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add_mem (x y : K) : x ∈ A → y ∈ A → x + y ∈ A := A.toSubring.add_mem
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
add_mem
null
mul_mem (x y : K) : x ∈ A → y ∈ A → x * y ∈ A := A.toSubring.mul_mem
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mul_mem
null
neg_mem (x : K) : x ∈ A → -x ∈ A := A.toSubring.neg_mem
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
neg_mem
null
mem_or_inv_mem (x : K) : x ∈ A ∨ x⁻¹ ∈ A := A.mem_or_inv_mem' _
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_or_inv_mem
null
toSubring_injective : Function.Injective (toSubring : ValuationSubring K → Subring K) := fun x y h => by cases x; cases y; congr
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
toSubring_injective
null
mem_top (x : K) : x ∈ (⊤ : ValuationSubring K) := trivial
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_top
null
le_top : A ≤ ⊤ := fun _a _ha => mem_top _
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
le_top
null
isLocalRing : IsLocalRing A := inferInstance @[simp]
instance
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
isLocalRing
null
algebraMap_apply (a : A) : algebraMap A K a = a := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
algebraMap_apply
null
ValueGroup := ValuationRing.ValueGroup A K deriving LinearOrderedCommGroupWithZero
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ValueGroup
The value group of the valuation associated to `A`. Note: it is actually a group with zero.
valuation : Valuation K A.ValueGroup := ValuationRing.valuation A K
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation
Any valuation subring of `K` induces a natural valuation on `K`.
inhabitedValueGroup : Inhabited A.ValueGroup := ⟨A.valuation 0⟩
instance
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
inhabitedValueGroup
null
valuation_le_one (a : A) : A.valuation a ≤ 1 := (ValuationRing.mem_integer_iff A K _).2 ⟨a, rfl⟩
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_le_one
null
mem_of_valuation_le_one (x : K) (h : A.valuation x ≤ 1) : x ∈ A := let ⟨a, ha⟩ := (ValuationRing.mem_integer_iff A K x).1 h ha ▸ a.2
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_of_valuation_le_one
null
valuation_le_one_iff (x : K) : A.valuation x ≤ 1 ↔ x ∈ A := ⟨mem_of_valuation_le_one _ _, fun ha => A.valuation_le_one ⟨x, ha⟩⟩
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_le_one_iff
null
valuation_eq_iff (x y : K) : A.valuation x = A.valuation y ↔ ∃ a : Aˣ, (a : K) * y = x := Quotient.eq''
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_eq_iff
null
valuation_le_iff (x y : K) : A.valuation x ≤ A.valuation y ↔ ∃ a : A, (a : K) * y = x := Iff.rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_le_iff
null
valuation_surjective : Function.Surjective A.valuation := Quot.mk_surjective
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_surjective
null
valuation_unit (a : Aˣ) : A.valuation a = 1 := by rw [← A.valuation.map_one, valuation_eq_iff]; use a; simp
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_unit
null
valuation_eq_one_iff (a : A) : IsUnit a ↔ A.valuation a = 1 := ⟨fun h => A.valuation_unit h.unit, fun h => by have ha : (a : K) ≠ 0 := by intro c rw [c, A.valuation.map_zero] at h exact zero_ne_one h have ha' : (a : K)⁻¹ ∈ A := by rw [← valuation_le_one_iff, map_inv₀, h, inv_one] apply isUnit_of_mul_eq_one a ⟨a⁻¹, ha'⟩; ext; simp [field]⟩
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_eq_one_iff
null
valuation_lt_one_or_eq_one (a : A) : A.valuation a < 1 ∨ A.valuation a = 1 := lt_or_eq_of_le (A.valuation_le_one a)
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_lt_one_or_eq_one
null
valuation_lt_one_iff (a : A) : a ∈ IsLocalRing.maximalIdeal A ↔ A.valuation a < 1 := by rw [IsLocalRing.mem_maximalIdeal] dsimp [nonunits]; rw [valuation_eq_one_iff] exact (A.valuation_le_one a).lt_iff_ne.symm
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuation_lt_one_iff
null
ofSubring (R : Subring K) (hR : ∀ x : K, x ∈ R ∨ x⁻¹ ∈ R) : ValuationSubring K := { R with mem_or_inv_mem' := hR } @[simp]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofSubring
A subring `R` of `K` such that for all `x : K` either `x ∈ R` or `x⁻¹ ∈ R` is a valuation subring of `K`.
