Documentation

Mathlib.Algebra.Group.Units.Equiv

Multiplicative and additive equivalence acting on units. #

def toAddUnits {G : Type u_5} [AddGroup G] :

An additive group is isomorphic to its group of additive units

Equations
  • toAddUnits = { toFun := fun (x : G) => { val := x, neg := -x, val_neg := , neg_val := }, invFun := fun (x : AddUnits G) => x, left_inv := , right_inv := , map_add' := }
Instances For
    @[simp]
    theorem val_toAddUnits_apply {G : Type u_5} [AddGroup G] (x : G) :
    (toAddUnits x) = x
    @[simp]
    theorem val_toUnits_apply {G : Type u_5} [Group G] (x : G) :
    (toUnits x) = x
    @[simp]
    theorem toAddUnits_symm_apply {G : Type u_5} [AddGroup G] (x : AddUnits G) :
    toAddUnits.symm x = x
    @[simp]
    theorem toUnits_symm_apply {G : Type u_5} [Group G] (x : Gˣ) :
    toUnits.symm x = x
    def toUnits {G : Type u_5} [Group G] :
    G ≃* Gˣ

    A group is isomorphic to its group of units.

    Equations
    • toUnits = { toFun := fun (x : G) => { val := x, inv := x⁻¹, val_inv := , inv_val := }, invFun := fun (x : Gˣ) => x, left_inv := , right_inv := , map_mul' := }
    Instances For
      @[simp]
      theorem toAddUnits_val_apply {G : Type u_6} [AddGroup G] (x : AddUnits G) :
      toAddUnits x = x
      @[simp]
      theorem toUnits_val_apply {G : Type u_6} [Group G] (x : Gˣ) :
      toUnits x = x
      def Units.mapEquiv {M : Type u_3} {N : Type u_4} [Monoid M] [Monoid N] (h : M ≃* N) :

      A multiplicative equivalence of monoids defines a multiplicative equivalence of their groups of units.

      Equations
      • Units.mapEquiv h = { toFun := (↑(Units.map h.toMonoidHom)).toFun, invFun := (Units.map h.symm.toMonoidHom), left_inv := , right_inv := , map_mul' := }
      Instances For
        @[simp]
        theorem Units.mapEquiv_symm {M : Type u_3} {N : Type u_4} [Monoid M] [Monoid N] (h : M ≃* N) :
        @[simp]
        theorem Units.coe_mapEquiv {M : Type u_3} {N : Type u_4} [Monoid M] [Monoid N] (h : M ≃* N) (x : Mˣ) :
        ((Units.mapEquiv h) x) = h x
        def AddUnits.addLeft {M : Type u_3} [AddMonoid M] (u : AddUnits M) :

        Left addition of an additive unit is a permutation of the underlying type.

        Equations
        • u.addLeft = { toFun := fun (x : M) => u + x, invFun := fun (x : M) => (-u) + x, left_inv := , right_inv := }
        Instances For
          @[simp]
          theorem Units.mulLeft_apply {M : Type u_3} [Monoid M] (u : Mˣ) :
          u.mulLeft = fun (x : M) => u * x
          @[simp]
          theorem AddUnits.addLeft_apply {M : Type u_3} [AddMonoid M] (u : AddUnits M) :
          u.addLeft = fun (x : M) => u + x
          def Units.mulLeft {M : Type u_3} [Monoid M] (u : Mˣ) :

          Left multiplication by a unit of a monoid is a permutation of the underlying type.

          Equations
          • u.mulLeft = { toFun := fun (x : M) => u * x, invFun := fun (x : M) => u⁻¹ * x, left_inv := , right_inv := }
          Instances For
            @[simp]
            theorem AddUnits.addLeft_symm {M : Type u_3} [AddMonoid M] (u : AddUnits M) :
            Equiv.symm u.addLeft = (-u).addLeft
            @[simp]
            theorem Units.mulLeft_symm {M : Type u_3} [Monoid M] (u : Mˣ) :
            Equiv.symm u.mulLeft = u⁻¹.mulLeft
            theorem AddUnits.addLeft_bijective {M : Type u_3} [AddMonoid M] (a : AddUnits M) :
            Function.Bijective fun (x : M) => a + x
            theorem Units.mulLeft_bijective {M : Type u_3} [Monoid M] (a : Mˣ) :
            Function.Bijective fun (x : M) => a * x
            def AddUnits.addRight {M : Type u_3} [AddMonoid M] (u : AddUnits M) :

            Right addition of an additive unit is a permutation of the underlying type.

            Equations
            • u.addRight = { toFun := fun (x : M) => x + u, invFun := fun (x : M) => x + (-u), left_inv := , right_inv := }
            Instances For
              @[simp]
              theorem AddUnits.addRight_apply {M : Type u_3} [AddMonoid M] (u : AddUnits M) :
              u.addRight = fun (x : M) => x + u
              @[simp]
              theorem Units.mulRight_apply {M : Type u_3} [Monoid M] (u : Mˣ) :
              u.mulRight = fun (x : M) => x * u
              def Units.mulRight {M : Type u_3} [Monoid M] (u : Mˣ) :

              Right multiplication by a unit of a monoid is a permutation of the underlying type.

