openAI-math-dataset / lean /OAI /Computability /DirectedFeedback /Games /ConditionalIncidences.lean
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import Mathlib
import OAI.Computability.DirectedFeedback.Games.KernelCardinality
namespace OAI
section
open scoped BigOperators
namespace DFVSGames.Soundness.ConditionalIncidences
noncomputable section
abbrev PositionInside {P : Type} (K : Finset P) := {j : P // j ∈ K}
abbrev PositionOutside {P : Type} (K : Finset P) := {j : P // j ∉ K}
abbrev Draw (P O : Type) := P → O × Fin 3
abbrev InsideDraw {P : Type} (K : Finset P) (O : Type) := PositionInside K → O × Fin 3
def incidence {O N : Type} (name : O → Fin 3 → N) (draw : O × Fin 3) : O × N :=
(draw.1, name draw.1 draw.2)
def insideDraw {P O : Type} (K : Finset P) (sample : Draw P O) : InsideDraw K O :=
fun j => sample j.val
def outsideRecord {P O N : Type} (K : Finset P) (name : O → Fin 3 → N)
(sample : Draw P O) : PositionOutside K → O × N :=
fun j => incidence name (sample j.val)
abbrev ObservationFibre {P O N : Type} (K : Finset P) (name : O → Fin 3 → N)
(observed : PositionOutside K → O × N) :=
{sample : Draw P O // outsideRecord K name sample = observed}
abbrev OutsideFibre {P O N : Type} (K : Finset P) (name : O → Fin 3 → N)
(observed : PositionOutside K → O × N) :=
{sample : PositionOutside K → O × Fin 3 //
(fun j => incidence name (sample j)) = observed}
instance observationFibreFintype {P O N : Type} [Fintype P] [Fintype O]
(K : Finset P) (name : O → Fin 3 → N) (observed : PositionOutside K → O × N) :
Fintype (ObservationFibre K name observed) := Fintype.ofFinite _
instance outsideFibreFintype {P O N : Type} [Fintype P] [Fintype O]
(K : Finset P) (name : O → Fin 3 → N) (observed : PositionOutside K → O × N) :
Fintype (OutsideFibre K name observed) := Fintype.ofFinite _
def observationFibreEquiv {P O N : Type} [DecidableEq P]
(K : Finset P) (name : O → Fin 3 → N)
(observed : PositionOutside K → O × N) :
ObservationFibre K name observed ≃ InsideDraw K O × OutsideFibre K name observed where
toFun sample :=
(insideDraw K sample.val, ⟨fun j => sample.val j.val, sample.property⟩)
invFun pieces :=
⟨fun j => if hj : j ∈ K then pieces.1 ⟨j, hj⟩ else pieces.2.val ⟨j, hj⟩, by
funext j
simp only [outsideRecord, j.property, ↓reduceDIte]
exact congrFun pieces.2.property j⟩
left_inv sample := by
apply Subtype.ext
funext j
simp only [insideDraw]
split <;> rfl
right_inv pieces := by
apply Prod.ext
· funext j
simp [insideDraw, j.property]
· apply Subtype.ext
funext j
simp [j.property]
def average {A : Type} [Fintype A] (f : A → ℚ) : ℚ :=
(∑ a, f a) / Fintype.card A
theorem average_equiv {A B : Type} [Fintype A] [Fintype B] (e : A ≃ B) (f : B → ℚ) :
average (fun a => f (e a)) = average f := by
unfold average
rw [e.sum_comp, Fintype.card_congr e]
theorem average_product_left {A B : Type} [Fintype A] [Fintype B]
(hB : Fintype.card B ≠ 0) (f : A → ℚ) :
average (fun ab : A × B => f ab.1) = average f := by
unfold average
rw [Fintype.sum_prod_type]
simp only [Finset.sum_const, Finset.card_univ, nsmul_eq_mul, Fintype.card_prod, Nat.cast_mul]
rw [← Finset.mul_sum]
have hBq : (Fintype.card B : ℚ) ≠ 0 := by exact_mod_cast hB
rw [mul_comm (Fintype.card A : ℚ)]
exact mul_div_mul_left _ _ hBq
theorem average_product_mul {A B : Type} [Fintype A] [Fintype B]
(f : A → ℚ) (g : B → ℚ) :
average (fun ab : A × B => f ab.1 * g ab.2) = average f * average g := by
unfold average
rw [Fintype.sum_prod_type]
simp_rw [← Finset.mul_sum]
rw [← Finset.sum_mul]
simp only [Fintype.card_prod, Nat.cast_mul]
exact (div_mul_div_comm _ _ _ _).symm
theorem average_coordinate_product {A X : Type} [Fintype A] [DecidableEq A] [Fintype X]
(f : A → X → ℚ) :
average (fun sample : A → X => ∏ a, f a (sample a)) = ∏ a, average (f a) := by
unfold average
rw [← Fintype.prod_sum]
simp only [Fintype.card_pi, Nat.cast_prod]
exact (Finset.prod_div_distrib _ _).symm
