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double_pow_half_succ_eq_pow_half (n : ℕ) : 2 • pow_half n.succ = pow_half n
by { rw two_nsmul, exact quotient.sound (pgame.add_pow_half_succ_self_eq_pow_half n) }
lemma
surreal.double_pow_half_succ_eq_pow_half
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[ "pgame.add_pow_half_succ_self_eq_pow_half" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nsmul_pow_two_pow_half (n : ℕ) : 2 ^ n • pow_half n = 1
begin induction n with n hn, { simp only [nsmul_one, pow_half_zero, nat.cast_one, pow_zero] }, { rw [← hn, ← double_pow_half_succ_eq_pow_half n, smul_smul (2^n) 2 (pow_half n.succ), mul_comm, pow_succ] } end
lemma
surreal.nsmul_pow_two_pow_half
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[ "mul_comm", "nat.cast_one", "nsmul_one", "pow_succ", "pow_zero", "smul_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nsmul_pow_two_pow_half' (n k : ℕ) : 2 ^ n • pow_half (n + k) = pow_half k
begin induction k with k hk, { simp only [add_zero, surreal.nsmul_pow_two_pow_half, nat.nat_zero_eq_zero, eq_self_iff_true, surreal.pow_half_zero] }, { rw [← double_pow_half_succ_eq_pow_half (n + k), ← double_pow_half_succ_eq_pow_half k, smul_algebra_smul_comm] at hk, rwa ← zsmul_eq_zsm...
lemma
surreal.nsmul_pow_two_pow_half'
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[ "smul_algebra_smul_comm", "surreal.nsmul_pow_two_pow_half", "surreal.pow_half_zero", "two_ne_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zsmul_pow_two_pow_half (m : ℤ) (n k : ℕ) : (m * 2 ^ n) • pow_half (n + k) = m • pow_half k
begin rw mul_zsmul, congr, norm_cast, exact nsmul_pow_two_pow_half' n k end
lemma
surreal.zsmul_pow_two_pow_half
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dyadic_aux {m₁ m₂ : ℤ} {y₁ y₂ : ℕ} (h₂ : m₁ * (2 ^ y₁) = m₂ * (2 ^ y₂)) : m₁ • pow_half y₂ = m₂ • pow_half y₁
begin revert m₁ m₂, wlog h : y₁ ≤ y₂, { intros m₁ m₂ aux, exact (this (le_of_not_le h) aux.symm).symm }, intros m₁ m₂ h₂, obtain ⟨c, rfl⟩ := le_iff_exists_add.mp h, rw [add_comm, pow_add, ← mul_assoc, mul_eq_mul_right_iff] at h₂, cases h₂, { rw [h₂, add_comm, zsmul_pow_two_pow_half m₂ c y₁] }, { have ...
lemma
surreal.dyadic_aux
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[ "aux", "mul_assoc", "mul_eq_mul_right_iff", "nat.one_le_pow", "nat.succ_pos'", "pow_add" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dyadic_map : localization.away (2 : ℤ) →+ surreal
{ to_fun := λ x, localization.lift_on x (λ x y, x • pow_half (submonoid.log y)) $ begin intros m₁ m₂ n₁ n₂ h₁, obtain ⟨⟨n₃, y₃, hn₃⟩, h₂⟩ := localization.r_iff_exists.mp h₁, simp only [subtype.coe_mk, mul_eq_mul_left_iff] at h₂, cases h₂, { simp only, obtain ⟨a₁, ha₁⟩ := n₁.prop, obt...
def
surreal.dyadic_map
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[ "add_smul", "int.pow_right_injective", "localization.add_mk", "localization.away", "localization.induction_on₂", "localization.lift_on", "localization.lift_on_mk", "localization.lift_on_zero", "mul_comm", "mul_eq_mul_left_iff", "nat.one_le_pow", "nat.succ_pos'", "one_lt_two", "submonoid.lo...
