Documentation

Foundation.FirstOrder.SetTheory.Z

Zermelo set theory #

reference: Ralf Schindler, "Set Theory, Exploring Independence and Truth" [Sch14]

Axiom of extentionality #

theorem LO.FirstOrder.SetTheory.mem_ext_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
x = y ∀ (z : V), z x z y
theorem LO.FirstOrder.SetTheory.mem_ext {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
(∀ (z : V), z x z y)x = y

Alias of the reverse direction of LO.FirstOrder.SetTheory.mem_ext_iff.

theorem LO.FirstOrder.SetTheory.subset_antisymm {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} (hxy : x y) (hyx : y x) :
x = y
theorem LO.FirstOrder.SetTheory.SSubset.iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
x y x y zy, zx
theorem LO.FirstOrder.SetTheory.SSubset.exists_not_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} (hxy : x y) :
zy, zx
theorem LO.FirstOrder.SetTheory.SSubset.of_subset_of_not_mem_of_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} (ss : x y) (hzx : zx) (hzy : z y) :
x y

Axiom of empty set #

@[simp]
theorem LO.FirstOrder.SetTheory.not_mem_empty {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x : V} :
x
@[simp]

Axiom of pairing #

theorem LO.FirstOrder.SetTheory.pairing_exists {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
∃ (z : V), ∀ (w : V), w z w = x w = y
theorem LO.FirstOrder.SetTheory.pairing_existsUnique {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
∃! z : V, ∀ (w : V), w z w = x w = y
noncomputable def LO.FirstOrder.SetTheory.doubleton {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
V
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    theorem LO.FirstOrder.SetTheory.mem_doubleton_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} :
    z doubleton x y z = x z = y
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      theorem LO.FirstOrder.SetTheory.mem_singleton_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x z : V} :
      z {x} z = x
      @[simp]
      theorem LO.FirstOrder.SetTheory.singleton_ext_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
      {x} = {y} x = y

      Axiom of union #

      theorem LO.FirstOrder.SetTheory.union_exists {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
      ∃ (y : V), ∀ (z : V), z y wx, z w
      theorem LO.FirstOrder.SetTheory.union_existsUnique {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
      ∃! y : V, ∀ (z : V), z y wx, z w
      noncomputable def LO.FirstOrder.SetTheory.sUnion {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
      V
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          theorem LO.FirstOrder.SetTheory.mem_sUnion_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x z : V} :
          z ⋃ˢ x yx, z y
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            Union of two sets #

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              theorem LO.FirstOrder.SetTheory.mem_union_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} :
              z x y z x z y
              @[simp]
              theorem LO.FirstOrder.SetTheory.union_self_eq {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
              x x = x
              theorem LO.FirstOrder.SetTheory.union_comm {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
              x y = y x
              theorem LO.FirstOrder.SetTheory.union_assoc {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y z : V) :
              x y z = x (y z)
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              @[simp]
              theorem LO.FirstOrder.SetTheory.union_eq_iff_right {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
              x y = x y x
              @[simp]
              theorem LO.FirstOrder.SetTheory.union_eq_iff_left {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
              x y = y x y

              Insert #

              noncomputable def LO.FirstOrder.SetTheory.insert {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
              V
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                  theorem LO.FirstOrder.SetTheory.mem_insert {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} :
                  z insert x y z = x z y
                  theorem LO.FirstOrder.SetTheory.union_insert {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {z : V} (x y : V) :
                  x insert y z = insert y (x z)
                  @[simp]
                  @[simp]
                  theorem LO.FirstOrder.SetTheory.subset_insert {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
                  y insert x y
                  @[simp]
                  theorem LO.FirstOrder.SetTheory.intsert_union {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y z : V) :
                  insert x y z = insert x (y z)
                  @[simp]
                  @[simp]
                  theorem LO.FirstOrder.SetTheory.insert_eq_self_of_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} (hx : x y) :
                  insert x y = y

                  Axiom of power set #

                  theorem LO.FirstOrder.SetTheory.power_exists {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                  ∃ (y : V), ∀ (z : V), z y z x
                  theorem LO.FirstOrder.SetTheory.power_existsUnique {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                  ∃! y : V, ∀ (z : V), z y z x
                  noncomputable def LO.FirstOrder.SetTheory.power {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                  V
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                    theorem LO.FirstOrder.SetTheory.mem_power_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x z : V} :
                    z x z x
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                      @[simp]

