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Mathlib.Algebra.Order.Monoid.Canonical.Defs

Canonically ordered monoids #

A canonically ordered additive monoid is an ordered commutative additive monoid in which the ordering coincides with the subtractibility relation, which is to say, a ≤ b iff there exists c with b = a + c. This is satisfied by the natural numbers, for example, but not the integers or other nontrivial OrderedAddCommGroups.

Instances
    class CanonicallyOrderedCommMonoid (α : Type u_1) extends OrderedCommMonoid α, OrderBot α :
    Type u_1

    A canonically ordered monoid is an ordered commutative monoid in which the ordering coincides with the divisibility relation, which is to say, a ≤ b iff there exists c with b = a * c. Examples seem rare; it seems more likely that the OrderDual of a naturally-occurring lattice satisfies this than the lattice itself (for example, dual of the lattice of ideals of a PID or Dedekind domain satisfy this; collections of all things ≤ 1 seem to be more natural that collections of all things ≥ 1).

    Instances
      @[instance 100]
      Equations
      • =
      @[instance 100]
      Equations
      • =
      theorem le_self_mul {α : Type u} [CanonicallyOrderedCommMonoid α] {a c : α} :
      a a * c
      theorem le_self_add {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a c : α} :
      a a + c
      theorem le_mul_self {α : Type u} [CanonicallyOrderedCommMonoid α] {a b : α} :
      a b * a
      theorem le_add_self {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b : α} :
      a b + a
      @[simp]
      theorem self_le_mul_right {α : Type u} [CanonicallyOrderedCommMonoid α] (a b : α) :
      a a * b
      @[simp]
      theorem self_le_add_right {α : Type u} [CanonicallyOrderedAddCommMonoid α] (a b : α) :
      a a + b
      @[simp]
      theorem self_le_mul_left {α : Type u} [CanonicallyOrderedCommMonoid α] (a b : α) :
      a b * a
      @[simp]
      theorem self_le_add_left {α : Type u} [CanonicallyOrderedAddCommMonoid α] (a b : α) :
      a b + a
      theorem le_of_mul_le_left {α : Type u} [CanonicallyOrderedCommMonoid α] {a b c : α} :
      a * b ca c
      theorem le_of_add_le_left {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b c : α} :
      a + b ca c
      theorem le_of_mul_le_right {α : Type u} [CanonicallyOrderedCommMonoid α] {a b c : α} :
      a * b cb c
      theorem le_of_add_le_right {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b c : α} :
      a + b cb c
      theorem le_mul_of_le_left {α : Type u} [CanonicallyOrderedCommMonoid α] {a b c : α} :
      a ba b * c
      theorem le_add_of_le_left {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b c : α} :
      a ba b + c
      theorem le_mul_of_le_right {α : Type u} [CanonicallyOrderedCommMonoid α] {a b c : α} :
      a ca b * c
      theorem le_add_of_le_right {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b c : α} :
      a ca b + c
      theorem le_iff_exists_mul {α : Type u} [CanonicallyOrderedCommMonoid α] {a b : α} :
      a b ∃ (c : α), b = a * c
      theorem le_iff_exists_add {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b : α} :
      a b ∃ (c : α), b = a + c
      theorem le_iff_exists_mul' {α : Type u} [CanonicallyOrderedCommMonoid α] {a b : α} :
      a b ∃ (c : α), b = c * a
      theorem le_iff_exists_add' {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b : α} :
      a b ∃ (c : α), b = c + a
      @[simp]
      theorem one_le {α : Type u} [CanonicallyOrderedCommMonoid α] (a : α) :
      1 a
      @[simp]
      theorem zero_le {α : Type u} [CanonicallyOrderedAddCommMonoid α] (a : α) :
      0 a
      Equations
      • CanonicallyOrderedCommMonoid.toUniqueUnits = { toInhabited := Units.instInhabited, uniq := }
      Equations
      • CanonicallyOrderedAddCommMonoid.toUniqueAddUnits = { toInhabited := AddUnits.instInhabited, uniq := }
      @[deprecated mul_eq_one]
      theorem mul_eq_one_iff {α : Type u} [CommMonoid α] [Subsingleton αˣ] {a b : α} :
      a * b = 1 a = 1 b = 1

      Alias of mul_eq_one.

      @[deprecated add_eq_zero]
      theorem add_eq_zero_iff {α : Type u} [AddCommMonoid α] [Subsingleton (AddUnits α)] {a b : α} :
      a + b = 0 a = 0 b = 0

      Alias of add_eq_zero.

      @[simp]
      theorem le_one_iff_eq_one {α : Type u} [CanonicallyOrderedCommMonoid α] {a : α} :
      a 1 a = 1
      @[simp]
      theorem nonpos_iff_eq_zero {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a : α} :
      a 0 a = 0
      theorem one_lt_iff_ne_one {α : Type u} [CanonicallyOrderedCommMonoid α] {a : α} :
      1 < a a 1
      theorem pos_iff_ne_zero {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a : α} :
      0 < a a 0
      theorem eq_one_or_one_lt {α : Type u} [CanonicallyOrderedCommMonoid α] (a : α) :
      a = 1 1 < a
      theorem eq_zero_or_pos {α : Type u} [CanonicallyOrderedAddCommMonoid α] (a : α) :
      a = 0 0 < a
      theorem one_not_mem_iff {α : Type u} [CanonicallyOrderedCommMonoid α] {s : Set α} :
      ¬1 s ∀ (x : α), x s1 < x
      theorem zero_not_mem_iff {α : Type u} [CanonicallyOrderedAddCommMonoid α] {s : Set α} :
      ¬0 s ∀ (x : α), x s0 < x
      @[simp]
      theorem one_lt_mul_iff {α : Type u} [CanonicallyOrderedCommMonoid α] {a b : α} :
      1 < a * b 1 < a 1 < b
      @[simp]
      theorem add_pos_iff {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b : α} :
      0 < a + b 0 < a 0 < b
      theorem exists_one_lt_mul_of_lt {α : Type u} [CanonicallyOrderedCommMonoid α] {a b : α} (h : a < b) :
      ∃ (c : α), ∃ (x : 1 < c), a * c = b
      theorem exists_pos_add_of_lt {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b : α} (h : a < b) :
      ∃ (c : α), ∃ (x : 0 < c), a + c = b
      theorem le_mul_left {α : Type u} [CanonicallyOrderedCommMonoid α] {a b c : α} (h : a c) :
      a b * c
      theorem le_add_left {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b c : α} (h : a c) :
      a b + c
      theorem le_mul_right {α : Type u} [CanonicallyOrderedCommMonoid α] {a b c : α} (h : a b) :
      a b * c
      theorem le_add_right {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b c : α} (h : a b) :
      a b + c
      theorem lt_iff_exists_mul {α : Type u} [CanonicallyOrderedCommMonoid α] {a b : α} [MulLeftStrictMono α] :
      a < b ∃ (c : α), c > 1 b = a * c
      theorem lt_iff_exists_add {α : Type u} [CanonicallyOrderedAddCommMonoid α] {a b : α} [AddLeftStrictMono α] :
      a < b ∃ (c : α), c > 0 b = a + c
      theorem pos_of_gt {M : Type u_1} [CanonicallyOrderedAddCommMonoid M] {n m : M} (h : n < m) :
      0 < m
      theorem NeZero.pos {M : Type u_1} (a : M) [CanonicallyOrderedAddCommMonoid M] [NeZero a] :
      0 < a
      theorem NeZero.of_gt {M : Type u_1} [CanonicallyOrderedAddCommMonoid M] {x y : M} (h : x < y) :
      @[instance 10]
      instance NeZero.of_gt' {M : Type u_1} [CanonicallyOrderedAddCommMonoid M] [One M] {y : M} [Fact (1 < y)] :
      Equations
      • =

      A canonically linear-ordered additive monoid is a canonically ordered additive monoid whose ordering is a linear order.

      Instances

        A canonically linear-ordered monoid is a canonically ordered monoid whose ordering is a linear order.

        Instances
          @[instance 100]
          Equations
          • CanonicallyLinearOrderedCommMonoid.semilatticeSup = SemilatticeSup.mk SemilatticeSup.sup
          @[instance 100]
          Equations
          • CanonicallyLinearOrderedAddCommMonoid.semilatticeSup = SemilatticeSup.mk SemilatticeSup.sup
          theorem min_mul_distrib {α : Type u} [CanonicallyLinearOrderedCommMonoid α] (a b c : α) :
          a b * c = a (a b) * (a c)
          theorem min_add_distrib {α : Type u} [CanonicallyLinearOrderedAddCommMonoid α] (a b c : α) :
          a (b + c) = a (a b + a c)
          theorem min_mul_distrib' {α : Type u} [CanonicallyLinearOrderedCommMonoid α] (a b c : α) :
          a * b c = (a c) * (b c) c
          theorem min_add_distrib' {α : Type u} [CanonicallyLinearOrderedAddCommMonoid α] (a b c : α) :
          (a + b) c = (a c + b c) c
          theorem one_min {α : Type u} [CanonicallyLinearOrderedCommMonoid α] (a : α) :
          1 a = 1
          theorem zero_min {α : Type u} [CanonicallyLinearOrderedAddCommMonoid α] (a : α) :
          0 a = 0
          theorem min_one {α : Type u} [CanonicallyLinearOrderedCommMonoid α] (a : α) :
          a 1 = 1
          theorem min_zero {α : Type u} [CanonicallyLinearOrderedAddCommMonoid α] (a : α) :
          a 0 = 0
          @[simp]

          In a linearly ordered monoid, we are happy for bot_eq_one to be a @[simp] lemma.

          @[simp]

          In a linearly ordered monoid, we are happy for bot_eq_zero to be a @[simp] lemma