The additive monoid morphism `dyadic_map` sends ⟦⟨m, 2^n⟩⟧ to m • half ^ n.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dyadic_map_apply (m : ℤ) (p : submonoid.powers (2 : ℤ)) : dyadic_map (is_localization.mk' (localization (submonoid.powers 2)) m p) = m • pow_half (submonoid.log p)
by { rw ← localization.mk_eq_mk', refl }
lemma
surreal.dyadic_map_apply
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[ "is_localization.mk'", "localization", "localization.mk_eq_mk'", "submonoid.log", "submonoid.powers" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dyadic_map_apply_pow (m : ℤ) (n : ℕ) : dyadic_map (is_localization.mk' (localization (submonoid.powers 2)) m (submonoid.pow 2 n)) = m • pow_half n
by rw [dyadic_map_apply, @submonoid.log_pow_int_eq_self 2 one_lt_two]
lemma
surreal.dyadic_map_apply_pow
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[ "is_localization.mk'", "localization", "one_lt_two", "submonoid.log_pow_int_eq_self", "submonoid.pow", "submonoid.powers" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dyadic : set surreal
set.range dyadic_map
def
surreal.dyadic
set_theory.surreal
src/set_theory/surreal/dyadic.lean
[ "algebra.algebra.basic", "set_theory.game.birthday", "set_theory.surreal.basic", "ring_theory.localization.basic" ]
[ "set.range", "surreal" ]
We define dyadic surreals as the range of the map `dyadic_map`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arity (α : Type u) : ℕ → Type u
| 0 := α | (n+1) := α → arity n
def
arity
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
The type of `n`-ary functions `α → α → ... → α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arity_zero (α : Type u) : arity α 0 = α
rfl
theorem
arity_zero
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arity_succ (α : Type u) (n : ℕ) : arity α n.succ = (α → arity α n)
rfl
theorem
arity_succ
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const {α : Type u} (a : α) : ∀ n, arity α n
| 0 := a | (n+1) := λ _, const n
def
arity.const
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
Constant `n`-ary function with value `a`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const_zero {α : Type u} (a : α) : const a 0 = a
rfl
theorem
arity.const_zero
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const_succ {α : Type u} (a : α) (n : ℕ) : const a n.succ = λ _, const a n
rfl
theorem
arity.const_succ
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const_succ_apply {α : Type u} (a : α) (n : ℕ) (x : α) : const a n.succ x = const a n
rfl
theorem
arity.const_succ_apply
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arity.inhabited {α n} [inhabited α] : inhabited (arity α n)
⟨const default _⟩
instance
arity.arity.inhabited
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pSet : Type (u+1) | mk (α : Type u) (A : α → pSet) : pSet
inductive
pSet
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
The type of pre-sets in universe `u`. A pre-set is a family of pre-sets indexed by a type in `Type u`. The ZFC universe is defined as a quotient of this to ensure extensionality.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
type : pSet → Type u
| ⟨α, A⟩ := α
def
pSet.type
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The underlying type of a pre-set
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
func : Π (x : pSet), x.type → pSet
| ⟨α, A⟩ := A
def
pSet.func
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The underlying pre-set family of a pre-set
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_type (α A) : type ⟨α, A⟩ = α
rfl
theorem
pSet.mk_type
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_func (α A) : func ⟨α, A⟩ = A
rfl
theorem
pSet.mk_func
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eta : Π (x : pSet), mk x.type x.func = x
| ⟨α, A⟩ := rfl
theorem
pSet.eta
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv (x y : pSet) : Prop
