import Mathlib import OAI.AlgebraicGeometry.Seshadri.Projective.ProjectiveCartier import OAI.AlgebraicGeometry.Seshadri.Intersection.FiniteLineEuler import OAI.AlgebraicGeometry.Seshadri.Nodal.NodalDivisorDegree import OAI.AlgebraicGeometry.Seshadri.Nodal.NodalIdealEuler import OAI.AlgebraicGeometry.Seshadri.Projective.QuarticDivision import OAI.AlgebraicGeometry.Seshadri.Intersection.CurveSectionDegree import OAI.AlgebraicGeometry.Seshadri.Sheaves.ClosedPushforwardExact import OAI.AlgebraicGeometry.Seshadri.Cohomology.CycleStructures import OAI.AlgebraicGeometry.Seshadri.Intersection.ArbitraryCartierEuler import OAI.AlgebraicGeometry.Seshadri.Sheaves.BaseChangeNatural import OAI.AlgebraicGeometry.Seshadri.Interpolation.SurfaceQuadrilateral import OAI.AlgebraicGeometry.Seshadri.Geometry.AmplePowers import OAI.AlgebraicGeometry.Seshadri.Blowup.BoundaryNef import OAI.AlgebraicGeometry.Seshadri.Interpolation.SeshadriUpper namespace OAI section namespace MaximalSeshadri.Geometry theorem maximalSeshadriConstants (S : Surface) (L : LineBundle S.scheme) (hL : LineBundle.IsAmple S.scheme L) : EventualMaximalSeshadri S L := by obtain ⟨r₀,hr₀,h⟩ := S.eventual_very_general_curve_lower L hL refine ⟨r₀,hr₀,fun r hr => ?_⟩ obtain ⟨Z,hZ,hne,hC⟩ := h r hr refine ⟨Z,hZ,hne,fun p hp => ?_⟩ have hrpos : 0 < r := hr₀.trans_le hr obtain ⟨B⟩ := S.pointBlowup_exists L hL r p exact ⟨⟨B,B.boundaryNef_of_curve_bound S L hL hrpos (hC p hp)⟩, S.seshadri_eq_of_curve_lower L hL hrpos p (hC p hp)⟩ end MaximalSeshadri.Geometry end end OAI