Normed fields

In this file we define (semi)normed rings and fields. We also prove some theorems about these definitions.

class NonUnitalSeminormedRing (α : Type u_5) extends Norm , NonUnitalRing , PseudoMetricSpace : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), SubNegMonoid.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), SubNegMonoid.zsmul (Int.ofNat (Nat.succ n)) a = a + SubNegMonoid.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), SubNegMonoid.zsmul (Int.negSucc n) a = -SubNegMonoid.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖

  The distance is induced by the norm.

• norm_mul : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖

  The norm is submultiplicative.

A non-unital seminormed ring is a not-necessarily-unital ring endowed with a seminorm which satisfies the inequality ‖x y‖ ≤ ‖x‖ ‖y‖.

class SeminormedRing (α : Type u_5) extends Norm , Ring , PseudoMetricSpace : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• one : α
• one_mul : ∀ (a : α), 1 * a = a
• mul_one : ∀ (a : α), a * 1 = a
• natCast : ℕ → α
• natCast_zero : NatCast.natCast 0 = 0
• natCast_succ : ∀ (n : ℕ), NatCast.natCast (n + 1) = NatCast.natCast n + 1
• npow : ℕ → α → α
• npow_zero : ∀ (x : α), Semiring.npow 0 x = 1
• npow_succ : ∀ (n : ℕ) (x : α), Semiring.npow (n + 1) x = x * Semiring.npow n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), Ring.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.ofNat (Nat.succ n)) a = a + Ring.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.negSucc n) a = -Ring.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• intCast : ℤ → α
• intCast_ofNat : ∀ (n : ℕ), IntCast.intCast ↑n = ↑n
• intCast_negSucc : ∀ (n : ℕ), IntCast.intCast (Int.negSucc n) = -↑(n + 1)
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖

  The distance is induced by the norm.

• norm_mul : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖

  The norm is submultiplicative.

A seminormed ring is a ring endowed with a seminorm which satisfies the inequality ‖x y‖ ≤ ‖x‖ ‖y‖.

instance SeminormedRing.toNonUnitalSeminormedRing {α : Type u_1} [β : SeminormedRing α] : NonUnitalSeminormedRing α

A seminormed ring is a non-unital seminormed ring.

Equations

• SeminormedRing.toNonUnitalSeminormedRing = NonUnitalSeminormedRing.mk (_ : ∀ (x y : α), dist x y = ‖x - y‖) (_ : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖)

class NonUnitalNormedRing (α : Type u_5) extends Norm , NonUnitalRing , MetricSpace : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), SubNegMonoid.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), SubNegMonoid.zsmul (Int.ofNat (Nat.succ n)) a = a + SubNegMonoid.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), SubNegMonoid.zsmul (Int.negSucc n) a = -SubNegMonoid.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• eq_of_dist_eq_zero : ∀ {x y : α}, dist x y = 0 → x = y
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖

  The distance is induced by the norm.

• norm_mul : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖

  The norm is submultiplicative.

A non-unital normed ring is a not-necessarily-unital ring endowed with a norm which satisfies the inequality ‖x y‖ ≤ ‖x‖ ‖y‖.

instance NonUnitalNormedRing.toNonUnitalSeminormedRing {α : Type u_1} [β : NonUnitalNormedRing α] : NonUnitalSeminormedRing α

A non-unital normed ring is a non-unital seminormed ring.

Equations

• NonUnitalNormedRing.toNonUnitalSeminormedRing = NonUnitalSeminormedRing.mk (_ : ∀ (x y : α), dist x y = ‖x - y‖) (_ : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖)

class NormedRing (α : Type u_5) extends Norm , Ring , MetricSpace : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• one : α
• one_mul : ∀ (a : α), 1 * a = a
• mul_one : ∀ (a : α), a * 1 = a
• natCast : ℕ → α
• natCast_zero : NatCast.natCast 0 = 0
• natCast_succ : ∀ (n : ℕ), NatCast.natCast (n + 1) = NatCast.natCast n + 1
• npow : ℕ → α → α
• npow_zero : ∀ (x : α), Semiring.npow 0 x = 1
• npow_succ : ∀ (n : ℕ) (x : α), Semiring.npow (n + 1) x = x * Semiring.npow n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), Ring.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.ofNat (Nat.succ n)) a = a + Ring.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.negSucc n) a = -Ring.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• intCast : ℤ → α
• intCast_ofNat : ∀ (n : ℕ), IntCast.intCast ↑n = ↑n
• intCast_negSucc : ∀ (n : ℕ), IntCast.intCast (Int.negSucc n) = -↑(n + 1)
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• eq_of_dist_eq_zero : ∀ {x y : α}, dist x y = 0 → x = y
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖

  The distance is induced by the norm.

• norm_mul : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖

  The norm is submultiplicative.

A normed ring is a ring endowed with a norm which satisfies the inequality ‖x y‖ ≤ ‖x‖ ‖y‖.

class NormedDivisionRing (α : Type u_5) extends Norm , DivisionRing , MetricSpace : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• one : α
• one_mul : ∀ (a : α), 1 * a = a
• mul_one : ∀ (a : α), a * 1 = a
• natCast : ℕ → α
• natCast_zero : NatCast.natCast 0 = 0
• natCast_succ : ∀ (n : ℕ), NatCast.natCast (n + 1) = NatCast.natCast n + 1
• npow : ℕ → α → α
• npow_zero : ∀ (x : α), Semiring.npow 0 x = 1
• npow_succ : ∀ (n : ℕ) (x : α), Semiring.npow (n + 1) x = x * Semiring.npow n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), Ring.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.ofNat (Nat.succ n)) a = a + Ring.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.negSucc n) a = -Ring.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• intCast : ℤ → α
• intCast_ofNat : ∀ (n : ℕ), IntCast.intCast ↑n = ↑n
• intCast_negSucc : ∀ (n : ℕ), IntCast.intCast (Int.negSucc n) = -↑(n + 1)
• inv : α → α
• div : α → α → α
• div_eq_mul_inv : ∀ (a b : α), a / b = a * b⁻¹
• zpow : ℤ → α → α
• zpow_zero' : ∀ (a : α), DivisionRing.zpow 0 a = 1
• zpow_succ' : ∀ (n : ℕ) (a : α), DivisionRing.zpow (Int.ofNat (Nat.succ n)) a = a * DivisionRing.zpow (Int.ofNat n) a
• zpow_neg' : ∀ (n : ℕ) (a : α), DivisionRing.zpow (Int.negSucc n) a = (DivisionRing.zpow (↑(Nat.succ n)) a)⁻¹
• exists_pair_ne : ∃ x y, x ≠ y
• ratCast : ℚ → α
• mul_inv_cancel : ∀ (a : α), a ≠ 0 → a * a⁻¹ = 1
• inv_zero : 0⁻¹ = 0
• ratCast_mk : ∀ (a : ℤ) (b : ℕ) (h1 : b ≠ 0) (h2 : Nat.Coprime (Int.natAbs a) b), ↑(Rat.mk' a b) = ↑a * (↑b)⁻¹
• qsmul : ℚ → α → α
• qsmul_eq_mul' : ∀ (a : ℚ) (x : α), DivisionRing.qsmul a x = ↑a * x
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• eq_of_dist_eq_zero : ∀ {x y : α}, dist x y = 0 → x = y
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖

  The distance is induced by the norm.

