Is D1 — one three small third eq eight
ProvedD1Bound5.IsD1.one_three_small_third_eq_eightdiophantine-tuplesnumber-theory
In any actual full ring, a D(1)-set of cardinality at least five containing 1 and 3 has exactly the third candidate 8 below modulus 15. The accepted negative-extension theorem supplies positivity and rationality.
Preamble
import Mathlib.Algebra.Polynomial.Monic import Mathlib.Algebra.QuadraticAlgebra.Basic import Mathlib.Algebra.Ring.Basic import Mathlib.Algebra.Ring.Equiv import Mathlib.Algebra.Squarefree.Basic import Mathlib.Analysis.Complex.Norm import Mathlib.Data.Finset.Card import Mathlib.Data.Fintype.EquivFin import Mathlib.Data.Int.GCD import Mathlib.Data.Int.Sqrt import Mathlib.LinearAlgebra.Dimension.Free import Mathlib.NumberTheory.NumberField.InfinitePlace.TotallyRealComplex import Mathlib.NumberTheory.NumberField.Norm import Mathlib.Tactic.IntervalCases import Mathlib.Tactic.Linarith import Mathlib.Tactic.LinearCombination import Definitions.Def_D1Bound5_IsD1
Formal statement
section
open scoped NumberField Classical
open Module
namespace D1Bound5
theorem _root_.D1Bound5.IsD1.one_three_small_third_eq_eight
{K : Type*} [Field K] [NumberField K] [NumberField.IsTotallyComplex K]
(hK : finrank ℚ K = 2) (phi : K →+* ℂ)
{A : Finset (𝓞 K)} (hA : IsD1 A)
(h1 : (1 : 𝓞 K) ∈ A) (h3 : (3 : 𝓞 K) ∈ A) (hcard : 4 < A.card)
(z : 𝓞 K) (hz : z ∈ A) (hz1 : z ≠ 1) (hz3 : z ≠ 3)
(hlo : 9 ≤ ‖phi (z : K)‖^2) (hhi : ‖phi (z : K)‖^2 < 225) : z = 8 := by sorry
end D1Bound5
end
Source
D1Bound5/OneThreeEight.lean, lines 17-43, SHA-256 60602e3caf285e30e5c1611b6c08cecf7eefe23af11cee872a9962bf384b646f. Project: https://github.com/tomislav-math/d1-bound5-lean