mem_ofSubring (R : Subring K) (hR : ∀ x : K, x ∈ R ∨ x⁻¹ ∈ R) (x : K) : x ∈ ofSubring R hR ↔ x ∈ R := Iff.refl _
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_ofSubring
null
ofLE (R : ValuationSubring K) (S : Subring K) (h : R.toSubring ≤ S) : ValuationSubring K := { S with mem_or_inv_mem' := fun x => (R.mem_or_inv_mem x).imp (@h x) (@h _) }
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofLE
An overring of a valuation ring is a valuation ring.
inclusion (R S : ValuationSubring K) (h : R ≤ S) : R →+* S := Subring.inclusion h
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
inclusion
The ring homomorphism induced by the partial order.
subtype (R : ValuationSubring K) : R →+* K := Subring.subtype R.toSubring @[simp]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
subtype
The canonical ring homomorphism from a valuation ring to its field of fractions.
subtype_apply {R : ValuationSubring K} (x : R) : R.subtype x = x := rfl
lemma
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
subtype_apply
null
subtype_injective (R : ValuationSubring K) : Function.Injective R.subtype := R.toSubring.subtype_injective @[simp]
lemma
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
subtype_injective
null
coe_subtype (R : ValuationSubring K) : ⇑(subtype R) = Subtype.val := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
coe_subtype
null
mapOfLE (R S : ValuationSubring K) (h : R ≤ S) : R.ValueGroup →*₀ S.ValueGroup where toFun := Quotient.map' id fun _ _ ⟨u, hu⟩ => ⟨Units.map (R.inclusion S h).toMonoidHom u, hu⟩ map_zero' := rfl map_one' := rfl map_mul' := by rintro ⟨⟩ ⟨⟩; rfl @[mono]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mapOfLE
The canonical map on value groups induced by a coarsening of valuation rings.
monotone_mapOfLE (R S : ValuationSubring K) (h : R ≤ S) : Monotone (R.mapOfLE S h) := by rintro ⟨⟩ ⟨⟩ ⟨a, ha⟩; exact ⟨R.inclusion S h a, ha⟩ @[simp]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
monotone_mapOfLE
null
mapOfLE_comp_valuation (R S : ValuationSubring K) (h : R ≤ S) : R.mapOfLE S h ∘ R.valuation = S.valuation := by ext; rfl @[simp]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mapOfLE_comp_valuation
null
mapOfLE_valuation_apply (R S : ValuationSubring K) (h : R ≤ S) (x : K) : R.mapOfLE S h (R.valuation x) = S.valuation x := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mapOfLE_valuation_apply
null
idealOfLE (R S : ValuationSubring K) (h : R ≤ S) : Ideal R := (IsLocalRing.maximalIdeal S).comap (R.inclusion S h)
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
idealOfLE
The ideal corresponding to a coarsening of a valuation ring.
prime_idealOfLE (R S : ValuationSubring K) (h : R ≤ S) : (idealOfLE R S h).IsPrime := (IsLocalRing.maximalIdeal S).comap_isPrime _
instance
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
prime_idealOfLE
null
ofPrime (A : ValuationSubring K) (P : Ideal A) [P.IsPrime] : ValuationSubring K := ofLE A (Localization.subalgebra.ofField K _ P.primeCompl_le_nonZeroDivisors).toSubring fun a ha => Subalgebra.mem_toSubring.mpr <| Subalgebra.algebraMap_mem (Localization.subalgebra.ofField K _ P.primeCompl_le_nonZeroDivisors) (⟨a, ha⟩ : A)
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofPrime
The coarsening of a valuation ring associated to a prime ideal.
