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import OAI.ModelTheory.Choiceless.Hereditary
namespace OAI
noncomputable section
namespace CPTSeparation.Forms
open Classical Counting Hereditary
open scoped BigOperators
private theorem card_eq_mul_fiber {X Y : Type*} [Fintype X] [Fintype Y]
(f : X → Y) (y₀ : Y)
(h : ∀ y, Fintype.card {x // f x = y} = Fintype.card {x // f x = y₀}) :
Fintype.card X = Fintype.card Y * Fintype.card {x // f x = y₀} := by
calc
Fintype.card X = Fintype.card (Σ y, {x // f x = y}) :=
Fintype.card_congr (Equiv.sigmaFiberEquiv f).symm
_ = ∑ y, Fintype.card {x // f x = y} := Fintype.card_sigma
_ = _ := by simp only [h,Finset.sum_const,Finset.card_univ,smul_eq_mul]
private theorem card_eq_of_uniform_fibers {X X' Y Y' : Type*}
[Fintype X] [Fintype X'] [Fintype Y] [Fintype Y']
(f : X → Y) (f' : X' → Y') (y : Y) (y' : Y')
(hx : Fintype.card X = Fintype.card X')
(hf : ∀ z, Fintype.card {x // f x = z} = Fintype.card {x // f x = y})
(hf' : ∀ z, Fintype.card {x // f' x = z} = Fintype.card {x // f' x = y'})
(hy : 0 < Fintype.card {x // f x = y})
(he : Fintype.card {x // f x = y} = Fintype.card {x // f' x = y'}) :
Fintype.card Y = Fintype.card Y' := by
have h := (card_eq_mul_fiber f y hf).symm.trans
(hx.trans (card_eq_mul_fiber f' y' hf'))
rw [←he] at h
exact Nat.eq_of_mul_eq_mul_right hy h
private theorem range_card_mul_fiber {X Y : Type*} [Fintype X]
(f : X → Y) (x₀ : X)
(h : ∀ x, Nat.card {z // f z = f x} = Nat.card {z // f z = f x₀}) :
Fintype.card X = Nat.card (Set.range f) * Nat.card {z // f z = f x₀} := by
let := (Set.finite_range f).fintype
let fR : X → Set.range f := fun x => ⟨f x,⟨x,rfl⟩⟩
have k (y : Set.range f) : Nat.card {x // fR x = y} =
Nat.card {z // f z = f x₀} := by
have hp (x : X) : fR x = y ↔ f x = y.1 := Subtype.ext_iff
rw [Nat.card_congr (Equiv.subtypeEquivRight hp)]
obtain ⟨x,hx⟩ := y.2
rw [←hx]
exact h x
have hh := card_eq_mul_fiber fR (fR x₀) (fun y => by
simpa only [←Nat.card_eq_fintype_card] using (k y).trans (k (fR x₀)).symm)
have hh' : Nat.card X = Nat.card (Set.range f) * Nat.card {x // fR x = fR x₀} := by
simpa only [←Nat.card_eq_fintype_card] using hh
rw [k] at hh'
simpa only [←Nat.card_eq_fintype_card] using hh'
variable {R I A B P : Type*} [finiteI : Fintype I] [DecidableEq I]
variable [finiteA : Fintype A] [Fintype B] [nonemptyA : Nonempty A] [Nonempty B] [finiteP : Fintype P]
variable {s : ℕ}
def Molecules (S : Structure R A) (ep : P ⊕ Fin s ↪ I)
(p : P → A) (τ : Set (Formula R I)) :=
{a : Fin s → A // tupleType S ep (Sum.elim p a) = τ}
instance (S : Structure R A) (ep : P ⊕ Fin s ↪ I)
(p : P → A) (τ : Set (Formula R I)) : Fintype (Molecules S ep p τ) :=
inferInstanceAs (Fintype {a : Fin s → A // tupleType S ep (Sum.elim p a) = τ})
def labelValues (S : Structure R A) (ep : P ⊕ Fin s ↪ I)
(e2 : Fin s ⊕ Fin s ↪ I) (p : P → A) (τ : Set (Formula R I))
(φ : Form (Fin s) (Set (Formula R I))) : Set (HF A) :=
Set.range (fun a : Molecules S ep p τ => Form.value S e2 φ a.1)
instance (S : Structure R A) (ep : P ⊕ Fin s ↪ I)
(e2 : Fin s ⊕ Fin s ↪ I) (p : P → A) (τ : Set (Formula R I))
(φ : Form (Fin s) (Set (Formula R I))) : Fintype (labelValues S ep e2 p τ φ) :=
(Set.finite_range _).fintype
section Group
variable {G : Type*} [Group G] [MulAction G A]
variable (S : Structure R A) (ep : P ⊕ Fin s ↪ I) (e2 : Fin s ⊕ Fin s ↪ I)
variable (hAut : ∀ (g : G) r a b, S.rel r (g • a) (g • b) ↔ S.rel r a b)
variable (p : P → A) (τ : Set (Formula R I))
omit R I A P s G S ep hAut p in
private theorem mol_type_smul.{uDecl1, uDecl2, uDecl3, uDecl5, uDecl6}
{R : Type uDecl1}
{I : Type uDecl2}
{A : Type uDecl3}
{P : Type uDecl5}
[Fintype I]
[DecidableEq I]
[Fintype A]
[Nonempty A]
[Fintype P]
{s : ℕ}
{G : Type uDecl6}
[Group G]
[MulAction G A]
(S : Counting.Structure R A)
(ep : P ⊕ Fin s ↪ I)
(hAut : ∀ (g : G) (r : R) (a b : A), S.rel r (g • a) (g • b) ↔ S.rel r a b)
(p : P → A) (g : G) (hp : ∀ i, g • p i = p i) (a : Fin s → A) :
tupleType S ep (Sum.elim p (fun i => g • a i)) = tupleType S ep (Sum.elim p a) := by
have hh := tupleType_iso S S ep (MulAction.toPerm g) (fun r a b => (hAut g r a b).symm)
(Sum.elim p a)
have hh' : (MulAction.toPerm g) ∘ Sum.elim p a = Sum.elim p (fun i => g • a i) := by
funext i; rcases i with i|i
· exact hp i
· rfl
rw [hh'] at hh
exact hh.symm
def moleculesPerm (g : G) (hp : ∀ i, g • p i = p i) :
Molecules S ep p τ ≃ Molecules S ep p τ :=
(Equiv.piCongrRight (fun _ : Fin s => MulAction.toPerm g)).subtypeEquiv
(fun a => by
change tupleType S ep (Sum.elim p a) = τ ↔
tupleType S ep (Sum.elim p (fun i => g • a i)) = τ
rw [mol_type_smul S ep hAut p g hp a])
include hAut in
omit R I A P s G S ep e2 hAut p τ in
theorem uniform_value_fibers.{uDecl1, uDecl2, uDecl3, uDecl5, uDecl6}
{R : Type uDecl1}
{I : Type uDecl2}
{A : Type uDecl3}
{P : Type uDecl5}
[Fintype I]
[DecidableEq I]
[Fintype A]
[Nonempty A]
[Fintype P]
{s : ℕ}
{G : Type uDecl6}
[Group G]
[MulAction G A]
(S : Counting.Structure R A)
(ep : P ⊕ Fin s ↪ I)
(e2 : Fin s ⊕ Fin s ↪ I)
(hAut : ∀ (g : G) (r : R) (a b : A), S.rel r (g • a) (g • b) ↔ S.rel r a b)
(p : P → A)
(τ : Set (Counting.Formula R I))
(hHom : ∀ a b : P ⊕ Fin s → A,
tupleType S ep a = tupleType S ep b → ∃ g : G, ∀ i, g • a i = b i)
(φ : Form (Fin s) (Set (Formula R I))) (a a' : Molecules S ep p τ) :
Fintype.card {b : Molecules S ep p τ // Form.value S e2 φ b.1 = Form.value S e2 φ a.1} =