pSet.rec (λ α z m ⟨β, B⟩, (∀ a, ∃ b, m a (B b)) ∧ (∀ b, ∃ a, m a (B b))) x y
def
pSet.equiv
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "pSet" ]
Two pre-sets are extensionally equivalent if every element of the first family is extensionally equivalent to some element of the second family and vice-versa.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_iff : Π {x y : pSet}, equiv x y ↔ (∀ i, ∃ j, equiv (x.func i) (y.func j)) ∧ (∀ j, ∃ i, equiv (x.func i) (y.func j))
| ⟨α, A⟩ ⟨β, B⟩ := iff.rfl
theorem
pSet.equiv_iff
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.exists_left {x y : pSet} (h : equiv x y) : ∀ i, ∃ j, equiv (x.func i) (y.func j)
(equiv_iff.1 h).1
theorem
pSet.equiv.exists_left
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.exists_right {x y : pSet} (h : equiv x y) : ∀ j, ∃ i, equiv (x.func i) (y.func j)
(equiv_iff.1 h).2
theorem
pSet.equiv.exists_right
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.refl (x) : equiv x x
pSet.rec_on x $ λ α A IH, ⟨λ a, ⟨a, IH a⟩, λ a, ⟨a, IH a⟩⟩
theorem
pSet.equiv.refl
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "equiv.refl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.rfl : ∀ {x}, equiv x x
equiv.refl
theorem
pSet.equiv.rfl
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "equiv.refl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.euc {x} : Π {y z}, equiv x y → equiv z y → equiv x z
pSet.rec_on x $ λ α A IH y, pSet.cases_on y $ λ β B ⟨γ, Γ⟩ ⟨αβ, βα⟩ ⟨γβ, βγ⟩, ⟨λ a, let ⟨b, ab⟩ := αβ a, ⟨c, bc⟩ := βγ b in ⟨c, IH a ab bc⟩, λ c, let ⟨b, cb⟩ := γβ c, ⟨a, ba⟩ := βα b in ⟨a, IH a ba cb⟩⟩
theorem
pSet.equiv.euc
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.symm {x y} : equiv x y → equiv y x
(equiv.refl y).euc
theorem
pSet.equiv.symm
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "equiv.refl", "equiv.symm" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.comm {x y} : equiv x y ↔ equiv y x
⟨equiv.symm, equiv.symm⟩
theorem
pSet.equiv.comm
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.trans {x y z} (h1 : equiv x y) (h2 : equiv y z) : equiv x z
h1.euc h2.symm
theorem
pSet.equiv.trans
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "equiv.trans" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_of_is_empty (x y : pSet) [is_empty x.type] [is_empty y.type] : equiv x y
equiv_iff.2 $ by simp
theorem
pSet.equiv_of_is_empty
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "is_empty", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
setoid : setoid pSet
⟨pSet.equiv, equiv.refl, λ x y, equiv.symm, λ x y z, equiv.trans⟩
instance
pSet.setoid
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv.refl", "equiv.symm", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subset (x y : pSet) : Prop
∀ a, ∃ b, equiv (x.func a) (y.func b)
def
pSet.subset
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "pSet" ]
A pre-set is a subset of another pre-set if every element of the first family is extensionally equivalent to some element of the second family.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.ext : Π (x y : pSet), equiv x y ↔ (x ⊆ y ∧ y ⊆ x)
| ⟨α, A⟩ ⟨β, B⟩ := ⟨λ ⟨αβ, βα⟩, ⟨αβ, λ b, let ⟨a, h⟩ := βα b in ⟨a, equiv.symm h⟩⟩, λ ⟨αβ, βα⟩, ⟨αβ, λ b, let ⟨a, h⟩ := βα b in ⟨a, equiv.symm h⟩⟩⟩
theorem
pSet.equiv.ext
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "equiv.ext", "equiv.symm", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subset.congr_left : Π {x y z : pSet}, equiv x y → (x ⊆ z ↔ y ⊆ z)
| ⟨α, A⟩ ⟨β, B⟩ ⟨γ, Γ⟩ ⟨αβ, βα⟩ := ⟨λ αγ b, let ⟨a, ba⟩ := βα b, ⟨c, ac⟩ := αγ a in ⟨c, (equiv.symm ba).trans ac⟩, λ βγ a, let ⟨b, ab⟩ := αβ a, ⟨c, bc⟩ := βγ b in ⟨c, equiv.trans ab bc⟩⟩
theorem
pSet.subset.congr_left
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "equiv.symm", "equiv.trans", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subset.congr_right : Π {x y z : pSet}, equiv x y → (z ⊆ x ↔ z ⊆ y)
