OAI/LinearAlgebra/CirculantHadamard/IntegerLocalDivisibility.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Reflecting prime-power divisibility from the localized integers
A denominator inverted in the localization at (p) is not divisible by p.
Clearing that denominator and using primality therefore reflects divisibility
by every power of p back to the integers. The argument includes the zeroth
power and the zero numerator, without any nonzero numerator hypothesis.
- theorem
OAI.CirculantHadamard.integer_prime_pow_dvd_of_localizationline 22Source documentation
Divisibility by a rational prime power in its actual integer localization implies the same divisibility in the integers.
theorem integer_prime_pow_dvd_of_localization {A : Type uA} [CommRing A] [Algebra ℤ A] {P : Ideal ℤ} [P.IsPrime] [IsLocalization.AtPrime A P] {p : ℕ} (hp : p.Prime) (hP : P = Ideal.span ({(p : ℤ)} : Set ℤ)) (t : ℕ) (x : ℤ) (hx : (p : A) ^ t ∣ algebraMap ℤ A x) : (p : ℤ) ^ t ∣ x := by … - theorem
OAI.CirculantHadamard.integer_prime_pow_dvd_localization_iffline 45Source documentation
Prime-power divisibility of integer coefficients is unchanged by localization at that prime.
theorem integer_prime_pow_dvd_localization_iff {A : Type uA} [CommRing A] [Algebra ℤ A] {P : Ideal ℤ} [P.IsPrime] [IsLocalization.AtPrime A P] {p : ℕ} (hp : p.Prime) (hP : P = Ideal.span ({(p : ℤ)} : Set ℤ)) (t : ℕ) (x : ℤ) : (p : A) ^ t ∣ algebraMap ℤ A x ↔ (p : ℤ) ^ t ∣ x := by …