Module

SigmaPowerDetection.lean

Nyll.ProCGroups.FiniteGroups.SigmaPowerDetection
1 declaration indexed from sourceView source ↗

Prime-power detection in finite Sigma groups

Declarations

ProCGroups.FiniteGroupClass.eq_one_of_primePower_roots

An element with an ℓ^s-th root for every allowed prime ℓ and positive s is trivial.

Source context 2 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace ProCGroups.FiniteGroupClass
universe u
theorem eq_one_of_primePower_roots
    {sigma : Set ℕ} {G : Type u} [Group G] [Finite G]
    (hG : FiniteGroupClass.sigmaGroup sigma G) (x : G)
    (hx : ∀ ℓ : ℕ, ℓ ∈ sigma → ℓ.Prime →
      ∀ s : ℕ, 0 < s → ∃ y : G, y ^ (ℓ ^ s) = x) : x = 1