Additional lemmas about elements of a ring satisfying IsCoprime
#
These lemmas are in a separate file to the definition of IsCoprime
as they require more imports.
Notably, this includes lemmas about Finset.prod
as this requires importing big_operators, and
lemmas about HasPow
since these are easiest to prove via Finset.prod
.
Alias of the forward direction of Nat.isCoprime_iff_coprime
.
Alias of the reverse direction of Nat.isCoprime_iff_coprime
.
theorem
ne_zero_or_ne_zero_of_nat_coprime
{A : Type u}
[CommRing A]
[Nontrivial A]
{a : ℕ}
{b : ℕ}
(h : Nat.Coprime a b)
:
theorem
IsCoprime.prod_left
{R : Type u}
{I : Type v}
[CommSemiring R]
{x : R}
{s : I → R}
{t : Finset I}
:
(∀ (i : I), i ∈ t → IsCoprime (s i) x) → IsCoprime (Finset.prod t fun i => s i) x
theorem
IsCoprime.prod_right
{R : Type u}
{I : Type v}
[CommSemiring R]
{x : R}
{s : I → R}
{t : Finset I}
:
(∀ (i : I), i ∈ t → IsCoprime x (s i)) → IsCoprime x (Finset.prod t fun i => s i)
theorem
IsCoprime.prod_left_iff
{R : Type u}
{I : Type v}
[CommSemiring R]
{x : R}
{s : I → R}
{t : Finset I}
:
IsCoprime (Finset.prod t fun i => s i) x ↔ ∀ (i : I), i ∈ t → IsCoprime (s i) x
theorem
IsCoprime.prod_right_iff
{R : Type u}
{I : Type v}
[CommSemiring R]
{x : R}
{s : I → R}
{t : Finset I}
:
IsCoprime x (Finset.prod t fun i => s i) ↔ ∀ (i : I), i ∈ t → IsCoprime x (s i)
theorem
IsCoprime.of_prod_left
{R : Type u}
{I : Type v}
[CommSemiring R]
{x : R}
{s : I → R}
{t : Finset I}
(H1 : IsCoprime (Finset.prod t fun i => s i) x)
(i : I)
(hit : i ∈ t)
:
IsCoprime (s i) x
theorem
IsCoprime.of_prod_right
{R : Type u}
{I : Type v}
[CommSemiring R]
{x : R}
{s : I → R}
{t : Finset I}
(H1 : IsCoprime x (Finset.prod t fun i => s i))
(i : I)
(hit : i ∈ t)
:
IsCoprime x (s i)
theorem
Finset.prod_dvd_of_coprime
{R : Type u}
{I : Type v}
[CommSemiring R]
{z : R}
{s : I → R}
{t : Finset I}
:
Set.Pairwise (↑t) (IsCoprime on s) → (∀ (i : I), i ∈ t → s i ∣ z) → (Finset.prod t fun x => s x) ∣ z
theorem
Fintype.prod_dvd_of_coprime
{R : Type u}
{I : Type v}
[CommSemiring R]
{z : R}
{s : I → R}
[Fintype I]
(Hs : Pairwise (IsCoprime on s))
(Hs1 : ∀ (i : I), s i ∣ z)
:
(Finset.prod Finset.univ fun x => s x) ∣ z
theorem
exists_sum_eq_one_iff_pairwise_coprime
{R : Type u}
{I : Type v}
[CommSemiring R]
{s : I → R}
{t : Finset I}
[DecidableEq I]
(h : Finset.Nonempty t)
:
(∃ μ, (Finset.sum t fun i => μ i * Finset.prod (t \ {i}) fun j => s j) = 1) ↔ Pairwise (IsCoprime on fun i => s ↑i)
theorem
exists_sum_eq_one_iff_pairwise_coprime'
{R : Type u}
{I : Type v}
[CommSemiring R]
{s : I → R}
[Fintype I]
[Nonempty I]
[DecidableEq I]
:
(∃ μ, (Finset.sum Finset.univ fun i => μ i * Finset.prod {i}ᶜ fun j => s j) = 1) ↔ Pairwise (IsCoprime on s)
theorem
pairwise_coprime_iff_coprime_prod
{R : Type u}
{I : Type v}
[CommSemiring R]
{s : I → R}
{t : Finset I}
[DecidableEq I]
:
theorem
IsCoprime.pow_left
{R : Type u}
[CommSemiring R]
{x : R}
{y : R}
{m : ℕ}
(H : IsCoprime x y)
:
theorem
IsCoprime.pow_right
{R : Type u}
[CommSemiring R]
{x : R}
{y : R}
{n : ℕ}
(H : IsCoprime x y)
:
theorem
IsCoprime.pow
{R : Type u}
[CommSemiring R]
{x : R}
{y : R}
{m : ℕ}
{n : ℕ}
(H : IsCoprime x y)
:
theorem
IsCoprime.pow_left_iff
{R : Type u}
[CommSemiring R]
{x : R}
{y : R}
{m : ℕ}
(hm : 0 < m)
:
theorem
IsCoprime.pow_right_iff
{R : Type u}
[CommSemiring R]
{x : R}
{y : R}
{m : ℕ}
(hm : 0 < m)
: