English
An extension IsGalois F E is equivalent to the conjunction of Algebra.IsSeparable F E and Normal F E; i.e., IsGalois F E iff the extension is separable and normal.
Русский
Расширение IsGalois F E эквивалентно сочетанию разделимости и нормальности: IsGalois F E ⇔ Algebra.IsSeparable F E ∧ Normal F E.
LaTeX
$$$IsGalois F E \\iff (Algebra.IsSeparable F E \\land Normal F E)$$$
Lean4
theorem isGalois_iff : IsGalois F E ↔ Algebra.IsSeparable F E ∧ Normal F E :=
⟨fun h => ⟨h.1, h.2⟩, fun h =>
{ to_isSeparable := h.1
to_normal := h.2 }⟩