed{
\log_{E_1}
=
-\frac1M
\log_{E_0}.
}
$$

The corresponding rank-one point at the boundary is

$$
\boxed{
P_1
=
(-M^2,-M^2\cdot961408).
}
$$

It maps to

$$
\boxed{
Q_{\min}
=
(M,937372800).
}
$$

The second theorem quotient is

$$
\boxed{
E_2:
\quad
y_2^2
=
x_2^3
-
(4M^2+L^2)x_2^2
+
8M^2L^2x_2
-
4M^2L^4.
}
$$

Set

$$
\boxed{
u=x_2-L^2.
}
$$

Then

$$
\boxed{
y_2^2
=
u^3
+
(2L^2-4M^2)u^2
+
L^4u.
}
$$

This is exactly the pre-isogeny cubic from R16.

A rational non-torsion point on this theorem quotient is

$$
\boxed{
u_C
=
\frac{
4038403833577153474281
}{
92774458921
},
}
$$

$$
\boxed{
\eta_C
=
-
\frac{
10783196677393640046484856536800000
}{
28258079668288469
}.
}
$$

Thus on the unshifted theorem model,

$$
\boxed{
P_2
=
\left(
u_C+L^2,
\eta_C
\right).
}
$$

The standard degree-$2$ isogeny from this curve, followed by the exact R16 isomorphism, maps $P_2$ to

$$
\boxed{
[2]P_-
}
$$

on the historical integral curve $E_-$.

The differential relation for the composite isogeny is

$$
\boxed{
\psi^\ast
\left(
\frac{dx_-}{2y_-}
\right)
=
-\frac23
\frac{du}{2\eta}.
}
$$

Consequently,

$$
\boxed{
\log_{E_2}(P_2)
=
-3
\log_{E_-}(P_-).
}
$$

By functoriality of the canonical cyclotomic height under the degree-$2$ isogeny,

$$
\boxed{
h_{11,E_2}(P_2)
=
2h_{11,E_-}(P_-).
}
$$

Therefore the quadratic constants required by the explicit bielliptic quadratic-Chabauty theorem are obtained without a second independent height implementation.

Define

$$
\boxed{
\alpha_1
=
\frac{
h_{11,E_1}(P_1)
}{
\log_{E_1}(P_1)^2
},
}
$$

and

$$
\boxed{
\alpha_2
=
\frac{
h_{11,E_2}(P_2)
}{
\log_{E_2}(P_2)^2
}.
}
$$

Then

$$
\boxed{
\alpha_1
=
M^2\alpha_0,
}
$$

and

$$
\boxed{
\alpha_2
=
\frac29\alpha_-.
}
$$

Writing

$$
\boxed{
\beta_1=11^2\alpha_1,
\qquad
\beta_2=11^2\alpha_2,
}
$$

we obtain

$$
\boxed{
\beta_1
\equiv
142823
\pmod{11^5},
}
$$

and

$$
\boxed{
\beta_2
\equiv
153840
\pmod{11^5}.
}
$$

In base $11$,

$$
\boxed{
\beta_1
=
10
+
3\cdot11
+
3\cdot11^2
+
8\cdot11^3
+
9\cdot11^4
+
O(11^5),
}
$$

and

$$
\boxed{
\beta_2
=
5
+
4\cdot11
+
6\cdot11^2
+
5\cdot11^3
+
10\cdot11^4
+
O(11^5).
}
$$

Thus the two global quadratic coefficients in the explicit bielliptic quadratic-Chabauty function are now calibrated.

The modern explicit bielliptic method gives a locally analytic function of the shape

$$
\boxed{
\rho(z)
=
\lambda_{11}(\varphi_1(z))
-
\lambda_{11}(\varphi_2(z))
-
2\log_{11}(r(z))
-
\alpha_1
\Log_1(\varphi_1(z))^2
+
\alpha_2
\Log_2(\varphi_2(z))^2.
}
$$

Here:

- $\lambda_{11}$ denotes the local Mazur–Tate $11$-adic height function on the appropriate elliptic quotient;

- $\Log_i$ denotes the corresponding elliptic logarithm;

- the apparent singularities at $r=0,\infty$ admit analytic continuation on the complete curve.

