Documentation

Mathlib.Algebra.Group.TypeTags

Type tags that turn additive structures into multiplicative, and vice versa #

We define two type tags:

We also define instances Additive.* and Multiplicative.* that actually transfer the structures.

See also #

This file is similar to Order.Synonym.

Porting notes #

def Additive (α : Type u_1) :
Type u_1

If α carries some multiplicative structure, then Additive α carries the corresponding additive structure.

Equations
Instances For
    def Multiplicative (α : Type u_1) :
    Type u_1

    If α carries some additive structure, then Multiplicative α carries the corresponding multiplicative structure.

    Equations
    Instances For
      def Additive.ofMul {α : Type u} :

      Reinterpret x : α as an element of Additive α.

      Equations
      • One or more equations did not get rendered due to their size.
      Instances For
        def Additive.toMul {α : Type u} :

        Reinterpret x : Additive α as an element of α.

        Equations
        • Additive.toMul = Additive.ofMul.symm
        Instances For
          @[simp]
          theorem Additive.ofMul_symm_eq {α : Type u} :
          Additive.ofMul.symm = Additive.toMul
          @[simp]
          theorem Additive.toMul_symm_eq {α : Type u} :
          Additive.toMul.symm = Additive.ofMul

          Reinterpret x : α as an element of Multiplicative α.

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

            Reinterpret x : Multiplicative α as an element of α.