ofPrimeAlgebra (A : ValuationSubring K) (P : Ideal A) [P.IsPrime] : Algebra A (A.ofPrime P) := Subalgebra.algebra (Localization.subalgebra.ofField K _ P.primeCompl_le_nonZeroDivisors)
instance
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofPrimeAlgebra
null
ofPrime_scalar_tower (A : ValuationSubring K) (P : Ideal A) [P.IsPrime] : letI : SMul A (A.ofPrime P) := SMulZeroClass.toSMul IsScalarTower A (A.ofPrime P) K := IsScalarTower.subalgebra' A K K (Localization.subalgebra.ofField K _ P.primeCompl_le_nonZeroDivisors)
instance
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofPrime_scalar_tower
null
ofPrime_localization (A : ValuationSubring K) (P : Ideal A) [P.IsPrime] : IsLocalization.AtPrime (A.ofPrime P) P := by apply Localization.subalgebra.isLocalization_ofField K P.primeCompl P.primeCompl_le_nonZeroDivisors
instance
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofPrime_localization
null
le_ofPrime (A : ValuationSubring K) (P : Ideal A) [P.IsPrime] : A ≤ ofPrime A P := fun a ha => Subalgebra.mem_toSubring.mpr <| Subalgebra.algebraMap_mem _ (⟨a, ha⟩ : A)
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
le_ofPrime
null
ofPrime_valuation_eq_one_iff_mem_primeCompl (A : ValuationSubring K) (P : Ideal A) [P.IsPrime] (x : A) : (ofPrime A P).valuation x = 1 ↔ x ∈ P.primeCompl := by rw [← IsLocalization.AtPrime.isUnit_to_map_iff (A.ofPrime P) P x, valuation_eq_one_iff]; rfl @[simp]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofPrime_valuation_eq_one_iff_mem_primeCompl
null
idealOfLE_ofPrime (A : ValuationSubring K) (P : Ideal A) [P.IsPrime] : idealOfLE A (ofPrime A P) (le_ofPrime A P) = P := by refine Ideal.ext (fun x => ?_) apply IsLocalization.AtPrime.to_map_mem_maximal_iff exact isLocalRing (ofPrime A P) @[simp]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
idealOfLE_ofPrime
null
ofPrime_idealOfLE (R S : ValuationSubring K) (h : R ≤ S) : ofPrime R (idealOfLE R S h) = S := by ext x; constructor · rintro ⟨a, r, hr, rfl⟩; apply mul_mem; · exact h a.2 · rw [← valuation_le_one_iff, map_inv₀, ← inv_one, inv_le_inv₀] · exact not_lt.1 ((not_iff_not.2 <| valuation_lt_one_iff S _).1 hr) · simpa [Valuation.pos_iff] using fun hr₀ ↦ hr₀ ▸ hr <| Ideal.zero_mem (R.idealOfLE S h) · exact zero_lt_one · intro hx; by_cases hr : x ∈ R; · exact R.le_ofPrime _ hr have : x ≠ 0 := fun h => hr (by rw [h]; exact R.zero_mem) replace hr := (R.mem_or_inv_mem x).resolve_left hr refine ⟨1, ⟨x⁻¹, hr⟩, ?_, ?_⟩ · simp only [Ideal.primeCompl, Submonoid.mem_mk, Subsemigroup.mem_mk, Set.mem_compl_iff, SetLike.mem_coe, idealOfLE, Ideal.mem_comap, IsLocalRing.mem_maximalIdeal, mem_nonunits_iff, not_not] change IsUnit (⟨x⁻¹, h hr⟩ : S) apply isUnit_of_mul_eq_one _ (⟨x, hx⟩ : S) ext; simp [field] · simp
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofPrime_idealOfLE
null
ofPrime_le_of_le (P Q : Ideal A) [P.IsPrime] [Q.IsPrime] (h : P ≤ Q) : ofPrime A Q ≤ ofPrime A P := fun _x ⟨a, s, hs, he⟩ => ⟨a, s, fun c => hs (h c), he⟩
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ofPrime_le_of_le
null
idealOfLE_le_of_le (R S : ValuationSubring K) (hR : A ≤ R) (hS : A ≤ S) (h : R ≤ S) : idealOfLE A S hS ≤ idealOfLE A R hR := fun x hx => (valuation_lt_one_iff R _).2 (by by_contra c; push_neg at c; replace c := monotone_mapOfLE R S h c rw [(mapOfLE _ _ _).map_one, mapOfLE_valuation_apply] at c apply not_le_of_gt ((valuation_lt_one_iff S _).1 hx) c)
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
idealOfLE_le_of_le
null
@[simps apply] primeSpectrumEquiv : PrimeSpectrum A ≃ {S // A ≤ S} where toFun P := ⟨ofPrime A P.asIdeal, le_ofPrime _ _⟩ invFun S := ⟨idealOfLE _ S S.2, inferInstance⟩ left_inv P := by ext1; simp right_inv S := by ext1; simp
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
primeSpectrumEquiv
The equivalence between coarsenings of a valuation ring and its prime ideals.
