Module

CommAlgIdealWildSubgroup.lean

Nyll.EtaleFundamentalGroups.Inertia.CommAlgIdealWildSubgroup
4 declarations indexed from sourceView source ↗

Native coefficient-algebra owner of the intrinsic wild subgroup

This is the same existing principal-unit subgroup. Its raw automorphism Group and action are retained inside the native owner, so original field consumers do not reopen them beside their scalar towers.

Declarations

EtaleFundamentalGroups.Inertia.commAlgIdealInertiaGroup_finite

Finite coefficient automorphisms give finite intrinsic ideal inertia.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
namespace EtaleFundamentalGroups.Inertia
universe u v
theorem commAlgIdealInertiaGroup_finite
    (A : Type u) [CommRing A] (B : CommAlgCat.{v} A)
    [Finite (B.carrier ≃ₐ[A] B.carrier)] (Q : Ideal B.carrier) :
    Finite (commAlgIdealInertiaGroup A B Q).carrier
EtaleFundamentalGroups.Inertia.commAlgIdealWildSubgroup

The intrinsic principal-unit wild subgroup on the native inertia carrier.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
namespace EtaleFundamentalGroups.Inertia
universe u v
def commAlgIdealWildSubgroup
    (A : Type u) [CommRing A] (B : CommAlgCat.{v} A)
    [IsDedekindDomain B.carrier]
    (Q : Ideal B.carrier) [Q.IsPrime] (hQ : Q ≠ ⊥) :
    Subgroup (commAlgIdealInertiaGroup A B Q).carrier
EtaleFundamentalGroups.Inertia.commAlgIdealWildSubgroup_card

Its literal cardinality is the independently computed wild order.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
namespace EtaleFundamentalGroups.Inertia
universe u v
theorem commAlgIdealWildSubgroup_card
    (A : Type u) [CommRing A] (B : CommAlgCat.{v} A)
    [IsDedekindDomain B.carrier]
    (Q : Ideal B.carrier) [Q.IsPrime] (hQ : Q ≠ ⊥) :
    Nat.card (commAlgIdealWildSubgroup A B Q hQ) = commAlgIdealWildOrder A B Q hQ
EtaleFundamentalGroups.Inertia.commAlgIdealWildSubgroup_index

Its index is the same independently computed tame degree.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
namespace EtaleFundamentalGroups.Inertia
universe u v
theorem commAlgIdealWildSubgroup_index
    (A : Type u) [CommRing A] (B : CommAlgCat.{v} A)
    [IsDedekindDomain B.carrier]
    (Q : Ideal B.carrier) [Q.IsPrime] (hQ : Q ≠ ⊥) :
    (commAlgIdealWildSubgroup A B Q hQ).index = commAlgIdealTameOrder A B Q hQ