| ⟨α, A⟩ ⟨β, B⟩ ⟨γ, Γ⟩ ⟨αβ, βα⟩ := ⟨λ γα c, let ⟨a, ca⟩ := γα c, ⟨b, ab⟩ := αβ a in ⟨b, ca.trans ab⟩, λ γβ c, let ⟨b, cb⟩ := γβ c, ⟨a, ab⟩ := βα b in ⟨a, cb.trans (equiv.symm ab)⟩⟩
theorem
pSet.subset.congr_right
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "equiv.symm", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem (x y : pSet.{u}) : Prop
∃ b, equiv x (y.func b)
def
pSet.mem
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
`x ∈ y` as pre-sets if `x` is extensionally equivalent to a member of the family `y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem.mk {α : Type u} (A : α → pSet) (a : α) : A a ∈ mk α A
⟨a, equiv.refl (A a)⟩
theorem
pSet.mem.mk
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv.refl", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
func_mem (x : pSet) (i : x.type) : x.func i ∈ x
by { cases x, apply mem.mk }
theorem
pSet.func_mem
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem.ext : Π {x y : pSet.{u}}, (∀ w : pSet.{u}, w ∈ x ↔ w ∈ y) → equiv x y
| ⟨α, A⟩ ⟨β, B⟩ h := ⟨λ a, (h (A a)).1 (mem.mk A a), λ b, let ⟨a, ha⟩ := (h (B b)).2 (mem.mk B b) in ⟨a, ha.symm⟩⟩
theorem
pSet.mem.ext
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem.congr_right : Π {x y : pSet.{u}}, equiv x y → (∀ {w : pSet.{u}}, w ∈ x ↔ w ∈ y)
| ⟨α, A⟩ ⟨β, B⟩ ⟨αβ, βα⟩ w := ⟨λ ⟨a, ha⟩, let ⟨b, hb⟩ := αβ a in ⟨b, ha.trans hb⟩, λ ⟨b, hb⟩, let ⟨a, ha⟩ := βα b in ⟨a, hb.euc ha⟩⟩
theorem
pSet.mem.congr_right
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_iff_mem {x y : pSet.{u}} : equiv x y ↔ (∀ {w : pSet.{u}}, w ∈ x ↔ w ∈ y)
⟨mem.congr_right, match x, y with | ⟨α, A⟩, ⟨β, B⟩, h := ⟨λ a, h.1 (mem.mk A a), λ b, let ⟨a, h⟩ := h.2 (mem.mk B b) in ⟨a, h.symm⟩⟩ end⟩
theorem
pSet.equiv_iff_mem
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem.congr_left : Π {x y : pSet.{u}}, equiv x y → (∀ {w : pSet.{u}}, x ∈ w ↔ y ∈ w)
| x y h ⟨α, A⟩ := ⟨λ ⟨a, ha⟩, ⟨a, h.symm.trans ha⟩, λ ⟨a, ha⟩, ⟨a, h.trans ha⟩⟩
theorem
pSet.mem.congr_left
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_wf_aux : Π {x y : pSet.{u}}, equiv x y → acc (∈) y
| ⟨α, A⟩ ⟨β, B⟩ H := ⟨_, begin rintros ⟨γ, C⟩ ⟨b, hc⟩, cases H.exists_right b with a ha, have H := ha.trans hc.symm, rw mk_func at H, exact mem_wf_aux H end⟩
theorem
pSet.mem_wf_aux
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_wf : @well_founded pSet (∈)
⟨λ x, mem_wf_aux $ equiv.refl x⟩
theorem
pSet.mem_wf
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv.refl", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_asymm {x y : pSet} : x ∈ y → y ∉ x
asymm
theorem
pSet.mem_asymm
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_irrefl (x : pSet) : x ∉ x
irrefl x
theorem
pSet.mem_irrefl
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_set (u : pSet.{u}) : set pSet.{u}
{x | x ∈ u}
def
pSet.to_set
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
Convert a pre-set to a `set` of pre-sets.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_to_set (a u : pSet.{u}) : a ∈ u.to_set ↔ a ∈ u
iff.rfl
theorem
pSet.mem_to_set
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonempty (u : pSet) : Prop
u.to_set.nonempty
def
pSet.nonempty
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
A nonempty set is one that contains some element.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonempty_def (u : pSet) : u.nonempty ↔ ∃ x, x ∈ u
iff.rfl
theorem
pSet.nonempty_def
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonempty_of_mem {x u : pSet} (h : x ∈ u) : u.nonempty
⟨x, h⟩
theorem
pSet.nonempty_of_mem
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonempty_to_set_iff {u : pSet} : u.to_set.nonempty ↔ u.nonempty
iff.rfl
theorem
pSet.nonempty_to_set_iff
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonempty_type_iff_nonempty {x : pSet} : nonempty x.type ↔ pSet.nonempty x
⟨λ ⟨i⟩, ⟨_, func_mem _ i⟩, λ ⟨i, j, h⟩, ⟨j⟩⟩
theorem
pSet.nonempty_type_iff_nonempty
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet", "pSet.nonempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonempty_of_nonempty_type (x : pSet) [h : nonempty x.type] : pSet.nonempty x
nonempty_type_iff_nonempty.1 h
theorem
pSet.nonempty_of_nonempty_type
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet", "pSet.nonempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv.eq {x y : pSet} : equiv x y ↔ to_set x = to_set y
equiv_iff_mem.trans set.ext_iff.symm
theorem
pSet.equiv.eq
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "pSet" ]
Two pre-sets are equivalent iff they have the same members.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
empty : pSet
⟨_, pempty.elim⟩
def
pSet.empty
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The empty pre-set
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
not_mem_empty (x : pSet.{u}) : x ∉ (∅ : pSet.{u})
is_empty.exists_iff.1
theorem
pSet.not_mem_empty
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_set_empty : to_set ∅ = ∅
by simp [to_set]
theorem
pSet.to_set_empty
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
empty_subset (x : pSet.{u}) : (∅ : pSet) ⊆ x
λ x, x.elim
theorem
pSet.empty_subset
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
not_nonempty_empty : ¬ pSet.nonempty ∅
by simp [pSet.nonempty]
theorem
pSet.not_nonempty_empty
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet.nonempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_empty (x : pSet) [is_empty x.type] : equiv x ∅
pSet.equiv_of_is_empty x _
theorem
pSet.equiv_empty
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "is_empty", "pSet", "pSet.equiv_of_is_empty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
insert (x y : pSet) : pSet
⟨option y.type, λ o, option.rec x y.func o⟩
def
pSet.insert
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
Insert an element into a pre-set
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_nat : ℕ → pSet
| 0 := ∅ | (n+1) := insert (of_nat n) (of_nat n)
def
pSet.of_nat
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The n-th von Neumann ordinal
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
omega : pSet
⟨ulift ℕ, λ n, of_nat n.down⟩
def
pSet.omega
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The von Neumann ordinal ω
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sep (p : pSet → Prop) (x : pSet) : pSet
⟨{a // p (x.func a)}, λ y, x.func y.1⟩
def
pSet.sep
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The pre-set separation operation `{x ∈ a | p x}`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerset (x : pSet) : pSet
⟨set x.type, λ p, ⟨{a // p a}, λ y, x.func y.1⟩⟩
def
pSet.powerset
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The pre-set powerset operator
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_powerset : Π {x y : pSet}, y ∈ powerset x ↔ y ⊆ x
| ⟨α, A⟩ ⟨β, B⟩ := ⟨λ ⟨p, e⟩, (subset.congr_left e).2 $ λ ⟨a, pa⟩, ⟨a, equiv.refl (A a)⟩, λ βα, ⟨{a | ∃ b, equiv (B b) (A a)}, λ b, let ⟨a, ba⟩ := βα b in ⟨⟨a, b, ba⟩, ba⟩, λ ⟨a, b, ba⟩, ⟨b, ba⟩⟩⟩
theorem
pSet.mem_powerset
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv", "equiv.refl", "pSet" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sUnion (a : pSet) : pSet
⟨Σ x, (a.func x).type, λ ⟨x, y⟩, (a.func x).func y⟩
def
pSet.sUnion
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The pre-set union operator
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_sUnion : Π {x y : pSet.{u}}, y ∈ ⋃₀ x ↔ ∃ z ∈ x, y ∈ z
| ⟨α, A⟩ y := ⟨λ ⟨⟨a, c⟩, (e : equiv y ((A a).func c))⟩, have func (A a) c ∈ mk (A a).type (A a).func, from mem.mk (A a).func c, ⟨_, mem.mk _ _, (mem.congr_left e).2 (by rwa eta at this)⟩, λ ⟨⟨β, B⟩, ⟨a, (e : equiv (mk β B) (A a))⟩, ⟨b, yb⟩⟩, by { rw ←(eta (A a)) at e, exact let ⟨βt, tβ⟩ := e, ⟨c, b...
theorem
pSet.mem_sUnion
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_set_sUnion (x : pSet.{u}) : (⋃₀ x).to_set = ⋃₀ (to_set '' x.to_set)
by { ext, simp }
theorem
pSet.to_set_sUnion
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image (f : pSet.{u} → pSet.{u}) (x : pSet.{u}) : pSet
⟨x.type, f ∘ x.func⟩
def
pSet.image
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
The image of a function from pre-sets to pre-sets.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_image {f : pSet.{u} → pSet.{u}} (H : ∀ {x y}, equiv x y → equiv (f x) (f y)) : Π {x y : pSet.{u}}, y ∈ image f x ↔ ∃ z ∈ x, equiv y (f z)
| ⟨α, A⟩ y := ⟨λ ⟨a, ya⟩, ⟨A a, mem.mk A a, ya⟩, λ ⟨z, ⟨a, za⟩, yz⟩, ⟨a, yz.trans (H za)⟩⟩
theorem
pSet.mem_image
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lift : pSet.{u} → pSet.{max u v}
| ⟨α, A⟩ := ⟨ulift α, λ ⟨x⟩, lift (A x)⟩
def
pSet.lift
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "lift" ]
Universe lift operation
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
embed : pSet.{max (u+1) v}
⟨ulift.{v u+1} pSet, λ ⟨x⟩, pSet.lift.{u (max (u+1) v)} x⟩
def
pSet.embed
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "pSet" ]
Embedding of one universe in another
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lift_mem_embed : Π (x : pSet.{u}), pSet.lift.{u (max (u+1) v)} x ∈ embed.{u v}
λ x, ⟨⟨x⟩, equiv.rfl⟩
theorem
pSet.lift_mem_embed
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arity.equiv : Π {n}, arity pSet.{u} n → arity pSet.{u} n → Prop
| 0 a b := equiv a b | (n+1) a b := ∀ x y, equiv x y → arity.equiv (a x) (b y)
def
pSet.arity.equiv
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity", "equiv" ]
Function equivalence is defined so that `f ~ g` iff `∀ x y, x ~ y → f x ~ g y`. This extends to equivalence of `n`-ary functions.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arity.equiv_const {a : pSet.{u}} : ∀ n, arity.equiv (arity.const a n) (arity.const a n)
| 0 := equiv.rfl | (n+1) := λ x y h, arity.equiv_const _
lemma
pSet.arity.equiv_const
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity.const" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp (n)
{x : arity pSet.{u} n // arity.equiv x x}
def
pSet.resp
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
`resp n` is the collection of n-ary functions on `pSet` that respect equivalence, i.e. when the inputs are equivalent the output is as well.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp.inhabited {n} : inhabited (resp n)
⟨⟨arity.const default _, arity.equiv_const _⟩⟩
instance
pSet.resp.inhabited
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp.f {n} (f : resp (n+1)) (x : pSet) : resp n
⟨f.1 x, f.2 _ _ $ equiv.refl x⟩
def
pSet.resp.f
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv.refl", "pSet" ]
The `n`-ary image of a `(n + 1)`-ary function respecting equivalence as a function respecting equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp.equiv {n} (a b : resp n) : Prop
arity.equiv a.1 b.1
def
pSet.resp.equiv
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
Function equivalence for functions respecting equivalence. See `pSet.arity.equiv`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp.equiv.refl {n} (a : resp n) : resp.equiv a a
a.2
theorem
pSet.resp.equiv.refl
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp.equiv.euc : Π {n} {a b c : resp n}, resp.equiv a b → resp.equiv c b → resp.equiv a c
| 0 a b c hab hcb := equiv.euc hab hcb | (n+1) a b c hab hcb := λ x y h, @resp.equiv.euc n (a.f x) (b.f y) (c.f y) (hab _ _ h) (hcb _ _ $ equiv.refl y)
theorem
pSet.resp.equiv.euc
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "equiv.refl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp.equiv.symm {n} {a b : resp n} : resp.equiv a b → resp.equiv b a
(resp.equiv.refl b).euc
theorem