• norm_mul' : ∀ (a b : α), ‖a * b‖ = ‖a‖ * ‖b‖

  The norm is multiplicative.

A normed division ring is a division ring endowed with a seminorm which satisfies the equality ‖x y‖ = ‖x‖ ‖y‖.

instance NormedDivisionRing.toNormedRing {α : Type u_1} [β : NormedDivisionRing α] : NormedRing α

A normed division ring is a normed ring.

Equations

• NormedDivisionRing.toNormedRing = NormedRing.mk (_ : ∀ (x y : α), dist x y = ‖x - y‖) (_ : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖)

instance NormedRing.toSeminormedRing {α : Type u_1} [β : NormedRing α] : SeminormedRing α

A normed ring is a seminormed ring.

Equations

• NormedRing.toSeminormedRing = SeminormedRing.mk (_ : ∀ (x y : α), dist x y = ‖x - y‖) (_ : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖)

instance NormedRing.toNonUnitalNormedRing {α : Type u_1} [β : NormedRing α] : NonUnitalNormedRing α

A normed ring is a non-unital normed ring.

Equations

• NormedRing.toNonUnitalNormedRing = NonUnitalNormedRing.mk (_ : ∀ (x y : α), dist x y = ‖x - y‖) (_ : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖)

class SeminormedCommRing (α : Type u_5) extends SeminormedRing : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• one : α
• one_mul : ∀ (a : α), 1 * a = a
• mul_one : ∀ (a : α), a * 1 = a
• natCast : ℕ → α
• natCast_zero : NatCast.natCast 0 = 0
• natCast_succ : ∀ (n : ℕ), NatCast.natCast (n + 1) = NatCast.natCast n + 1
• npow : ℕ → α → α
• npow_zero : ∀ (x : α), Semiring.npow 0 x = 1
• npow_succ : ∀ (n : ℕ) (x : α), Semiring.npow (n + 1) x = x * Semiring.npow n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), Ring.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.ofNat (Nat.succ n)) a = a + Ring.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.negSucc n) a = -Ring.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• intCast : ℤ → α
• intCast_ofNat : ∀ (n : ℕ), IntCast.intCast ↑n = ↑n
• intCast_negSucc : ∀ (n : ℕ), IntCast.intCast (Int.negSucc n) = -↑(n + 1)
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖
• norm_mul : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖
• mul_comm : ∀ (x y : α), x * y = y * x

  Multiplication is commutative.

A seminormed commutative ring is a commutative ring endowed with a seminorm which satisfies the inequality ‖x y‖ ≤ ‖x‖ ‖y‖.

class NormedCommRing (α : Type u_5) extends NormedRing : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• one : α
• one_mul : ∀ (a : α), 1 * a = a
• mul_one : ∀ (a : α), a * 1 = a
• natCast : ℕ → α
• natCast_zero : NatCast.natCast 0 = 0
• natCast_succ : ∀ (n : ℕ), NatCast.natCast (n + 1) = NatCast.natCast n + 1
• npow : ℕ → α → α
• npow_zero : ∀ (x : α), Semiring.npow 0 x = 1
• npow_succ : ∀ (n : ℕ) (x : α), Semiring.npow (n + 1) x = x * Semiring.npow n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), Ring.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.ofNat (Nat.succ n)) a = a + Ring.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.negSucc n) a = -Ring.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• intCast : ℤ → α
• intCast_ofNat : ∀ (n : ℕ), IntCast.intCast ↑n = ↑n
• intCast_negSucc : ∀ (n : ℕ), IntCast.intCast (Int.negSucc n) = -↑(n + 1)
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• eq_of_dist_eq_zero : ∀ {x y : α}, dist x y = 0 → x = y
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖
• norm_mul : ∀ (a b : α), ‖a * b‖ ≤ ‖a‖ * ‖b‖
• mul_comm : ∀ (x y : α), x * y = y * x

  Multiplication is commutative.

A normed commutative ring is a commutative ring endowed with a norm which satisfies the inequality ‖x y‖ ≤ ‖x‖ ‖y‖.

instance NormedCommRing.toSeminormedCommRing {α : Type u_1} [β : NormedCommRing α] : SeminormedCommRing α

A normed commutative ring is a seminormed commutative ring.

Equations

• NormedCommRing.toSeminormedCommRing = SeminormedCommRing.mk (_ : ∀ (x y : α), x * y = y * x)

instance PUnit.normedCommRing : NormedCommRing PUnit.{u_5 + 1}

Equations

• PUnit.normedCommRing = let src := PUnit.normedAddCommGroup; let src_1 := PUnit.commRing; NormedCommRing.mk (_ : ∀ (a b : PUnit.{u_5 + 1} ), a * b = b * a)

class NormOneClass (α : Type u_5) [Norm α] [One α] : Prop

• norm_one : ‖1‖ = 1

  The norm of the multiplicative identity is 1.

A mixin class with the axiom ‖1‖ = 1. Many NormedRings and all NormedFields satisfy this axiom.

@[simp]

theorem nnnorm_one {α : Type u_1} [SeminormedAddCommGroup α] [One α] [NormOneClass α] : ‖1‖₊ = 1

theorem NormOneClass.nontrivial (α : Type u_5) [SeminormedAddCommGroup α] [One α] [NormOneClass α] : Nontrivial α

instance SeminormedCommRing.toCommRing {α : Type u_1} [β : SeminormedCommRing α] : CommRing α

Equations

• SeminormedCommRing.toCommRing = CommRing.mk (_ : ∀ (x y : α), x * y = y * x)

instance NonUnitalNormedRing.toNormedAddCommGroup {α : Type u_1} [β : NonUnitalNormedRing α] : NormedAddCommGroup α

Equations

• NonUnitalNormedRing.toNormedAddCommGroup = NormedAddCommGroup.mk

instance NonUnitalSeminormedRing.toSeminormedAddCommGroup {α : Type u_1} [NonUnitalSeminormedRing α] : SeminormedAddCommGroup α

Equations

• NonUnitalSeminormedRing.toSeminormedAddCommGroup = let src := inst; SeminormedAddCommGroup.mk

instance ULift.normOneClass {α : Type u_1} [SeminormedAddCommGroup α] [One α] [NormOneClass α] : NormOneClass (ULift.{u_5, u_1} α)

Equations

• @ULift.normOneClass = @ULift.normOneClass.proof_1

instance Prod.normOneClass {α : Type u_1} {β : Type u_2} [SeminormedAddCommGroup α] [One α] [NormOneClass α] [SeminormedAddCommGroup β] [One β] [NormOneClass β] : NormOneClass (α × β)

Equations

• @Prod.normOneClass = @Prod.normOneClass.proof_1

instance Pi.normOneClass {ι : Type u_5} {α : ι → Type u_6} [Nonempty ι] [Fintype ι] [(i : ι) → SeminormedAddCommGroup (α i)] [(i : ι) → One (α i)] [∀ (i : ι), NormOneClass (α i)] : NormOneClass ((i : ι) → α i)

Equations

• @Pi.normOneClass = @Pi.normOneClass.proof_1

instance MulOpposite.normOneClass {α : Type u_1} [SeminormedAddCommGroup α] [One α] [NormOneClass α] : NormOneClass αᵐᵒᵖ

