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LeanPool.BrillNoetherGraphs.Bananas.CrossOneOff.OneOffPeriodBound

The affine-period bound for the same-strand one-off marking #

The three residue formulas of Lemma 4.23 force every positive affine period to lie strictly beyond g + floor(g/(n-1)), the exact natural-number form of the paper's rational cutoff (n/(n-1))g.

theorem Bananas.oneOff_affine_period_gt_cutoff {g k : ℕ} (B : Banana g) (alpha : Fin (g + 1)) (tau : ℤ → ℤ) (hg : 2 ≤ g) (hk : 0 < k) (hLength : 1 < B.length alpha) (hTau : IsTransmissionPermutation (mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (leftEndpoint B) (strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩)) (g • oneChip (rightEndpoint B)) tau) (hAffine : IsKAffine k tau) :
crossOneOffCutoff g (B.length alpha) < k

Lemma 4.23's period consequence, in exact integral form.

Bijectivity is not needed here: the forced transmission rows together with k-affinity already exclude every positive k at or below the cutoff.