pSet.resp.equiv.symm
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp.equiv.trans {n} {x y z : resp n} (h1 : resp.equiv x y) (h2 : resp.equiv y z) : resp.equiv x z
h1.euc h2.symm
theorem
pSet.resp.equiv.trans
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
resp.setoid {n} : setoid (resp n)
⟨resp.equiv, resp.equiv.refl, λ x y, resp.equiv.symm, λ x y z, resp.equiv.trans⟩
instance
pSet.resp.setoid
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Set : Type (u+1)
quotient pSet.setoid.{u}
def
Set
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[]
The ZFC universe of sets consists of the type of pre-sets, quotiented by extensional equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eval_aux : Π {n}, {f : resp n → arity Set.{u} n // ∀ (a b : resp n), resp.equiv a b → f a = f b}
| 0 := ⟨λ a, ⟦a.1⟧, λ a b h, quotient.sound h⟩ | (n+1) := let F : resp (n + 1) → arity Set (n + 1) := λ a, @quotient.lift _ _ pSet.setoid (λ x, eval_aux.1 (a.f x)) (λ b c h, eval_aux.2 _ _ (a.2 _ _ h)) in ⟨F, λ b c h, funext $ @quotient.ind _ _ (λ q, F b q = F c q) $ λ z, eval_aux.2 (resp.f b z) (resp.f c z...
def
pSet.resp.eval_aux
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "Set", "arity", "pSet.equiv.refl", "pSet.setoid" ]
Helper function for `pSet.eval`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eval (n) : resp n → arity Set.{u} n
eval_aux.1
def
pSet.resp.eval
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
An equivalence-respecting function yields an n-ary ZFC set function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eval_val {n f x} : (@eval (n+1) f : Set → arity Set n) ⟦x⟧ = eval n (resp.f f x)
rfl
theorem
pSet.resp.eval_val
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "Set", "arity" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
definable (n) : arity Set.{u} n → Type (u+1) | mk (f) : definable (resp.eval n f)
class inductive
pSet.definable
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
A set function is "definable" if it is the image of some n-ary pre-set function. This isn't exactly definability, but is useful as a sufficient condition for functions that have a computable image.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
definable.eq_mk {n} (f) : Π {s : arity Set.{u} n} (H : resp.eval _ f = s), definable n s
| ._ rfl := ⟨f⟩
def
pSet.definable.eq_mk
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
The evaluation of a function respecting equivalence is definable, by that same function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
definable.resp {n} : Π (s : arity Set.{u} n) [definable n s], resp n
| ._ ⟨f⟩ := f
def
pSet.definable.resp
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
Turns a definable function into a function that respects equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
definable.eq {n} : Π (s : arity Set.{u} n) [H : definable n s], (@definable.resp n s H).eval _ = s
| ._ ⟨f⟩ := rfl
theorem
pSet.definable.eq
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
all_definable : Π {n} (F : arity Set.{u} n), definable n F
| 0 F := let p := @quotient.exists_rep pSet _ F in definable.eq_mk ⟨some p, equiv.rfl⟩ (some_spec p) | (n+1) (F : arity Set.{u} (n + 1)) := begin have I := λ x, (all_definable (F x)), refine definable.eq_mk ⟨λ x : pSet, (@definable.resp _ _ (I ⟦x⟧)).1, _⟩ _, { dsimp [arity.equiv], in...
def
classical.all_definable
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "arity", "pSet", "subtype.coe_eta", "subtype.val_eq_coe" ]
All functions are classically definable.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk : pSet → Set
quotient.mk
def
Set.mk
set_theory.zfc
src/set_theory/zfc/basic.lean
[ "data.set.lattice", "logic.small.basic", "order.well_founded" ]
[ "Set", "pSet" ]
Turns a pre-set into a ZFC set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83