English
There is a canonical IsScalarTower structure between F, K, and the normalClosure F K L, making the scalar actions compatible.
Русский
Существует каноническая структура IsScalarTower между F, K и normalClosure F K L, обеспечивающая совместимость действия скаляров.
LaTeX
$$$\text{IsScalarTower } F\ K\ (\operatorname{normalClosure}(F,K,L))$$$
Lean4
@[stacks 0BMG "When `L` is normal over `K`, this agrees with 0BMG (1) finiteness."]
instance is_finiteDimensional [FiniteDimensional F K] : FiniteDimensional F (normalClosure F K L) :=
by
haveI : ∀ f : K →ₐ[F] L, FiniteDimensional F f.fieldRange := fun f ↦ f.toLinearMap.finiteDimensional_range
apply IntermediateField.finiteDimensional_iSup_of_finite