Product Five rank Two det general
ProvedD1Bound5.productFive_rankTwo_det_generaldiophantine-tuplesnumber-theory
The exact rank-two determinant formula for the fifth-entry Schur complement. No symmetry is assumed: both cross forms occur. In the symmetric case the two cross forms coincide.
Preamble
import Mathlib.Analysis.CStarAlgebra.Matrix import Mathlib.Analysis.Complex.Basic import Mathlib.Analysis.Complex.Polynomial.Basic import Mathlib.Analysis.InnerProductSpace.PiL2 import Mathlib.Analysis.SpecificLimits.Normed import Mathlib.Data.Complex.Basic import Mathlib.LinearAlgebra.Matrix.Determinant.Basic import Mathlib.LinearAlgebra.Matrix.NonsingularInverse import Mathlib.LinearAlgebra.Matrix.Permutation import Mathlib.LinearAlgebra.Matrix.SchurComplement import Mathlib.Tactic.FieldSimp import Mathlib.Tactic.FinCases import Mathlib.Tactic.Linarith import Mathlib.Tactic.LinearCombination import Mathlib.Tactic.NormNum import Mathlib.Tactic.Ring import Definitions.Def_D1Bound5_ProductFiveRankTwo_Definitions
Formal statement
section
open Matrix
namespace D1Bound5
theorem _root_.D1Bound5.productFive_rankTwo_det_general
(F : Matrix (Fin 4) (Fin 4) ℂ)
(f w : Fin 4 → ℂ) (d : ℂ)
(hF : F.det ≠ 0) (hd : d ≠ 0) :
(F + productFiveColumns f w * productFiveRows f w d).det =
F.det *
(1 - ((w ⬝ᵥ (F⁻¹ *ᵥ f)) + (f ⬝ᵥ (F⁻¹ *ᵥ w))) / d +
((w ⬝ᵥ (F⁻¹ *ᵥ f)) * (f ⬝ᵥ (F⁻¹ *ᵥ w)) -
(f ⬝ᵥ (F⁻¹ *ᵥ f)) * (w ⬝ᵥ (F⁻¹ *ᵥ w)) -
(f ⬝ᵥ (F⁻¹ *ᵥ f))) / d^2) := by sorry
end D1Bound5
end
Source
D1Bound5/ProductFiveRankTwo.lean, lines 87-131, SHA-256 0cec92c96e51a0a3fbd94ad6a62d3e917e83332e75de37d2fd74599e197b4902. Project: https://github.com/tomislav-math/d1-bound5-lean