Module

SeparableClosedRange.lean

Nyll.ValuedFieldTheory.Valuation.Completion.SeparableClosedRange
1 declaration indexed from sourceView source ↗

Separable elements lie in an embedded separably closed field

An embedding from a separably closed field contains every element that is separable over the common base, without any algebraicity assumption on the ambient extension or on the separably closed field over that base.

Declarations

ValuationTheory.Completion.mem_fieldRange_of_isSeparable_of_isSepClosed

An element separable over the common base lies in the image of every embedding from a separably closed field.

Source context 2 commands

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

namespace ValuationTheory.Completion
variable {K S E : Type*} [Field K] [Field S] [Field E]
  [Algebra K S] [Algebra K E] [IsSepClosed S]
theorem mem_fieldRange_of_isSeparable_of_isSepClosed
    (i : S →ₐ[K] E) {x : E} (hx : IsSeparable K x) : x ∈ i.fieldRange