              Equations
              • u.mulRight = { toFun := fun (x : M) => x * u, invFun := fun (x : M) => x * u⁻¹, left_inv := , right_inv := }
              Instances For
                @[simp]
                theorem AddUnits.addRight_symm {M : Type u_3} [AddMonoid M] (u : AddUnits M) :
                Equiv.symm u.addRight = (-u).addRight
                @[simp]
                theorem Units.mulRight_symm {M : Type u_3} [Monoid M] (u : Mˣ) :
                Equiv.symm u.mulRight = u⁻¹.mulRight
                theorem AddUnits.addRight_bijective {M : Type u_3} [AddMonoid M] (a : AddUnits M) :
                Function.Bijective fun (x : M) => x + a
                theorem Units.mulRight_bijective {M : Type u_3} [Monoid M] (a : Mˣ) :
                Function.Bijective fun (x : M) => x * a
                def Equiv.addLeft {G : Type u_5} [AddGroup G] (a : G) :

                Left addition in an AddGroup is a permutation of the underlying type.

                Equations
                Instances For
                  def Equiv.mulLeft {G : Type u_5} [Group G] (a : G) :

                  Left multiplication in a Group is a permutation of the underlying type.

                  Equations
                  Instances For
                    @[simp]
                    theorem Equiv.coe_addLeft {G : Type u_5} [AddGroup G] (a : G) :
                    (Equiv.addLeft a) = fun (x : G) => a + x
                    @[simp]
                    theorem Equiv.coe_mulLeft {G : Type u_5} [Group G] (a : G) :
                    (Equiv.mulLeft a) = fun (x : G) => a * x
                    theorem Equiv.addLeft_symm_apply {G : Type u_5} [AddGroup G] (a : G) :
                    (Equiv.symm (Equiv.addLeft a)) = fun (x : G) => -a + x

                    Extra simp lemma that dsimp can use. simp will never use this.

                    @[simp]
                    theorem Equiv.mulLeft_symm_apply {G : Type u_5} [Group G] (a : G) :
                    (Equiv.symm (Equiv.mulLeft a)) = fun (x : G) => a⁻¹ * x

                    Extra simp lemma that dsimp can use. simp will never use this.

                    @[simp]
                    @[simp]
                    theorem AddGroup.addLeft_bijective {G : Type u_5} [AddGroup G] (a : G) :
                    Function.Bijective fun (x : G) => a + x
                    theorem Group.mulLeft_bijective {G : Type u_5} [Group G] (a : G) :
                    Function.Bijective fun (x : G) => a * x
                    def Equiv.addRight {G : Type u_5} [AddGroup G] (a : G) :

                    Right addition in an AddGroup is a permutation of the underlying type.

                    Equations
                    Instances For
                      def Equiv.mulRight {G : Type u_5} [Group G] (a : G) :

                      Right multiplication in a Group is a permutation of the underlying type.

                      Equations
                      Instances For
                        @[simp]
                        theorem Equiv.coe_addRight {G : Type u_5} [AddGroup G] (a : G) :
                        (Equiv.addRight a) = fun (x : G) => x + a
                        @[simp]
                        theorem Equiv.coe_mulRight {G : Type u_5} [Group G] (a : G) :
                        (Equiv.mulRight a) = fun (x : G) => x * a
                        @[simp]
                        theorem Equiv.addRight_symm_apply {G : Type u_5} [AddGroup G] (a : G) :
                        (Equiv.symm (Equiv.addRight a)) = fun (x : G) => x + -a

                        Extra simp lemma that dsimp can use. simp will never use this.

                        @[simp]
                        theorem Equiv.mulRight_symm_apply {G : Type u_5} [Group G] (a : G) :
                        (Equiv.symm (Equiv.mulRight a)) = fun (x : G) => x * a⁻¹

                        Extra simp lemma that dsimp can use. simp will never use this.

                        theorem AddGroup.addRight_bijective {G : Type u_5} [AddGroup G] (a : G) :
                        Function.Bijective fun (x : G) => x + a
                        theorem Group.mulRight_bijective {G : Type u_5} [Group G] (a : G) :
                        Function.Bijective fun (x : G) => x * a
                        def Equiv.subLeft {G : Type u_5} [AddGroup G] (a : G) :
                        G G

                        A version of Equiv.addLeft a (-b) that is defeq to a - b.