@[simps!] primeSpectrumOrderEquiv : (PrimeSpectrum A)ᵒᵈ ≃o {S // A ≤ S} := { OrderDual.ofDual.trans (primeSpectrumEquiv A) with map_rel_iff' {a b} := ⟨a.rec <| fun a => b.rec <| fun b => fun h => by simp only [OrderDual.toDual_le_toDual] dsimp at h have := idealOfLE_le_of_le A _ _ ?_ ?_ h · rwa [idealOfLE_ofPrime, idealOfLE_ofPrime] at this all_goals exact le_ofPrime A (PrimeSpectrum.asIdeal _), fun h => by apply ofPrime_le_of_le; exact h⟩ }
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
primeSpectrumOrderEquiv
An ordered variant of `primeSpectrumEquiv`.
le_total_ideal : IsTotal {S // A ≤ S} LE.le := by classical let _ : IsTotal (PrimeSpectrum A) (· ≤ ·) := ⟨fun ⟨x, _⟩ ⟨y, _⟩ => LE.isTotal.total x y⟩ exact ⟨(primeSpectrumOrderEquiv A).symm.toRelEmbedding.isTotal.total⟩ open scoped Classical in
instance
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
le_total_ideal
null
linearOrderOverring : LinearOrder {S // A ≤ S} where le_total := (le_total_ideal A).1 max_def a b := congr_fun₂ sup_eq_maxDefault a b toDecidableLE := _
instance
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
linearOrderOverring
null
valuationSubring : ValuationSubring K := { v.integer with mem_or_inv_mem' := by intro x rcases val_le_one_or_val_inv_le_one v x with h | h exacts [Or.inl h, Or.inr h] } @[simp]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuationSubring
The valuation subring associated to a valuation.
mem_valuationSubring_iff (x : K) : x ∈ v.valuationSubring ↔ v x ≤ 1 := Iff.refl _
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_valuationSubring_iff
null
isEquiv_iff_valuationSubring : v₁.IsEquiv v₂ ↔ v₁.valuationSubring = v₂.valuationSubring := by constructor · intro h; ext x; specialize h x 1; simpa using h · intro h; apply isEquiv_of_val_le_one intro x have : x ∈ v₁.valuationSubring ↔ x ∈ v₂.valuationSubring := by rw [h] simpa using this
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
isEquiv_iff_valuationSubring
null
isEquiv_valuation_valuationSubring : v.IsEquiv v.valuationSubring.valuation := by rw [isEquiv_iff_val_le_one] intro x rw [ValuationSubring.valuation_le_one_iff] rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
isEquiv_valuation_valuationSubring
null
valuationSubring.integers : v.Integers v.valuationSubring := Valuation.integer.integers _
lemma
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuationSubring.integers
null
@[simp] valuationSubring_valuation : A.valuation.valuationSubring = A := by ext; rw [← A.valuation_le_one_iff]; rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
valuationSubring_valuation
null
unitGroup : Subgroup Kˣ := (A.valuation.toMonoidWithZeroHom.toMonoidHom.comp (Units.coeHom K)).ker @[simp]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitGroup
The unit group of a valuation subring, as a subgroup of `Kˣ`.
mem_unitGroup_iff (x : Kˣ) : x ∈ A.unitGroup ↔ A.valuation x = 1 := Iff.rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_unitGroup_iff
null
unitGroupMulEquiv : A.unitGroup ≃* Aˣ where toFun x := { val := ⟨(x : Kˣ), mem_of_valuation_le_one A _ x.prop.le⟩ inv := ⟨((x⁻¹ : A.unitGroup) : Kˣ), mem_of_valuation_le_one _ _ x⁻¹.prop.le⟩ val_inv := Subtype.ext (by simp) inv_val := Subtype.ext (by simp) } invFun x := ⟨Units.map A.subtype.toMonoidHom x, A.valuation_unit x⟩ map_mul' a b := by ext; rfl @[simp]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitGroupMulEquiv
For a valuation subring `A`, `A.unitGroup` agrees with the units of `A`.