Fintype.card {b : Molecules S ep p τ // Form.value S e2 φ b.1 = Form.value S e2 φ a'.1} := by
obtain ⟨g,hg⟩ := hHom (Sum.elim p a.1) (Sum.elim p a'.1) (a.2.trans a'.2.symm)
have hp : ∀ i, g • p i = p i := fun i => hg (.inl i)
have ha : (fun i => g • a.1 i) = a'.1 := funext (fun i => hg (.inr i))
let f := moleculesPerm S ep hAut p τ g hp
have hv (b : Molecules S ep p τ) :
Form.value S e2 φ (f b).1 = g • Form.value S e2 φ b.1 := by
exact (value_smul S e2 hAut g φ b.1).symm
have hv' : Form.value S e2 φ a'.1 = g • Form.value S e2 φ a.1 := by
rw [←ha]
exact (value_smul S e2 hAut g φ a.1).symm
apply Fintype.card_congr
apply f.subtypeEquiv
intro b
rw [hv,hv']
exact (MulAction.injective g).eq_iff.symm
omit R I A P s G S ep e2 hAut p τ in
private theorem label_orbit.{uDecl1, uDecl2, uDecl3, uDecl5, uDecl6}
{R : Type uDecl1}
{I : Type uDecl2}
{A : Type uDecl3}
{P : Type uDecl5}
[Fintype I]
[DecidableEq I]
[Fintype A]
[Nonempty A]
[Fintype P]
{s : ℕ}
{G : Type uDecl6}
[Group G]
[MulAction G A]
(S : Counting.Structure R A)
(ep : P ⊕ Fin s ↪ I)
(e2 : Fin s ⊕ Fin s ↪ I)
(hAut : ∀ (g : G) (r : R) (a b : A), S.rel r (g • a) (g • b) ↔ S.rel r a b)
(p : P → A)
(τ : Set (Counting.Formula R I))
(hHom : ∀ a b : P ⊕ Fin s → A,
tupleType S ep a = tupleType S ep b → ∃ g : G, ∀ i, g • a i = b i)
(φ : Form (Fin s) (Set (Formula R I))) (x y : HF A)
(hx : x ∈ labelValues S ep e2 p τ φ) (hy : y ∈ labelValues S ep e2 p τ φ) :
∃ g : G, (∀ i, g • p i = p i) ∧ g • x = y := by
obtain ⟨a,rfl⟩ := hx
obtain ⟨b,rfl⟩ := hy
obtain ⟨g,hg⟩ := hHom (Sum.elim p a.1) (Sum.elim p b.1) (a.2.trans b.2.symm)
refine ⟨g,fun i => hg (.inl i),?_⟩
rw [value_smul S e2 hAut]
exact congrArg (Form.value S e2 φ) (funext (fun i => hg (.inr i)))
omit R I A P s G S ep e2 hAut p τ in
private theorem label_smul_mem.{uDecl1, uDecl2, uDecl3, uDecl5, uDecl6}
{R : Type uDecl1}
{I : Type uDecl2}
{A : Type uDecl3}
{P : Type uDecl5}
[Fintype I]
[DecidableEq I]
[Fintype A]
[Nonempty A]
[Fintype P]
{s : ℕ}
{G : Type uDecl6}
[Group G]
[MulAction G A]
(S : Counting.Structure R A)
(ep : P ⊕ Fin s ↪ I)
(e2 : Fin s ⊕ Fin s ↪ I)
(hAut : ∀ (g : G) (r : R) (a b : A), S.rel r (g • a) (g • b) ↔ S.rel r a b)
(p : P → A)
(τ : Set (Counting.Formula R I)) (g : G) (hp : ∀ i, g • p i = p i)
(φ : Form (Fin s) (Set (Formula R I))) (x : HF A)
(hx : x ∈ labelValues S ep e2 p τ φ) : g • x ∈ labelValues S ep e2 p τ φ := by
obtain ⟨a,rfl⟩ := hx
refine ⟨moleculesPerm S ep hAut p τ g hp a,?_⟩
exact (value_smul S e2 hAut g φ a.1).symm
include hAut in
theorem label_partition
(hHom : ∀ a b : P ⊕ Fin s → A,
tupleType S ep a = tupleType S ep b → ∃ g : G, ∀ i, g • a i = b i)
(φ ψ : Form (Fin s) (Set (Formula R I))) (σ : Set (Formula R I)) (x : HF A)
(hx : x ∈ labelValues S ep e2 p τ φ) (hx' : x ∈ labelValues S ep e2 p σ ψ) :
labelValues S ep e2 p τ φ = labelValues S ep e2 p σ ψ := by
ext y
constructor
· intro hy
obtain ⟨g,hp,hg⟩ := label_orbit S ep e2 hAut p τ hHom φ x y hx hy
rw [←hg]
exact label_smul_mem S ep e2 hAut p σ g hp ψ x hx'
· intro hy
obtain ⟨g,hp,hg⟩ := label_orbit S ep e2 hAut p σ hHom ψ x y hx' hy
rw [←hg]
exact label_smul_mem S ep e2 hAut p τ g hp φ x hx
end Group
variable (S : Structure R A) (T : Structure R B)
variable (ep : P ⊕ Fin s ↪ I) (epp : (P ⊕ Fin s) ⊕ Fin s ↪ I)
variable (e2 : Fin s ⊕ Fin s ↪ I)
variable (e3 : (Fin s ⊕ Fin s) ⊕ Fin s ↪ I)
variable (e4 : ((Fin s ⊕ Fin s) ⊕ Fin s) ⊕ Fin s ↪ I)
private def skipMiddle : P ⊕ Fin s ↪ (P ⊕ Fin s) ⊕ Fin s :=
Function.Embedding.sumMap Function.Embedding.inl (Function.Embedding.refl _)
private def lastTwo : Fin s ⊕ Fin s ↪ (P ⊕ Fin s) ⊕ Fin s :=
Function.Embedding.sumMap Function.Embedding.inr (Function.Embedding.refl _)
omit A P s in
@[simp] private theorem elim_skipMiddle.{uDecl3, uDecl5}
{A : Type uDecl3}
{P : Type uDecl5}
[Fintype A]
[Nonempty A]
[Fintype P]
{s : ℕ} (p : P → A) (a b : Fin s → A) :
(Sum.elim (Sum.elim p a) b) ∘ skipMiddle = Sum.elim p b := by
funext j; cases j <;> rfl
omit A P s in
@[simp] private theorem elim_lastTwo.{uDecl3, uDecl5}
{A : Type uDecl3}
{P : Type uDecl5}
[Fintype A]
[Nonempty A]
[Fintype P]
{s : ℕ} (p : P → A) (a b : Fin s → A) :
(Sum.elim (Sum.elim p a) b) ∘ lastTwo = Sum.elim a b := by
funext j; cases j <;> rfl
include epp e3 e4 in
theorem value_fiber_equiv (p : P → A) (q : P → B) (τ : Set (Formula R I))
(φ : Form (Fin s) (Set (Formula R I)))
(a : Molecules S ep p τ) (a' : Molecules T ep q τ) :
Nonempty ({b : Molecules S ep p τ // Form.value S e2 φ b.1 = Form.value S e2 φ a.1} ≃
{b : Molecules T ep q τ // Form.value T e2 φ b.1 = Form.value T e2 φ a'.1}) := by
obtain ⟨f,hf⟩ := tupleType_append_bijection S T ep epp
(Sum.elim p a.1) (Sum.elim q a'.1) (a.2.trans a'.2.symm)
have htype (b : Fin s → A) : tupleType S ep (Sum.elim p b) =
tupleType T ep (Sum.elim q (f b)) := by
have hh := tupleType_project S T epp ep skipMiddle _ _ (hf b)
simpa only [elim_skipMiddle] using hh
have hval (b : Fin s → A) : Form.value S e2 φ b = Form.value S e2 φ a.1 ↔
Form.value T e2 φ (f b) = Form.value T e2 φ a'.1 := by
have hh := tupleType_project S T epp e2 lastTwo _ _ (hf b)
simp only [elim_lastTwo] at hh
simpa only [eq_comm] using equality_transfer S T e2 e3 e4 φ φ a.1 b a'.1 (f b) hh
let F : {b : Fin s → A // tupleType S ep (Sum.elim p b) = τ ∧
Form.value S e2 φ b = Form.value S e2 φ a.1} ≃