Equations

• @MulOpposite.normOneClass = @MulOpposite.normOneClass.proof_1

theorem norm_mul_le {α : Type u_1} [NonUnitalSeminormedRing α] (a : α) (b : α) : ‖a * b‖ ≤ ‖a‖ * ‖b‖

theorem nnnorm_mul_le {α : Type u_1} [NonUnitalSeminormedRing α] (a : α) (b : α) : ‖a * b‖₊ ≤ ‖a‖₊ * ‖b‖₊

theorem one_le_norm_one (β : Type u_5) [NormedRing β] [Nontrivial β] : 1 ≤ ‖1‖

theorem one_le_nnnorm_one (β : Type u_5) [NormedRing β] [Nontrivial β] : 1 ≤ ‖1‖₊

theorem Filter.Tendsto.zero_mul_isBoundedUnder_le {α : Type u_1} {ι : Type u_4} [NonUnitalSeminormedRing α] {f : ι → α} {g : ι → α} {l : Filter ι} (hf : Filter.Tendsto f l (nhds 0)) (hg : Filter.IsBoundedUnder (fun x x_1 => x ≤ x_1) l ((fun x => ‖x‖) ∘ g)) : Filter.Tendsto (fun x => f x * g x) l (nhds 0)

theorem Filter.isBoundedUnder_le_mul_tendsto_zero {α : Type u_1} {ι : Type u_4} [NonUnitalSeminormedRing α] {f : ι → α} {g : ι → α} {l : Filter ι} (hf : Filter.IsBoundedUnder (fun x x_1 => x ≤ x_1) l (norm ∘ f)) (hg : Filter.Tendsto g l (nhds 0)) : Filter.Tendsto (fun x => f x * g x) l (nhds 0)

theorem mulLeft_bound {α : Type u_1} [NonUnitalSeminormedRing α] (x : α) (y : α) : ‖↑(AddMonoidHom.mulLeft x) y‖ ≤ ‖x‖ * ‖y‖

In a seminormed ring, the left-multiplication AddMonoidHom is bounded.

theorem mulRight_bound {α : Type u_1} [NonUnitalSeminormedRing α] (x : α) (y : α) : ‖↑(AddMonoidHom.mulRight x) y‖ ≤ ‖x‖ * ‖y‖

In a seminormed ring, the right-multiplication AddMonoidHom is bounded.

instance ULift.nonUnitalSeminormedRing {α : Type u_1} [NonUnitalSeminormedRing α] : NonUnitalSeminormedRing (ULift.{u_5, u_1} α)

Equations

• One or more equations did not get rendered due to their size.

instance Prod.nonUnitalSeminormedRing {α : Type u_1} {β : Type u_2} [NonUnitalSeminormedRing α] [NonUnitalSeminormedRing β] : NonUnitalSeminormedRing (α × β)

Non-unital seminormed ring structure on the product of two non-unital seminormed rings, using the sup norm.

Equations

• One or more equations did not get rendered due to their size.

instance Pi.nonUnitalSeminormedRing {ι : Type u_4} {π : ι → Type u_5} [Fintype ι] [(i : ι) → NonUnitalSeminormedRing (π i)] : NonUnitalSeminormedRing ((i : ι) → π i)

Non-unital seminormed ring structure on the product of finitely many non-unital seminormed rings, using the sup norm.

Equations

• One or more equations did not get rendered due to their size.

instance MulOpposite.nonUnitalSeminormedRing {α : Type u_1} [NonUnitalSeminormedRing α] : NonUnitalSeminormedRing αᵐᵒᵖ

Equations

• One or more equations did not get rendered due to their size.

instance Subalgebra.seminormedRing {𝕜 : Type u_5} [CommRing 𝕜] {E : Type u_6} [SeminormedRing E] [Algebra 𝕜 E] (s : Subalgebra 𝕜 E) : SeminormedRing { x // x ∈ s }

A subalgebra of a seminormed ring is also a seminormed ring, with the restriction of the norm.

See note [implicit instance arguments].

Equations

• One or more equations did not get rendered due to their size.

instance Subalgebra.normedRing {𝕜 : Type u_5} [CommRing 𝕜] {E : Type u_6} [NormedRing E] [Algebra 𝕜 E] (s : Subalgebra 𝕜 E) : NormedRing { x // x ∈ s }

A subalgebra of a normed ring is also a normed ring, with the restriction of the norm.

See note [implicit instance arguments].

Equations

• Subalgebra.normedRing s = let src := Subalgebra.seminormedRing s; NormedRing.mk (_ : ∀ (x y : { x // x ∈ s }), dist x y = ‖x - y‖) (_ : ∀ (a b : { x // x ∈ s }), ‖a * b‖ ≤ ‖a‖ * ‖b‖)

theorem Nat.norm_cast_le {α : Type u_1} [SeminormedRing α] (n : ℕ) : ‖↑n‖ ≤ ↑n * ‖1‖

theorem List.norm_prod_le' {α : Type u_1} [SeminormedRing α] {l : List α} : l ≠ [] → ‖List.prod l‖ ≤ List.prod (List.map norm l)

theorem List.nnnorm_prod_le' {α : Type u_1} [SeminormedRing α] {l : List α} (hl : l ≠ []) : ‖List.prod l‖₊ ≤ List.prod (List.map nnnorm l)

theorem List.norm_prod_le {α : Type u_1} [SeminormedRing α] [NormOneClass α] (l : List α) : ‖List.prod l‖ ≤ List.prod (List.map norm l)

theorem List.nnnorm_prod_le {α : Type u_1} [SeminormedRing α] [NormOneClass α] (l : List α) : ‖List.prod l‖₊ ≤ List.prod (List.map nnnorm l)

theorem Finset.norm_prod_le' {ι : Type u_4} {α : Type u_5} [NormedCommRing α] (s : Finset ι) (hs : Finset.Nonempty s) (f : ι → α) : ‖Finset.prod s fun i => f i‖ ≤ Finset.prod s fun i => ‖f i‖

theorem Finset.nnnorm_prod_le' {ι : Type u_4} {α : Type u_5} [NormedCommRing α] (s : Finset ι) (hs : Finset.Nonempty s) (f : ι → α) : ‖Finset.prod s fun i => f i‖₊ ≤ Finset.prod s fun i => ‖f i‖₊

theorem Finset.norm_prod_le {ι : Type u_4} {α : Type u_5} [NormedCommRing α] [NormOneClass α] (s : Finset ι) (f : ι → α) : ‖Finset.prod s fun i => f i‖ ≤ Finset.prod s fun i => ‖f i‖

theorem Finset.nnnorm_prod_le {ι : Type u_4} {α : Type u_5} [NormedCommRing α] [NormOneClass α] (s : Finset ι) (f : ι → α) : ‖Finset.prod s fun i => f i‖₊ ≤ Finset.prod s fun i => ‖f i‖₊

theorem nnnorm_pow_le' {α : Type u_1} [SeminormedRing α] (a : α) {n : ℕ} : 0 < n → ‖a ^ n‖₊ ≤ ‖a‖₊ ^ n

If α is a seminormed ring, then ‖a ^ n‖₊ ≤ ‖a‖₊ ^ n for n > 0. See also nnnorm_pow_le.

theorem nnnorm_pow_le {α : Type u_1} [SeminormedRing α] [NormOneClass α] (a : α) (n : ℕ) : ‖a ^ n‖₊ ≤ ‖a‖₊ ^ n

If α is a seminormed ring with ‖1‖₊ = 1, then ‖a ^ n‖₊ ≤ ‖a‖₊ ^ n. See also nnnorm_pow_le'.

