Over a finite field, the exceptional divisors with tangent pattern `P` are in bijection with tuples, indexed by degrees `i + 1`, of colorings of the nonboundary directions of that degree by `Fin s.deg
ProvedTypeDensity.patternDivisors_equiv_coloringstype-density
Over a finite field, the exceptional divisors with tangent pattern P are in bijection with tuples, indexed by degrees i + 1, of colorings of the nonboundary directions of that degree by Fin s.degree ⊕ none with color counts P.other (i, j).
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Blowup_Directions import Definitions.Def_TypeDensity_Measure_AdicCylinders import Definitions.Def_TypeDensity_Formula_LawAlgebra import Definitions.Def_TypeDensity_Measure_HenselProducts import Definitions.Def_TypeDensity_Surfaces_Lengths import Definitions.Def_TypeDensity_Surfaces_PowerSeries import Definitions.Def_TypeDensity_Formula_FiniteFieldCounts import Definitions.Def_TypeDensity_Formula_StateCombinatorics import Definitions.Def_TypeDensity_Formula_PatternCounts import Mathlib.FieldTheory.RatFunc.Basic import Mathlib.MeasureTheory.Measure.Haar.Unique import Mathlib.NumberTheory.ArithmeticFunction.Moebius import Mathlib.NumberTheory.Padics.PadicIntegers import Mathlib.RingTheory.IntegralClosure.IntegralRestrict import Mathlib.RingTheory.MvPowerSeries.Basic import Mathlib.RingTheory.RamificationInertia.Basic import Mathlib.Topology.Algebra.Nonarchimedean.AdicTopology import Mathlib.Topology.Algebra.MvPolynomial import Mathlib.FieldTheory.Finite.GaloisField import Mathlib.RingTheory.AdicCompletion.Algebra import Mathlib.RingTheory.RegularLocalRing.Defs import Mathlib.Algebra.Group.Pi.Units import Mathlib.Order.CompletePartialOrder import Mathlib.RingTheory.Henselian import Mathlib.RingTheory.Polynomial.Resultant.Basic import Mathlib.RingTheory.SimpleRing.Principal import Mathlib.FieldTheory.Finite.Extension import Mathlib.RingTheory.AdicCompletion.Noetherian import Mathlib.RingTheory.MvPowerSeries.Equiv import Mathlib.RingTheory.PicardGroup set_option autoImplicit false open TypeDensity open scoped BigOperators ENNReal
Formal statement
theorem TypeDensity.patternDivisors_equiv_colorings (k : Type) [Field k] [Finite k] (s : State)
(P : TangentPattern s.degree) (hP : P.rt.val + P.rx.val + patternWeight P.other = P.d.val)
(hrx : ∀ a c, s = State.single a c → P.rx.val = 0) :
Nonempty (patternDivisors k s P ≃ ∀ i : Fin s.degree,
{f : {Q : ClosedDirection k // Q ∉ boundaryDirections k s ∧
directionDegree k Q = i.val + 1} → Option (Fin s.degree) //
∀ j : Fin s.degree, Nat.card {Q // f Q = some j} = (P.other (i, j)).val}) := by sorrySource
TypeDensity/Formula/PatternCounts.lean#L494-L507