The inner native unit
Abstract
The inner native unit
Definition 1.1 (A native series with constant coefficient one).
Lean statement: D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.innerUnitSeries
Formalization. D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.innerUnitSeries (✓ std3).
Source. Repository-derived.
Commentary.
In cumulative coefficient coordinates for b,z,x, the exact unit is (1-T-ST)^k (1-T)^k (1+S)^H. It has constant coefficient one over every commutative complex algebra, including the zero algebra.
Definition 1.2 (Signed native inverse coefficients).
Lean statement: D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.rawInnerCoefficient
Formalization. D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.rawInnerCoefficient (✓ std3).
Source. Repository-derived.
Commentary.
The generally infinite native numerator is reordered and placed in the cumulative coefficient chart. The coefficient of the inverse unit times this chart is read at the signed index (b+k,b+z+k+a1+a2,x+b+z+a0+3k+a1+a2), with zero extension outside the nonnegative chart.
Theorem 1.3 (Exact action of the original polynomial).
Lean statement: D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.raw_inner_action
Proof. Machine-checked in Lean as D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.raw_inner_action (✓ std3). ∎
Source. Repository-derived.
Commentary.
Finite signed monomial translations, sums, products and powers prove that multiplication by the literal original polynomial recovers the original numerator at every signed target. The native unit equation cancels only a native series unit.
Theorem 1.4 (Support of the inverse expression).
Lean statement: D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.raw_inner_support
Proof. Machine-checked in Lean as D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.raw_inner_support (✓ std3). ∎
Source. Repository-derived.
Commentary.
The inverse expression vanishes below b=-k. At each fixed b it vanishes below z=-(b+k+a1+a2), with the signed zero cases included. This proves support of the constructed inverse; it does not impose support on actual fields.
References
- Truth anchor:
D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.innerUnitSeries - Truth anchor:
D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.rawInnerCoefficient - Truth anchor:
D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.raw_inner_action - Truth anchor:
D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerNativeInverse.raw_inner_support - Dependency: D5/S3/VertexAlgebra/FormalSeries/ThreeFieldFinalLaurentAction
- Dependency: D5/S3/VertexAlgebra/FormalSeries/ThreeFieldInnerPolynomial