theorem norm_pow_le' {α : Type u_1} [SeminormedRing α] (a : α) {n : ℕ} (h : 0 < n) : ‖a ^ n‖ ≤ ‖a‖ ^ n

If α is a seminormed ring, then ‖a ^ n‖ ≤ ‖a‖ ^ n for n > 0. See also norm_pow_le.

theorem norm_pow_le {α : Type u_1} [SeminormedRing α] [NormOneClass α] (a : α) (n : ℕ) : ‖a ^ n‖ ≤ ‖a‖ ^ n

If α is a seminormed ring with ‖1‖ = 1, then ‖a ^ n‖ ≤ ‖a‖ ^ n. See also norm_pow_le'.

theorem eventually_norm_pow_le {α : Type u_1} [SeminormedRing α] (a : α) : ∀ᶠ (n : ℕ) in Filter.atTop, ‖a ^ n‖ ≤ ‖a‖ ^ n

instance ULift.seminormedRing {α : Type u_1} [SeminormedRing α] : SeminormedRing (ULift.{u_5, u_1} α)

Equations

• One or more equations did not get rendered due to their size.

instance Prod.seminormedRing {α : Type u_1} {β : Type u_2} [SeminormedRing α] [SeminormedRing β] : SeminormedRing (α × β)

Seminormed ring structure on the product of two seminormed rings, using the sup norm.

Equations

• Prod.seminormedRing = let src := Prod.nonUnitalSeminormedRing; let src_1 := Prod.instRing; SeminormedRing.mk (_ : ∀ (x y : α × β), dist x y = ‖x - y‖) (_ : ∀ (a b : α × β), ‖a * b‖ ≤ ‖a‖ * ‖b‖)

instance Pi.seminormedRing {ι : Type u_4} {π : ι → Type u_5} [Fintype ι] [(i : ι) → SeminormedRing (π i)] : SeminormedRing ((i : ι) → π i)

Seminormed ring structure on the product of finitely many seminormed rings, using the sup norm.

Equations

• One or more equations did not get rendered due to their size.

instance MulOpposite.seminormedRing {α : Type u_1} [SeminormedRing α] : SeminormedRing αᵐᵒᵖ

Equations

• One or more equations did not get rendered due to their size.

instance ULift.nonUnitalNormedRing {α : Type u_1} [NonUnitalNormedRing α] : NonUnitalNormedRing (ULift.{u_5, u_1} α)

Equations

• One or more equations did not get rendered due to their size.

instance Prod.nonUnitalNormedRing {α : Type u_1} {β : Type u_2} [NonUnitalNormedRing α] [NonUnitalNormedRing β] : NonUnitalNormedRing (α × β)

Non-unital normed ring structure on the product of two non-unital normed rings, using the sup norm.

Equations

• One or more equations did not get rendered due to their size.

instance Pi.nonUnitalNormedRing {ι : Type u_4} {π : ι → Type u_5} [Fintype ι] [(i : ι) → NonUnitalNormedRing (π i)] : NonUnitalNormedRing ((i : ι) → π i)

Normed ring structure on the product of finitely many non-unital normed rings, using the sup norm.

Equations

• One or more equations did not get rendered due to their size.

instance MulOpposite.nonUnitalNormedRing {α : Type u_1} [NonUnitalNormedRing α] : NonUnitalNormedRing αᵐᵒᵖ

Equations

• One or more equations did not get rendered due to their size.

theorem Units.norm_pos {α : Type u_1} [NormedRing α] [Nontrivial α] (x : αˣ) : 0 < ‖↑x‖

theorem Units.nnnorm_pos {α : Type u_1} [NormedRing α] [Nontrivial α] (x : αˣ) : 0 < ‖↑x‖₊

instance ULift.normedRing {α : Type u_1} [NormedRing α] : NormedRing (ULift.{u_5, u_1} α)

Equations

• One or more equations did not get rendered due to their size.

instance Prod.normedRing {α : Type u_1} {β : Type u_2} [NormedRing α] [NormedRing β] : NormedRing (α × β)

Normed ring structure on the product of two normed rings, using the sup norm.

Equations

• Prod.normedRing = let src := Prod.nonUnitalNormedRing; let src_1 := Prod.instRing; NormedRing.mk (_ : ∀ (x y : α × β), dist x y = ‖x - y‖) (_ : ∀ (a b : α × β), ‖a * b‖ ≤ ‖a‖ * ‖b‖)

instance Pi.normedRing {ι : Type u_4} {π : ι → Type u_5} [Fintype ι] [(i : ι) → NormedRing (π i)] : NormedRing ((i : ι) → π i)

Normed ring structure on the product of finitely many normed rings, using the sup norm.

Equations

• One or more equations did not get rendered due to their size.

instance MulOpposite.normedRing {α : Type u_1} [NormedRing α] : NormedRing αᵐᵒᵖ

Equations

• One or more equations did not get rendered due to their size.

instance semi_normed_ring_top_monoid {α : Type u_1} [NonUnitalSeminormedRing α] : ContinuousMul α

Equations

• @semi_normed_ring_top_monoid = @semi_normed_ring_top_monoid.proof_1

instance semi_normed_top_ring {α : Type u_1} [NonUnitalSeminormedRing α] : TopologicalRing α

A seminormed ring is a topological ring.

Equations

• @semi_normed_top_ring = @semi_normed_top_ring.proof_1

@[simp]

theorem norm_mul {α : Type u_1} [NormedDivisionRing α] (a : α) (b : α) : ‖a * b‖ = ‖a‖ * ‖b‖

instance NormedDivisionRing.to_normOneClass {α : Type u_1} [NormedDivisionRing α] : NormOneClass α

Equations

• @NormedDivisionRing.to_normOneClass = @NormedDivisionRing.to_normOneClass.proof_1

instance isAbsoluteValue_norm {α : Type u_1} [NormedDivisionRing α] : IsAbsoluteValue norm

Equations

• @isAbsoluteValue_norm = @isAbsoluteValue_norm.proof_1

@[simp]

theorem nnnorm_mul {α : Type u_1} [NormedDivisionRing α] (a : α) (b : α) : ‖a * b‖₊ = ‖a‖₊ * ‖b‖₊

@[simp]

theorem normHom_apply {α : Type u_1} [NormedDivisionRing α] : ∀ (x : α), ↑normHom x = ‖x‖

def normHom {α : Type u_1} [NormedDivisionRing α] : α →*₀ ℝ

norm as a MonoidWithZeroHom.

Equations

• normHom = { toZeroHom := { toFun := fun x => ‖x‖, map_zero' := (_ : ‖0‖ = 0) }, map_one' := (_ : ‖1‖ = 1), map_mul' := (_ : ∀ (a b : α), ‖a * b‖ = ‖a‖ * ‖b‖) }

@[simp]

theorem nnnormHom_apply {α : Type u_1} [NormedDivisionRing α] : ∀ (x : α), ↑nnnormHom x = ‖x‖₊

def nnnormHom {α : Type u_1} [NormedDivisionRing α] : α →*₀ NNReal

nnnorm as a MonoidWithZeroHom.