                        Equations
                        • Equiv.subLeft a = { toFun := fun (b : G) => a - b, invFun := fun (b : G) => -b + a, left_inv := , right_inv := }
                        Instances For
                          @[simp]
                          theorem Equiv.divLeft_symm_apply {G : Type u_5} [Group G] (a : G) (b : G) :
                          (Equiv.divLeft a).symm b = b⁻¹ * a
                          @[simp]
                          theorem Equiv.subLeft_symm_apply {G : Type u_5} [AddGroup G] (a : G) (b : G) :
                          (Equiv.subLeft a).symm b = -b + a
                          @[simp]
                          theorem Equiv.subLeft_apply {G : Type u_5} [AddGroup G] (a : G) (b : G) :
                          (Equiv.subLeft a) b = a - b
                          @[simp]
                          theorem Equiv.divLeft_apply {G : Type u_5} [Group G] (a : G) (b : G) :
                          (Equiv.divLeft a) b = a / b
                          def Equiv.divLeft {G : Type u_5} [Group G] (a : G) :
                          G G

                          A version of Equiv.mulLeft a b⁻¹ that is defeq to a / b.

                          Equations
                          • Equiv.divLeft a = { toFun := fun (b : G) => a / b, invFun := fun (b : G) => b⁻¹ * a, left_inv := , right_inv := }
                          Instances For
                            def Equiv.subRight {G : Type u_5} [AddGroup G] (a : G) :
                            G G

                            A version of Equiv.addRight (-a) b that is defeq to b - a.

                            Equations
                            • Equiv.subRight a = { toFun := fun (b : G) => b - a, invFun := fun (b : G) => b + a, left_inv := , right_inv := }
                            Instances For
                              @[simp]
                              theorem Equiv.divRight_symm_apply {G : Type u_5} [Group G] (a : G) (b : G) :
                              (Equiv.divRight a).symm b = b * a
                              @[simp]
                              theorem Equiv.subRight_apply {G : Type u_5} [AddGroup G] (a : G) (b : G) :
                              (Equiv.subRight a) b = b - a
                              @[simp]
                              theorem Equiv.subRight_symm_apply {G : Type u_5} [AddGroup G] (a : G) (b : G) :
                              (Equiv.subRight a).symm b = b + a
                              @[simp]
                              theorem Equiv.divRight_apply {G : Type u_5} [Group G] (a : G) (b : G) :
                              (Equiv.divRight a) b = b / a
                              def Equiv.divRight {G : Type u_5} [Group G] (a : G) :
                              G G

                              A version of Equiv.mulRight a⁻¹ b that is defeq to b / a.

                              Equations
                              • Equiv.divRight a = { toFun := fun (b : G) => b / a, invFun := fun (b : G) => b * a, left_inv := , right_inv := }
                              Instances For
                                @[simp]
                                theorem unitsEquivProdSubtype_apply_coe (α : Type u_2) [Monoid α] (u : αˣ) :
                                ((unitsEquivProdSubtype α) u) = (u, u⁻¹)
                                @[simp]
                                theorem val_inv_unitsEquivProdSubtype_symm_apply (α : Type u_2) [Monoid α] (p : { p : α × α // p.1 * p.2 = 1 p.2 * p.1 = 1 }) :
                                ((unitsEquivProdSubtype α).symm p)⁻¹ = (↑p).2
                                @[simp]
                                theorem val_unitsEquivProdSubtype_symm_apply (α : Type u_2) [Monoid α] (p : { p : α × α // p.1 * p.2 = 1 p.2 * p.1 = 1 }) :
                                ((unitsEquivProdSubtype α).symm p) = (↑p).1
                                def unitsEquivProdSubtype (α : Type u_2) [Monoid α] :
                                αˣ { p : α × α // p.1 * p.2 = 1 p.2 * p.1 = 1 }

                                The αˣ type is equivalent to a subtype of α × α.

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

                                  When the AddGroup is commutative, Equiv.neg is an AddEquiv.

                                  Equations
                                  • AddEquiv.neg G = { toFun := Neg.neg, invFun := Neg.neg, left_inv := , right_inv := , map_add' := }
                                  Instances For
                                    @[simp]
                                    theorem MulEquiv.inv_apply (G : Type u_6) [DivisionCommMonoid G] :
                                    ∀ (a : G), (MulEquiv.inv G) a = a⁻¹
                                    @[simp]
                                    theorem AddEquiv.neg_apply (G : Type u_6) [SubtractionCommMonoid G] :
                                    ∀ (a : G), (AddEquiv.neg G) a = -a
                                    def MulEquiv.inv (G : Type u_6) [DivisionCommMonoid G] :
                                    G ≃* G

                                    In a DivisionCommMonoid, Equiv.inv is a MulEquiv. There is a variant of this MulEquiv.inv' G : G ≃* Gᵐᵒᵖ for the non-commutative case.

                                    Equations
                                    • MulEquiv.inv G = { toFun := Inv.inv, invFun := Inv.inv, left_inv := , right_inv := , map_mul' := }
                                    Instances For
                                      @[simp]
                                      theorem isLocalHom_equiv {F : Type u_1} {M : Type u_3} {N : Type u_4} [Monoid M] [Monoid N] [EquivLike F M N] [MulEquivClass F M N] (f : F) :
                                      @[deprecated isLocalHom_equiv]
                                      theorem isLocalRingHom_equiv {F : Type u_1} {M : Type u_3} {N : Type u_4} [Monoid M] [Monoid N] [EquivLike F M N] [MulEquivClass F M N] (f : F) :

                                      Alias of isLocalHom_equiv.