{b : Fin s → B // tupleType T ep (Sum.elim q b) = τ ∧
Form.value T e2 φ b = Form.value T e2 φ a'.1} := f.subtypeEquiv (fun b => show
(tupleType S ep (Sum.elim p b) = τ ∧ Form.value S e2 φ b = Form.value S e2 φ a.1) ↔
(tupleType T ep (Sum.elim q (f b)) = τ ∧ Form.value T e2 φ (f b) = Form.value T e2 φ a'.1)
from and_congr (by rw [htype b]) (hval b))
exact ⟨(Equiv.subtypeSubtypeEquivSubtypeInter _ _).trans
(F.trans (Equiv.subtypeSubtypeEquivSubtypeInter _ _).symm)⟩
include epp e3 e4 in
theorem label_overlap_transfer (e0 : P ↪ I) (p : P → A) (q : P → B)
(hp : tupleType S e0 p = tupleType T e0 q)
(φ ψ : Form (Fin s) (Set (Formula R I))) (τ σ : Set (Formula R I))
(hx : ∃ x, x ∈ labelValues S ep e2 p τ φ ∧ x ∈ labelValues S ep e2 p σ ψ) :
∃ y, y ∈ labelValues T ep e2 q τ φ ∧ y ∈ labelValues T ep e2 q σ ψ := by
obtain ⟨x,⟨a,ha⟩,⟨b,hb⟩⟩ := hx
obtain ⟨a',ha'⟩ := tupleType_append S T e0 ep p q a.1 hp
obtain ⟨b',hb'⟩ := tupleType_append S T ep epp
(Sum.elim p a.1) (Sum.elim q a') b.1 ha'
have ht := tupleType_project S T epp ep skipMiddle _ _ hb'
simp only [elim_skipMiddle] at ht
have he := tupleType_project S T epp e2 lastTwo _ _ hb'
simp only [elim_lastTwo] at he
have hv := (equality_transfer S T e2 e3 e4 φ ψ a.1 b.1 a' b' he).mp (ha.trans hb.symm)
refine ⟨Form.value T e2 φ a',?_,?_⟩
· exact ⟨⟨a',ha'.symm.trans a.2⟩,rfl⟩
· exact ⟨⟨b',ht.symm.trans b.2⟩,hv.symm⟩
include epp e3 e4 in
theorem label_values_card
{G H : Type*} [Group G] [MulAction G A] [Group H] [MulAction H B]
(hAutA : ∀ (g : G) r a b, S.rel r (g • a) (g • b) ↔ S.rel r a b)
(hAutB : ∀ (g : H) r a b, T.rel r (g • a) (g • b) ↔ T.rel r a b)
(hHomA : ∀ a b : P ⊕ Fin s → A,
tupleType S ep a = tupleType S ep b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB : ∀ a b : P ⊕ Fin s → B,
tupleType T ep a = tupleType T ep b → ∃ g : H, ∀ i, g • a i = b i)
(p : P → A) (q : P → B) (τ : Set (Formula R I))
(φ : Form (Fin s) (Set (Formula R I)))
(a : Molecules S ep p τ) (a' : Molecules T ep q τ) :
Nat.card (labelValues S ep e2 p τ φ) = Nat.card (labelValues T ep e2 q τ φ) := by
let va : Molecules S ep p τ → HF A := fun b => Form.value S e2 φ b.1
let vb : Molecules T ep q τ → HF B := fun b => Form.value T e2 φ b.1
have ha := range_card_mul_fiber va a (fun b => by simpa only [←Nat.card_eq_fintype_card] using uniform_value_fibers S ep e2 hAutA p τ hHomA φ b a)
have hb := range_card_mul_fiber vb a' (fun b => by simpa only [←Nat.card_eq_fintype_card] using uniform_value_fibers T ep e2 hAutB q τ hHomB φ b a')
let e0 := Function.Embedding.inl.trans ep
have hp := tupleType_project S T ep e0 Function.Embedding.inl
(Sum.elim p a.1) (Sum.elim q a'.1) (a.2.trans a'.2.symm)
change tupleType S e0 p = tupleType T e0 q at hp
obtain ⟨f⟩ := tupleType_extension_equiv S T e0 ep p q hp τ
have hn : Fintype.card (Molecules S ep p τ) = Fintype.card (Molecules T ep q τ) :=
Fintype.card_congr f
obtain ⟨fv⟩ := value_fiber_equiv S T ep epp e2 e3 e4 p q τ φ a a'
have he : Nat.card {b // va b = va a} = Nat.card {b // vb b = vb a'} :=
Nat.card_congr fv
have hpos : 0 < Nat.card {b // va b = va a} := by
rw [Nat.card_eq_fintype_card]
exact Fintype.card_pos_iff.mpr ⟨⟨a,rfl⟩⟩
have hc := ha.symm.trans (hn.trans hb)
rw [←he] at hc
have hh := Nat.eq_of_mul_eq_mul_right hpos hc
simpa only [←Nat.card_eq_fintype_card,labelValues,va,vb] using hh
end CPTSeparation.Forms
namespace CPTSeparation
open Classical
private def cellSetoid {L X : Type*} (C : L → Set X) : Setoid L :=
⟨fun l k => C l = C k,⟨fun _ => rfl,Eq.symm,Eq.trans⟩⟩
theorem glue_finite_cells {L X Y : Type*} (C : L → Set X) (D : L → Set Y)
(coverC : ∀ x, ∃ l, x ∈ C l) (coverD : ∀ y, ∃ l, y ∈ D l)
(partC : ∀ l k x, x ∈ C l → x ∈ C k → C l = C k)
(partD : ∀ l k y, y ∈ D l → y ∈ D k → D l = D k)
(same : ∀ l k, C l = C k ↔ D l = D k)
(finC : ∀ l, (C l).Finite) (finD : ∀ l, (D l).Finite)
(card : ∀ l, Nat.card (C l) = Nat.card (D l)) :
∃ f : X ≃ Y, ∀ x, ∃ l, x ∈ C l ∧ f x ∈ D l := by
let Q := Quotient (cellSetoid C)
let lc : X → L := fun x => (coverC x).choose
let ld : Y → L := fun y => (coverD y).choose
have hc (x : X) : x ∈ C (lc x) := (coverC x).choose_spec
have hd (y : Y) : y ∈ D (ld y) := (coverD y).choose_spec
let c : X → Q := fun x => Quotient.mk _ (lc x)
let d : Y → Q := fun y => Quotient.mk _ (ld y)
have ce (x : X) (q : Q) : c x = q ↔ x ∈ C q.out := by
constructor
· intro h
have he : C (lc x) = C q.out := Quotient.exact (h.trans (Quotient.out_eq q).symm)
rw [←he]; exact hc x
· intro h
have he := partC (lc x) q.out x (hc x) h
exact (Quotient.sound he).trans (Quotient.out_eq q)
have de (y : Y) (q : Q) : d y = q ↔ y ∈ D q.out := by
constructor
· intro h
have he : C (ld y) = C q.out := Quotient.exact (h.trans (Quotient.out_eq q).symm)
rw [←(same _ _).mp he]; exact hd y
· intro h
have he := (same _ _).mpr (partD (ld y) q.out y (hd y) h)
exact (Quotient.sound he).trans (Quotient.out_eq q)
have ef (q : Q) : Nonempty ({x // c x = q} ≃ {y // d y = q}) := by
let := (finC q.out).fintype
let := (finD q.out).fintype
have hcard : Fintype.card (C q.out) = Fintype.card (D q.out) := by
simpa only [Nat.card_eq_fintype_card] using card q.out
let e := Fintype.equivOfCardEq hcard
exact ⟨(Equiv.subtypeEquivRight (fun x => ce x q)).trans
(e.trans (Equiv.subtypeEquivRight (fun y => de y q)).symm)⟩
let F := Equiv.ofFiberEquiv (fun q => Classical.choice (ef q))
refine ⟨F,fun x => ⟨(c x).out,(ce x (c x)).mp rfl,?_⟩⟩
apply (de (F x) (c x)).mp
exact Equiv.ofFiberEquiv_map _ x
end CPTSeparation
namespace CPTSeparation.Forms
section
open Classical Counting Hereditary
variable {R I A B P G H : Type*}
variable [Fintype I] [DecidableEq I] [Fintype A] [Fintype B]
variable [Nonempty A] [Nonempty B] [Fintype P]
variable [Group G] [MulAction G A] [Group H] [MulAction H B]
variable {s : ℕ}
abbrev Domain (G : Type*) [Group G] [MulAction G A] (s : ℕ) :=
{x : HF A // HereditarilySupported (G := G) s x}
def Cell (S : Structure R A) (ep : P ⊕ Fin s ↪ I) (e2 : Fin s ⊕ Fin s ↪ I)
(p : P → A) (φ : Form (Fin s) (Set (Formula R I))) (τ : Set (Formula R I)) :
Set (Domain (A := A) G s) :=
{x | x.1 ∈ labelValues S ep e2 p τ φ}
variable (S : Structure R A) (T : Structure R B)
variable (ep : P ⊕ Fin s ↪ I) (epp : (P ⊕ Fin s) ⊕ Fin s ↪ I)
variable (e2 : Fin s ⊕ Fin s ↪ I) (e3 : (Fin s ⊕ Fin s) ⊕ Fin s ↪ I)
variable (e4 : ((Fin s ⊕ Fin s) ⊕ Fin s) ⊕ Fin s ↪ I)
variable (hAutA : ∀ (g : G) r a b, S.rel r (g • a) (g • b) ↔ S.rel r a b)
variable (hAutB : ∀ (g : H) r a b, T.rel r (g • a) (g • b) ↔ T.rel r a b)
def cellEquiv (p : P → A) (φ : Form (Fin s) (Set (Formula R I))) (τ : Set (Formula R I)) :
Cell (G := G) S ep e2 p φ τ ≃ labelValues S ep e2 p τ φ :=
Equiv.subtypeSubtypeEquivSubtype
(p := HereditarilySupported (G := G) s)
(q := fun x => x ∈ labelValues S ep e2 p τ φ) (fun hx => by
obtain ⟨a,rfl⟩ := hx
exact value_hereditarily_supported S e2 hAutA φ a.1)
include hAutA in
private theorem cell_finite (p : P → A) (φ : Form (Fin s) (Set (Formula R I))) (τ : Set (Formula R I)) :
(Cell (G := G) S ep e2 p φ τ).Finite := by
let := Fintype.ofEquiv (labelValues S ep e2 p τ φ) (cellEquiv S ep e2 hAutA p φ τ).symm
exact Set.toFinite _
include hAutA hAutB epp e3 e4 in
theorem supported_domain_bijection (hs : 0 < s) (e0 : P ↪ I)
(hHomA2 : ∀ a b : Fin s ⊕ Fin s → A,
tupleType S e2 a = tupleType S e2 b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB2 : ∀ a b : Fin s ⊕ Fin s → B,
tupleType T e2 a = tupleType T e2 b → ∃ g : H, ∀ i, g • a i = b i)
(hHomA : ∀ a b : P ⊕ Fin s → A,
tupleType S ep a = tupleType S ep b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB : ∀ a b : P ⊕ Fin s → B,
tupleType T ep a = tupleType T ep b → ∃ g : H, ∀ i, g • a i = b i)
(p : P → A) (q : P → B) (hp : tupleType S e0 p = tupleType T e0 q) :
∃ f : Domain (A := A) G s ≃ Domain (A := B) H s,
∀ x, ∃ φ : Form (Fin s) (Set (Formula R I)), ∃ a : Fin s → A, ∃ b : Fin s → B,
Form.value S e2 φ a = x.1 ∧ Form.value T e2 φ b = (f x).1 ∧
tupleType S ep (Sum.elim p a) = tupleType T ep (Sum.elim q b) := by
let L := {l : Form (Fin s) (Set (Formula R I)) × Set (Formula R I) //
Nonempty (Molecules S ep p l.2)}
let C : L → Set (Domain (A := A) G s) := fun l => Cell S ep e2 p l.1.1 l.1.2
let D : L → Set (Domain (A := B) H s) := fun l => Cell T ep e2 q l.1.1 l.1.2
have nonemptyB (l : L) : Nonempty (Molecules T ep q l.1.2) := by
obtain ⟨f⟩ := tupleType_extension_equiv S T e0 ep p q hp l.1.2
exact Nonempty.map f l.2
have coverC : ∀ x, ∃ l, x ∈ C l := by
intro x
obtain ⟨φ,a,ha⟩ := representation S e2 hAutA hs hHomA2 x.1 x.2
let τ := tupleType S ep (Sum.elim p a)
let l : L := ⟨(φ,τ),⟨⟨a,rfl⟩⟩⟩
exact ⟨l,⟨⟨a,rfl⟩,ha⟩⟩
have coverD : ∀ y, ∃ l, y ∈ D l := by
intro y
obtain ⟨φ,b,hb⟩ := representation T e2 hAutB hs hHomB2 y.1 y.2
obtain ⟨a,ha⟩ := tupleType_append T S e0 ep q p b hp.symm
let τ := tupleType T ep (Sum.elim q b)
let l : L := ⟨(φ,τ),⟨⟨a,ha.symm⟩⟩⟩
exact ⟨l,⟨⟨b,rfl⟩,hb⟩⟩
have partC : ∀ l k x, x ∈ C l → x ∈ C k → C l = C k := by
intro l k x hx hk
have hh := label_partition S ep e2 hAutA p l.1.2 hHomA l.1.1 k.1.1 k.1.2 x.1 hx hk
exact congrArg (fun Z : Set (HF A) => {x : Domain G s | x.1 ∈ Z}) hh
have partD : ∀ l k x, x ∈ D l → x ∈ D k → D l = D k := by
intro l k x hx hk
have hh := label_partition T ep e2 hAutB q l.1.2 hHomB l.1.1 k.1.1 k.1.2 x.1 hx hk
exact congrArg (fun Z : Set (HF B) => {x : Domain H s | x.1 ∈ Z}) hh
have same : ∀ l k, C l = C k ↔ D l = D k := by
intro l k
constructor
· intro he
obtain ⟨a⟩ := l.2
let x : Domain G s := ⟨Form.value S e2 l.1.1 a.1,
value_hereditarily_supported S e2 hAutA _ _⟩
have hx : x ∈ C l := ⟨a,rfl⟩
have hk : x ∈ C k := he ▸ hx
obtain ⟨y,hy,hy'⟩ := label_overlap_transfer S T ep epp e2 e3 e4 e0 p q hp
l.1.1 k.1.1 l.1.2 k.1.2 ⟨x.1,hx,hk⟩
have hsupp : HereditarilySupported (G := H) s y := by
obtain ⟨b,rfl⟩ := hy
exact value_hereditarily_supported T e2 hAutB _ _
exact partD l k ⟨y,hsupp⟩ hy hy'
· intro he
obtain ⟨b⟩ := nonemptyB l
let y : Domain H s := ⟨Form.value T e2 l.1.1 b.1,
value_hereditarily_supported T e2 hAutB _ _⟩
have hy : y ∈ D l := ⟨b,rfl⟩
have hk : y ∈ D k := he ▸ hy
obtain ⟨x,hx,hx'⟩ := label_overlap_transfer T S ep epp e2 e3 e4 e0 q p hp.symm
l.1.1 k.1.1 l.1.2 k.1.2 ⟨y.1,hy,hk⟩
have hsupp : HereditarilySupported (G := G) s x := by
obtain ⟨a,rfl⟩ := hx
exact value_hereditarily_supported S e2 hAutA _ _
exact partC l k ⟨x,hsupp⟩ hx hx'
have card : ∀ l, Nat.card (C l) = Nat.card (D l) := by
intro l
obtain ⟨a⟩ := l.2
obtain ⟨b⟩ := nonemptyB l
have hh := label_values_card S T ep epp e2 e3 e4 hAutA hAutB hHomA hHomB
p q l.1.2 l.1.1 a b
have he := Nat.card_congr (cellEquiv S ep e2 hAutA p l.1.1 l.1.2)
have hf := Nat.card_congr (cellEquiv T ep e2 hAutB q l.1.1 l.1.2)
exact he.trans (hh.trans hf.symm)
obtain ⟨f,hf⟩ := CPTSeparation.glue_finite_cells C D coverC coverD partC partD same
(fun l => cell_finite S ep e2 hAutA p l.1.1 l.1.2)
(fun l => cell_finite T ep e2 hAutB q l.1.1 l.1.2) card
refine ⟨f,fun x => ?_⟩
obtain ⟨l,⟨a,ha⟩,⟨b,hb⟩⟩ := hf x
exact ⟨l.1.1,a.1,b.1,ha,hb,a.2.trans b.2.symm⟩
end
open Classical Counting Hereditary
variable {R I A B V G H : Type*}
variable [finiteI : Fintype I] [DecidableEq I] [finiteA : Fintype A] [Fintype B]
variable [nonemptyA : Nonempty A] [Nonempty B] [finiteV : Fintype V] [decidableV : DecidableEq V]
variable [Group G] [MulAction G A] [Group H] [MulAction H B]
variable {s : ℕ}
inductive HFRelation (R : Type*)
| mem | atom | base (r : R)
def hfStructure (S : Structure R A) : Structure (HFRelation R) (Domain (A := A) G s) where
rel
| .mem, x, y => x.1 ∈ y.1
| .atom, x, _ => isSet x.1 = false
| .base r, x, y => ∃ a b, x.1 = Hereditary.atom a ∧ y.1 = Hereditary.atom b ∧ S.rel r a b
def Represented (S : Structure R A) (T : Structure R B)
(ef : V × Fin s ↪ I) (e2 : Fin s ⊕ Fin s ↪ I)
(v : V → Domain (A := A) G s) (w : V → Domain (A := B) H s) : Prop :=
∃ φ : V → Form (Fin s) (Set (Formula R I)), ∃ a : V × Fin s → A,
∃ b : V × Fin s → B,
(∀ i, Form.value S e2 (φ i) (fun j => a (i,j)) = (v i).1) ∧
(∀ i, Form.value T e2 (φ i) (fun j => b (i,j)) = (w i).1) ∧
tupleType S ef a = tupleType T ef b
def twoBlocks (i j : V) (h : i ≠ j) : Fin s ⊕ Fin s ↪ V × Fin s where
toFun := Sum.elim (Prod.mk i) (Prod.mk j)
inj' := by
intro a b hab
cases a <;> cases b <;> simp only [Sum.elim_inl,Sum.elim_inr,Prod.mk.injEq] at hab
· congr 1; exact hab.2
· exact (h hab.1).elim
· exact (h hab.1.symm).elim
· congr 1; exact hab.2
omit A V s in
@[simp] theorem comp_twoBlocks.{uDecl3, uDecl5}
{A : Type uDecl3}
{V : Type uDecl5}
[Fintype A]
[Nonempty A]
[Fintype V]
[DecidableEq V]
{s : ℕ} (i j : V) (h : i ≠ j) (a : V × Fin s → A) :
a ∘ twoBlocks i j h = Sum.elim (fun k => a (i,k)) (fun k => a (j,k)) := by
funext x; cases x <;> rfl
def splitBlock (i : V) : ({j : V // j ≠ i} × Fin s) ⊕ Fin s ≃ V × Fin s where
toFun := Sum.elim (fun x => (x.1.1,x.2)) (fun j => (i,j))
invFun := fun x => if h : x.1 = i then .inr x.2 else .inl (⟨x.1,h⟩,x.2)
left_inv := by
intro x; cases x with
| inl x => simp [x.1.2]
| inr j => simp
right_inv := by
intro x; by_cases h : x.1 = i
· simp [h]; exact Prod.ext h.symm rfl
· simp [h]
variable (S : Structure R A) (T : Structure R B)
variable (ef : V × Fin s ↪ I) (e2 : Fin s ⊕ Fin s ↪ I)
variable (e3 : (Fin s ⊕ Fin s) ⊕ Fin s ↪ I)
variable (e4 : ((Fin s ⊕ Fin s) ⊕ Fin s) ⊕ Fin s ↪ I)
include e3 e4 in
theorem represented_equal (v : V → Domain (A := A) G s) (w : V → Domain (A := B) H s)
(h : Represented S T ef e2 v w) (i j : V) : v i = v j ↔ w i = w j := by
by_cases hij : i = j
· subst j; simp
obtain ⟨φ,a,b,ha,hb,ht⟩ := h
have hh := tupleType_project S T ef e2 (twoBlocks i j hij) a b ht
simp only [comp_twoBlocks] at hh
have he := equality_transfer S T e2 e3 e4 (φ i) (φ j) _ _ _ _ hh
simpa only [ha,hb,Subtype.ext_iff] using he
include e3 e4 in
theorem represented_mem (v : V → Domain (A := A) G s) (w : V → Domain (A := B) H s)
(h : Represented S T ef e2 v w) (i j : V) : (v i).1 ∈ (v j).1 ↔ (w i).1 ∈ (w j).1 := by
by_cases hij : i = j
· subst j
exact iff_of_false (fun h => (Nat.lt_irrefl _ (rank_lt_of_mem h)))
(fun h => (Nat.lt_irrefl _ (rank_lt_of_mem h)))
obtain ⟨φ,a,b,ha,hb,ht⟩ := h
have hh := tupleType_project S T ef e2 (twoBlocks i j hij) a b ht
simp only [comp_twoBlocks] at hh
have he := membership_transfer S T e2 e3 e4 (φ i) (φ j) _ _ _ _ hh
simpa only [ha,hb] using he
omit R I A B V G H s S T ef e2 in
theorem represented_atom.{uDecl1, uDecl2, uDecl3, uDecl4, uDecl5, uDecl6, uDecl7}
{R : Type uDecl1}
{I : Type uDecl2}
{A : Type uDecl3}
{B : Type uDecl4}
{V : Type uDecl5}
{G : Type uDecl6}
{H : Type uDecl7}
[Fintype I]
[DecidableEq I]
[Fintype A]
[Fintype B]
[Nonempty A]
[Nonempty B]
[Fintype V]
[DecidableEq V]
[Group G]
[MulAction G A]
[Group H]
[MulAction H B]
{s : ℕ}
(S : Counting.Structure R A)
(T : Counting.Structure R B)
(ef : V × Fin s ↪ I)
(e2 : Fin s ⊕ Fin s ↪ I) (v : V → Domain (A := A) G s) (w : V → Domain (A := B) H s)
(h : Represented S T ef e2 v w) (i : V) : isSet (v i).1 = false ↔ isSet (w i).1 = false := by
obtain ⟨φ,a,b,ha,hb,ht⟩ := h
rw [←ha i,←hb i]
cases φ i <;> simp
omit R I A s S e2 in
private theorem base_value.{uDecl1, uDecl2, uDecl3}
{R : Type uDecl1}
{I : Type uDecl2}
{A : Type uDecl3}
[Fintype I]
[DecidableEq I]
[Fintype A]
[Nonempty A]
{s : ℕ}
(S : Counting.Structure R A)
(e2 : Fin s ⊕ Fin s ↪ I) (φ ψ : Form (Fin s) (Set (Formula R I)))
(a b : Fin s → A) (r : R) :
(∃ x y, Form.value S e2 φ a = Hereditary.atom x ∧
Form.value S e2 ψ b = Hereditary.atom y ∧ S.rel r x y) ↔
match φ,ψ with
| .atom i, .atom j => S.rel r (a i) (b j)
| _, _ => False := by
have hn (n : ℕ) (child : Fin n → Form (Fin s) (Set (Formula R I)))
(label : Fin n → Set (Formula R I)) (c : Fin s → A) (x : A) :
Form.value S e2 (.set n child label) c ≠ Hereditary.atom x := by
intro h; have hh := congrArg isSet h; simp at hh
cases φ <;> cases ψ <;> simp [Form.value_atom,atom_injective.eq_iff,hn]
omit R I A B V G H s S T ef e2 in
theorem represented_base.{uDecl1, uDecl2, uDecl3, uDecl4, uDecl5, uDecl6, uDecl7}
{R : Type uDecl1}
{I : Type uDecl2}
{A : Type uDecl3}
{B : Type uDecl4}
{V : Type uDecl5}
{G : Type uDecl6}
{H : Type uDecl7}
[Fintype I]
[DecidableEq I]
[Fintype A]
