In a ring isomorphic to a concrete surface, the images of `(t, x)` and `(x, t)` are regular parameter pairs;
ProvedTypeDensity.concrete_surface_equiv_regular_pairtype-density
In a ring isomorphic to a concrete surface, the images of (t, x) and (x, t) are regular parameter pairs; in particular t is a non-zero-divisor.
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Blowup_Directions import Definitions.Def_TypeDensity_Measure_AdicCylinders import Definitions.Def_TypeDensity_Measure_HenselProducts import Definitions.Def_TypeDensity_Surfaces_Lengths import Definitions.Def_TypeDensity_Unramified_Extension import Definitions.Def_TypeDensity_Blowup_Charts import Definitions.Def_TypeDensity_Formula_LawAlgebra import Definitions.Def_TypeDensity_Surfaces_PowerSeries import Definitions.Def_TypeDensity_Algebra_AlgebraType import Definitions.Def_TypeDensity_Measure_PrimitiveLocus import Definitions.Def_TypeDensity_Algebra_FactorInvariant import Theorems.Thm_TypeDensity_concrete_surface_regular_pair_tx import Theorems.Thm_TypeDensity_concrete_surface_regular_pair_xt 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.Algebra.Group.Pi.Units import Mathlib.Order.CompletePartialOrder import Mathlib.RingTheory.Henselian import Mathlib.RingTheory.Polynomial.Resultant.Basic import Mathlib.RingTheory.RegularLocalRing.Defs import Mathlib.RingTheory.SimpleRing.Principal import Mathlib.FieldTheory.Finite.Extension import Mathlib.RingTheory.AdicCompletion.Noetherian import Mathlib.RingTheory.MvPowerSeries.Equiv import Mathlib.RingTheory.PicardGroup import Mathlib.FieldTheory.Finite.GaloisField import Mathlib.RingTheory.AdicCompletion.Algebra import Mathlib.Algebra.GroupWithZero.Submonoid.CancelMulZero import Mathlib.Algebra.Module.StablyFree.Basic import Mathlib.NumberTheory.Padics.RingHoms import Mathlib.Algebra.Azumaya.Basic import Mathlib.RingTheory.AdicCompletion.Completeness import Mathlib.RingTheory.AdicCompletion.RingHom import Mathlib.RingTheory.TotallySplit import Mathlib.RingTheory.AdicCompletion.LocalRing import Mathlib.RingTheory.KrullDimension.NonZeroDivisors set_option autoImplicit false open TypeDensity
Formal statement
theorem TypeDensity.concrete_surface_equiv_regular_pair (S : Type) [CommRing S] (O' : Type) [CommRing O']
[IsDomain O'] [IsDiscreteValuationRing O'] (pi' : O') (hpi' : Irreducible pi')
(u' : (TwoSeries O')ˣ) (a' b' : ℕ) (ha' : 0 < a') (Eq : S ≃+* ConcreteSurface O' pi' u' a' b') :
RegularParameterPair S (Eq.symm (surfaceT O' pi' u' a' b'))
(Eq.symm (surfaceX O' pi' u' a' b')) ∧ RegularParameterPair S
(Eq.symm (surfaceX O' pi' u' a' b')) (Eq.symm (surfaceT O' pi' u' a' b')) ∧ Function.Injective
(fun y : S ↦ Eq.symm (surfaceT O' pi' u' a' b') * y) := by sorrySource
TypeDensity/Surfaces/Regularity.lean#L298-L310