Equations

• nnnormHom = { toZeroHom := { toFun := fun x => ‖x‖₊, map_zero' := (_ : ‖0‖₊ = 0) }, map_one' := (_ : ‖1‖₊ = 1), map_mul' := (_ : ∀ (a b : α), ‖a * b‖₊ = ‖a‖₊ * ‖b‖₊) }

@[simp]

theorem norm_pow {α : Type u_1} [NormedDivisionRing α] (a : α) (n : ℕ) : ‖a ^ n‖ = ‖a‖ ^ n

@[simp]

theorem nnnorm_pow {α : Type u_1} [NormedDivisionRing α] (a : α) (n : ℕ) : ‖a ^ n‖₊ = ‖a‖₊ ^ n

theorem List.norm_prod {α : Type u_1} [NormedDivisionRing α] (l : List α) : ‖List.prod l‖ = List.prod (List.map norm l)

theorem List.nnnorm_prod {α : Type u_1} [NormedDivisionRing α] (l : List α) : ‖List.prod l‖₊ = List.prod (List.map nnnorm l)

@[simp]

theorem norm_div {α : Type u_1} [NormedDivisionRing α] (a : α) (b : α) : ‖a / b‖ = ‖a‖ / ‖b‖

@[simp]

theorem nnnorm_div {α : Type u_1} [NormedDivisionRing α] (a : α) (b : α) : ‖a / b‖₊ = ‖a‖₊ / ‖b‖₊

@[simp]

theorem norm_inv {α : Type u_1} [NormedDivisionRing α] (a : α) : ‖a⁻¹‖ = ‖a‖⁻¹

@[simp]

theorem nnnorm_inv {α : Type u_1} [NormedDivisionRing α] (a : α) : ‖a⁻¹‖₊ = ‖a‖₊⁻¹

@[simp]

theorem norm_zpow {α : Type u_1} [NormedDivisionRing α] (a : α) (n : ℤ) : ‖a ^ n‖ = ‖a‖ ^ n

@[simp]

theorem nnnorm_zpow {α : Type u_1} [NormedDivisionRing α] (a : α) (n : ℤ) : ‖a ^ n‖₊ = ‖a‖₊ ^ n

theorem dist_inv_inv₀ {α : Type u_1} [NormedDivisionRing α] {z : α} {w : α} (hz : z ≠ 0) (hw : w ≠ 0) : dist z⁻¹ w⁻¹ = dist z w / (‖z‖ * ‖w‖)

theorem nndist_inv_inv₀ {α : Type u_1} [NormedDivisionRing α] {z : α} {w : α} (hz : z ≠ 0) (hw : w ≠ 0) : nndist z⁻¹ w⁻¹ = nndist z w / (‖z‖₊ * ‖w‖₊)

theorem Filter.tendsto_mul_left_cobounded {α : Type u_1} [NormedDivisionRing α] {a : α} (ha : a ≠ 0) : Filter.Tendsto ((fun x x_1 => x * x_1) a) (Filter.comap norm Filter.atTop) (Filter.comap norm Filter.atTop)

Multiplication on the left by a nonzero element of a normed division ring tends to infinity at infinity. TODO: use Bornology.cobounded instead of Filter.comap Norm.norm Filter.atTop.

theorem Filter.tendsto_mul_right_cobounded {α : Type u_1} [NormedDivisionRing α] {a : α} (ha : a ≠ 0) : Filter.Tendsto (fun x => x * a) (Filter.comap norm Filter.atTop) (Filter.comap norm Filter.atTop)

Multiplication on the right by a nonzero element of a normed division ring tends to infinity at infinity. TODO: use Bornology.cobounded instead of Filter.comap Norm.norm Filter.atTop.

instance NormedDivisionRing.to_hasContinuousInv₀ {α : Type u_1} [NormedDivisionRing α] : HasContinuousInv₀ α

Equations

• @NormedDivisionRing.to_hasContinuousInv₀ = @NormedDivisionRing.to_hasContinuousInv₀.proof_1

instance NormedDivisionRing.to_topologicalDivisionRing {α : Type u_1} [NormedDivisionRing α] : TopologicalDivisionRing α

A normed division ring is a topological division ring.

Equations

• @NormedDivisionRing.to_topologicalDivisionRing = @NormedDivisionRing.to_topologicalDivisionRing.proof_1

theorem norm_map_one_of_pow_eq_one {α : Type u_1} {β : Type u_2} [NormedDivisionRing α] [Monoid β] (φ : β →* α) {x : β} {k : ℕ+} (h : x ^ ↑k = 1) : ‖↑φ x‖ = 1

theorem norm_one_of_pow_eq_one {α : Type u_1} [NormedDivisionRing α] {x : α} {k : ℕ+} (h : x ^ ↑k = 1) : ‖x‖ = 1

class NormedField (α : Type u_5) extends Norm , Field , MetricSpace : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• one : α
• one_mul : ∀ (a : α), 1 * a = a
• mul_one : ∀ (a : α), a * 1 = a
• natCast : ℕ → α
• natCast_zero : NatCast.natCast 0 = 0
• natCast_succ : ∀ (n : ℕ), NatCast.natCast (n + 1) = NatCast.natCast n + 1
• npow : ℕ → α → α
• npow_zero : ∀ (x : α), Semiring.npow 0 x = 1
• npow_succ : ∀ (n : ℕ) (x : α), Semiring.npow (n + 1) x = x * Semiring.npow n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), Ring.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.ofNat (Nat.succ n)) a = a + Ring.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.negSucc n) a = -Ring.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• intCast : ℤ → α
• intCast_ofNat : ∀ (n : ℕ), IntCast.intCast ↑n = ↑n
• intCast_negSucc : ∀ (n : ℕ), IntCast.intCast (Int.negSucc n) = -↑(n + 1)
• mul_comm : ∀ (a b : α), a * b = b * a
• inv : α → α
• div : α → α → α
• div_eq_mul_inv : ∀ (a b : α), a / b = a * b⁻¹
• zpow : ℤ → α → α
• zpow_zero' : ∀ (a : α), Field.zpow 0 a = 1
• zpow_succ' : ∀ (n : ℕ) (a : α), Field.zpow (Int.ofNat (Nat.succ n)) a = a * Field.zpow (Int.ofNat n) a
• zpow_neg' : ∀ (n : ℕ) (a : α), Field.zpow (Int.negSucc n) a = (Field.zpow (↑(Nat.succ n)) a)⁻¹
• exists_pair_ne : ∃ x y, x ≠ y
• ratCast : ℚ → α
• mul_inv_cancel : ∀ (a : α), a ≠ 0 → a * a⁻¹ = 1
• inv_zero : 0⁻¹ = 0
• ratCast_mk : ∀ (a : ℤ) (b : ℕ) (h1 : b ≠ 0) (h2 : Nat.Coprime (Int.natAbs a) b), ↑(Rat.mk' a b) = ↑a * (↑b)⁻¹
• qsmul : ℚ → α → α
• qsmul_eq_mul' : ∀ (a : ℚ) (x : α), Field.qsmul a x = ↑a * x
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• eq_of_dist_eq_zero : ∀ {x y : α}, dist x y = 0 → x = y
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖

  The distance is induced by the norm.

• norm_mul' : ∀ (a b : α), ‖a * b‖ = ‖a‖ * ‖b‖

  The norm is multiplicative.