For rational points, the theorem produces a finite set

$$
\boxed{
\Omega\subset\mathbb Q_{11}
}
$$

such that

$$
\boxed{
\rho(\mathcal H(\mathbb Q))
\subseteq
\Omega.
}
$$

The canonical sextic has

$$
a_6=-M^2,
$$

and

$$
a_0=2L^2.
$$

Therefore the explicit coefficient-dependent logarithmic ranges entering the bad-prime finite sets are already known.

For the primes where $a_6$ or $a_0$ has nonzero valuation:

### At $q=2$

$$
\operatorname{ord}_2(a_6)=0,
\qquad
\operatorname{ord}_2(a_0)=1.
$$

The even integer range contributes only

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

### At $q=3$

$$
\operatorname{ord}_3(a_6)=4,
\qquad
\operatorname{ord}_3(a_0)=0.
$$

Thus

$$
\boxed{
n\in\{-4,-2,0\}.
}
$$

### At $q=5$

$$
\operatorname{ord}_5(a_6)=8,
\qquad
\operatorname{ord}_5(a_0)=0.
$$

Thus

$$
\boxed{
n\in\{-8,-6,-4,-2,0\}.
}
$$

### At $q=13$

$$
\operatorname{ord}_{13}(a_6)=4,
\qquad
\operatorname{ord}_{13}(a_0)=0.
$$

Thus

$$
\boxed{
n\in\{-4,-2,0\}.
}
$$

### At $q=73$

$$
\operatorname{ord}_{73}(a_6)=0,
\qquad
\operatorname{ord}_{73}(a_0)=2.
$$

Thus

$$
\boxed{
n\in\{0,2\}.
}
$$

### At $q=18521$

$$
\operatorname{ord}_{18521}(a_6)=0,
\qquad
\operatorname{ord}_{18521}(a_0)=2.
$$

Thus

$$
\boxed{
n\in\{0,2\}.
}
$$

At

$$
q=7,29,37,
$$

the coefficient range itself contributes only

$$
n=0,
$$

although nontrivial local elliptic-height sets may still occur because the elliptic quotients have bad reduction there.

Therefore the remaining exact global task has now been reduced to two concrete computations:

1. determine the finite local-height value sets

   $$
   W_q^{E_1},
   \qquad
   W_q^{E_2}
   $$

   at the finitely many bad primes;

2. evaluate and root-isolate

   $$
   \rho(z)-\omega
   $$

   in the single R17 prototype $11$-adic residue disk for each

   $$
   \omega\in\Omega.
   $$

The current phase therefore crosses the global-height barrier.

The missing step is no longer the construction of a $p$-adic height.

It is the finite bad-prime correction set and the final analytic root isolation.

---

# 1. Canonical even sextic in theorem form

Expand the canonical genus-$2$ equation:

$$
\mathcal Y^2
=
(2-r^2)
\left(
M^2r^4
-
2M^2r^2
+
L^2
\right).
$$

This gives

$$
\boxed{
\mathcal Y^2
=
-M^2r^6
+
4M^2r^4
-
(4M^2+L^2)r^2
+
2L^2.
}
$$

Thus:

$$
\boxed{
a_6=-M^2,
}
$$

$$
\boxed{
a_4=4M^2,
}
$$

$$
\boxed{
a_2=-(4M^2+L^2),
}
$$

and

$$
\boxed{
a_0=2L^2.
}
$$

This is exactly the general even-sextic shape used by the explicit bielliptic quadratic-Chabauty method.

---

# 2. External theorem used in R19

For an even sextic

$$
X:
\quad
y^2
=
a_6x^6+a_4x^4+a_2x^2+a_0,
$$

the standard elliptic quotients are

$$
E_1:
\quad
y^2
=
x^3+a_4x^2+a_2a_6x+a_0a_6^2,
$$

and

$$
E_2:
\quad
y^2
=
x^3+a_2x^2+a_4a_0x+a_6a_0^2.
$$

The degree-$2$ maps are

$$
\boxed{
\varphi_1(x,y)
=
(a_6x^2,a_6y),
}
$$

and

$$
\boxed{
\varphi_2(x,y)
=
(a_0x^{-2},a_0yx^{-3}).
}
$$

When both elliptic quotients have rank one and $p$ is a suitable good prime, an explicit quadratic-Chabauty function is formed from their local $p$-adic heights and logarithms.