            Equations
            • Multiplicative.toAdd = Multiplicative.ofAdd.symm
            Instances For
              @[simp]
              theorem Multiplicative.ofAdd_symm_eq {α : Type u} :
              Multiplicative.ofAdd.symm = Multiplicative.toAdd
              @[simp]
              theorem Multiplicative.toAdd_symm_eq {α : Type u} :
              Multiplicative.toAdd.symm = Multiplicative.ofAdd
              @[simp]
              theorem toAdd_ofAdd {α : Type u} (x : α) :
              Multiplicative.toAdd (Multiplicative.ofAdd x) = x
              @[simp]
              theorem ofAdd_toAdd {α : Type u} (x : Multiplicative α) :
              Multiplicative.ofAdd (Multiplicative.toAdd x) = x
              @[simp]
              theorem toMul_ofMul {α : Type u} (x : α) :
              Additive.toMul (Additive.ofMul x) = x
              @[simp]
              theorem ofMul_toMul {α : Type u} (x : Additive α) :
              Additive.ofMul (Additive.toMul x) = x
              Equations
              • instInhabitedAdditive = { default := Additive.ofMul default }
              Equations
              • instInhabitedMultiplicative = { default := Multiplicative.ofAdd default }
              instance instInfiniteAdditive {α : Type u} [h : Infinite α] :
              Equations
              Equations
              instance Additive.add {α : Type u} [Mul α] :
              Equations
              • Additive.add = { add := fun x y => Additive.ofMul (Additive.toMul x * Additive.toMul y) }
              instance Multiplicative.mul {α : Type u} [Add α] :
              Equations
              • Multiplicative.mul = { mul := fun x y => Multiplicative.ofAdd (Multiplicative.toAdd x + Multiplicative.toAdd y) }
              @[simp]
              theorem ofAdd_add {α : Type u} [Add α] (x : α) (y : α) :
              Multiplicative.ofAdd (x + y) = Multiplicative.ofAdd x * Multiplicative.ofAdd y
              @[simp]
              theorem toAdd_mul {α : Type u} [Add α] (x : Multiplicative α) (y : Multiplicative α) :
              Multiplicative.toAdd (x * y) = Multiplicative.toAdd x + Multiplicative.toAdd y
              @[simp]
              theorem ofMul_mul {α : Type u} [Mul α] (x : α) (y : α) :
              Additive.ofMul (x * y) = Additive.ofMul x + Additive.ofMul y
              @[simp]
              theorem toMul_add {α : Type u} [Mul α] (x : Additive α) (y : Additive α) :
              Additive.toMul (x + y) = Additive.toMul x * Additive.toMul y
              Equations
              • Additive.addSemigroup = let src := Additive.add; AddSemigroup.mk (_ : ∀ (a b c : α), a * b * c = a * (b * c))
              Equations
              • Multiplicative.semigroup = let src := Multiplicative.mul; Semigroup.mk (_ : ∀ (a b c : α), a + b + c = a + (b + c))
              Equations
              • Additive.addCommSemigroup = let src := Additive.addSemigroup; AddCommSemigroup.mk (_ : ∀ (a b : α), a * b = b * a)
              Equations
              • Multiplicative.commSemigroup = let src := Multiplicative.semigroup; CommSemigroup.mk (_ : ∀ (a b : α), a + b = b + a)
              Equations
              • One or more equations did not get rendered due to their size.
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              • One or more equations did not get rendered due to their size.
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              • One or more equations did not get rendered due to their size.
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              • One or more equations did not get rendered due to their size.
              instance instZeroAdditive {α : Type u} [One α] :
              Equations
              • instZeroAdditive = { zero := Additive.ofMul 1 }
              @[simp]
              theorem ofMul_one {α : Type u} [One α] :
              Additive.ofMul 1 = 0
              @[simp]
              theorem ofMul_eq_zero {A : Type u_1} [One A] {x : A} :
              Additive.ofMul x = 0 x = 1
              @[simp]
              theorem toMul_zero {α : Type u} [One α] :
              Additive.toMul 0 = 1
              instance instOneMultiplicative {α : Type u} [Zero α] :
              Equations
              • instOneMultiplicative = { one := Multiplicative.ofAdd 0 }
              @[simp]
              theorem ofAdd_zero {α : Type u} [Zero α] :
              Multiplicative.ofAdd 0 = 1
              @[simp]
              theorem ofAdd_eq_one {A : Type u_1} [Zero A] {x : A} :
              Multiplicative.ofAdd x = 1 x = 0
              @[simp]
              theorem toAdd_one {α : Type u} [Zero α] :
              Multiplicative.toAdd 1 = 0
              Equations
              Equations
              • Multiplicative.mulOneClass = MulOneClass.mk (_ : ∀ (a : α), 0 + a = a) (_ : ∀ (a : α), a + 0 = a)
              instance Additive.addMonoid {α : Type u} [h : Monoid α] :
              Equations
              • Additive.addMonoid = let src := Additive.addZeroClass; let src_1 := Additive.addSemigroup; AddMonoid.mk (_ : ∀ (a : Additive α), 0 + a = a) (_ : ∀ (a : Additive α), a + 0 = a) Monoid.npow
              instance Multiplicative.monoid {α : Type u} [h : AddMonoid α] :
              Equations
              • One or more equations did not get rendered due to their size.
              Equations
              • One or more equations did not get rendered due to their size.
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              • One or more equations did not get rendered due to their size.
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              • One or more equations did not get rendered due to their size.
              Equations
              • One or more equations did not get rendered due to their size.
              Equations
              • Additive.addCommMonoid = let src := Additive.addMonoid; let src_1 := Additive.addCommSemigroup; AddCommMonoid.mk (_ : ∀ (a b : Additive α), a + b = b + a)
              Equations
              • Multiplicative.commMonoid = let src := Multiplicative.monoid; let src_1 := Multiplicative.commSemigroup; CommMonoid.mk (_ : ∀ (a b : Multiplicative α), a * b = b * a)
              instance Additive.neg {α : Type u} [Inv α] :
              Equations
              • Additive.neg = { neg := fun x => Multiplicative.ofAdd (Additive.toMul x)⁻¹ }
              @[simp]
              theorem ofMul_inv {α : Type u} [Inv α] (x : α) :
              Additive.ofMul x⁻¹ = -Additive.ofMul x
              @[simp]
              theorem toMul_neg {α : Type u} [Inv α] (x : Additive α) :
              Additive.toMul (-x) = (Additive.toMul x)⁻¹
              instance Multiplicative.inv {α : Type u} [Neg α] :
              Equations
              • Multiplicative.inv = { inv := fun x => Additive.ofMul (-Multiplicative.toAdd x) }
              @[simp]
              theorem ofAdd_neg {α : Type u} [Neg α] (x : α) :
              Multiplicative.ofAdd (-x) = (Multiplicative.ofAdd x)⁻¹
              @[simp]
              theorem toAdd_inv {α : Type u} [Neg α] (x : Multiplicative α) :
              Multiplicative.toAdd x⁻¹ = -Multiplicative.toAdd x
              instance Additive.sub {α : Type u} [Div α] :
              Equations
              • Additive.sub = { sub := fun x y => Additive.ofMul (Additive.toMul x / Additive.toMul y) }
              instance Multiplicative.div {α : Type u} [Sub α] :
              Equations
              • Multiplicative.div = { div := fun x y => Multiplicative.ofAdd (Multiplicative.toAdd x - Multiplicative.toAdd y) }
              @[simp]
              theorem ofAdd_sub {α : Type u} [Sub α] (x : α) (y : α) :
              Multiplicative.ofAdd (x - y) = Multiplicative.ofAdd x / Multiplicative.ofAdd y
              @[simp]
              theorem toAdd_div {α : Type u} [Sub α] (x : Multiplicative α) (y : Multiplicative α) :
              Multiplicative.toAdd (x / y) = Multiplicative.toAdd x - Multiplicative.toAdd y
              @[simp]
              theorem ofMul_div {α : Type u} [Div α] (x : α) (y : α) :
              Additive.ofMul (x / y) = Additive.ofMul x - Additive.ofMul y
              @[simp]
              theorem toMul_sub {α : Type u} [Div α] (x : Additive α) (y : Additive α) :
              Additive.toMul (x - y) = Additive.toMul x / Additive.toMul y
              Equations
              Equations
              • Multiplicative.involutiveInv = let src := Multiplicative.inv; InvolutiveInv.mk (_ : ∀ (a : α), - -a = a)
              Equations
              • Additive.subNegMonoid = let src := Additive.neg; let src_1 := Additive.sub; let src_2 := Additive.addMonoid; SubNegMonoid.mk DivInvMonoid.zpow
              Equations
              • Multiplicative.divInvMonoid = let src := Multiplicative.inv; let src_1 := Multiplicative.div; let src_2 := Multiplicative.monoid; DivInvMonoid.mk SubNegMonoid.zsmul
              Equations
              • One or more equations did not get rendered due to their size.
              Equations
              • One or more equations did not get rendered due to their size.
              Equations
              • Additive.subtractionCommMonoid = let src := Additive.subtractionMonoid; let src_1 := Additive.addCommSemigroup; SubtractionCommMonoid.mk (_ : ∀ (a b : Additive α), a + b = b + a)
              Equations
              instance Additive.addGroup {α : Type u} [Group α] :
              Equations
              • Additive.addGroup = let src := Additive.subNegMonoid; AddGroup.mk (_ : ∀ (a : α), a⁻¹ * a = 1)
              Equations
              • Multiplicative.group = let src := Multiplicative.divInvMonoid; Group.mk (_ : ∀ (a : α), -a + a = 0)
              Equations
              • Additive.addCommGroup = let src := Additive.addGroup; let src_1 := Additive.addCommMonoid; AddCommGroup.mk (_ : ∀ (a b : Additive α), a + b = b + a)
              Equations
              • Multiplicative.commGroup = let src := Multiplicative.group; let src_1 := Multiplicative.commMonoid; CommGroup.mk (_ : ∀ (a b : Multiplicative α), a * b = b * a)
              @[simp]
              theorem AddMonoidHom.toMultiplicative_symm_apply_apply {α : Type u} {β : Type v} [AddZeroClass α] [AddZeroClass β] (f : Multiplicative α →* Multiplicative β) (a : α) :
              ↑(AddMonoidHom.toMultiplicative.symm f) a = Multiplicative.toAdd (f (Multiplicative.ofAdd a))
              @[simp]
              theorem AddMonoidHom.toMultiplicative_apply_apply {α : Type u} {β : Type v} [AddZeroClass α] [AddZeroClass β] (f : α →+ β) (a : Multiplicative α) :
              ↑(AddMonoidHom.toMultiplicative f) a = Multiplicative.ofAdd (f (Multiplicative.toAdd a))