A normed field is a field with a norm satisfying ‖x y‖ = ‖x‖ ‖y‖.

class NontriviallyNormedField (α : Type u_5) extends NormedField : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• one : α
• one_mul : ∀ (a : α), 1 * a = a
• mul_one : ∀ (a : α), a * 1 = a
• natCast : ℕ → α
• natCast_zero : NatCast.natCast 0 = 0
• natCast_succ : ∀ (n : ℕ), NatCast.natCast (n + 1) = NatCast.natCast n + 1
• npow : ℕ → α → α
• npow_zero : ∀ (x : α), Semiring.npow 0 x = 1
• npow_succ : ∀ (n : ℕ) (x : α), Semiring.npow (n + 1) x = x * Semiring.npow n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), Ring.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.ofNat (Nat.succ n)) a = a + Ring.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.negSucc n) a = -Ring.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• intCast : ℤ → α
• intCast_ofNat : ∀ (n : ℕ), IntCast.intCast ↑n = ↑n
• intCast_negSucc : ∀ (n : ℕ), IntCast.intCast (Int.negSucc n) = -↑(n + 1)
• mul_comm : ∀ (a b : α), a * b = b * a
• inv : α → α
• div : α → α → α
• div_eq_mul_inv : ∀ (a b : α), a / b = a * b⁻¹
• zpow : ℤ → α → α
• zpow_zero' : ∀ (a : α), Field.zpow 0 a = 1
• zpow_succ' : ∀ (n : ℕ) (a : α), Field.zpow (Int.ofNat (Nat.succ n)) a = a * Field.zpow (Int.ofNat n) a
• zpow_neg' : ∀ (n : ℕ) (a : α), Field.zpow (Int.negSucc n) a = (Field.zpow (↑(Nat.succ n)) a)⁻¹
• exists_pair_ne : ∃ x y, x ≠ y
• ratCast : ℚ → α
• mul_inv_cancel : ∀ (a : α), a ≠ 0 → a * a⁻¹ = 1
• inv_zero : 0⁻¹ = 0
• ratCast_mk : ∀ (a : ℤ) (b : ℕ) (h1 : b ≠ 0) (h2 : Nat.Coprime (Int.natAbs a) b), ↑(Rat.mk' a b) = ↑a * (↑b)⁻¹
• qsmul : ℚ → α → α
• qsmul_eq_mul' : ∀ (a : ℚ) (x : α), Field.qsmul a x = ↑a * x
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• eq_of_dist_eq_zero : ∀ {x y : α}, dist x y = 0 → x = y
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖
• norm_mul' : ∀ (a b : α), ‖a * b‖ = ‖a‖ * ‖b‖
• non_trivial : ∃ x, 1 < ‖x‖

  The norm attains a value exceeding 1.

A nontrivially normed field is a normed field in which there is an element of norm different from 0 and 1. This makes it possible to bring any element arbitrarily close to 0 by multiplication by the powers of any element, and thus to relate algebra and topology.

class DenselyNormedField (α : Type u_5) extends NormedField : Type u_5

• norm : α → ℝ
• add : α → α → α
• add_assoc : ∀ (a b c : α), a + b + c = a + (b + c)
• zero : α
• zero_add : ∀ (a : α), 0 + a = a
• add_zero : ∀ (a : α), a + 0 = a
• nsmul : ℕ → α → α
• nsmul_zero : ∀ (x : α), AddMonoid.nsmul 0 x = 0
• nsmul_succ : ∀ (n : ℕ) (x : α), AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
• add_comm : ∀ (a b : α), a + b = b + a
• mul : α → α → α
• left_distrib : ∀ (a b c : α), a * (b + c) = a * b + a * c
• right_distrib : ∀ (a b c : α), (a + b) * c = a * c + b * c
• zero_mul : ∀ (a : α), 0 * a = 0
• mul_zero : ∀ (a : α), a * 0 = 0
• mul_assoc : ∀ (a b c : α), a * b * c = a * (b * c)
• one : α
• one_mul : ∀ (a : α), 1 * a = a
• mul_one : ∀ (a : α), a * 1 = a
• natCast : ℕ → α
• natCast_zero : NatCast.natCast 0 = 0
• natCast_succ : ∀ (n : ℕ), NatCast.natCast (n + 1) = NatCast.natCast n + 1
• npow : ℕ → α → α
• npow_zero : ∀ (x : α), Semiring.npow 0 x = 1
• npow_succ : ∀ (n : ℕ) (x : α), Semiring.npow (n + 1) x = x * Semiring.npow n x
• neg : α → α
• sub : α → α → α
• sub_eq_add_neg : ∀ (a b : α), a - b = a + -b
• zsmul : ℤ → α → α
• zsmul_zero' : ∀ (a : α), Ring.zsmul 0 a = 0
• zsmul_succ' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.ofNat (Nat.succ n)) a = a + Ring.zsmul (Int.ofNat n) a
• zsmul_neg' : ∀ (n : ℕ) (a : α), Ring.zsmul (Int.negSucc n) a = -Ring.zsmul (↑(Nat.succ n)) a
• add_left_neg : ∀ (a : α), -a + a = 0
• intCast : ℤ → α
• intCast_ofNat : ∀ (n : ℕ), IntCast.intCast ↑n = ↑n
• intCast_negSucc : ∀ (n : ℕ), IntCast.intCast (Int.negSucc n) = -↑(n + 1)
• mul_comm : ∀ (a b : α), a * b = b * a
• inv : α → α
• div : α → α → α
• div_eq_mul_inv : ∀ (a b : α), a / b = a * b⁻¹
• zpow : ℤ → α → α
• zpow_zero' : ∀ (a : α), Field.zpow 0 a = 1
• zpow_succ' : ∀ (n : ℕ) (a : α), Field.zpow (Int.ofNat (Nat.succ n)) a = a * Field.zpow (Int.ofNat n) a
• zpow_neg' : ∀ (n : ℕ) (a : α), Field.zpow (Int.negSucc n) a = (Field.zpow (↑(Nat.succ n)) a)⁻¹
• exists_pair_ne : ∃ x y, x ≠ y
• ratCast : ℚ → α
• mul_inv_cancel : ∀ (a : α), a ≠ 0 → a * a⁻¹ = 1
• inv_zero : 0⁻¹ = 0
• ratCast_mk : ∀ (a : ℤ) (b : ℕ) (h1 : b ≠ 0) (h2 : Nat.Coprime (Int.natAbs a) b), ↑(Rat.mk' a b) = ↑a * (↑b)⁻¹
• qsmul : ℚ → α → α
• qsmul_eq_mul' : ∀ (a : ℚ) (x : α), Field.qsmul a x = ↑a * x
• dist : α → α → ℝ
• dist_self : ∀ (x : α), dist x x = 0
• dist_comm : ∀ (x y : α), dist x y = dist y x
• dist_triangle : ∀ (x y z : α), dist x z ≤ dist x y + dist y z
• edist : α → α → ENNReal
• edist_dist : ∀ (x y : α), PseudoMetricSpace.edist x y = ENNReal.ofReal (dist x y)
• toUniformSpace : UniformSpace α
• uniformity_dist : uniformity α = ⨅ (ε : ℝ) (_ : ε > 0), Filter.principal {p | dist p.fst p.snd < ε}
• toBornology : Bornology α
• cobounded_sets : (Bornology.cobounded α).sets = {s_1 | ∃ C, ∀ (x : α), x ∈ s_1ᶜ → ∀ (y : α), y ∈ s_1ᶜ → dist x y ≤ C}
• eq_of_dist_eq_zero : ∀ {x y : α}, dist x y = 0 → x = y
• dist_eq : ∀ (x y : α), dist x y = ‖x - y‖
• norm_mul' : ∀ (a b : α), ‖a * b‖ = ‖a‖ * ‖b‖
• lt_norm_lt : ∀ (x y : ℝ), 0 ≤ x → x < y → ∃ a, x < ‖a‖ ∧ ‖a‖ < y

  The range of the norm is dense in the collection of nonnegative real numbers.