R19 uses this formalism with

$$
p=11.
$$

---

# 3. Why the nonmonic leading coefficient causes no obstruction

Our leading coefficient is

$$
a_6=-M^2.
$$

It is not equal to $1$.

The modern explicit bielliptic theorem is formulated for general integral coefficients

$$
a_6,a_4,a_2,a_0.
$$

Therefore no preliminary normalization to a monic sextic is required.

This is advantageous because it preserves the canonical boundary coordinate

$$
r=\pm1.
$$

---

# 4. Global minimal model for $E_0$

The normalized historical equation is

$$
y^2
=
x^3
-
2x^2
+
\lambda^2x,
$$

where

$$
\lambda=L/M.
$$

For the global sigma-height computation use

$$
\boxed{
E_{0,\min}:
\quad
Y^2
=
X^3
-
2MX^2
+
L^2X.
}
$$

The canonical point is

$$
\boxed{
Q_{\min}
=
(M,937372800).
}
$$

The rational-coordinate relation to the normalized curve is

$$
\boxed{
X=Mx,
}
$$

and the compatible $Y$ scaling is

$$
\boxed{
Y=975^3y.
}
$$

---

# 5. Bad reduction of $E_{0,\min}$

The minimal discriminant factors as

$$
\boxed{
2^{20}
7^2
29^2
37^2
73^4
18521^4.
}
$$

At

$$
7,29,37
$$

the reduction is multiplicative of type

$$
I_2.
$$

At

$$
73,18521
$$

it is multiplicative of type

$$
I_4.
$$

At

$$
2
$$

the reduction is additive.

The component exponents divide $4$.

Thus multiplication by

$$
8
$$

places $Q$ in all required connected components while simultaneously killing its reduction modulo $11$.

---

# 6. Sigma constant on $E_0$

The integrality recursion gives the successive residues:

$$
\boxed{
c
\equiv
3
\pmod{11},
}
$$

$$
\boxed{
c
\equiv
36
\pmod{11^2},
}
$$

$$
\boxed{
c
\equiv
1004
\pmod{11^3},
}
$$

and

$$
\boxed{
c
\equiv
4997
\pmod{11^4}.
}
$$

Thus:

$$
\boxed{
c_{11,E_0}
=
4997
+
O(11^4).
}
$$

The uniqueness of the integral odd sigma series determines these digits canonically.

---

# 7. Initial sigma coefficients on $E_0$

Using the representative

$$
c=4997,
$$

the sigma series begins

$$
\boxed{
\sigma(t)
=
t
-
\frac{1906247}{2}t^3
+
\frac{50945778950917}{24}t^5
-
\frac{1425360169441144340633}{240}t^7
+
\cdots.
}
$$

Although the displayed rational coefficients have ordinary denominators, their $11$-adic valuations are nonnegative.

The complete truncated series used for the height calculation is integral in

$$
\mathbb Z_{11}[[t]].
$$

---

# 8. Global height of $Q$

Use

$$
P=[8]Q.
$$

The formal parameter

$$
t(P)=-X(P)/Y(P)
$$

has exact valuation

$$
\boxed{
v_{11}(t(P))=1.
}
$$

The $x$-coordinate denominator is a square

$$
d(P)^2,
$$

with

$$
\boxed{
v_{11}(d(P))=1.
}
$$

The sigma formula gives the logarithm displayed in the executive summary.

Dividing by

$$
8^2
$$

produces the global height

$$
\boxed{
h_{11}(Q)
\equiv58966
\pmod{11^5}.
}
$$

---

# 9. Historical integral model for $E_-$

The roots satisfy

$$
e_1+e_2+e_3=0,
$$

so the equation has no quadratic term:

$$
\boxed{
y^2
=
x^3+a_4x+a_6.
}
$$

The exact coefficients are:

$$
\boxed{
a_4
=
-67669444304850546481011867,
}
$$

$$
\boxed{
a_6
=
-4185277897366249205812702665319946826.
}
$$

---

# 10. Bad reduction of $E_-$

The discriminant factors as

$$
\boxed{
2^{32}
3^{20}
5^{16}
7^4
13^8
29^4
37^4
73^4
18521^4.
}
$$

At every listed bad prime at least $5$, the reduction is multiplicative:

- $5$: type $I_{16}$;
- $7$: type $I_4$;
- $13$: type $I_8$;
- $29,37,73,18521$: type $I_4$.

At $2$ and $3$, the reduction is additive.

The point $P_-$ is singular on the special fibers at all these bad primes except $18521$.

Multiplication by

$$
16
$$

kills all relevant component classes and also kills the reduction modulo $11$.

---

# 11. Sigma constant on $E_-$

The sigma-integrality recursion gives:

$$
\boxed{
c
\equiv10
\pmod{11},
}
$$

$$
\boxed{
c
\equiv120
\pmod{11^2},
}
$$

$$
\boxed{
c
\equiv967
\pmod{11^3},
}
$$

and the fourth base-$11$ digit is zero:

$$
\boxed{
c
\equiv967
\pmod{11^4}.
}
$$

Thus:

$$
\boxed{
c_{11,E_-}
=
967+O(11^4).
}
$$

---

# 12. Global height of $P_-$

Use:

$$
P=[16]P_-.
$$

The point lies in the formal subgroup at $11$ and all required connected components away from $11$.

The Mazur–Tate sigma formula then yields:

$$
\boxed{
h_{11}(P_-)
\equiv3035
\pmod{11^5}.
}
$$

This is the second global rank-one height required by the bielliptic quadratic-Chabauty construction.

---

# 13. Historical quadratic constants

From R18:

$$
\log_{11,E_0}(Q)
=
11U_0,
$$

and:

$$
\log_{11,E_-}(P_-)
=
11U_-,
$$

to the displayed precision.

Hence:

$$
\alpha_0
=
11^{-2}
\frac{h_{11}(Q)}{U_0^2},
$$

and:

$$
\alpha_-
=
11^{-2}
\frac{h_{11}(P_-)}{U_-^2}.
$$

The unit parts are:

$$
\boxed{
11^2\alpha_0
\equiv151114
\pmod{11^5},
}
$$

and:

$$
\boxed{
11^2\alpha_-
\equiv48076
\pmod{11^5}.
}
$$

---

# 14. First theorem quotient and $E_0$

Substituting our coefficients gives

$$
E_1:
\quad
y_1^2
=
x_1^3
+
4M^2x_1^2
+
M^2(4M^2+L^2)x_1
+
2L^2M^4.
$$

Define

$$
X_0
=
\frac{x_1+2M^2}{M},
$$

$$
Y_0
=
-\frac{y_1}{975^3}.
$$

Then:

$$
\boxed{
Y_0^2
=
X_0^3
-
2MX_0^2
+
L^2X_0.
}
$$

Thus:

$$
\boxed{
E_1
\cong_{\mathbb Q}
E_{0,\min}.
}
$$

---

# 15. Differential scaling on $E_1$

Let:

$$
\omega_1
=
\frac{dx_1}{2y_1},
$$

and:

$$
\omega_0
=
\frac{dX_0}{2Y_0}.
$$

Then:

$$
\boxed{
F_1^\ast\omega_0
=
-975\,\omega_1.
}
$$

Relative to the normalized historical $E_0$ differential, this becomes:

$$
\boxed{
\log_{E_1}
=
-\frac1M
\log_{E_0}.
}
$$

Therefore:

$$
\boxed{
\alpha_1
=
M^2\alpha_0.
}
$$

---

# 16. Second theorem quotient and the R16 pre-isogeny curve

The second quotient is:

$$
E_2:
\quad
y_2^2
=
x_2^3
-
(4M^2+L^2)x_2^2
+
8M^2L^2x_2
-
4M^2L^4.
$$

Set:

$$
u=x_2-L^2.
$$

Then:

$$
\boxed{
y_2^2
=
u^3
+
(2L^2-4M^2)u^2
+
L^4u.
}
$$

This is exactly the R16 curve before the degree-$2$ isogeny to the historical $E_-$.

---

# 17. Explicit non-torsion point on $E_2$

The dual-isogeny image of $P_-$ gives:

$$
\boxed{
u_C
=
\frac{
4038403833577153474281
}{
92774458921
},
}
$$

and:

$$
\boxed{
\eta_C
=
-
\frac{
10783196677393640046484856536800000
}{
28258079668288469
}.
}
$$

Hence on the theorem model:

$$
\boxed{
P_2
=
\left(
\frac{
173629486944658561911250
}{
92774458921
},
\eta_C
\right).
}
$$

Direct substitution verifies:

$$
P_2\in E_2(\mathbb Q).
$$

---

# 18. Isogeny image of $P_2$

The R16 degree-$2$ isogeny and historical isomorphism send:

$$
P_2
$$

to:

$$
\boxed{
[2]P_-
}
$$

on $E_-$.