coe_unitGroupMulEquiv_apply (a : A.unitGroup) : ((A.unitGroupMulEquiv a : A) : K) = ((a : Kˣ) : K) := rfl @[simp]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
coe_unitGroupMulEquiv_apply
null
coe_unitGroupMulEquiv_symm_apply (a : Aˣ) : ((A.unitGroupMulEquiv.symm a : Kˣ) : K) = a := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
coe_unitGroupMulEquiv_symm_apply
null
unitGroup_le_unitGroup {A B : ValuationSubring K} : A.unitGroup ≤ B.unitGroup ↔ A ≤ B := by constructor · intro h x hx rw [← A.valuation_le_one_iff x, le_iff_lt_or_eq] at hx by_cases h_1 : x = 0; · simp only [h_1, zero_mem] by_cases h_2 : 1 + x = 0 · simp only [← add_eq_zero_iff_neg_eq.1 h_2, neg_mem _ _ (one_mem _)] rcases hx with hx | hx · have := h (show Units.mk0 _ h_2 ∈ A.unitGroup from A.valuation.map_one_add_of_lt hx) simpa using B.add_mem _ _ (show 1 + x ∈ B from SetLike.coe_mem (B.unitGroupMulEquiv ⟨_, this⟩ : B)) (B.neg_mem _ B.one_mem) · have := h (show Units.mk0 x h_1 ∈ A.unitGroup from hx) exact SetLike.coe_mem (B.unitGroupMulEquiv ⟨_, this⟩ : B) · rintro h x (hx : A.valuation x = 1) apply_fun A.mapOfLE B h at hx simpa using hx
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitGroup_le_unitGroup
null
unitGroup_injective : Function.Injective (unitGroup : ValuationSubring K → Subgroup _) := fun A B h => by simpa only [le_antisymm_iff, unitGroup_le_unitGroup] using h
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitGroup_injective
null
eq_iff_unitGroup {A B : ValuationSubring K} : A = B ↔ A.unitGroup = B.unitGroup := unitGroup_injective.eq_iff.symm
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
eq_iff_unitGroup
null
unitGroupOrderEmbedding : ValuationSubring K ↪o Subgroup Kˣ where toFun A := A.unitGroup inj' := unitGroup_injective map_rel_iff' {_A _B} := unitGroup_le_unitGroup
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitGroupOrderEmbedding
The map on valuation subrings to their unit groups is an order embedding.
unitGroup_strictMono : StrictMono (unitGroup : ValuationSubring K → Subgroup _) := unitGroupOrderEmbedding.strictMono
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitGroup_strictMono
null
nonunits : Subsemigroup K where carrier := {x | A.valuation x < 1} mul_mem' ha hb := (mul_lt_mul'' (Set.mem_setOf.mp ha) (Set.mem_setOf.mp hb) zero_le' zero_le').trans_eq <| mul_one _
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
nonunits
The nonunits of a valuation subring of `K`, as a subsemigroup of `K`
mem_nonunits_iff {x : K} : x ∈ A.nonunits ↔ A.valuation x < 1 := Iff.rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_nonunits_iff
null
nonunits_le_nonunits {A B : ValuationSubring K} : B.nonunits ≤ A.nonunits ↔ A ≤ B := by constructor · intro h x hx by_cases h_1 : x = 0; · simp only [h_1, zero_mem] rw [← valuation_le_one_iff, ← not_lt, Valuation.one_lt_val_iff _ h_1] at hx ⊢ by_contra h_2; exact hx (h h_2) · intro h x hx by_contra h_1; exact not_lt.2 (monotone_mapOfLE _ _ h (not_lt.1 h_1)) hx
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
nonunits_le_nonunits
null
nonunits_injective : Function.Injective (nonunits : ValuationSubring K → Subsemigroup _) := fun A B h => by simpa only [le_antisymm_iff, nonunits_le_nonunits] using h.symm
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
nonunits_injective
null
nonunits_inj {A B : ValuationSubring K} : A.nonunits = B.nonunits ↔ A = B := nonunits_injective.eq_iff
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
nonunits_inj
null
nonunitsOrderEmbedding : ValuationSubring K ↪o (Subsemigroup K)ᵒᵈ where toFun A := A.nonunits inj' := nonunits_injective map_rel_iff' {_A _B} := nonunits_le_nonunits variable {A}
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
nonunitsOrderEmbedding
The map on valuation subrings to their nonunits is a dual order embedding.
