EulerNineDissection
Abstract
The actual Euler quotient has three genuine restricted partition sections.
The Jacobi products are identified with E times Q_r by multiplying the actual restricted-partition HasProd by the Euler HasProd. Allowed geometric factors cancel exactly; each finite block of nine leaves precisely the three forbidden factors. The finite-block identity is proved for arbitrary cutoff and then passed to its true coefficientwise limit. The constant-one Euler inverse gives J_r P=Q_r. Thus R=E(q)/E(q^3) has the required signed dissection; it is not an assumed partition identity. EulerNineSquareDissection consumes R_dissection.
Theorem 1.1 (J_eq_euler_mul_Q).
Lean statement: D5/S3/Arith/ModularForms/EulerNineDissection.J_eq_euler_mul_Q
Proof. Machine-checked in Lean as D5/S3/Arith/ModularForms/EulerNineDissection.J_eq_euler_mul_Q (✓ std3). ∎
Source. Repository-derived.
Acknowledgement. Kathrin Bringmann, Guoniu Han, Bernhard Heim and Ben Kane (2024). Periodic sign changes for weakly holomorphic eta-quotients. DOI: 10.48550/arXiv.2409.07164. URL: https://arxiv.org/abs/2409.07164v1.
Commentary.
For r=1,2,4, the weighted Jacobi series is E times the actual allowed-part counting series.
Theorem 1.2 (J_mul_inverse).
Lean statement: D5/S3/Arith/ModularForms/EulerNineDissection.J_mul_inverse
Proof. Machine-checked in Lean as D5/S3/Arith/ModularForms/EulerNineDissection.J_mul_inverse (✓ std3). ∎
Source. Repository-derived.
Acknowledgement. Kathrin Bringmann, Guoniu Han, Bernhard Heim and Ben Kane (2024). Periodic sign changes for weakly holomorphic eta-quotients. DOI: 10.48550/arXiv.2409.07164. URL: https://arxiv.org/abs/2409.07164v1.
Commentary.
Multiplying by the genuine Euler inverse yields the restricted partition section.
Definition 1.3 (R).
Lean statement: D5/S3/Arith/ModularForms/EulerNineDissection.R
Formalization. D5/S3/Arith/ModularForms/EulerNineDissection.R (✓ std3).
Source. Repository-derived.
Acknowledgement. Kathrin Bringmann, Guoniu Han, Bernhard Heim and Ben Kane (2024). Periodic sign changes for weakly holomorphic eta-quotients. DOI: 10.48550/arXiv.2409.07164. URL: https://arxiv.org/abs/2409.07164v1.
Commentary.
The actual Euler quotient E(q) times P(q^3).
Theorem 1.4 (R_dissection).
Lean statement: D5/S3/Arith/ModularForms/EulerNineDissection.R_dissection
Proof. Machine-checked in Lean as D5/S3/Arith/ModularForms/EulerNineDissection.R_dissection (✓ std3). ∎
Source. Repository-derived.
Acknowledgement. Kathrin Bringmann, Guoniu Han, Bernhard Heim and Ben Kane (2024). Periodic sign changes for weakly holomorphic eta-quotients. DOI: 10.48550/arXiv.2409.07164. URL: https://arxiv.org/abs/2409.07164v1.
Commentary.
The all-degree equality R=Q4(q^3)-qQ2(q^3)-q^2Q1(q^3).
References
- Truth anchor:
D5/S3/Arith/ModularForms/EulerNineDissection.J_eq_euler_mul_Q - Truth anchor:
D5/S3/Arith/ModularForms/EulerNineDissection.J_mul_inverse - Truth anchor:
D5/S3/Arith/ModularForms/EulerNineDissection.R - Truth anchor:
D5/S3/Arith/ModularForms/EulerNineDissection.R_dissection - Dependency: D5/S3/Arith/ModularForms/CubicThetaIdentities
- Dependency: D5/S3/Arith/ModularForms/EulerPentagonalTrisection
- Dependency: D5/S3/Combinatorics/Partitions/EulerNineComparison