[Fintype B]
[Nonempty A]
[Nonempty B]
[Fintype V]
[DecidableEq V]
[Group G]
[MulAction G A]
[Group H]
[MulAction H B]
{s : ℕ}
(S : Counting.Structure R A)
(T : Counting.Structure R B)
(ef : V × Fin s ↪ I)
(e2 : Fin s ⊕ Fin s ↪ I) (v : V → Domain (A := A) G s) (w : V → Domain (A := B) H s)
(h : Represented S T ef e2 v w) (r : R) (i j : V) :
(hfStructure S).rel (.base r) (v i) (v j) ↔ (hfStructure T).rel (.base r) (w i) (w j) := by
obtain ⟨φ,a,b,ha,hb,ht⟩ := h
change (∃ x y, (v i).1 = Hereditary.atom x ∧ (v j).1 = Hereditary.atom y ∧ S.rel r x y) ↔
(∃ x y, (w i).1 = Hereditary.atom x ∧ (w j).1 = Hereditary.atom y ∧ T.rel r x y)
rw [←ha i,←ha j,←hb i,←hb j,base_value S e2,base_value T e2]
cases hi : φ i with
| set n child label => simp
| atom k =>
cases hj : φ j with
| set n child label => simp
| atom l =>
have he := (typeOf_eq_iff S T (tupleNames ef) _ _).mp ht
(.relation r (ef (i,k)) (ef (j,l))) (by
intro p hp
simp only [Formula.free,Finset.mem_insert,Finset.mem_singleton] at hp
rcases hp with rfl | rfl <;> exact (mem_tupleNames _ _).mpr ⟨_,rfl⟩)
simpa only [Formula.eval,tupleAssignment_apply] using he
omit V s in
@[simp] theorem splitBlock_symm_new.{uDecl5}
{V : Type uDecl5}
[Fintype V]
[DecidableEq V]
{s : ℕ} (i : V) (k : Fin s) :
(splitBlock (s := s) i).symm (i,k) = .inr k := by simp [splitBlock]
omit V s in
@[simp] theorem splitBlock_symm_old.{uDecl5}
{V : Type uDecl5}
[Fintype V]
[DecidableEq V]
{s : ℕ} (i j : V) (h : j ≠ i) (k : Fin s) :
(splitBlock (s := s) i).symm (j,k) = .inl (⟨j,h⟩,k) := by simp [splitBlock,h]
omit R I A G in
private theorem homogeneity_reindex.{uDecl1, uDecl2, uDecl3, uDecl6, uDecl8, uDecl9}
{R : Type uDecl1}
{I : Type uDecl2}
{A : Type uDecl3}
{G : Type uDecl6}
[Fintype I]
[DecidableEq I]
[Fintype A]
[Nonempty A]
[Group G]
[MulAction G A] {J : Type uDecl8} {K : Type uDecl9} [Fintype J] [Fintype K]
(S : Structure R A) (e : J ↪ I) (f : K ↪ I) (u : K ≃ J)
(hh : ∀ a b : J → A, tupleType S e a = tupleType S e b →
∃ g : G, ∀ j, g • a j = b j) :
∀ a b : K → A, tupleType S f a = tupleType S f b → ∃ g : G, ∀ j, g • a j = b j := by
intro a b hab
have h := tupleType_project S S f e u.symm.toEmbedding a b hab
obtain ⟨g,hg⟩ := hh _ _ h
exact ⟨g,fun j => by simpa using hg (u j)⟩
variable (eplus : (V × Fin s) ⊕ Fin s ↪ I)
variable (hAutA : ∀ (g : G) r a b, S.rel r (g • a) (g • b) ↔ S.rel r a b)
variable (hAutB : ∀ (g : H) r a b, T.rel r (g • a) (g • b) ↔ T.rel r a b)
include eplus e3 e4 hAutA hAutB in
theorem represented_extension (hs : 0 < s)
(hHomA2 : ∀ a b : Fin s ⊕ Fin s → A,
tupleType S e2 a = tupleType S e2 b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB2 : ∀ a b : Fin s ⊕ Fin s → B,
tupleType T e2 a = tupleType T e2 b → ∃ g : H, ∀ i, g • a i = b i)
(hHomA : ∀ a b : V × Fin s → A,
tupleType S ef a = tupleType S ef b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB : ∀ a b : V × Fin s → B,
tupleType T ef a = tupleType T ef b → ∃ g : H, ∀ i, g • a i = b i)
(v : V → Domain (A := A) G s) (w : V → Domain (A := B) H s)
(h : Represented S T ef e2 v w) (i : V) :
∃ f : Domain (A := A) G s ≃ Domain (A := B) H s,
∀ x, Represented S T ef e2 (Function.update v i x) (Function.update w i (f x)) := by
obtain ⟨φ,a,b,ha,hb,ht⟩ := h
let P := {j : V // j ≠ i} × Fin s
let u : P ⊕ Fin s ≃ V × Fin s := splitBlock i
let ep := u.toEmbedding.trans ef
let epp := (Equiv.sumCongr u (Equiv.refl (Fin s))).toEmbedding.trans eplus
let e0 := Function.Embedding.inl.trans ep
let keep : P ↪ V × Fin s := Function.Embedding.inl.trans u.toEmbedding
let p : P → A := a ∘ keep
let q : P → B := b ∘ keep
have hp : tupleType S e0 p = tupleType T e0 q :=
tupleType_project S T ef e0 keep a b ht
have homA := homogeneity_reindex S ef ep u hHomA
have homB := homogeneity_reindex T ef ep u hHomB
obtain ⟨f,hf⟩ := supported_domain_bijection S T ep epp e2 e3 e4
hAutA hAutB hs e0 hHomA2 hHomB2 homA homB p q hp
refine ⟨f,fun x => ?_⟩
obtain ⟨ψ,c,d,hc,hd,hcd⟩ := hf x
let a' := Sum.elim p c ∘ u.symm
let b' := Sum.elim q d ∘ u.symm
refine ⟨Function.update φ i ψ,a',b',?_,?_,?_⟩
· intro j
by_cases hj : j = i
· subst j
simpa [a',u,Function.comp_def,splitBlock] using hc
· simpa [a',u,p,keep,Function.comp_def,splitBlock_symm_old i j hj,
Function.update_of_ne hj,splitBlock,hj] using ha j
· intro j
by_cases hj : j = i
· subst j
simpa [b',u,Function.comp_def,splitBlock] using hd
· simpa [b',u,q,keep,Function.comp_def,splitBlock_symm_old i j hj,
Function.update_of_ne hj,splitBlock,hj] using hb j
· exact tupleType_project S T ep ef u.symm.toEmbedding _ _ hcd
include eplus e3 e4 hAutA hAutB in
theorem supported_eval_transfer (hs : 0 < s)
(hHomA2 : ∀ a b : Fin s ⊕ Fin s → A,
tupleType S e2 a = tupleType S e2 b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB2 : ∀ a b : Fin s ⊕ Fin s → B,
tupleType T e2 a = tupleType T e2 b → ∃ g : H, ∀ i, g • a i = b i)
(hHomA : ∀ a b : V × Fin s → A,
tupleType S ef a = tupleType S ef b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB : ∀ a b : V × Fin s → B,
tupleType T ef a = tupleType T ef b → ∃ g : H, ∀ i, g • a i = b i)
(φ : Formula (HFRelation R) V)
(v : V → Domain (A := A) G s) (w : V → Domain (A := B) H s)
(h : Represented S T ef e2 v w) :
φ.eval (hfStructure S) v ↔ φ.eval (hfStructure T) w := by
apply Formula.eval_of_bijectionSystem (hfStructure S) (hfStructure T)
(Represented S T ef e2) _ _ _ φ v w h
