Module

NativeIdealInertiaInclusion.lean

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

Ideal inertia included into its actual stabilizer

The subgroup order and pointwise ideal-action interfaces are closed here, with only a ring and its acting group. The map is the literal inclusion.

Declarations

EtaleFundamentalGroups.Inertia.nativeIdealInertiaToStabilizer

The standard subgroup inclusion supplied by actual inertia stability.

Source context 3 commands

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

namespace EtaleFundamentalGroups.Inertia
open scoped Pointwise
universe u v
def nativeIdealInertiaToStabilizer
    (B : Type u) [CommRing B] (G : Type v) [Group G] [MulSemiringAction G B]
    (Q : Ideal B) : Q.inertia G →* MulAction.stabilizer G Q
EtaleFundamentalGroups.Inertia.nativeIdealInertiaToStabilizer_conjugate

This literal inclusion identifies the native conjugate with stabilizer conjugation.

Source context 3 commands

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

namespace EtaleFundamentalGroups.Inertia
open scoped Pointwise
universe u v
theorem nativeIdealInertiaToStabilizer_conjugate
    (B : Type u) [CommRing B] (G : Type v) [Group G] [MulSemiringAction G B]
    (Q : Ideal B) (d : MulAction.stabilizer G Q) (σ : Q.inertia G) :
    (nativeIdealInertiaToStabilizer B G Q).toFun
        (nativeIdealInertiaConjugate B G Q d σ) =
      d * (nativeIdealInertiaToStabilizer B G Q).toFun σ * d⁻¹
EtaleFundamentalGroups.Inertia.nativeIdealInertiaToStabilizer_injective

The literal ideal-inertia inclusion is injective.

Source context 3 commands

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

namespace EtaleFundamentalGroups.Inertia
open scoped Pointwise
universe u v
theorem nativeIdealInertiaToStabilizer_injective
    (B : Type u) [CommRing B] (G : Type v) [Group G] [MulSemiringAction G B]
    (Q : Ideal B) : Function.Injective (nativeIdealInertiaToStabilizer B G Q).toFun
EtaleFundamentalGroups.Inertia.nativeIdealInertiaToStabilizer_range_map

Its range has exactly the original inertia image in the acting group.

Source context 3 commands

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

namespace EtaleFundamentalGroups.Inertia
open scoped Pointwise
universe u v
theorem nativeIdealInertiaToStabilizer_range_map
    (B : Type u) [CommRing B] (G : Type v) [Group G] [MulSemiringAction G B]
    (Q : Ideal B) :
    (nativeIdealInertiaToStabilizer B G Q).range.map
        (MulAction.stabilizer G Q).subtype = Q.inertia G