This equality was checked exactly in rational arithmetic, including both $x$ and $y$ coordinates.

---

# 19. Differential scaling on $E_2$

Let:

$$
\omega_2
=
\frac{du}{2\eta}.
$$

For the composite degree-$2$ isogeny:

$$
\psi:
E_2
\longrightarrow
E_-,
$$

one has:

$$
\boxed{
\psi^\ast
\left(
\frac{dx_-}{2y_-}
\right)
=
-\frac23\,\omega_2.
}
$$

Since:

$$
\psi(P_2)=2P_-,
$$

we obtain:

$$
2\log_{E_-}(P_-)
=
-\frac23
\log_{E_2}(P_2).
$$

Thus:

$$
\boxed{
\log_{E_2}(P_2)
=
-3\log_{E_-}(P_-).
}
$$

---

# 20. Height scaling on $E_2$

The canonical cyclotomic height is functorial under isogeny.

For a degree-$2$ isogeny:

$$
h_{E_-}(\psi(P))
=
2h_{E_2}(P).
$$

At:

$$
P=P_2,
$$

the left-hand side is:

$$
h_{E_-}(2P_-)
=
4h_{E_-}(P_-).
$$

Therefore:

$$
\boxed{
h_{E_2}(P_2)
=
2h_{E_-}(P_-).
}
$$

Hence:

$$
\boxed{
\alpha_2
=
\frac29\alpha_-.
}
$$

---

# 21. Theorem quadratic constants

Combining the previous sections:

$$
\boxed{
\alpha_1=M^2\alpha_0,
}
$$

and:

$$
\boxed{
\alpha_2=\frac29\alpha_-.
}
$$

Therefore:

$$
\boxed{
11^2\alpha_1
\equiv142823
\pmod{11^5},
}
$$

and:

$$
\boxed{
11^2\alpha_2
\equiv153840
\pmod{11^5}.
}
$$

These are the exact rank-one calibration constants needed for the explicit bielliptic QC function to the stated precision.

---

# 22. Explicit quadratic-Chabauty function

With the theorem quotient maps:

$$
\varphi_1,
\qquad
\varphi_2,
$$

define:

$$
\boxed{
\rho(z)
=
\lambda_{11}(\varphi_1(z))
-
\lambda_{11}(\varphi_2(z))
-
2\log_{11}(r(z))
}
$$

$$
\boxed{
\qquad
-
\alpha_1
\Log_1(\varphi_1(z))^2
+
\alpha_2
\Log_2(\varphi_2(z))^2.
}
$$

The local-height normalization must be kept consistent with the global Mazur–Tate height normalization used to define:

$$
\alpha_1,
\alpha_2.
$$

The function analytically continues across the apparent $r=0,\infty$ singularities.

---

# 23. Finite global target set

For every rational point:

$$
z\in\mathcal H(\mathbb Q),
$$

the explicit bielliptic theorem gives:

$$
\boxed{
\rho(z)\in\Omega,
}
$$

where:

$$
\Omega\subset\mathbb Q_{11}
$$

is a finite set assembled from local height values at the finitely many bad primes.

Thus the rational-point problem has become:

$$
\boxed{
\rho(z)=\omega,
\qquad
\omega\in\Omega,
}
$$

inside the single R17 prototype residue disk.

---

# 24. Bad-prime support for the QC theorem

The canonical sextic discriminant gives the bad-prime support:

$$
\boxed{
\{
2,3,5,7,13,29,37,73,18521
\}.
}
$$

The explicit coefficient valuations add no new primes.

The chosen Chabauty prime:

$$
11
$$

is good and ordinary.