· exact represented_equal S T ef e2 e3 e4
· intro v w h r i j
cases r with
| mem => exact represented_mem S T ef e2 e3 e4 v w h i j
| atom => exact represented_atom S T ef e2 v w h i
| base r => exact represented_base S T ef e2 v w h r i j
· exact represented_extension S T ef e2 e3 e4 eplus hAutA hAutB hs
hHomA2 hHomB2 hHomA hHomB
include eplus e3 e4 hAutA hAutB in
theorem supported_sentences_transfer (hs : 0 < s)
(hHomA2 : ∀ a b : Fin s ⊕ Fin s → A,
tupleType S e2 a = tupleType S e2 b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB2 : ∀ a b : Fin s ⊕ Fin s → B,
tupleType T e2 a = tupleType T e2 b → ∃ g : H, ∀ i, g • a i = b i)
(hHomA : ∀ a b : V × Fin s → A,
tupleType S ef a = tupleType S ef b → ∃ g : G, ∀ i, g • a i = b i)
(hHomB : ∀ a b : V × Fin s → B,
tupleType T ef a = tupleType T ef b → ∃ g : H, ∀ i, g • a i = b i)
(hbase : tupleType S (Function.Embedding.ofIsEmpty : Empty ↪ I) Empty.elim =
tupleType T (Function.Embedding.ofIsEmpty : Empty ↪ I) Empty.elim)
(φ : Formula (HFRelation R) V) (hφ : φ.free = ∅)
(v : V → Domain (A := A) G s) (w : V → Domain (A := B) H s) :
φ.eval (hfStructure S) v ↔ φ.eval (hfStructure T) w := by
let a : V × Fin s → A := fun _ => Classical.choice inferInstance
have he : tupleType S (Function.Embedding.ofIsEmpty : Empty ↪ I)
(a ∘ (Function.Embedding.ofIsEmpty : Empty ↪ V × Fin s)) =
tupleType T (Function.Embedding.ofIsEmpty : Empty ↪ I) Empty.elim := by
convert hbase using 1
congr 1; funext x; exact x.elim
obtain ⟨b,_,hab⟩ := tupleType_extend S T
(Function.Embedding.ofIsEmpty : Empty ↪ I) ef
(Function.Embedding.ofIsEmpty : Empty ↪ V × Fin s) a Empty.elim he
let emptyForm : Form (Fin s) (Set (Formula R I)) := .set 0 Fin.elim0 Fin.elim0
let v' : V → Domain (A := A) G s := fun i =>
⟨Form.value S e2 emptyForm (fun j => a (i,j)),
value_hereditarily_supported S e2 hAutA emptyForm _⟩
let w' : V → Domain (A := B) H s := fun i =>
⟨Form.value T e2 emptyForm (fun j => b (i,j)),
value_hereditarily_supported T e2 hAutB emptyForm _⟩
have hr : Represented S T ef e2 v' w' :=
⟨(fun _ => emptyForm),a,b,(fun _ => rfl),(fun _ => rfl),hab⟩
have hh := supported_eval_transfer S T ef e2 e3 e4 eplus hAutA hAutB hs
hHomA2 hHomB2 hHomA hHomB φ v' w' hr
exact (Formula.eval_congr _ φ (fun i hi => by simp [hφ] at hi)).trans
(hh.trans (Formula.eval_congr _ φ (fun i hi => by simp [hφ] at hi)))
def namesOfCard {J : Type*} [Fintype J] {M : ℕ} (h : Fintype.card J ≤ M) : J ↪ Fin M :=
(Fintype.equivFin J).toEmbedding.trans (Fin.castLEEmb h)
def HomogeneousThrough (S : Structure R A) (G : Type*) [Group G] [MulAction G A]
(M r : ℕ) : Prop :=
∀ k ≤ r, ∀ e : Fin k ↪ Fin M, ∀ a b : Fin k → A,
tupleType S e a = tupleType S e b → ∃ g : G, ∀ j, g • a j = b j
omit R A in
private theorem homogeneous_tuple.{uDecl1, uDecl3, uDecl8, uDecl9}
{R : Type uDecl1}
{A : Type uDecl3}
[Fintype A]
[Nonempty A] {J : Type uDecl8} [Fintype J] {M r : ℕ}
(S : Structure R A) (G : Type uDecl9) [Group G] [MulAction G A]
(h : HomogeneousThrough S G M r) (e : J ↪ Fin M)
(hc : Fintype.card J ≤ r) :
∀ a b : J → A, tupleType S e a = tupleType S e b → ∃ g : G, ∀ j, g • a j = b j := by
exact homogeneity_reindex S ((Fintype.equivFin J).symm.toEmbedding.trans e) e
(Fintype.equivFin J) (h _ hc _)
theorem hf_transfer {m M : ℕ} (hs : 0 < s) (_ : 0 < m) (hM : 0 < M)
(hwidth : max 4 (m+1) * s ≤ M)
(hAutA : ∀ (g : G) r a b, S.rel r (g • a) (g • b) ↔ S.rel r a b)
(hAutB : ∀ (g : H) r a b, T.rel r (g • a) (g • b) ↔ T.rel r a b)
(hHomA : HomogeneousThrough S G M (max 2 m * s))
(hHomB : HomogeneousThrough T H M (max 2 m * s))
(hbase : tupleType S (Function.Embedding.ofIsEmpty : Empty ↪ Fin M) Empty.elim =
tupleType T (Function.Embedding.ofIsEmpty : Empty ↪ Fin M) Empty.elim)
(φ : Formula (HFRelation R) (Fin m)) (hφ : φ.free = ∅)
(v : Fin m → Domain (A := A) G s) (w : Fin m → Domain (A := B) H s) :
φ.eval (hfStructure S) v ↔ φ.eval (hfStructure T) w := by
have h4 : 4*s ≤ M := (Nat.mul_le_mul_right s (le_max_left _ _)).trans hwidth
have hp : (m+1)*s ≤ M := (Nat.mul_le_mul_right s (le_max_right _ _)).trans hwidth
have h2 : Fintype.card (Fin s ⊕ Fin s) ≤ M := by simp only [Fintype.card_sum,Fintype.card_fin]; omega
have h3 : Fintype.card ((Fin s ⊕ Fin s) ⊕ Fin s) ≤ M := by simp only [Fintype.card_sum,Fintype.card_fin]; omega
have h4' : Fintype.card (((Fin s ⊕ Fin s) ⊕ Fin s) ⊕ Fin s) ≤ M := by simp only [Fintype.card_sum,Fintype.card_fin]; omega
have hpf : Fintype.card ((Fin m × Fin s) ⊕ Fin s) ≤ M := by simpa [Nat.add_mul] using hp
have hfull : Fintype.card (Fin m × Fin s) ≤ M := by simp only [Fintype.card_prod,Fintype.card_fin]; nlinarith
have hom2 : Fintype.card (Fin s ⊕ Fin s) ≤ max 2 m*s := by
simpa [two_mul] using Nat.mul_le_mul_right s (le_max_left 2 m)
have homf : Fintype.card (Fin m × Fin s) ≤ max 2 m*s := by
simpa using Nat.mul_le_mul_right s (le_max_right 2 m)
exact supported_sentences_transfer S T (namesOfCard hfull) (namesOfCard h2)
(namesOfCard h3) (namesOfCard h4') (namesOfCard hpf) hAutA hAutB hs
(homogeneous_tuple S G hHomA _ hom2) (homogeneous_tuple T H hHomB _ hom2)
(homogeneous_tuple S G hHomA _ homf) (homogeneous_tuple T H hHomB _ homf)
hbase φ hφ v w
end CPTSeparation.Forms
namespace CPTSeparation.Hereditary
variable {A G : Type*} [Group G] [MulAction G A]
theorem supports_pad {k s : ℕ} (hks : k ≤ s) (a₀ : A) (alpha : Fin k → A)
