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Mathlib.Algebra.Order.Group.Defs

Ordered groups #

This file defines bundled ordered groups and develops a few basic results.

Implementation details #

Unfortunately, the number of ' appended to lemmas in this file may differ between the multiplicative and the additive version of a lemma. The reason is that we did not want to change existing names in the library.

class OrderedAddCommGroup (α : Type u) extends AddCommGroup α, PartialOrder α :

An ordered additive commutative group is an additive commutative group with a partial order in which addition is strictly monotone.

Instances
    class OrderedCommGroup (α : Type u) extends CommGroup α, PartialOrder α :

    An ordered commutative group is a commutative group with a partial order in which multiplication is strictly monotone.

    Instances
      @[instance 100]
      Equations
      @[instance 100]
      Equations

      A choice-free shortcut instance.

      A choice-free shortcut instance.

      A choice-free shortcut instance.

      A choice-free shortcut instance.

      theorem OrderedCommGroup.mul_lt_mul_left' {α : Type u_1} [Mul α] [LT α] [MulLeftStrictMono α] {b c : α} (bc : b < c) (a : α) :
      a * b < a * c

      Alias of mul_lt_mul_left'.

      theorem OrderedAddCommGroup.add_lt_add_left {α : Type u_1} [Add α] [LT α] [AddLeftStrictMono α] {b c : α} (bc : b < c) (a : α) :
      a + b < a + c
      theorem OrderedCommGroup.le_of_mul_le_mul_left {α : Type u_1} [Mul α] [LE α] [MulLeftReflectLE α] {a b c : α} (bc : a * b a * c) :
      b c

      Alias of le_of_mul_le_mul_left'.

      theorem OrderedAddCommGroup.le_of_add_le_add_left {α : Type u_1} [Add α] [LE α] [AddLeftReflectLE α] {a b c : α} (bc : a + b a + c) :
      b c
      theorem OrderedCommGroup.lt_of_mul_lt_mul_left {α : Type u_1} [Mul α] [LT α] [MulLeftReflectLT α] {a b c : α} (bc : a * b < a * c) :
      b < c

      Alias of lt_of_mul_lt_mul_left'.

      theorem OrderedAddCommGroup.lt_of_add_lt_add_left {α : Type u_1} [Add α] [LT α] [AddLeftReflectLT α] {a b c : α} (bc : a + b < a + c) :
      b < c

      Linearly ordered commutative groups #

      A linearly ordered additive commutative group is an additive commutative group with a linear order in which addition is monotone.

      Instances

        A linearly ordered commutative group is a commutative group with a linear order in which multiplication is monotone.

        Instances
          theorem LinearOrderedCommGroup.mul_lt_mul_left' {α : Type u} [LinearOrderedCommGroup α] (a b : α) (h : a < b) (c : α) :
          c * a < c * b
          theorem LinearOrderedAddCommGroup.add_lt_add_left {α : Type u} [LinearOrderedAddCommGroup α] (a b : α) (h : a < b) (c : α) :
          c + a < c + b
          theorem eq_one_of_inv_eq' {α : Type u} [LinearOrderedCommGroup α] {a : α} (h : a⁻¹ = a) :
          a = 1
          theorem eq_zero_of_neg_eq {α : Type u} [LinearOrderedAddCommGroup α] {a : α} (h : -a = a) :
          a = 0
          theorem exists_one_lt' {α : Type u} [LinearOrderedCommGroup α] [Nontrivial α] :
          ∃ (a : α), 1 < a
          theorem exists_zero_lt {α : Type u} [LinearOrderedAddCommGroup α] [Nontrivial α] :
          ∃ (a : α), 0 < a
          @[instance 100]
          Equations
          • One or more equations did not get rendered due to their size.
          @[instance 100]
          Equations
          • One or more equations did not get rendered due to their size.
          @[simp]
          theorem inv_le_self_iff {α : Type u} [LinearOrderedCommGroup α] {a : α} :
          a⁻¹ a 1 a
          @[simp]
          theorem neg_le_self_iff {α : Type u} [LinearOrderedAddCommGroup α] {a : α} :
          -a a 0 a
          @[simp]
          theorem inv_lt_self_iff {α : Type u} [LinearOrderedCommGroup α] {a : α} :
          a⁻¹ < a 1 < a
          @[simp]
          theorem neg_lt_self_iff {α : Type u} [LinearOrderedAddCommGroup α] {a : α} :
          -a < a 0 < a
          @[simp]
          theorem le_inv_self_iff {α : Type u} [LinearOrderedCommGroup α] {a : α} :
          a a⁻¹ a 1
          @[simp]
          theorem le_neg_self_iff {α : Type u} [LinearOrderedAddCommGroup α] {a : α} :
          a -a a 0
          @[simp]
          theorem lt_inv_self_iff {α : Type u} [LinearOrderedCommGroup α] {a : α} :
          a < a⁻¹ a < 1
          @[simp]
          theorem lt_neg_self_iff {α : Type u} [LinearOrderedAddCommGroup α] {a : α} :
          a < -a a < 0
          theorem inv_le_inv' {α : Type u} [OrderedCommGroup α] {a b : α} :
          a bb⁻¹ a⁻¹
          theorem neg_le_neg {α : Type u} [OrderedAddCommGroup α] {a b : α} :
          a b-b -a
          theorem inv_lt_inv' {α : Type u} [OrderedCommGroup α] {a b : α} :
          a < bb⁻¹ < a⁻¹
          theorem neg_lt_neg {α : Type u} [OrderedAddCommGroup α] {a b : α} :
          a < b-b < -a
          theorem inv_lt_one_of_one_lt {α : Type u} [OrderedCommGroup α] {a : α} :
          1 < aa⁻¹ < 1
          theorem neg_neg_of_pos {α : Type u} [OrderedAddCommGroup α] {a : α} :
          0 < a-a < 0
          theorem inv_le_one_of_one_le {α : Type u} [OrderedCommGroup α] {a : α} :
          1 aa⁻¹ 1
          theorem neg_nonpos_of_nonneg {α : Type u} [OrderedAddCommGroup α] {a : α} :
          0 a-a 0
          theorem one_le_inv_of_le_one {α : Type u} [OrderedCommGroup α] {a : α} :
          a 11 a⁻¹
          theorem neg_nonneg_of_nonpos {α : Type u} [OrderedAddCommGroup α] {a : α} :
          a 00 -a