OAI/NumberTheory/DukePrimeDegree/Dynamics/VectorAvoidance.lean
2 declarations, 0 contain sorry, 0 declared as axioms
A lattice vector off all coordinate hyperplanes
For a matrix with nonzero determinant, use the integer coefficient vector
(1,N,...,N^(n-1)). Each coordinate of its row product is a nonzero
polynomial in N. Finitely many polynomials exclude only finitely many
integers, so a suitable integer N exists. This gives the vector selection
used to deduce ordinary ball bounds from vector-box counts.
- theorem
OAI.DukePrimeDegree.exists_integer_row_all_ne_zeroline 24Source documentation
An invertible real matrix admits an integral row combination with no zero coordinate. No bound on the chosen coefficients is required.
theorem exists_integer_row_all_ne_zero {n : ℕ} (A : Matrix (Fin n) (Fin n) ℝ) (hA : A.det ≠ 0) : ∃ c : Fin n → ℤ, ∀ j, (Matrix.vecMul (fun i => (c i : ℝ)) A) j ≠ 0 := by … - theorem
OAI.DukePrimeDegree.submodule_exists_all_coordinates_ne_zeroline 60Source documentation
Every additive integer lattice containing the rows of an invertible real matrix contains a vector with all coordinates nonzero.
theorem submodule_exists_all_coordinates_ne_zero {n : ℕ} (Λ : Submodule ℤ (Fin n → ℝ)) (A : Matrix (Fin n) (Fin n) ℝ) (hA : A.det ≠ 0) (hrows : ∀ i, A i ∈ Λ) : ∃ v ∈ Λ, ∀ j, v j ≠ 0 := by …