coe_mem_nonunits_iff {a : A} : (a : K) ∈ A.nonunits ↔ a ∈ IsLocalRing.maximalIdeal A := (valuation_lt_one_iff _ _).symm
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
coe_mem_nonunits_iff
The elements of `A.nonunits` are those of the maximal ideal of `A` after coercion to `K`. See also `mem_nonunits_iff_exists_mem_maximalIdeal`, which gets rid of the coercion to `K`, at the expense of a more complicated right-hand side.
nonunits_le : A.nonunits ≤ A.toSubring.toSubmonoid.toSubsemigroup := fun _a ha => (A.valuation_le_one_iff _).mp (A.mem_nonunits_iff.mp ha).le
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
nonunits_le
null
nonunits_subset : (A.nonunits : Set K) ⊆ A := nonunits_le
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
nonunits_subset
null
mem_nonunits_iff_exists_mem_maximalIdeal {a : K} : a ∈ A.nonunits ↔ ∃ ha, (⟨a, ha⟩ : A) ∈ IsLocalRing.maximalIdeal A := ⟨fun h => ⟨nonunits_subset h, coe_mem_nonunits_iff.mp h⟩, fun ⟨_, h⟩ => coe_mem_nonunits_iff.mpr h⟩
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_nonunits_iff_exists_mem_maximalIdeal
The elements of `A.nonunits` are those of the maximal ideal of `A`. See also `coe_mem_nonunits_iff`, which has a simpler right-hand side but requires the element to be in `A` already.
image_maximalIdeal : ((↑) : A → K) '' IsLocalRing.maximalIdeal A = A.nonunits := by ext a simp only [Set.mem_image, SetLike.mem_coe, mem_nonunits_iff_exists_mem_maximalIdeal] rw [Subtype.exists] simp_rw [exists_and_right, exists_eq_right]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
image_maximalIdeal
`A.nonunits` agrees with the maximal ideal of `A`, after taking its image in `K`.
principalUnitGroup : Subgroup Kˣ where carrier := {x | A.valuation (x - 1) < 1} mul_mem' := by intro a b ha hb rw [Set.mem_setOf] at ha hb ⊢ refine lt_of_le_of_lt ?_ (max_lt hb ha) rw [← one_mul (A.valuation (b - 1)), ← A.valuation.map_one_add_of_lt ha, add_sub_cancel, ← Valuation.map_mul, mul_sub_one, ← sub_add_sub_cancel] exact A.valuation.map_add _ _ one_mem' := by simp inv_mem' := by dsimp intro a ha conv => lhs rw [← mul_one (A.valuation _), ← A.valuation.map_one_add_of_lt ha] rwa [add_sub_cancel, ← Valuation.map_mul, sub_mul, Units.inv_mul, ← neg_sub, one_mul, Valuation.map_neg]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
principalUnitGroup
The principal unit group of a valuation subring, as a subgroup of `Kˣ`.
principal_units_le_units : A.principalUnitGroup ≤ A.unitGroup := fun a h => by simpa only [add_sub_cancel] using A.valuation.map_one_add_of_lt h
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
principal_units_le_units
null
mem_principalUnitGroup_iff (x : Kˣ) : x ∈ A.principalUnitGroup ↔ A.valuation ((x : K) - 1) < 1 := Iff.rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
mem_principalUnitGroup_iff
null
principalUnitGroup_le_principalUnitGroup {A B : ValuationSubring K} : B.principalUnitGroup ≤ A.principalUnitGroup ↔ A ≤ B := by constructor · intro h x hx by_cases h_1 : x = 0; · simp only [h_1, zero_mem] by_cases h_2 : x⁻¹ + 1 = 0 · rw [add_eq_zero_iff_eq_neg, inv_eq_iff_eq_inv, inv_neg, inv_one] at h_2 simpa only [h_2] using B.neg_mem _ B.one_mem · rw [← valuation_le_one_iff, ← not_lt, Valuation.one_lt_val_iff _ h_1, ← add_sub_cancel_right x⁻¹, ← Units.val_mk0 h_2, ← mem_principalUnitGroup_iff] at hx ⊢ simpa only [hx] using @h (Units.mk0 (x⁻¹ + 1) h_2) · intro h x hx by_contra h_1; exact not_lt.2 (monotone_mapOfLE _ _ h (not_lt.1 h_1)) hx
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
principalUnitGroup_le_principalUnitGroup
null
principalUnitGroup_injective : Function.Injective (principalUnitGroup : ValuationSubring K → Subgroup _) := fun A B h => by simpa [le_antisymm_iff, principalUnitGroup_le_principalUnitGroup] using h.symm
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
principalUnitGroup_injective
null
eq_iff_principalUnitGroup {A B : ValuationSubring K} : A = B ↔ A.principalUnitGroup = B.principalUnitGroup := principalUnitGroup_injective.eq_iff.symm
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
eq_iff_principalUnitGroup
null
principalUnitGroupOrderEmbedding : ValuationSubring K ↪o (Subgroup Kˣ)ᵒᵈ where toFun A := A.principalUnitGroup inj' := principalUnitGroup_injective map_rel_iff' {_A _B} := principalUnitGroup_le_principalUnitGroup
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
principalUnitGroupOrderEmbedding
The map on valuation subrings to their principal unit groups is an order embedding.
