fact
stringlengths
6
3.84k
type
stringclasses
11 values
library
stringclasses
32 values
imports
listlengths
1
14
filename
stringlengths
20
95
symbolic_name
stringlengths
1
90
docstring
stringlengths
7
20k
aleph0_lt_continuum : ℵ₀ < 𝔠 := cantor ℵ₀
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
aleph0_lt_continuum
null
aleph0_le_continuum : ℵ₀ ≤ 𝔠 := aleph0_lt_continuum.le @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
aleph0_le_continuum
null
beth_one : ℶ_ 1 = 𝔠 := by simpa using beth_succ 0
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
beth_one
null
nat_lt_continuum (n : ℕ) : ↑n < 𝔠 := (nat_lt_aleph0 n).trans aleph0_lt_continuum
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
nat_lt_continuum
null
mk_set_nat : #(Set ℕ) = 𝔠 := by simp
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
mk_set_nat
null
continuum_pos : 0 < 𝔠 := nat_lt_continuum 0
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_pos
null
continuum_ne_zero : 𝔠 ≠ 0 := continuum_pos.ne'
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_ne_zero
null
aleph_one_le_continuum : ℵ₁ ≤ 𝔠 := by rw [← succ_aleph0] exact Order.succ_le_of_lt aleph0_lt_continuum @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
aleph_one_le_continuum
null
continuum_toNat : toNat continuum = 0 := toNat_apply_of_aleph0_le aleph0_le_continuum @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_toNat
null
continuum_toENat : toENat continuum = ⊤ := (toENat_eq_top.2 aleph0_le_continuum) /-!
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_toENat
null
@[simp] aleph0_add_continuum : ℵ₀ + 𝔠 = 𝔠 := add_eq_right aleph0_le_continuum aleph0_le_continuum @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
aleph0_add_continuum
null
continuum_add_aleph0 : 𝔠 + ℵ₀ = 𝔠 := (add_comm _ _).trans aleph0_add_continuum @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_add_aleph0
null
continuum_add_self : 𝔠 + 𝔠 = 𝔠 := add_eq_self aleph0_le_continuum @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_add_self
null
nat_add_continuum (n : ℕ) : ↑n + 𝔠 = 𝔠 := nat_add_eq n aleph0_le_continuum @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
nat_add_continuum
null
continuum_add_nat (n : ℕ) : 𝔠 + n = 𝔠 := (add_comm _ _).trans (nat_add_continuum n) @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_add_nat
null
ofNat_add_continuum {n : ℕ} [Nat.AtLeastTwo n] : ofNat(n) + 𝔠 = 𝔠 := nat_add_continuum n @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
ofNat_add_continuum
null
continuum_add_ofNat {n : ℕ} [Nat.AtLeastTwo n] : 𝔠 + ofNat(n) = 𝔠 := continuum_add_nat n /-!
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_add_ofNat
null
@[simp] continuum_mul_self : 𝔠 * 𝔠 = 𝔠 := mul_eq_left aleph0_le_continuum le_rfl continuum_ne_zero @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_mul_self
null
continuum_mul_aleph0 : 𝔠 * ℵ₀ = 𝔠 := mul_eq_left aleph0_le_continuum aleph0_le_continuum aleph0_ne_zero @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_mul_aleph0
null
aleph0_mul_continuum : ℵ₀ * 𝔠 = 𝔠 := (mul_comm _ _).trans continuum_mul_aleph0 @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
aleph0_mul_continuum
null
nat_mul_continuum {n : ℕ} (hn : n ≠ 0) : ↑n * 𝔠 = 𝔠 := mul_eq_right aleph0_le_continuum (nat_lt_continuum n).le (Nat.cast_ne_zero.2 hn) @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
nat_mul_continuum
null
continuum_mul_nat {n : ℕ} (hn : n ≠ 0) : 𝔠 * n = 𝔠 := (mul_comm _ _).trans (nat_mul_continuum hn) @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_mul_nat
null
ofNat_mul_continuum {n : ℕ} [Nat.AtLeastTwo n] : ofNat(n) * 𝔠 = 𝔠 := nat_mul_continuum (OfNat.ofNat_ne_zero n) @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
ofNat_mul_continuum
null
continuum_mul_ofNat {n : ℕ} [Nat.AtLeastTwo n] : 𝔠 * ofNat(n) = 𝔠 := continuum_mul_nat (OfNat.ofNat_ne_zero n) /-!
