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Project-declaredLean 4.31.0 · mathlib@fabf563a7c95

Emultiplicity four pow sub one

ArkLib.Lattices.CyclotomicModulus.emultiplicity_four_pow_sub_one

Plain-language statement

2-adic LTE for g = 4·2^κ + 1: v₂(gⁿ − 1) = (κ+2) + v₂(n).

Exact Lean statement

theorem emultiplicity_four_pow_sub_one (κ n : ℕ) :
    emultiplicity 2 ((4 * 2 ^ κ + 1 : ℤ) ^ n - 1)
      = (κ + 2 : ℕ) + emultiplicity 2 (n : ℤ)

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
theorem emultiplicity_four_pow_sub_one (κ n : ) :    emultiplicity 2 ((4 * 2 ^ κ + 1 : ) ^ n - 1)      =+ 2 : ) + emultiplicity 2 (n : ) := by  have hodd : Odd (4 * 2 ^ κ + 1 : ) := 2 * 2 ^ κ, by ring  have hx : ¬ (2 : ) ∣ (4 * 2 ^ κ + 1) := by rcases hodd with m, hm; omega  have hxy : (4 : ) ∣ (4 * 2 ^ κ + 1) - 1 := 2 ^ κ, by ring  have hsub : (4 * 2 ^ κ + 1 : ) - 1 = 2 ^+ 2) := by rw [pow_add]; ring  have h := Int.two_pow_sub_pow' (x := 4 * 2 ^ κ + 1) (y := 1) n hxy hx  rw [one_pow, hsub, emultiplicity_pow_self_of_prime Int.prime_two] at h  exact h
Project
ArkLib
License
Apache-2.0
Commit
fad5cbf80877
Source
ArkLib/Data/Lattices/CyclotomicRing/Galois/Order.lean:34-43

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Project-declaredLean 4.31.0

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Plain-language statement

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cryptographyproof systemscoding theory

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Person-level attribution pending.

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Project-declaredLean 4.31.0

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ArkLib.Lattices.Ajtai.gadgetDecompose_lawful

Plain-language statement

The base-b gadget decomposition is a lawful gadget decomposition.

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Person-level attribution pending.

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