              Reinterpret α →+ β as Multiplicative α →* Multiplicative β.

              Equations
              • One or more equations did not get rendered due to their size.
              Instances For
                @[simp]
                theorem MonoidHom.toAdditive_apply_apply {α : Type u} {β : Type v} [MulOneClass α] [MulOneClass β] (f : α →* β) (a : Additive α) :
                ↑(MonoidHom.toAdditive f) a = Additive.ofMul (f (Additive.toMul a))
                @[simp]
                theorem MonoidHom.toAdditive_symm_apply_apply {α : Type u} {β : Type v} [MulOneClass α] [MulOneClass β] (f : Additive α →+ Additive β) (a : α) :
                ↑(MonoidHom.toAdditive.symm f) a = Additive.toMul (f (Additive.ofMul a))
                def MonoidHom.toAdditive {α : Type u} {β : Type v} [MulOneClass α] [MulOneClass β] :
                (α →* β) (Additive α →+ Additive β)

                Reinterpret α →* β as Additive α →+ Additive β.

                Equations
                • One or more equations did not get rendered due to their size.
                Instances For
                  @[simp]
                  theorem AddMonoidHom.toMultiplicative'_apply_apply {α : Type u} {β : Type v} [MulOneClass α] [AddZeroClass β] (f : Additive α →+ β) (a : α) :
                  ↑(AddMonoidHom.toMultiplicative' f) a = Multiplicative.ofAdd (f (Additive.ofMul a))
                  @[simp]
                  theorem AddMonoidHom.toMultiplicative'_symm_apply_apply {α : Type u} {β : Type v} [MulOneClass α] [AddZeroClass β] (f : α →* Multiplicative β) (a : Additive α) :
                  ↑(AddMonoidHom.toMultiplicative'.symm f) a = Multiplicative.toAdd (f (Additive.toMul a))

                  Reinterpret Additive α →+ β as α →* Multiplicative β.

