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Theorems · Theorem · number theory

IsCyclotomicExtension.Rat.card_subgroupGalEquivSubgroupChar

∀ (n : ℕ) [inst : NeZero n] (K : Type u_1) [inst_1 : Field K] [inst_2 : NumberField K]
  [hK : IsCyclotomicExtension {n} ℚ K] (R : Type u_2) [inst_3 : CommRing R]
  [inst_4 : HasEnoughRootsOfUnity R (Monoid.exponent (ZMod n)ˣ)] [IsMulCommutative Gal(K/ℚ)] (H : Subgroup Gal(K/ℚ)),
  Nat.card ↥(OrderDual.ofDual ((IsCyclotomicExtension.Rat.subgroupGalEquivSubgroupChar n K R) H)) =
    Nat.card (Gal(K/ℚ) ⧸ H)
Defined in
Mathlib.NumberTheory.NumberField.Cyclotomic.Galois
Cited by
1 results in Mathlib
Foundations
Depth 218 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
NeZeroFieldNumberFieldIsCyclotomicExtensionCommRingHasEnoughRootsOfUnityIsMulCommutative

Around this declaration

Dashed lines are statement dependencies; solid lines are citations in proofs.

Cites32

Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.

  • DFunLike.coestatement and proof · cited by 62,936
  • Setstatement · cited by 53,352
  • CommRingstatement and proof · cited by 17,173
  • Equivstatement · cited by 8,337
  • Fieldstatement and proof · cited by 7,404
  • Subgroupstatement and proof · cited by 3,593
  • Unitsstatement and proof · cited by 2,804
  • HasQuotient.Quotientstatement and proof · cited by 2,301
  • AlgEquivstatement and proof · cited by 1,681
  • ZModstatement and proof · cited by 1,024
  • OrderDualstatement and proof · cited by 927
  • OrderIsostatement and proof · cited by 874

Cited by1

Results whose statement or proof uses this declaration.