                      Aussonderungsaxiom #

                      theorem LO.FirstOrder.SetTheory.separation_exists_eval {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) (φ : Semiformula ℒₛₑₜ V 1) :
                      ∃ (y : V), ∀ (z : V), z y z x (Semiformula.Evalm V ![z] id) φ
                      theorem LO.FirstOrder.SetTheory.separation_exists {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) (P : VProp) (hP : ℒₛₑₜ-predicate P) :
                      ∃ (y : V), ∀ (z : V), z y z x P z
                      theorem LO.FirstOrder.SetTheory.separation_existsUnique {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) (P : VProp) (hP : ℒₛₑₜ-predicate P) :
                      ∃! y : V, ∀ (z : V), z y z x P z
                      noncomputable def LO.FirstOrder.SetTheory.sep {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) (P : VProp) (hP : ℒₛₑₜ-predicate P) :
                      V
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                        @[simp]
                        theorem LO.FirstOrder.SetTheory.mem_sep_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {P : VProp} {hP : ℒₛₑₜ-predicate P} {z x : V} :
                        z sep x P hP z x P z
                        @[simp]
                        @[simp]
                        theorem LO.FirstOrder.SetTheory.sep_subset {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {P : VProp} {hP : ℒₛₑₜ-predicate P} {x : V} :
                        sep x P hP x

                        Set-builder notation.

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                              Intersection #

                              noncomputable def LO.FirstOrder.SetTheory.sInter {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                              V
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                                  theorem LO.FirstOrder.SetTheory.mem_sInter_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {z x : V} :
                                  z ⋂ˢ x IsNonempty x yx, z y
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                                    theorem LO.FirstOrder.SetTheory.mem_sInter_iff_of_nonempty {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {z x : V} [hx : IsNonempty x] :
                                    z ⋂ˢ x yx, z y
                                    @[simp]
                                    theorem LO.FirstOrder.SetTheory.subset_sInter_iff_of_nonempty {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} [IsNonempty y] :
                                    x ⋂ˢ y zy, x z

                                    Intersection of two sets #

                                    noncomputable def LO.FirstOrder.SetTheory.inter {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
                                    V
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                                      theorem LO.FirstOrder.SetTheory.mem_inter_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} :
                                      z x y z x z y
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                                        theorem LO.FirstOrder.SetTheory.inter_self {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                                        x x = x
                                        theorem LO.FirstOrder.SetTheory.inter_comm {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
                                        x y = y x
                                        theorem LO.FirstOrder.SetTheory.inter_assoc {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y z : V) :
                                        x y z = x (y z)
                                        @[simp]
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                                        theorem LO.FirstOrder.SetTheory.sInter_insert {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) [hy : IsNonempty y] :
                                        @[simp]
                                        theorem LO.FirstOrder.SetTheory.intsert_inter_of_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y z : V) (hx : x z) :
                                        insert x y z = insert x (y z)
                                        @[simp]
                                        theorem LO.FirstOrder.SetTheory.intsert_inter_of_not_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y z : V) (hx : xz) :
                                        insert x y z = y z
                                        @[simp]
                                        theorem LO.FirstOrder.SetTheory.singleton_inter_of_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} (hx : x y) :
                                        {x} y = {x}
                                        @[simp]
                                        theorem LO.FirstOrder.SetTheory.singleton_inter_of_not_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} (hx : xy) :
                                        {x} y =

                                        Set difference #

                                        noncomputable def LO.FirstOrder.SetTheory.sdiff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
                                        V
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                                          theorem LO.FirstOrder.SetTheory.sdiff_def {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
                                          x \ y = sep x (fun (z : V) => zy)
                                          @[simp]
                                          theorem LO.FirstOrder.SetTheory.mem_sdiff_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} :
                                          z x \ y z x zy
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                                            theorem LO.FirstOrder.SetTheory.sdiff_empty {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                                            x \ = x
                                            @[simp]
                                            @[simp]
                                            theorem LO.FirstOrder.SetTheory.singleton_sdiff_of_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x z : V} (hx : x z) :
                                            {x} \ z =
                                            @[simp]
                                            theorem LO.FirstOrder.SetTheory.singleton_sdiff_of_not_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x z : V} (hx : xz) :
                                            {x} \ z = {x}
                                            @[simp]
                                            theorem LO.FirstOrder.SetTheory.insert_sdiff_of_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} (hx : x z) :
                                            insert x y \ z = y \ z
                                            @[simp]
                                            theorem LO.FirstOrder.SetTheory.insert_sdiff_of_not_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} (hx : xz) :
                                            insert x y \ z = insert x (y \ z)

