∀ {K : Type u_1} [inst : Field K] {ζ : K} {hζ : IsPrimitiveRoot ζ 3} (S : FermatLastTheoremForThreeGen.Solution hζ)
  [inst_1 : NumberField K] [inst_2 : IsCyclotomicExtension {3} ℚ K],
  (hζ.toInteger - 1) ^ (S.multiplicity - 1) * FermatLastTheoremForThreeGen.Solution.X✝ S = 0 →
    FermatLastTheoremForThreeGen.Solution.X✝¹ S = 0