Exclusion of nondegenerate sextuples with exactly two small entries
ProvedD1Bound5.IsD1Tuple.two_small_nondegenerate_impossiblediophantine-tuplesnumber-theory
Let K be an imaginary quadratic number field, let phi be a complex embedding, and let t be a Diophantine sextuple in its full ring of integers. Assume that the absolute values of the images of its entries are nondecreasing. Such a sextuple is impossible if the second absolute value is below 3, the third is at least 3, and the product of the first two entries plus one is nonzero.
The sextuple consists of distinct nonzero algebraic integers, and the product of any two distinct entries plus one is a square in the full ring of integers. Equal absolute values are permitted. This is one of the exhaustive branches used to establish the cardinality bound.
Preamble
import Definitions.Def_D1Bound5_IsD1Tuple import Definitions.Def_D1Bound5_MainStatement import Mathlib.Analysis.Complex.Basic open scoped NumberField open Module D1Bound5
Formal statement
theorem D1Bound5.IsD1Tuple.two_small_nondegenerate_impossible
{K : Type*} [Field K] [NumberField K] [NumberField.IsTotallyComplex K]
(hK : finrank ℚ K = 2) (phi : K →+* ℂ)
(t : Fin 6 → 𝓞 K) (ht : IsD1Tuple t)
(hmon : Monotone (fun i => ‖phi (t i : K)‖))
(hsmall : ‖phi (t 1 : K)‖ < 3)
(hlarge : 3 ≤ ‖phi (t 2 : K)‖)
(hnondeg : t 0*t 1+1 ≠ 0) : False := by sorrySource
D1Bound5/TwoSmallNondegenerateImpossible.lean, D1Bound5.IsD1Tuple.two_small_nondegenerate_impossible, lines 12-19; exact source SHA-256 cd2e46669d5180d170708c2c6e146711677502487bd331463fa9c364e4d7b7bb. Project: https://github.com/tomislav-math/d1-bound5-lean