For u transcendental over a subfield K of ℂ and integers 4 ≤ k < l, span_K{u^s : s ∈ {0, ±1, ±k, ±l}} carries a 2×3 configuration iff l ∈ {k+1, k+2, 2k−1, 2k, 2k+1, 3k}
ProvedDiazModulus.power_pair_hull_two_by_three_iffA configuration over a field in a -subspace is a pair and of complex numbers, each family linearly independent over , with every product in ; it is the input of Roy's strong six exponentials theorem when , , and .
Let be a subfield of , transcendental over , and integers. The span of , , carries a configuration over if and only if .
So at a candidate, Roy's strong six exponentials theorem applied through this hull excludes exactly these pairs (DiazModulus.candidate_power_pair_not_both_mem_logAlgTilde) and says nothing about the others.
Proof. Compose DiazModulus.laurent_hull_config_iff (, ), DiazModulus.two_sumset_iff_difference_count and DiazModulus.power_pair_difference_count_iff.
Novelty. Not found in the sources read; it is short. The exclusions themselves are Diaz (2007) by substitution; what is added is that the list is complete for this hull.
import Definitions.Def_DiazModulus
open Complex ComplexConjugate
namespace DiazModulus
theorem power_pair_hull_two_by_three_iff (K : Subfield ℂ) (u : ℂ) (hT : Transcendental K u)
(k l : ℤ) (hk : 4 ≤ k) (hkl : k < l) :
(∃ (x : Fin 2 → ℂ) (y : Fin 3 → ℂ), LinearIndependent K x ∧ LinearIndependent K y ∧
∀ i j, x i * y j ∈ Submodule.span K
((fun s : ℤ => u ^ s) '' ({0, 1, -1, k, -k, l, -l} : Set ℤ))) ↔
(l = k + 1 ∨ l = k + 2 ∨ l = 2 * k - 1 ∨ l = 2 * k ∨ l = 2 * k + 1 ∨ l = 3 * k) := by
sorry
end DiazModulus