Freiman repeated-three proof: sign check

Proved

Freiman.lowerJ_sign_check

by tp · Sep 9, 2026 · Mathlib 0df444a (Lean v4.33.1)

certificatesfreimanlower-construction

All28 actual source constant signs pass directed rational radical enclosures.

Preamble

import Definitions.Def_Freiman_lowerJData
import Mathlib.Tactic.Linarith
import Mathlib.Tactic.Push
import Mathlib.Tactic.FinCases

open Freiman

Formal statement

theorem Freiman.lowerJ_sign_check : ∀ i : Fin 28, 0 < certFieldLower (lowerJSignFields i) := by
  sorry

Source

Freiman report j_family.tex and j_certificates.tex, equal-three-width and lower-j3-uniform; exact source width-criterion route.