coe_mem_principalUnitGroup_iff {x : A.unitGroup} : (x : Kˣ) ∈ A.principalUnitGroup ↔ A.unitGroupMulEquiv x ∈ (Units.map (IsLocalRing.residue A).toMonoidHom).ker := by rw [MonoidHom.mem_ker, Units.ext_iff] let π := Ideal.Quotient.mk (IsLocalRing.maximalIdeal A); convert_to _ ↔ π _ = 1 rw [← π.map_one, ← sub_eq_zero, ← π.map_sub, Ideal.Quotient.eq_zero_iff_mem, valuation_lt_one_iff] simp [mem_principalUnitGroup_iff]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
coe_mem_principalUnitGroup_iff
null
principalUnitGroupEquiv : A.principalUnitGroup ≃* (Units.map (IsLocalRing.residue A).toMonoidHom).ker where toFun x := ⟨A.unitGroupMulEquiv ⟨_, A.principal_units_le_units x.2⟩, A.coe_mem_principalUnitGroup_iff.1 x.2⟩ invFun x := ⟨A.unitGroupMulEquiv.symm x, by rw [A.coe_mem_principalUnitGroup_iff]; simp⟩ left_inv x := by simp right_inv x := by simp map_mul' _ _ := rfl
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
principalUnitGroupEquiv
The principal unit group agrees with the kernel of the canonical map from the units of `A` to the units of the residue field of `A`.
principalUnitGroupEquiv_apply (a : A.principalUnitGroup) : (((principalUnitGroupEquiv A a : Aˣ) : A) : K) = (a : Kˣ) := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
principalUnitGroupEquiv_apply
null
principalUnitGroup_symm_apply (a : (Units.map (IsLocalRing.residue A).toMonoidHom).ker) : ((A.principalUnitGroupEquiv.symm a : Kˣ) : K) = ((a : Aˣ) : A) := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
principalUnitGroup_symm_apply
null
unitGroupToResidueFieldUnits : A.unitGroup →* (IsLocalRing.ResidueField A)ˣ := MonoidHom.comp (Units.map <| (Ideal.Quotient.mk _).toMonoidHom) A.unitGroupMulEquiv.toMonoidHom @[simp]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitGroupToResidueFieldUnits
The canonical map from the unit group of `A` to the units of the residue field of `A`.