A densely normed field is a normed field for which the image of the norm is dense in ℝ≥0, which means it is also nontrivially normed. However, not all nontrivally normed fields are densely normed; in particular, the Padics exhibit this fact.

instance DenselyNormedField.toNontriviallyNormedField {α : Type u_1} [DenselyNormedField α] : NontriviallyNormedField α

A densely normed field is always a nontrivially normed field. See note [lower instance priority].

Equations

• DenselyNormedField.toNontriviallyNormedField = NontriviallyNormedField.mk (_ : ∃ x, 1 < ‖x‖)

instance NormedField.toNormedDivisionRing {α : Type u_1} [NormedField α] : NormedDivisionRing α

Equations

• NormedField.toNormedDivisionRing = let src := inst; NormedDivisionRing.mk (_ : ∀ (x y : α), dist x y = ‖x - y‖) (_ : ∀ (a b : α), ‖a * b‖ = ‖a‖ * ‖b‖)

instance NormedField.toNormedCommRing {α : Type u_1} [NormedField α] : NormedCommRing α

Equations

• NormedField.toNormedCommRing = let src := inst; NormedCommRing.mk (_ : ∀ (a b : α), a * b = b * a)

@[simp]

theorem norm_prod {α : Type u_1} {β : Type u_2} [NormedField α] (s : Finset β) (f : β → α) : ‖Finset.prod s fun b => f b‖ = Finset.prod s fun b => ‖f b‖

@[simp]

theorem nnnorm_prod {α : Type u_1} {β : Type u_2} [NormedField α] (s : Finset β) (f : β → α) : ‖Finset.prod s fun b => f b‖₊ = Finset.prod s fun b => ‖f b‖₊

theorem NormedField.exists_one_lt_norm (α : Type u_1) [NontriviallyNormedField α] : ∃ x, 1 < ‖x‖

theorem NormedField.exists_lt_norm (α : Type u_1) [NontriviallyNormedField α] (r : ℝ) : ∃ x, r < ‖x‖

theorem NormedField.exists_norm_lt (α : Type u_1) [NontriviallyNormedField α] {r : ℝ} (hr : 0 < r) : ∃ x, 0 < ‖x‖ ∧ ‖x‖ < r

theorem NormedField.exists_norm_lt_one (α : Type u_1) [NontriviallyNormedField α] : ∃ x, 0 < ‖x‖ ∧ ‖x‖ < 1

theorem NormedField.punctured_nhds_neBot {α : Type u_1} [NontriviallyNormedField α] (x : α) : Filter.NeBot (nhdsWithin x {x}ᶜ)

theorem NormedField.nhdsWithin_isUnit_neBot {α : Type u_1} [NontriviallyNormedField α] : Filter.NeBot (nhdsWithin 0 {x | IsUnit x})

theorem NormedField.exists_lt_norm_lt (α : Type u_1) [DenselyNormedField α] {r₁ : ℝ} {r₂ : ℝ} (h₀ : 0 ≤ r₁) (h : r₁ < r₂) : ∃ x, r₁ < ‖x‖ ∧ ‖x‖ < r₂

theorem NormedField.exists_lt_nnnorm_lt (α : Type u_1) [DenselyNormedField α] {r₁ : NNReal} {r₂ : NNReal} (h : r₁ < r₂) : ∃ x, r₁ < ‖x‖₊ ∧ ‖x‖₊ < r₂

instance NormedField.denselyOrdered_range_norm (α : Type u_1) [DenselyNormedField α] : DenselyOrdered ↑(Set.range norm)

Equations

• NormedField.denselyOrdered_range_norm = NormedField.denselyOrdered_range_norm.proof_1

instance NormedField.denselyOrdered_range_nnnorm (α : Type u_1) [DenselyNormedField α] : DenselyOrdered ↑(Set.range nnnorm)

Equations

• NormedField.denselyOrdered_range_nnnorm = NormedField.denselyOrdered_range_nnnorm.proof_1

theorem NormedField.denseRange_nnnorm (α : Type u_1) [DenselyNormedField α] : DenseRange nnnorm

instance Real.normedCommRing : NormedCommRing ℝ

Equations

• Real.normedCommRing = let src := Real.normedAddCommGroup; let src_1 := Real.commRing; NormedCommRing.mk (_ : ∀ (a b : ℝ), a * b = b * a)

noncomputable instance Real.normedField : NormedField ℝ

Equations

• Real.normedField = let src := Real.normedAddCommGroup; let src_1 := Real.field; NormedField.mk (_ : ∀ (x y : ℝ), dist x y = ‖x - y‖) (_ : ∀ (a b : ℝ), |a * b| = |a| * |b|)

noncomputable instance Real.denselyNormedField : DenselyNormedField ℝ

Equations

• Real.denselyNormedField = DenselyNormedField.mk Real.denselyNormedField.proof_1

theorem Real.toNNReal_mul_nnnorm {x : ℝ} (y : ℝ) (hx : 0 ≤ x) : Real.toNNReal x * ‖y‖₊ = ‖x * y‖₊

theorem Real.nnnorm_mul_toNNReal (x : ℝ) {y : ℝ} (hy : 0 ≤ y) : ‖x‖₊ * Real.toNNReal y = ‖x * y‖₊

theorem NNReal.norm_eq (x : NNReal) : ‖↑x‖ = ↑x

@[simp]

theorem NNReal.nnnorm_eq (x : NNReal) : ‖↑x‖₊ = x

@[simp]

theorem norm_norm {α : Type u_1} [SeminormedAddCommGroup α] (x : α) : ‖‖x‖‖ = ‖x‖

@[simp]

theorem nnnorm_norm {α : Type u_1} [SeminormedAddCommGroup α] (a : α) : ‖‖a‖‖₊ = ‖a‖₊

theorem NormedAddCommGroup.tendsto_atTop {α : Type u_1} [Nonempty α] [SemilatticeSup α] {β : Type u_5} [SeminormedAddCommGroup β] {f : α → β} {b : β} : Filter.Tendsto f Filter.atTop (nhds b) ↔ ∀ (ε : ℝ), 0 < ε → ∃ N, ∀ (n : α), N ≤ n → ‖f n - b‖ < ε

A restatement of MetricSpace.tendsto_atTop in terms of the norm.

theorem NormedAddCommGroup.tendsto_atTop' {α : Type u_1} [Nonempty α] [SemilatticeSup α] [NoMaxOrder α] {β : Type u_5} [SeminormedAddCommGroup β] {f : α → β} {b : β} : Filter.Tendsto f Filter.atTop (nhds b) ↔ ∀ (ε : ℝ), 0 < ε → ∃ N, ∀ (n : α), N < n → ‖f n - b‖ < ε

A variant of NormedAddCommGroup.tendsto_atTop that uses ∃ N, ∀ n > N, ... rather than ∃ N, ∀ n ≥ N, ...

instance Int.normedCommRing : NormedCommRing ℤ

Equations

• Int.normedCommRing = let src := Int.normedAddCommGroup; let src_1 := Int.instRingInt; NormedCommRing.mk (_ : ∀ (a b : ℤ), a * b = b * a)

instance Int.normOneClass : NormOneClass ℤ

Equations

• Int.normOneClass = Int.normOneClass.proof_1

instance Rat.normedField : NormedField ℚ

Equations

• Rat.normedField = let src := Rat.normedAddCommGroup; let src_1 := Rat.field; NormedField.mk (_ : ∀ (x y : ℚ), dist x y = ‖x - y‖) Rat.normedField.proof_1

instance Rat.denselyNormedField : DenselyNormedField ℚ

Equations

• Rat.denselyNormedField = DenselyNormedField.mk Rat.denselyNormedField.proof_1

class RingHomIsometric {R₁ : Type u_5} {R₂ : Type u_6} [Semiring R₁] [Semiring R₂] [Norm R₁] [Norm R₂] (σ : R₁ →+* R₂) : Prop

• is_iso : ∀ {x : R₁}, ‖↑σ x‖ = ‖x‖

  The ring homomorphism is an isometry.

