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Mathlib.RingTheory.OreLocalization.Ring

Module and Ring instances of Ore Localizations #

The Monoid and DistribMulAction instances and additive versions are provided in Mathlib/RingTheory/OreLocalization/Basic.lean.

theorem OreLocalization.zero_smul {R : Type u_1} [Semiring R] {S : Submonoid R} [OreLocalization.OreSet S] {X : Type u_2} [AddCommMonoid X] [Module R X] (x : OreLocalization S X) :
0 x = 0
theorem OreLocalization.add_smul {R : Type u_1} [Semiring R] {S : Submonoid R} [OreLocalization.OreSet S] {X : Type u_2} [AddCommMonoid X] [Module R X] (y : OreLocalization S R) (z : OreLocalization S R) (x : OreLocalization S X) :
(y + z) x = y x + z x
theorem OreLocalization.left_distrib {R : Type u_1} [Semiring R] {S : Submonoid R} [OreLocalization.OreSet S] (x : OreLocalization S R) (y : OreLocalization S R) (z : OreLocalization S R) :
x * (y + z) = x * y + x * z
theorem OreLocalization.right_distrib {R : Type u_1} [Semiring R] {S : Submonoid R} [OreLocalization.OreSet S] (x : OreLocalization S R) (y : OreLocalization S R) (z : OreLocalization S R) :
(x + y) * z = x * z + y * z
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def OreLocalization.universalHom {R : Type u_1} [Semiring R] {S : Submonoid R} [OreLocalization.OreSet S] {T : Type u_3} [Semiring T] (f : R →+* T) (fS : S →* Tˣ) (hf : ∀ (s : S), f s = (fS s)) :

The universal lift from a ring homomorphism f : R →+* T, which maps elements in S to units of T, to a ring homomorphism R[S⁻¹] →+* T. This extends the construction on monoids.

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    theorem OreLocalization.universalHom_apply {R : Type u_1} [Semiring R] {S : Submonoid R} [OreLocalization.OreSet S] {T : Type u_3} [Semiring T] (f : R →+* T) (fS : S →* Tˣ) (hf : ∀ (s : S), f s = (fS s)) {r : R} {s : S} :
    (OreLocalization.universalHom f fS hf) (r /ₒ s) = (fS s)⁻¹ * f r
    theorem OreLocalization.universalHom_commutes {R : Type u_1} [Semiring R] {S : Submonoid R} [OreLocalization.OreSet S] {T : Type u_3} [Semiring T] (f : R →+* T) (fS : S →* Tˣ) (hf : ∀ (s : S), f s = (fS s)) {r : R} :
    (OreLocalization.universalHom f fS hf) (OreLocalization.numeratorHom r) = f r
    theorem OreLocalization.universalHom_unique {R : Type u_1} [Semiring R] {S : Submonoid R} [OreLocalization.OreSet S] {T : Type u_3} [Semiring T] (f : R →+* T) (fS : S →* Tˣ) (hf : ∀ (s : S), f s = (fS s)) (φ : OreLocalization S R →+* T) (huniv : ∀ (r : R), φ (OreLocalization.numeratorHom r) = f r) :
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    • One or more equations did not get rendered due to their size.
    theorem OreLocalization.numeratorHom_inj {R : Type u_1} [Ring R] {S : Submonoid R} [OreLocalization.OreSet S] (hS : S nonZeroDivisorsRight R) :
    Function.Injective OreLocalization.numeratorHom

    The inversion of Ore fractions for a ring without zero divisors, satisying 0⁻¹ = 0 and (r /ₒ r')⁻¹ = r' /ₒ r for r ≠ 0.

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      • OreLocalization.inv' = { inv := OreLocalization.inv }
      theorem OreLocalization.inv_def {R : Type u_1} [Ring R] [Nontrivial R] [OreLocalization.OreSet (nonZeroDivisors R)] [NoZeroDivisors R] {r : R} {s : (nonZeroDivisors R)} :
      (r /ₒ s)⁻¹ = if hr : r = 0 then 0 else s /ₒ r,
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