                  Equations
                  • One or more equations did not get rendered due to their size.
                  Instances For
                    @[simp]
                    theorem MonoidHom.toAdditive'_symm_apply_apply {α : Type u} {β : Type v} [MulOneClass α] [AddZeroClass β] :
                    ∀ (a : Additive α →+ β) (a_1 : α), ↑(MonoidHom.toAdditive'.symm a) a_1 = Multiplicative.ofAdd (a (Additive.ofMul a_1))
                    @[simp]
                    theorem MonoidHom.toAdditive'_apply_apply {α : Type u} {β : Type v} [MulOneClass α] [AddZeroClass β] :
                    ∀ (a : α →* Multiplicative β) (a_1 : Additive α), ↑(MonoidHom.toAdditive' a) a_1 = Multiplicative.toAdd (a (Additive.toMul a_1))
                    def MonoidHom.toAdditive' {α : Type u} {β : Type v} [MulOneClass α] [AddZeroClass β] :

                    Reinterpret α →* Multiplicative β as Additive α →+ β.

                    Equations
                    • MonoidHom.toAdditive' = AddMonoidHom.toMultiplicative'.symm
                    Instances For
                      @[simp]
                      theorem AddMonoidHom.toMultiplicative''_apply_apply {α : Type u} {β : Type v} [AddZeroClass α] [MulOneClass β] (f : α →+ Additive β) (a : Multiplicative α) :
                      ↑(AddMonoidHom.toMultiplicative'' f) a = Additive.toMul (f (Multiplicative.toAdd a))
                      @[simp]
                      theorem AddMonoidHom.toMultiplicative''_symm_apply_apply {α : Type u} {β : Type v} [AddZeroClass α] [MulOneClass β] (f : Multiplicative α →* β) (a : α) :
                      ↑(AddMonoidHom.toMultiplicative''.symm f) a = Additive.ofMul (f (Multiplicative.ofAdd a))

                      Reinterpret α →+ Additive β as Multiplicative α →* β.

                      Equations
                      • One or more equations did not get rendered due to their size.
                      Instances For
                        @[simp]
                        theorem MonoidHom.toAdditive''_apply_apply {α : Type u} {β : Type v} [AddZeroClass α] [MulOneClass β] :
                        ∀ (a : Multiplicative α →* β) (a_1 : α), ↑(MonoidHom.toAdditive'' a) a_1 = Additive.ofMul (a (Multiplicative.ofAdd a_1))
                        @[simp]
                        theorem MonoidHom.toAdditive''_symm_apply_apply {α : Type u} {β : Type v} [AddZeroClass α] [MulOneClass β] :
                        ∀ (a : α →+ Additive β) (a_1 : Multiplicative α), ↑(MonoidHom.toAdditive''.symm a) a_1 = Additive.toMul (a (Multiplicative.toAdd a_1))
                        def MonoidHom.toAdditive'' {α : Type u} {β : Type v} [AddZeroClass α] [MulOneClass β] :

                        Reinterpret Multiplicative α →* β as α →+ Additive β.

                        Equations
                        • MonoidHom.toAdditive'' = AddMonoidHom.toMultiplicative''.symm
                        Instances For
                          instance Additive.coeToFun {α : Type u_1} {β : αSort u_2} [CoeFun α β] :
                          CoeFun (Additive α) fun a => β (Additive.toMul a)

                          If α has some multiplicative structure and coerces to a function, then Additive α should also coerce to the same function.

                          This allows Additive to be used on bundled function types with a multiplicative structure, which is often used for composition, without affecting the behavior of the function itself.

                          Equations
                          • Additive.coeToFun = { coe := fun a => CoeFun.coe (Additive.toMul a) }
                          instance Multiplicative.coeToFun {α : Type u_1} {β : αSort u_2} [CoeFun α β] :
                          CoeFun (Multiplicative α) fun a => β (Multiplicative.toAdd a)

                          If α has some additive structure and coerces to a function, then Multiplicative α should also coerce to the same function.

                          This allows Multiplicative to be used on bundled function types with an additive structure, which is often used for composition, without affecting the behavior of the function itself.

                          Equations
                          • Multiplicative.coeToFun = { coe := fun a => CoeFun.coe (Multiplicative.toAdd a) }