English
If L/K is algebraic and K is a perfect field, then L/K is separable.
Русский
Если расширение L/K алгебраическое и K — совершенное поле, то расширение L/K расслоимо.
LaTeX
$$$\text{ Algebra.IsSeparable } K L$ (при условии PerfectField K) $$$
Lean4
/-- If `L / K` is an algebraic extension, `K` is a perfect field, then `L / K` is separable. -/
instance isSeparable_of_perfectField {K L : Type*} [Field K] [Field L] [Algebra K L] [Algebra.IsAlgebraic K L]
[PerfectField K] : Algebra.IsSeparable K L :=
⟨fun x ↦ PerfectField.separable_of_irreducible <| minpoly.irreducible (Algebra.IsIntegral.isIntegral x)⟩