This class states that a ring homomorphism is isometric. This is a sufficient assumption for a continuous semilinear map to be bounded and this is the main use for this typeclass.

instance RingHomIsometric.ids {R₁ : Type u_5} [SeminormedRing R₁] : RingHomIsometric (RingHom.id R₁)

Equations

• @RingHomIsometric.ids = @RingHomIsometric.ids.proof_1

Induced normed structures

@[reducible]

def NonUnitalSeminormedRing.induced {F : Type u_5} (R : Type u_6) (S : Type u_7) [NonUnitalRing R] [NonUnitalSeminormedRing S] [NonUnitalRingHomClass F R S] (f : F) : NonUnitalSeminormedRing R

A non-unital ring homomorphism from a NonUnitalRing to a NonUnitalSeminormedRing induces a NonUnitalSeminormedRing structure on the domain.

See note [reducible non-instances]

Equations

• One or more equations did not get rendered due to their size.

@[reducible]

def NonUnitalNormedRing.induced {F : Type u_5} (R : Type u_6) (S : Type u_7) [NonUnitalRing R] [NonUnitalNormedRing S] [NonUnitalRingHomClass F R S] (f : F) (hf : Function.Injective ↑f) : NonUnitalNormedRing R

An injective non-unital ring homomorphism from a NonUnitalRing to a NonUnitalNormedRing induces a NonUnitalNormedRing structure on the domain.

See note [reducible non-instances]

Equations

• One or more equations did not get rendered due to their size.

@[reducible]

def SeminormedRing.induced {F : Type u_5} (R : Type u_6) (S : Type u_7) [Ring R] [SeminormedRing S] [NonUnitalRingHomClass F R S] (f : F) : SeminormedRing R

A non-unital ring homomorphism from a Ring to a SeminormedRing induces a SeminormedRing structure on the domain.

See note [reducible non-instances]

Equations

• One or more equations did not get rendered due to their size.

@[reducible]

def NormedRing.induced {F : Type u_5} (R : Type u_6) (S : Type u_7) [Ring R] [NormedRing S] [NonUnitalRingHomClass F R S] (f : F) (hf : Function.Injective ↑f) : NormedRing R

An injective non-unital ring homomorphism from a Ring to a NormedRing induces a NormedRing structure on the domain.

See note [reducible non-instances]

Equations

• One or more equations did not get rendered due to their size.

@[reducible]

def SeminormedCommRing.induced {F : Type u_5} (R : Type u_6) (S : Type u_7) [CommRing R] [SeminormedRing S] [NonUnitalRingHomClass F R S] (f : F) : SeminormedCommRing R

A non-unital ring homomorphism from a CommRing to a SeminormedRing induces a SeminormedCommRing structure on the domain.

See note [reducible non-instances]

Equations

• One or more equations did not get rendered due to their size.

@[reducible]

def NormedCommRing.induced {F : Type u_5} (R : Type u_6) (S : Type u_7) [CommRing R] [NormedRing S] [NonUnitalRingHomClass F R S] (f : F) (hf : Function.Injective ↑f) : NormedCommRing R

An injective non-unital ring homomorphism from a CommRing to a NormedRing induces a NormedCommRing structure on the domain.

See note [reducible non-instances]

Equations

• NormedCommRing.induced R S f hf = let src := SeminormedCommRing.induced R S f; let src_1 := NormedAddCommGroup.induced R S f hf; NormedCommRing.mk (_ : ∀ (x y : R), x * y = y * x)

@[reducible]

def NormedDivisionRing.induced {F : Type u_5} (R : Type u_6) (S : Type u_7) [DivisionRing R] [NormedDivisionRing S] [NonUnitalRingHomClass F R S] (f : F) (hf : Function.Injective ↑f) : NormedDivisionRing R

An injective non-unital ring homomorphism from a DivisionRing to a NormedRing induces a NormedDivisionRing structure on the domain.

See note [reducible non-instances]

Equations

• One or more equations did not get rendered due to their size.

@[reducible]

def NormedField.induced {F : Type u_5} (R : Type u_6) (S : Type u_7) [Field R] [NormedField S] [NonUnitalRingHomClass F R S] (f : F) (hf : Function.Injective ↑f) : NormedField R

An injective non-unital ring homomorphism from a Field to a NormedRing induces a NormedField structure on the domain.

See note [reducible non-instances]

Equations

• NormedField.induced R S f hf = let src := NormedDivisionRing.induced R S f hf; NormedField.mk (_ : ∀ (x y : R), dist x y = ‖x - y‖) (_ : ∀ (a b : R), ‖a * b‖ = ‖a‖ * ‖b‖)

theorem NormOneClass.induced {F : Type u_8} (R : Type u_9) (S : Type u_10) [Ring R] [SeminormedRing S] [NormOneClass S] [RingHomClass F R S] (f : F) : NormOneClass R

A ring homomorphism from a Ring R to a SeminormedRing S which induces the norm structure SeminormedRing.induced makes R satisfy ‖(1 : R)‖ = 1 whenever ‖(1 : S)‖ = 1.

instance SubringClass.toSeminormedRing {S : Type u_5} {R : Type u_6} [SetLike S R] [SeminormedRing R] [SubringClass S R] (s : S) : SeminormedRing { x // x ∈ s }

Equations

• SubringClass.toSeminormedRing s = SeminormedRing.induced { x // x ∈ s } R (SubringClass.subtype s)

instance SubringClass.toNormedRing {S : Type u_5} {R : Type u_6} [SetLike S R] [NormedRing R] [SubringClass S R] (s : S) : NormedRing { x // x ∈ s }

Equations

• SubringClass.toNormedRing s = NormedRing.induced { x // x ∈ s } R (SubringClass.subtype s) (_ : Function.Injective Subtype.val)

instance SubringClass.toSeminormedCommRing {S : Type u_5} {R : Type u_6} [SetLike S R] [SeminormedCommRing R] [_h : SubringClass S R] (s : S) : SeminormedCommRing { x // x ∈ s }

Equations

• SubringClass.toSeminormedCommRing s = let src := SubringClass.toSeminormedRing s; SeminormedCommRing.mk (_ : ∀ (a b : { x // x ∈ s }), a * b = b * a)

instance SubringClass.toNormedCommRing {S : Type u_5} {R : Type u_6} [SetLike S R] [NormedCommRing R] [SubringClass S R] (s : S) : NormedCommRing { x // x ∈ s }

Equations

• SubringClass.toNormedCommRing s = let src := SubringClass.toNormedRing s; NormedCommRing.mk (_ : ∀ (a b : { x // x ∈ s }), a * b = b * a)