coe_unitGroupToResidueFieldUnits_apply (x : A.unitGroup) : (A.unitGroupToResidueFieldUnits x : IsLocalRing.ResidueField A) = Ideal.Quotient.mk _ (A.unitGroupMulEquiv x : A) := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
coe_unitGroupToResidueFieldUnits_apply
null
ker_unitGroupToResidueFieldUnits : A.unitGroupToResidueFieldUnits.ker = A.principalUnitGroup.comap A.unitGroup.subtype := by ext simp_rw [Subgroup.mem_comap, Subgroup.coe_subtype, coe_mem_principalUnitGroup_iff, unitGroupToResidueFieldUnits, IsLocalRing.residue, RingHom.toMonoidHom_eq_coe, MulEquiv.toMonoidHom_eq_coe, MonoidHom.mem_ker, MonoidHom.coe_comp, MonoidHom.coe_coe, Function.comp_apply]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
ker_unitGroupToResidueFieldUnits
null
surjective_unitGroupToResidueFieldUnits : Function.Surjective A.unitGroupToResidueFieldUnits := (IsLocalRing.surjective_units_map_of_local_ringHom _ Ideal.Quotient.mk_surjective IsLocalRing.isLocalHom_residue).comp (MulEquiv.surjective _)
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
surjective_unitGroupToResidueFieldUnits
null
unitsModPrincipalUnitsEquivResidueFieldUnits : A.unitGroup ⧸ A.principalUnitGroup.comap A.unitGroup.subtype ≃* (IsLocalRing.ResidueField A)ˣ := (QuotientGroup.quotientMulEquivOfEq A.ker_unitGroupToResidueFieldUnits.symm).trans (QuotientGroup.quotientKerEquivOfSurjective _ A.surjective_unitGroupToResidueFieldUnits)
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitsModPrincipalUnitsEquivResidueFieldUnits
The quotient of the unit group of `A` by the principal unit group of `A` agrees with the units of the residue field of `A`.
unitsModPrincipalUnitsEquivResidueFieldUnits_comp_quotientGroup_mk : (A.unitsModPrincipalUnitsEquivResidueFieldUnits : _ ⧸ Subgroup.comap _ _ →* _).comp (QuotientGroup.mk' (A.principalUnitGroup.subgroupOf A.unitGroup)) = A.unitGroupToResidueFieldUnits := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitsModPrincipalUnitsEquivResidueFieldUnits_comp_quotientGroup_mk
null
unitsModPrincipalUnitsEquivResidueFieldUnits_comp_quotientGroup_mk_apply (x : A.unitGroup) : A.unitsModPrincipalUnitsEquivResidueFieldUnits.toMonoidHom (QuotientGroup.mk x) = A.unitGroupToResidueFieldUnits x := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
unitsModPrincipalUnitsEquivResidueFieldUnits_comp_quotientGroup_mk_apply
null
pointwiseHasSMul : SMul G (ValuationSubring K) where smul g S :=-- TODO: if we add `ValuationSubring.map` at a later date, we should use it here { g • S.toSubring with mem_or_inv_mem' := fun x => (mem_or_inv_mem S (g⁻¹ • x)).imp Subring.mem_pointwise_smul_iff_inv_smul_mem.mpr fun h => Subring.mem_pointwise_smul_iff_inv_smul_mem.mpr <| by rwa [smul_inv''] } scoped[Pointwise] attribute [instance] ValuationSubring.pointwiseHasSMul open scoped Pointwise @[simp]
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
pointwiseHasSMul
The action on a valuation subring corresponding to applying the action to every element. This is available as an instance in the `Pointwise` locale.
coe_pointwise_smul (g : G) (S : ValuationSubring K) : ↑(g • S) = g • (S : Set K) := rfl @[simp]
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
coe_pointwise_smul
null
pointwise_smul_toSubring (g : G) (S : ValuationSubring K) : (g • S).toSubring = g • S.toSubring := rfl
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
pointwise_smul_toSubring
null
pointwiseMulAction : MulAction G (ValuationSubring K) := toSubring_injective.mulAction toSubring pointwise_smul_toSubring scoped[Pointwise] attribute [instance] ValuationSubring.pointwiseMulAction open scoped Pointwise
def
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
pointwiseMulAction
The action on a valuation subring corresponding to applying the action to every element. This is available as an instance in the `Pointwise` locale. This is a stronger version of `ValuationSubring.pointwiseSMul`.
smul_mem_pointwise_smul (g : G) (x : K) (S : ValuationSubring K) : x ∈ S → g • x ∈ g • S := (Set.smul_mem_smul_set : _ → _ ∈ g • (S : Set K))
theorem
RingTheory
[ "Mathlib.RingTheory.Valuation.ValuationRing", "Mathlib.RingTheory.Localization.AsSubring", "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.Ring.Subring.Pointwise", "Mathlib.Algebra.Ring.Action.Field", "Mathlib.RingTheory.LocalRing.ResidueField.Basic" ]
Mathlib/RingTheory/Valuation/ValuationSubring.lean
smul_mem_pointwise_smul
null