theorem
GaloisTheory.card_aut_le_finrank
(F : Type u_3)
(E : Type u_4)
[Field F]
[Field E]
[Algebra F E]
[FiniteDimensional F E]
[Algebra.IsSeparable F E]
:
theorem
GaloisTheory.isGalois_iff_card_aut_eq_finrank
(F : Type u_3)
(E : Type u_4)
[Field F]
[Field E]
[Algebra F E]
[FiniteDimensional F E]
:
theorem
GaloisTheory.galois_group_size
(F : Type u_3)
(E : Type u_4)
[Field F]
[Field E]
[Algebra F E]
[FiniteDimensional F E]
[Algebra.IsSeparable F E]
:
noncomputable def
GaloisTheory.fundamentalTheoremSymmetricPolynomials
(σ : Type u_3)
(R : Type u_4)
{n : ℕ}
[Fintype σ]
[CommRing R]
(hn : Fintype.card σ = n)
:
Instances For
theorem
GaloisTheory.symmetric_polynomial_in_esymm
{F : Type u_3}
[Field F]
{P : Polynomial F}
(hP : P.Monic)
(hsplit : P.Splits)
(n : ℕ)
(hn : P.natDegree = n)
(f : MvPolynomial (Fin n) F)
(hf : f.IsSymmetric)
(α : Fin n → F)
(hα : P = ∏ i : Fin n, (Polynomial.X - Polynomial.C (α i)))
:
∃ (q : MvPolynomial (Fin n) F),
(MvPolynomial.eval α) f = (MvPolynomial.eval fun (i : Fin n) => (-1) ^ (↑i + 1) * P.coeff (n - (↑i + 1))) q
theorem
GaloisTheory.all_minpoly_split_in_splitting_field
{F : Type u_3}
[Field F]
(p : Polynomial F)
(α : p.SplittingField)
:
(Polynomial.map (algebraMap F p.SplittingField) (minpoly F α)).Splits
@[reducible, inline]
Instances For
theorem
GaloisTheory.symmetric_group_not_solvable
{n : ℕ}
(hn : 5 ≤ n)
:
¬IsSolvable (Equiv.Perm (Fin n))
theorem
GaloisTheory.not_solvableByRad_of_gal_iso_S5
{F : Type u_3}
{E : Type u_4}
[Field F]
[Field E]
[Algebra F E]
{p : Polynomial F}
(hp : Irreducible p)
(hiso : p.Gal ≃* Equiv.Perm (Fin 5))
{x : E}
(hpx : (Polynomial.aeval x) p = 0)
:
x ∉ solvableByRad F E