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_mul_ofNat
null
@[simp] aleph0_power_aleph0 : ℵ₀ ^ ℵ₀ = 𝔠 := power_self_eq le_rfl @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
aleph0_power_aleph0
null
nat_power_aleph0 {n : ℕ} (hn : 2 ≤ n) : n ^ ℵ₀ = 𝔠 := nat_power_eq le_rfl hn @[simp]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
nat_power_aleph0
null
continuum_power_aleph0 : 𝔠 ^ ℵ₀ = 𝔠 := by rw [← two_power_aleph0, ← power_mul, mul_eq_left le_rfl le_rfl aleph0_ne_zero]
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
continuum_power_aleph0
null
power_aleph0_of_le_continuum {x : Cardinal} (h₁ : 2 ≤ x) (h₂ : x ≤ 𝔠) : x ^ ℵ₀ = 𝔠 := by apply le_antisymm · rw [← continuum_power_aleph0] exact power_le_power_right h₂ · rw [← two_power_aleph0] exact power_le_power_right h₁
theorem
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic" ]
Mathlib/SetTheory/Cardinal/Continuum.lean
power_aleph0_of_le_continuum
null
mk_subtype_le_of_countable_eventually_mem_aux {α ι : Type u} {a : Cardinal} [Countable ι] {f : ι → Set α} {l : Filter ι} [NeBot l] {t : Set α} (ht : ∀ x ∈ t, ∀ᶠ i in l, x ∈ f i) (h'f : ∀ i, #(f i) ≤ a) : #t ≤ a := by rcases lt_or_ge a ℵ₀ with ha|ha /- case `a` finite. In this case, it suffices to show that any finite subset `s` of `t` has cardinality at most `a`. For this, we pick `i` such that `f i` contains all the points in `s`, and apply the assumption that the cardinality of `f i` is at most `a`. -/ · obtain ⟨n, rfl⟩ : ∃ (n : ℕ), a = n := lt_aleph0.1 ha apply mk_le_iff_forall_finset_subset_card_le.2 (fun s hs ↦ ?_) have A : ∀ x ∈ s, ∀ᶠ i in l, x ∈ f i := fun x hx ↦ ht x (hs hx) have B : ∀ᶠ i in l, ∀ x ∈ s, x ∈ f i := (s.eventually_all).2 A rcases B.exists with ⟨i, hi⟩ have : ∀ i, Fintype (f i) := fun i ↦ (lt_aleph0_iff_fintype.1 ((h'f i).trans_lt ha)).some let u : Finset α := (f i).toFinset have I1 : s.card ≤ u.card := by have : s ⊆ u := fun x hx ↦ by simpa only [u, Set.mem_toFinset] using hi x hx exact Finset.card_le_card this have I2 : (u.card : Cardinal) ≤ n := by convert h'f i; simp only [u, Set.toFinset_card, mk_fintype] exact I1.trans (Nat.cast_le.1 I2) · have : t ⊆ ⋃ i, f i := by intro x hx obtain ⟨i, hi⟩ : ∃ i, x ∈ f i := (ht x hx).exists exact mem_iUnion_of_mem i hi calc #t ≤ #(⋃ i, f i) := mk_le_mk_of_subset this _ ≤ sum (fun i ↦ #(f i)) := mk_iUnion_le_sum_mk _ ≤ sum (fun _ ↦ a) := sum_le_sum _ _ h'f _ = #ι * a := by simp _ ≤ ℵ₀ * a := mul_le_mul_right' mk_le_aleph0 a _ = a := aleph0_mul_eq ha
lemma
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic", "Mathlib.Order.Filter.Finite", "Mathlib.Order.Filter.Map" ]
Mathlib/SetTheory/Cardinal/CountableCover.lean
mk_subtype_le_of_countable_eventually_mem_aux
If a set `t` is eventually covered by a countable family of sets, all with cardinality at most `a`, then the cardinality of `t` is also bounded by `a`. Superseded by `mk_le_of_countable_eventually_mem` which does not assume that the indexing set lives in the same universe.
mk_subtype_le_of_countable_eventually_mem {α : Type u} {ι : Type v} {a : Cardinal} [Countable ι] {f : ι → Set α} {l : Filter ι} [NeBot l] {t : Set α} (ht : ∀ x ∈ t, ∀ᶠ i in l, x ∈ f i) (h'f : ∀ i, #(f i) ≤ a) : #t ≤ a := by let g : ULift.{u, v} ι → Set (ULift.{v, u} α) := (ULift.down ⁻¹' ·) ∘ f ∘ ULift.down suffices #(ULift.down.{v} ⁻¹' t) ≤ Cardinal.lift.{v, u} a by simpa let l' : Filter (ULift.{u} ι) := Filter.map ULift.up l have : NeBot l' := map_neBot apply mk_subtype_le_of_countable_eventually_mem_aux (ι := ULift.{u} ι) (l := l') (f := g) · intro x hx simpa only [Function.comp_apply, mem_preimage, eventually_map] using ht _ hx · intro i simpa [g] using h'f i.down
lemma
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic", "Mathlib.Order.Filter.Finite", "Mathlib.Order.Filter.Map" ]
Mathlib/SetTheory/Cardinal/CountableCover.lean
mk_subtype_le_of_countable_eventually_mem
If a set `t` is eventually covered by a countable family of sets, all with cardinality at most `a`, then the cardinality of `t` is also bounded by `a`.
mk_le_of_countable_eventually_mem {α : Type u} {ι : Type v} {a : Cardinal} [Countable ι] {f : ι → Set α} {l : Filter ι} [NeBot l] (ht : ∀ x, ∀ᶠ i in l, x ∈ f i) (h'f : ∀ i, #(f i) ≤ a) : #α ≤ a := by rw [← mk_univ] exact mk_subtype_le_of_countable_eventually_mem (l := l) (fun x _ ↦ ht x) h'f
lemma
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic", "Mathlib.Order.Filter.Finite", "Mathlib.Order.Filter.Map" ]
Mathlib/SetTheory/Cardinal/CountableCover.lean
mk_le_of_countable_eventually_mem
If a space is eventually covered by a countable family of sets, all with cardinality at most `a`, then the cardinality of the space is also bounded by `a`.
mk_of_countable_eventually_mem {α : Type u} {ι : Type v} {a : Cardinal} [Countable ι] {f : ι → Set α} {l : Filter ι} [NeBot l] (ht : ∀ x, ∀ᶠ i in l, x ∈ f i) (h'f : ∀ i, #(f i) = a) : #α = a := by apply le_antisymm · apply mk_le_of_countable_eventually_mem ht (fun i ↦ (h'f i).le) · obtain ⟨i⟩ : Nonempty ι := nonempty_of_neBot l rw [← (h'f i)] exact mk_set_le (f i)
lemma
SetTheory
[ "Mathlib.SetTheory.Cardinal.Arithmetic", "Mathlib.Order.Filter.Finite", "Mathlib.Order.Filter.Map" ]
Mathlib/SetTheory/Cardinal/CountableCover.lean
mk_of_countable_eventually_mem
If a space is eventually covered by a countable family of sets, all with cardinality `a`, then the cardinality of the space is also `a`.
Cardinal.isEquivalent : Setoid (Type u) where r α β := Nonempty (α ≃ β) iseqv := ⟨ fun α => ⟨Equiv.refl α⟩, fun ⟨e⟩ => ⟨e.symm⟩, fun ⟨e₁⟩ ⟨e₂⟩ => ⟨e₁.trans e₂⟩⟩
instance
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
Cardinal.isEquivalent
The equivalence relation on types given by equivalence (bijective correspondence) of types. Quotienting by this equivalence relation gives the cardinal numbers.
@[pp_with_univ] Cardinal : Type (u + 1) := Quotient Cardinal.isEquivalent
def
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
Cardinal
`Cardinal.{u}` is the type of cardinal numbers in `Type u`, defined as the quotient of `Type u` by existence of an equivalence (a bijection with explicit inverse).
mk : Type u → Cardinal := Quotient.mk' @[inherit_doc] scoped prefix:max "#" => Cardinal.mk
def
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk
The cardinal number of a type
canLiftCardinalType : CanLift Cardinal.{u} (Type u) mk fun _ => True := ⟨fun c _ => Quot.inductionOn c fun α => ⟨α, rfl⟩⟩ @[elab_as_elim]
instance
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
canLiftCardinalType
null
inductionOn {p : Cardinal → Prop} (c : Cardinal) (h : ∀ α, p #α) : p c := Quotient.inductionOn c h @[elab_as_elim]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
inductionOn
null
inductionOn₂ {p : Cardinal → Cardinal → Prop} (c₁ : Cardinal) (c₂ : Cardinal) (h : ∀ α β, p #α #β) : p c₁ c₂ := Quotient.inductionOn₂ c₁ c₂ h @[elab_as_elim]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
inductionOn₂
null
inductionOn₃ {p : Cardinal → Cardinal → Cardinal → Prop} (c₁ : Cardinal) (c₂ : Cardinal) (c₃ : Cardinal) (h : ∀ α β γ, p #α #β #γ) : p c₁ c₂ c₃ := Quotient.inductionOn₃ c₁ c₂ c₃ h
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
inductionOn₃
null
induction_on_pi {ι : Type u} {p : (ι → Cardinal.{v}) → Prop} (f : ι → Cardinal.{v}) (h : ∀ f : ι → Type v, p fun i ↦ #(f i)) : p f := Quotient.induction_on_pi f h
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
induction_on_pi
null
protected eq : #α = #β ↔ Nonempty (α ≃ β) := Quotient.eq' @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
eq
null
mk_out (c : Cardinal) : #c.out = c := Quotient.out_eq _
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_out
null
outMkEquiv {α : Type v} : (#α).out ≃ α := Nonempty.some <| Cardinal.eq.mp (by simp)
def
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
outMkEquiv
The representative of the cardinal of a type is equivalent to the original type.
mk_congr (e : α ≃ β) : #α = #β := Quot.sound ⟨e⟩ alias _root_.Equiv.cardinal_eq := mk_congr
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_congr
null
map (f : Type u → Type v) (hf : ∀ α β, α ≃ β → f α ≃ f β) : Cardinal.{u} → Cardinal.{v} := Quotient.map f fun α β ⟨e⟩ => ⟨hf α β e⟩ @[simp]
def
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
map
Lift a function between `Type*`s to a function between `Cardinal`s.
map_mk (f : Type u → Type v) (hf : ∀ α β, α ≃ β → f α ≃ f β) (α : Type u) : map f hf #α = #(f α) := rfl
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
map_mk
null
map₂ (f : Type u → Type v → Type w) (hf : ∀ α β γ δ, α ≃ β → γ ≃ δ → f α γ ≃ f β δ) : Cardinal.{u} → Cardinal.{v} → Cardinal.{w} := Quotient.map₂ f fun α β ⟨e₁⟩ γ δ ⟨e₂⟩ => ⟨hf α β γ δ e₁ e₂⟩ /-! ### Lifting cardinals to a higher universe -/
def
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
map₂
Lift a binary operation `Type* → Type* → Type*` to a binary operation on `Cardinal`s.
@[pp_with_univ] lift (c : Cardinal.{v}) : Cardinal.{max v u} := map ULift.{u, v} (fun _ _ e => Equiv.ulift.trans <| e.trans Equiv.ulift.symm) c @[simp]
def
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift
The universe lift operation on cardinals. You can specify the universes explicitly with `lift.{u v} : Cardinal.{v} → Cardinal.{max v u}`
mk_uLift (α) : #(ULift.{v, u} α) = lift.{v} #α := rfl
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_uLift
null
lift_umax : lift.{max u v, u} = lift.{v, u} := funext fun a => inductionOn a fun _ => (Equiv.ulift.trans Equiv.ulift.symm).cardinal_eq
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_umax
`lift.{max u v, u}` equals `lift.{v, u}`. Unfortunately, the simp lemma doesn't work.
lift_id' (a : Cardinal.{max u v}) : lift.{u} a = a := inductionOn a fun _ => mk_congr Equiv.ulift
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_id'
A cardinal lifted to a lower or equal universe equals itself. Unfortunately, the simp lemma doesn't work.
@[simp] lift_id (a : Cardinal) : lift.{u, u} a = a := lift_id'.{u, u} a
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_id
A cardinal lifted to the same universe equals itself.
@[simp] lift_uzero (a : Cardinal.{u}) : lift.{0} a = a := lift_id'.{0, u} a @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_uzero
A cardinal lifted to the zero universe equals itself.
lift_lift.{u_1} (a : Cardinal.{u_1}) : lift.{w} (lift.{v} a) = lift.{max v w} a := inductionOn a fun _ => (Equiv.ulift.trans <| Equiv.ulift.trans Equiv.ulift.symm).cardinal_eq
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_lift.
null
out_lift_equiv (a : Cardinal.{u}) : Nonempty ((lift.{v} a).out ≃ a.out) := by rw [← mk_out a, ← mk_uLift, mk_out] exact ⟨outMkEquiv.trans Equiv.ulift⟩
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
out_lift_equiv
null
lift_mk_eq {α : Type u} {β : Type v} : lift.{max v w} #α = lift.{max u w} #β ↔ Nonempty (α ≃ β) := Quotient.eq'.trans ⟨fun ⟨f⟩ => ⟨Equiv.ulift.symm.trans <| f.trans Equiv.ulift⟩, fun ⟨f⟩ => ⟨Equiv.ulift.trans <| f.trans Equiv.ulift.symm⟩⟩
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_mk_eq
null
lift_mk_eq' {α : Type u} {β : Type v} : lift.{v} #α = lift.{u} #β ↔ Nonempty (α ≃ β) := lift_mk_eq.{u, v, 0}
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_mk_eq'
A variant of `Cardinal.lift_mk_eq` with specialized universes. Because Lean often cannot realize it should use this specialization itself, we provide this statement separately so you don't have to solve the specialization problem either.
mk_congr_lift {α : Type u} {β : Type v} (e : α ≃ β) : lift.{v} #α = lift.{u} #β := lift_mk_eq'.2 ⟨e⟩ alias _root_.Equiv.lift_cardinal_eq := mk_congr_lift /-! ### Basic cardinals -/
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_congr_lift
null
@[simp] mk_eq_zero (α : Type u) [IsEmpty α] : #α = 0 := (Equiv.equivOfIsEmpty α (ULift (Fin 0))).cardinal_eq @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_eq_zero
null
lift_zero : lift 0 = 0 := mk_eq_zero _
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_zero
null
mk_eq_zero_iff {α : Type u} : #α = 0 ↔ IsEmpty α := ⟨fun e => let ⟨h⟩ := Quotient.exact e h.isEmpty, @mk_eq_zero α⟩
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_eq_zero_iff
null
mk_ne_zero_iff {α : Type u} : #α ≠ 0 ↔ Nonempty α := (not_iff_not.2 mk_eq_zero_iff).trans not_isEmpty_iff @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_ne_zero_iff
null
mk_ne_zero (α : Type u) [Nonempty α] : #α ≠ 0 := mk_ne_zero_iff.2 ‹_›
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_ne_zero
null
mk_eq_one (α : Type u) [Subsingleton α] [Nonempty α] : #α = 1 := let ⟨_⟩ := nonempty_unique α; (Equiv.ofUnique α (ULift (Fin 1))).cardinal_eq
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_eq_one
null
add_def (α β : Type u) : #α + #β = #(α ⊕ β) := rfl
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
add_def
null
@[simp] mk_sum (α : Type u) (β : Type v) : #(α ⊕ β) = lift.{v, u} #α + lift.{u, v} #β := mk_congr (Equiv.ulift.symm.sumCongr Equiv.ulift.symm) @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_sum
null
mk_option {α : Type u} : #(Option α) = #α + 1 := by rw [(Equiv.optionEquivSumPUnit.{u, u} α).cardinal_eq, mk_sum, mk_eq_one PUnit, lift_id, lift_id] @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_option
null
mk_psum (α : Type u) (β : Type v) : #(α ⊕' β) = lift.{v} #α + lift.{u} #β := (mk_congr (Equiv.psumEquivSum α β)).trans (mk_sum α β)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_psum
null
mul_def (α β : Type u) : #α * #β = #(α × β) := rfl @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mul_def
null
mk_prod (α : Type u) (β : Type v) : #(α × β) = lift.{v, u} #α * lift.{u, v} #β := mk_congr (Equiv.ulift.symm.prodCongr Equiv.ulift.symm)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_prod
null
instPowCardinal : Pow Cardinal.{u} Cardinal.{u} := ⟨map₂ (fun α β => β → α) fun _ _ _ _ e₁ e₂ => e₂.arrowCongr e₁⟩
instance
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
instPowCardinal
The cardinal exponential. `#α ^ #β` is the cardinal of `β → α`.
power_def (α β : Type u) : #α ^ #β = #(β → α) := rfl
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
power_def
null
mk_arrow (α : Type u) (β : Type v) : #(α → β) = (lift.{u} #β^lift.{v} #α) := mk_congr (Equiv.ulift.symm.arrowCongr Equiv.ulift.symm) @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_arrow
null
lift_power (a b : Cardinal.{u}) : lift.{v} (a ^ b) = lift.{v} a ^ lift.{v} b := inductionOn₂ a b fun _ _ => mk_congr <| Equiv.ulift.trans (Equiv.ulift.arrowCongr Equiv.ulift).symm @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_power
null
power_zero (a : Cardinal) : a ^ (0 : Cardinal) = 1 := inductionOn a fun _ => mk_eq_one _ @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
power_zero
null
power_one (a : Cardinal.{u}) : a ^ (1 : Cardinal) = a := inductionOn a fun α => mk_congr (Equiv.funUnique (ULift.{u} (Fin 1)) α)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
power_one
null
power_add (a b c : Cardinal) : a ^ (b + c) = a ^ b * a ^ c := inductionOn₃ a b c fun α β γ => mk_congr <| Equiv.sumArrowEquivProdArrow β γ α @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
power_add
null
one_power {a : Cardinal} : (1 : Cardinal) ^ a = 1 := inductionOn a fun _ => mk_eq_one _ @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
one_power
null
zero_power {a : Cardinal} : a ≠ 0 → (0 : Cardinal) ^ a = 0 := inductionOn a fun _ heq => mk_eq_zero_iff.2 <| isEmpty_pi.2 <| let ⟨a⟩ := mk_ne_zero_iff.1 heq ⟨a, inferInstance⟩
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
zero_power
null
power_ne_zero {a : Cardinal} (b : Cardinal) : a ≠ 0 → a ^ b ≠ 0 := inductionOn₂ a b fun _ _ h => let ⟨a⟩ := mk_ne_zero_iff.1 h mk_ne_zero_iff.2 ⟨fun _ => a⟩
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
power_ne_zero
null
mul_power {a b c : Cardinal} : (a * b) ^ c = a ^ c * b ^ c := inductionOn₃ a b c fun _ _ γ => mk_congr <| Equiv.arrowProdEquivProdArrow γ _ _ @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mul_power
null
lift_one : lift 1 = 1 := mk_eq_one _ @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_one
null
lift_add (a b : Cardinal.{u}) : lift.{v} (a + b) = lift.{v} a + lift.{v} b := inductionOn₂ a b fun _ _ => mk_congr <| Equiv.ulift.trans (Equiv.sumCongr Equiv.ulift Equiv.ulift).symm /-! ### Indexed cardinal `sum` -/
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_add
null
sum {ι} (f : ι → Cardinal) : Cardinal := mk (Σ i, (f i).out) @[simp]
def
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
sum
The indexed sum of cardinals is the cardinality of the indexed disjoint union, i.e. sigma type.
mk_sigma {ι} (f : ι → Type*) : #(Σ i, f i) = sum fun i => #(f i) := mk_congr <| Equiv.sigmaCongrRight fun _ => outMkEquiv.symm
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_sigma
null
mk_sigma_congr_lift {ι : Type v} {ι' : Type v'} {f : ι → Type w} {g : ι' → Type w'} (e : ι ≃ ι') (h : ∀ i, lift.{w'} #(f i) = lift.{w} #(g (e i))) : lift.{max v' w'} #(Σ i, f i) = lift.{max v w} #(Σ i, g i) := Cardinal.lift_mk_eq'.2 ⟨.sigmaCongr e fun i ↦ Classical.choice <| Cardinal.lift_mk_eq'.1 (h i)⟩
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_sigma_congr_lift
null
mk_sigma_congr {ι ι' : Type u} {f : ι → Type v} {g : ι' → Type v} (e : ι ≃ ι') (h : ∀ i, #(f i) = #(g (e i))) : #(Σ i, f i) = #(Σ i, g i) := mk_congr <| Equiv.sigmaCongr e fun i ↦ Classical.choice <| Cardinal.eq.mp (h i)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_sigma_congr
null
mk_sigma_congr' {ι : Type u} {ι' : Type v} {f : ι → Type max w (max u v)} {g : ι' → Type max w (max u v)} (e : ι ≃ ι') (h : ∀ i, #(f i) = #(g (e i))) : #(Σ i, f i) = #(Σ i, g i) := mk_congr <| Equiv.sigmaCongr e fun i ↦ Classical.choice <| Cardinal.eq.mp (h i)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_sigma_congr'
Similar to `mk_sigma_congr` with indexing types in different universes. This is not a strict generalization.