{x : HF A} (h : Supports (G := G) alpha x) : Supported (G := G) s x := by
classical
let beta (i : Fin s) : A := if hi : i.val < k then alpha ⟨i.val,hi⟩ else a₀
refine ⟨beta,?_⟩
intro g hg
apply h g
intro i
have hi := hg (i.castLE hks)
simpa only [beta, Fin.val_castLE, dite_eq_left i.isLt] using hi
end CPTSeparation.Hereditary
namespace CPTSeparation.Grid
section
open Support Hereditary
variable {n : ℕ} {b : Vertex n → Scalar}
@[simp] theorem central_smul_HF (k : CentralGroup n) (x : HF (Atom b)) :
k • x = centralHom k • x := rfl
theorem small_orbit_supported (hn : 1 ≤ n) (x : HF (Atom b))
(N : ℕ) (hN : 0 < N) (q : ℝ) (hq : 0 ≤ q)
(horbit : (Nat.card (MulAction.orbit (BoxGroup n) x) : ℝ) ≤ (N : ℝ)^q) :
Supported (G := CentralGroup n) ⌈2 * (n+1 : ℝ) * (q * Real.logb 3 N)^2⌉₊ x := by
classical
obtain ⟨T,hT,hfix⟩ := small_orbit_support_edges x N hN q hq horbit
obtain ⟨alpha,ha⟩ := edge_support_tuple (b := b) T x hfix
have hsupport : Supports (G := CentralGroup n) alpha x := by
intro k hk
exact ha k hk
have hlen : T.card ≤ ⌈2 * (n+1 : ℝ) * (q * Real.logb 3 N)^2⌉₊ := by
exact_mod_cast le_trans hT (Nat.le_ceil _)
let a₀ : Atom b := zeroEdgeAtom b (ex ⟨0,by omega⟩ 0 0)
exact supports_pad hlen a₀ alpha hsupport
theorem orbit_card_le_invariant_family (F : Finset (HF (Atom b)))
(hF : ∀ g : BoxGroup n, ∀ x ∈ F, g • x ∈ F) {x : HF (Atom b)} (hx : x ∈ F) :
Nat.card (MulAction.orbit (BoxGroup n) x) ≤ F.card := by
classical
let f : MulAction.orbit (BoxGroup n) x → {y // y ∈ F} := fun y =>
⟨y.val,by obtain ⟨g,hg⟩ := y.property; rw [← hg]; exact hF g x hx⟩
have hf : Function.Injective f := by
intro a c h
exact Subtype.ext (congrArg (fun z : {y // y ∈ F} => z.val) h)
have hn := Nat.card_le_card_of_injective f hf
simpa only [Nat.card_eq_fintype_card, Fintype.card_coe] using hn
theorem invariant_family_hereditarily_supported (hn : 1 ≤ n)
(F : Finset (HF (Atom b)))
(hF : ∀ g : BoxGroup n, ∀ x ∈ F, g • x ∈ F)
(htrans : ∀ x ∈ F, ∀ y, y ∈ x → y ∈ F)
(N : ℕ) (hN : 0 < N) (q : ℝ) (hq : 0 ≤ q)
(hsize : (F.card : ℝ) ≤ (N : ℝ)^q) :
∀ x ∈ F, HereditarilySupported (G := CentralGroup n)
⌈2 * (n+1 : ℝ) * (q * Real.logb 3 N)^2⌉₊ x := by
intro x hx y hy
have hymem : y ∈ F := by
induction hy with
| refl => exact hx
| @tail z w hpath hmem ih => exact ih (htrans w hx z hmem)
apply small_orbit_supported hn y N hN q hq
exact le_trans (by exact_mod_cast orbit_card_le_invariant_family F hF hymem) hsize
end
open Classical Finset
variable {n M m s : ℕ} {b : Vertex n → Scalar}
theorem atom_nonempty (hn : 1 ≤ n) (b : Vertex n → Scalar) : Nonempty (Atom b) :=
⟨.inr ⟨(0,0,0),someConfiguration hn b (0,0,0)⟩⟩
instance atom_nonempty_succ (b : Vertex (n+1) → Scalar) : Nonempty (Atom b) := atom_nonempty (by omega) b
theorem central_analysis_isomorphism (k : CentralGroup n) (r : AnalysisSymbol) (x y : Atom b) :
(analysisStructure b).rel r (k • x) (k • y) ↔ (analysisStructure b).rel r x y :=
((central_atomShift k x).analysisRelation (central_atomShift k y) r).symm
theorem homogeneous_through_numeric (hn : 1 ≤ n) [Nonempty (Atom b)] (R : ℕ)
(hw : (7*R:ℝ)+7*((6*R:ℝ)/boxConstant)^((3:ℝ)/2)+1 ≤ M) :
Forms.HomogeneousThrough (analysisStructure b) (CentralGroup n) M R := by
intro k hk names a a' ht
apply quantitative_homogeneity hn names a a' _ ht
simp only [Fintype.card_fin]
have hkr : (k:ℝ) ≤ R := by exact_mod_cast hk
have hp : ((6*k:ℝ)/boxConstant)^((3:ℝ)/2) ≤ ((6*R:ℝ)/boxConstant)^((3:ℝ)/2) := by
apply Real.rpow_le_rpow (div_nonneg (by positivity) boxConstant_pos.le) _ (by norm_num)
exact div_le_div_of_nonneg_right (by linarith) boxConstant_pos.le
linarith
theorem base_empty_type (hn : 1 ≤ n) (hbound : GiantBound n M) (vstar : Vertex n)
[Nonempty (Atom (0 : Vertex n → Scalar))] [Nonempty (Atom (Pi.single vstar 1))] :
Counting.tupleType (analysisStructure (0 : Vertex n → Scalar))
(Function.Embedding.ofIsEmpty : Empty ↪ Fin M) Empty.elim =
Counting.tupleType (analysisStructure (Pi.single vstar 1))
(Function.Embedding.ofIsEmpty : Empty ↪ Fin M) Empty.elim := by
apply (Counting.typeOf_eq_iff _ _ _ _ _).mpr
intro φ hφ
have he : φ.free = ∅ := by
apply subset_empty.mp
simpa only [Counting.tupleNames,Finset.univ_eq_empty,Finset.map_empty] using hφ
exact base_equivalence_numeric hn hbound vstar φ he _ _
theorem grid_hf_transfer (hn : 1 ≤ n) (hs : 0 < s) (hm : 0 < m)
(vstar : Vertex n) [Nonempty (Atom (0 : Vertex n → Scalar))]
[Nonempty (Atom (Pi.single vstar 1))]
(hwidth : max 4 (m+1)*s ≤ M)
(hhom : (7*(max 2 m*s):ℝ)+7*((6*(max 2 m*s):ℝ)/boxConstant)^((3:ℝ)/2)+1 ≤ M)
(hgiant : GiantBound n M)
(φ : Counting.Formula (Forms.HFRelation AnalysisSymbol) (Fin m)) (hφ : φ.free = ∅)
(v : Fin m → Forms.Domain (A := Atom (0 : Vertex n → Scalar)) (CentralGroup n) s)
(w : Fin m → Forms.Domain (A := Atom (Pi.single vstar 1)) (CentralGroup n) s) :
φ.eval (Forms.hfStructure (analysisStructure (0 : Vertex n → Scalar))) v ↔
φ.eval (Forms.hfStructure (analysisStructure (Pi.single vstar 1))) w := by
have hM : 0 < M := lt_of_lt_of_le (Nat.mul_pos (by omega) hs) hwidth
exact Forms.hf_transfer _ _ hs hm hM hwidth
(fun g r a b => central_analysis_isomorphism g r a b)
(fun g r a b => central_analysis_isomorphism g r a b)
(homogeneous_through_numeric hn _ (by simpa only [Nat.cast_mul] using hhom))
(homogeneous_through_numeric hn _ (by simpa only [Nat.cast_mul] using hhom))
(base_empty_type hn hgiant vstar) φ hφ v w
end CPTSeparation.Grid
end
end OAI