EtaleFundamentalGroups.Inertia.commAlgCanonicalTameMorphism_exact_of_coprime
Coprimality of the actual tame order and actual e/n normalization exponent makes the SAME normalized character onto with its SAME principal-unit kernel.
Source context 3 commands
Surrounding namespaces, section variables, and local commands at this declaration.
open scoped Pointwise
namespace EtaleFundamentalGroups.Inertia
universe u vLean source · statement
theorem commAlgCanonicalTameMorphism_exact_of_coprime
(A : Type u) [CommRing A] (B : CommAlgCat.{v} A)
[IsDedekindDomain B.carrier] [Finite (B.carrier ≃ₐ[A] B.carrier)]
(q : Ideal B.carrier) [q.IsPrime] (hq : q ≠ ⊥)
(hcop : Nat.Coprime (commAlgIdealTameOrder A B q hq)
(q.ramificationIdx A / commAlgIdealTameOrder A B q hq)) :
Function.Surjective (commAlgCanonicalTameMorphism A B q hq).hom'.toFun ∧
(commAlgCanonicalTameMorphism A B q hq).hom'.ker =
commAlgIdealWildSubgroup A B q hq