                                            Kuratowski's ordered pair #

                                            noncomputable def LO.FirstOrder.SetTheory.kpair {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y : V) :
                                            V
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                                              ⟨x, y, z, ...⟩ₖ notation for kpair

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                                                  noncomputable def LO.FirstOrder.SetTheory.kpair.π₁ {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (z : V) :
                                                  V
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                                                    noncomputable def LO.FirstOrder.SetTheory.kpair.π₂ {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (z : V) :
                                                    V
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                                                            theorem LO.FirstOrder.SetTheory.kpair_inj {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x₁ x₂ y₁ y₂ : V} :
                                                            x₁, y₁⟩ₖ = x₂, y₂⟩ₖx₁ = x₂ y₁ = y₂
                                                            @[simp]
                                                            theorem LO.FirstOrder.SetTheory.kpair_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x₁ x₂ y₁ y₂ : V} :
                                                            x₁, y₁⟩ₖ = x₂, y₂⟩ₖ x₁ = x₂ y₁ = y₂

                                                            Product #

                                                            noncomputable def LO.FirstOrder.SetTheory.prod {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (X Y : V) :
                                                            V
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                                                                theorem LO.FirstOrder.SetTheory.mem_prod_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {X Y z : V} :
                                                                z X ×ˢ Y xX, yY, z = x, y⟩ₖ
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                                                                  theorem LO.FirstOrder.SetTheory.kpair_mem_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y X Y : V} :
                                                                  x, y⟩ₖ X ×ˢ Y x X y Y
                                                                  theorem LO.FirstOrder.SetTheory.prod_subset_prod_of_subset {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {X₁ X₂ Y₁ Y₂ : V} (hX : X₁ X₂) (hY : Y₁ Y₂) :
                                                                  X₁ ×ˢ Y₁ X₂ ×ˢ Y₂
                                                                  theorem LO.FirstOrder.SetTheory.union_prod {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x y z : V) :
                                                                  x y ×ˢ z = (x ×ˢ z) (y ×ˢ z)

                                                                  Axiom of infinity #

                                                                  noncomputable def LO.FirstOrder.SetTheory.succ {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                                                                  V
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                                                                    theorem LO.FirstOrder.SetTheory.mem_succ_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
                                                                    y succ x y = x y x
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                                                                      theorem LO.FirstOrder.SetTheory.IsInductive.succ {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {I : V} (hI : IsInductive I) {x : V} (hx : x I) :
                                                                      theorem LO.FirstOrder.SetTheory.omega_existsUnique {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] :
                                                                      ∃! ω : V, ∀ (x : V), x ω ∀ (I : V), IsInductive Ix I
                                                                      noncomputable def LO.FirstOrder.SetTheory.ω {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] :
                                                                      V
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                                                                          theorem LO.FirstOrder.SetTheory.num_succ_def {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (n : ) :
                                                                          ↑(n + 1) = succ n
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                                                                          theorem LO.FirstOrder.SetTheory.mem_two_iff {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                                                                          x 2 x = 0 x = 1
                                                                          @[simp]
                                                                          theorem LO.FirstOrder.SetTheory.naturalNumber_induction {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (P : VProp) (hP : ℒₛₑₜ-predicate P) (zero : P 0) (succ : xω, P xP (succ x)) (x : V) :
                                                                          x ωP x

                                                                          Axiom of foundation #

                                                                          theorem LO.FirstOrder.SetTheory.foundation {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) [IsNonempty x] :
                                                                          yx, zx, zy
                                                                          theorem LO.FirstOrder.SetTheory.foundation' {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) [IsNonempty x] :
                                                                          yx, x y =
                                                                          @[simp]
                                                                          theorem LO.FirstOrder.SetTheory.mem_irrefl {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                                                                          xx
                                                                          theorem LO.FirstOrder.SetTheory.ne_of_mem {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
                                                                          x yx y
                                                                          theorem LO.FirstOrder.SetTheory.mem_asymm {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y : V} :
                                                                          x yyx
                                                                          theorem LO.FirstOrder.SetTheory.mem_asymm₃ {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] {x y z : V} :
                                                                          x yy zzx
                                                                          @[simp]
                                                                          theorem LO.FirstOrder.SetTheory.ne_succ {V : Type u_1} [SetStructure V] [Nonempty V] [V ⊧ₘ* 𝗭] (x : V) :
                                                                          x succ x