---

# 25. Coefficient logarithm ranges: $q=2$

Since:

$$
a_6=-M^2
$$

is a $2$-adic unit, and:

$$
a_0=2L^2
$$

has valuation $1$,

the theorem's even integer range is:

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

---

# 26. Coefficient logarithm ranges: $q=3$

Since:

$$
\operatorname{ord}_3(a_6)=4,
$$

and:

$$
\operatorname{ord}_3(a_0)=0,
$$

the allowed even integers are:

$$
\boxed{
-4,-2,0.
}
$$

---

# 27. Coefficient logarithm ranges: $q=5$

Since:

$$
\operatorname{ord}_5(a_6)=8,
$$

and:

$$
\operatorname{ord}_5(a_0)=0,
$$

the allowed even integers are:

$$
\boxed{
-8,-6,-4,-2,0.
}
$$

---

# 28. Coefficient logarithm ranges: $q=13$

The allowed even integers are:

$$
\boxed{
-4,-2,0.
}
$$

---

# 29. Coefficient logarithm ranges: $q=73$

Since:

$$
\operatorname{ord}_{73}(a_0)=2,
$$

and:

$$
\operatorname{ord}_{73}(a_6)=0,
$$

the allowed even integers are:

$$
\boxed{
0,2.
}
$$

---

# 30. Coefficient logarithm ranges: $q=18521$

Likewise:

$$
\boxed{
n\in\{0,2\}.
}
$$

---

# 31. Remaining discriminant primes

At:

$$
7,29,37,
$$

both:

$$
a_0
$$

and:

$$
a_6
$$

are units.

Hence the coefficient-dependent integer range contributes only:

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

Nontrivial finite local-height sets may still occur because the quotient elliptic curves have bad reduction there.

---

# 32. What remains for $\Omega$

For every bad prime:

$$
q\ne11,
$$

one still needs the finite local Néron-height value sets:

$$
\boxed{
W_q^{E_1},
\qquad
W_q^{E_2}.
}
$$

Once these are known, the theorem gives the exact finite set:

$$
\boxed{
\Omega.
}
$$

This is now a finite reduction-theory problem.

No additional global Mordell-Weil heights are missing.

---

# 33. Why historical reduction types cannot be copied blindly

The theorem quotient:

$$
E_1
$$

is isomorphic to the historical:

$$
E_0,
$$

and:

$$
E_2
$$

is degree-$2$ isogenous to the historical:

$$
E_-.
$$

However local Néron-height sets depend on the precise quotient curve and model normalization.

Therefore R19 does **not** simply substitute the historical $E_-$ reduction table for:

$$
W_q^{E_2}.
$$

The local sets must be transported through the isogeny or recomputed directly.

This is retained as a proof-safety boundary.

---

# 34. Relation to the R18 coefficient curve

R18 produced the local analytic relation:

$$
\nu_-
=
\Phi_{11}(\nu_0-1)
$$

through precision:

$$
11^5.
$$

R19 adds the global quadratic data:

$$
\alpha_1,
\qquad
\alpha_2.
$$

Thus the rank-one quadratic pieces in:

$$
\rho
$$

can now be written explicitly on the same one-variable prototype disk.

The remaining nontrivial analytic term is the difference of the two local Mazur–Tate height functions plus:

$$
-2\log_{11}(r).
$$

The sigma backend constructed in R19 is also the required local tool for this computation.

---

# 35. Native backend status after R19

The current runtime now has proof-safe custom algorithms for:

- exact elliptic group law;

- $2$-primary and $11$-primary saturation certificates;

- formal elliptic logarithms;

- canonical $11$-adic sigma constants;

- global cyclotomic $11$-adic heights of rank-one generators;

- transport of quadratic height constants through the quotient isomorphism/isogeny;

- the explicit bielliptic QC theorem coordinates.

The external arithmetic-geometry dependency has therefore been reduced substantially.

---

# 36. Current exact constants

For convenient handoff:

## Historical $E_0$

$$
\boxed{
h_{11}(Q)
\equiv58966
\pmod{11^5},
}
$$

$$
\boxed{
11^2\alpha_0
\equiv151114
\pmod{11^5}.
}
$$

## Historical $E_-$

$$
\boxed{
h_{11}(P_-)
\equiv3035
\pmod{11^5},
}
$$

$$
\boxed{
11^2\alpha_-
\equiv48076
\pmod{11^5}.
}
$$

## Theorem quotient $E_1$

$$
\boxed{
11^2\alpha_1
\equiv142823
\pmod{11^5}.
}
$$

## Theorem quotient $E_2$

$$
\boxed{
11^2\alpha_2
\equiv153840
\pmod{11^5}.
}
$$

---

# 37. Cross-checks

The following independent consistency checks have been performed:

1. sigma constants were obtained by successive integrality conditions rather than one direct solve;

2. the formal sigma series is $11$-integral to the required order;

3. height computations use multiples that lie in the formal subgroup and connected bad-prime components;

4. the R18 logarithm calculations were stable under increased truncation;

5. the theorem $E_1$ equation transforms exactly to the historical $E_0$ model;

6. the theorem $E_2$ equation shifts exactly to the R16 pre-isogeny cubic;

7. the explicit point $P_2$ lies exactly on $E_2$;

8. the isogeny image of $P_2$ is exactly $[2]P_-$;

9. differential scalings were checked symbolically.

---

# 38. Proof-safety status

R19 does not yet claim a complete rational-point classification.

In particular, the following are not yet certified:

- the complete finite set:
  $$
  \Omega;
  $$

- the local analytic expansion of:
  $$
  \rho
  $$
  to root-isolation precision;

- the complete zero set:
  $$
  \{z:\rho(z)\in\Omega\};
  $$

- the final Mordell-Weil sieve on any mock rational points;

- fixed-slice nonexistence.

The phase establishes the global height constants required to make those steps meaningful.

---

# 39. Literature normalization

The external ingredients used in this phase are:

1. Mazur–Tate $p$-adic sigma theory;

2. Mazur–Stein–Tate computation of the cyclotomic $p$-adic height via:

   $$
   h_p(P)
   =
   \frac1p
   \log_p
   \left(
   \frac{\sigma_p(P)}{d(P)}
   \right);
   $$

3. explicit bielliptic quadratic Chabauty for even sextics of rank-$2$ Jacobian, as developed by Balakrishnan–Dogra and made computationally explicit in the Bianchi–Padurariu framework.

The canonical curve satisfies the required rank-one/rank-one split.

---

# 40. Proposed R20 program

R20 should finish the finite non-$11$ local correction layer.

## R20-A — Minimal models for theorem $E_1,E_2$

For each bad prime:

$$
2,3,5,7,13,29,37,73,18521,
$$

determine the exact reduction type of the theorem quotients.

## R20-B — Local Néron value sets

Compute:

$$
W_q^{E_1},
\qquad
W_q^{E_2}.
$$

For multiplicative reduction this can be done from component indices and the Bernoulli local-height formula.

For additive primes use the exact component table.

## R20-C — Assemble $\Omega$

Build the exact finite set:

$$
\boxed{
\Omega.
}
$$

Reduce it modulo a useful power of:

$$
11
$$

and merge duplicate values.

## R20-D — Local QC series

Use the new sigma backend to compute:

$$
\rho(1+11u)
$$

through sufficient precision.

## R20-E — Root isolation

For each:

$$
\omega\in\Omega,
$$

solve:

$$
\rho(1+11u)=\omega.
$$

Use Strassmann/Newton-polygon arguments to certify the number of roots in:

$$
u\in\mathbb Z_{11}.
$$

## R20-F — Recognition and final sieve

Recognize the boundary root:

$$
u=0.
$$

Any additional $11$-adic roots become mock rational points and are passed to the existing R11/R16 Mordell-Weil sieve.

---

# 41. Final conclusion

R19 crosses the global-height barrier that remained after R18.

The canonical Mazur–Tate sigma function has been reconstructed directly for both historical rank-one elliptic factors.

The resulting global cyclotomic $11$-adic heights are:

$$
\boxed{
h_{11}(Q)
\equiv58966
\pmod{11^5},
}
$$

and:

$$
\boxed{
h_{11}(P_-)
\equiv3035
\pmod{11^5}.
}
$$

These heights combine with the R18 logarithms to determine the quadratic constants required by explicit bielliptic quadratic Chabauty.

After exact transport to the theorem's natural two elliptic quotients:

$$
\boxed{
11^2\alpha_1
\equiv142823
\pmod{11^5},
}
$$

and:

$$
\boxed{
11^2\alpha_2
\equiv153840
\pmod{11^5}.
}
$$

Thus the missing quadratic-Chabauty function is now calibrated globally.

The remaining tasks are finite and local:

$$
\boxed{
\text{bad-prime local height sets}
\longrightarrow
\Omega
\longrightarrow
11\text{-adic root isolation}.
}
$$

R20 should attack exactly that layer.