mk_sigma_congrRight {ι : Type u} {f g : ι → Type v} (h : ∀ i, #(f i) = #(g i)) : #(Σ i, f i) = #(Σ i, g i) := mk_sigma_congr (Equiv.refl ι) h
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_sigma_congrRight
null
mk_psigma_congrRight {ι : Type u} {f g : ι → Type v} (h : ∀ i, #(f i) = #(g i)) : #(Σ' i, f i) = #(Σ' i, g i) := mk_congr <| .psigmaCongrRight fun i => Classical.choice <| Cardinal.eq.mp (h i)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_psigma_congrRight
null
mk_psigma_congrRight_prop {ι : Prop} {f g : ι → Type v} (h : ∀ i, #(f i) = #(g i)) : #(Σ' i, f i) = #(Σ' i, g i) := mk_congr <| .psigmaCongrRight fun i => Classical.choice <| Cardinal.eq.mp (h i)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_psigma_congrRight_prop
null
mk_sigma_arrow {ι} (α : Type*) (f : ι → Type*) : #(Sigma f → α) = #(Π i, f i → α) := mk_congr <| Equiv.piCurry fun _ _ ↦ α @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_sigma_arrow
null
sum_const (ι : Type u) (a : Cardinal.{v}) : (sum fun _ : ι => a) = lift.{v} #ι * lift.{u} a := inductionOn a fun α => mk_congr <| calc (Σ _ : ι, Quotient.out #α) ≃ ι × Quotient.out #α := Equiv.sigmaEquivProd _ _ _ ≃ ULift ι × ULift α := Equiv.ulift.symm.prodCongr (outMkEquiv.trans Equiv.ulift.symm)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
sum_const
null
sum_const' (ι : Type u) (a : Cardinal.{u}) : (sum fun _ : ι => a) = #ι * a := by simp @[simp]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
sum_const'
null
lift_sum {ι : Type u} (f : ι → Cardinal.{v}) : Cardinal.lift.{w} (Cardinal.sum f) = Cardinal.sum fun i => Cardinal.lift.{w} (f i) := Equiv.cardinal_eq <| Equiv.ulift.trans <| Equiv.sigmaCongrRight fun a => Nonempty.some <| by rw [← lift_mk_eq.{_,_,v}, mk_out, mk_out, lift_lift]
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
lift_sum
null
sum_nat_eq_add_sum_succ (f : ℕ → Cardinal.{u}) : Cardinal.sum f = f 0 + Cardinal.sum fun i => f (i + 1) := by refine (Equiv.sigmaNatSucc fun i => Quotient.out (f i)).cardinal_eq.trans ?_ simp only [mk_sum, mk_out, lift_id, mk_sigma] /-! ### Indexed cardinal `prod` -/
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
sum_nat_eq_add_sum_succ
null
prod {ι : Type u} (f : ι → Cardinal) : Cardinal := #(Π i, (f i).out) @[simp]
def
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
prod
The indexed product of cardinals is the cardinality of the Pi type (dependent product).
mk_pi {ι : Type u} (α : ι → Type v) : #(Π i, α i) = prod fun i => #(α i) := mk_congr <| Equiv.piCongrRight fun _ => outMkEquiv.symm
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_pi
null
mk_pi_congr_lift {ι : Type v} {ι' : Type v'} {f : ι → Type w} {g : ι' → Type w'} (e : ι ≃ ι') (h : ∀ i, lift.{w'} #(f i) = lift.{w} #(g (e i))) : lift.{max v' w'} #(Π i, f i) = lift.{max v w} #(Π i, g i) := Cardinal.lift_mk_eq'.2 ⟨.piCongr e fun i ↦ Classical.choice <| Cardinal.lift_mk_eq'.1 (h i)⟩
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_pi_congr_lift
null
mk_pi_congr {ι ι' : Type u} {f : ι → Type v} {g : ι' → Type v} (e : ι ≃ ι') (h : ∀ i, #(f i) = #(g (e i))) : #(Π i, f i) = #(Π i, g i) := mk_congr <| Equiv.piCongr e fun i ↦ Classical.choice <| Cardinal.eq.mp (h i)
theorem
SetTheory
[ "Mathlib.Data.ULift", "Mathlib.Util.Delaborators", "Mathlib.Util.AssertExists" ]
Mathlib/SetTheory/Cardinal/Defs.lean
mk_pi_congr
null