Integer_to_Power_of_Multiple_of_Order
Provedmodular-arithmeticnumber-theoryproofwiki
Let a and n be coprime integers. Let c be the multiplicative order of a modulo n. Then a^k = 1 mod n iff c divides k.
Preamble
import Mathlib.Analysis.Complex.Basic import Mathlib.Data.Nat.GCD.Basic
Formal statement
theorem Integer_to_Power_of_Multiple_of_Order (a n c k : ℕ) (hn : 0 < n) (hcop : Nat.Coprime a n) (hc : 0 < c) (hord : a ^ c ≡ 1 [MOD n]) (hk : c ∣ k) : a ^ k ≡ 1 [MOD n] := by sorry
Source