English
For an algebraic extension L/K, the set of all K-automorphisms of L is totally separated in the Krull topology.
Русский
Для алгебраического расширения L/K множество всех K-автоморфизмов L полностью разделено в топологии Круль.
LaTeX
$$$\\text{IsTotallySeparated}(\\mathrm{Aut}_K(L)).$$$
Lean4
/-- If `L/K` is an algebraic field extension, then the Krull topology on `L ≃ₐ[K] L` is
totally disconnected. -/
theorem krullTopology_isTotallySeparated {K L : Type*} [Field K] [Field L] [Algebra K L] [Algebra.IsIntegral K L] :
IsTotallySeparated (Set.univ : Set (L ≃ₐ[K] L)) :=
(totallySeparatedSpace_iff _).mp inferInstance