theorem uniform_conditional_ratio {A : Type} [Fintype A]
(p : A → Prop) [Fintype {a // p a}]
(hpos : 0 < Fintype.card {a // p a}) (f : {a // p a} → ℚ) :
((∑ a, f a) / (Fintype.card A : ℚ)) /
((Fintype.card {a // p a} : ℚ) / Fintype.card A) = average f := by
have hA : Fintype.card A ≠ 0 :=
Nat.ne_of_gt (Nat.lt_of_lt_of_le hpos (Fintype.card_subtype_le p))
have hAq : (Fintype.card A : ℚ) ≠ 0 := by exact_mod_cast hA
exact div_div_div_cancel_right₀ hAq _ _
section ConditionalLaw
variable {P O N : Type} [Fintype P] [DecidableEq P] [Fintype O]
theorem conditional_inside_average (K : Finset P) (name : O → Fin 3 → N)
(observed : PositionOutside K → O × N)
(hpos : 0 < Fintype.card (ObservationFibre K name observed))
(f : InsideDraw K O → ℚ) :
average (fun sample : ObservationFibre K name observed => f (insideDraw K sample.val)) =
average f := by
let e := observationFibreEquiv K name observed
have hcard : Fintype.card (ObservationFibre K name observed) =
Fintype.card (InsideDraw K O) * Fintype.card (OutsideFibre K name observed) := by
rw [Fintype.card_congr e, Fintype.card_prod]
have hout : Fintype.card (OutsideFibre K name observed) ≠ 0 := by
intro hz
rw [hcard, hz, Nat.mul_zero] at hpos
exact (Nat.lt_irrefl 0) hpos
calc
average (fun sample : ObservationFibre K name observed => f (insideDraw K sample.val)) =
average (fun pieces : InsideDraw K O × OutsideFibre K name observed => f pieces.1) :=
average_equiv e (fun pieces => f pieces.1)
_ = average f := average_product_left hout f
theorem conditional_incidence_average (K : Finset P) (name : O → Fin 3 → N)
(observed : PositionOutside K → O × N)
(hpos : 0 < Fintype.card (ObservationFibre K name observed))
(f : (PositionInside K → O × N) → ℚ) :
average (fun sample : ObservationFibre K name observed =>
f (fun j => incidence name (sample.val j.val))) =
average (fun fresh : InsideDraw K O => f (fun j => incidence name (fresh j))) := by
exact conditional_inside_average K name observed hpos
(fun fresh => f (fun j => incidence name (fresh j)))
end ConditionalLaw
abbrev RawSlot {P : Type} (J : Finset P) :=
Option ((PositionOutside J × Fin 2) ⊕ PositionInside J)
abbrev RawCoefficients {P : Type} (J : Finset P) (D : Type) := RawSlot J → D
def zeroSet {P D : Type} [DecidableEq P] [Zero D] [DecidableEq D]
(J : Finset P) (gamma : RawCoefficients J D) : Finset P :=
J.attach.filter (fun j => gamma (some (.inr j)) = 0) |>.map ⟨Subtype.val, Subtype.val_injective⟩
theorem mem_zeroSet {P D : Type} [DecidableEq P] [Zero D] [DecidableEq D]
(J : Finset P) (gamma : RawCoefficients J D) (j : P) :
j ∈ zeroSet J gamma ↔ ∃ hj : j ∈ J, gamma (some (.inr ⟨j, hj⟩)) = 0 := by
simp [zeroSet]
abbrev RawSample {P : Type} (J : Finset P) (D O : Type) :=
RawCoefficients J D × Draw P O
abbrev RawObservationFibre {P D O N : Type} [DecidableEq P] [Zero D] [DecidableEq D]
(J : Finset P) (name : O → Fin 3 → N) (gamma : RawCoefficients J D)
(observed : PositionOutside (zeroSet J gamma) → O × N) :=
{sample : RawSample J D O // sample.1 = gamma ∧
outsideRecord (zeroSet J gamma) name sample.2 = observed}
instance rawObservationFibreFintype {P D O N : Type} [Fintype P] [DecidableEq P]
[Fintype D] [Zero D] [DecidableEq D] [Fintype O]
(J : Finset P) (name : O → Fin 3 → N) (gamma : RawCoefficients J D)
(observed : PositionOutside (zeroSet J gamma) → O × N) :
Fintype (RawObservationFibre J name gamma observed) := Fintype.ofFinite _
def rawObservationFibreEquiv {P D O N : Type} [DecidableEq P] [Zero D] [DecidableEq D]
(J : Finset P) (name : O → Fin 3 → N) (gamma : RawCoefficients J D)
(observed : PositionOutside (zeroSet J gamma) → O × N) :
RawObservationFibre J name gamma observed ≃
ObservationFibre (zeroSet J gamma) name observed where
toFun sample := ⟨sample.val.2, sample.property.2⟩
invFun sample := ⟨(gamma, sample.val), rfl, sample.property⟩
left_inv sample := by
apply Subtype.ext
exact Prod.ext sample.property.1.symm rfl
right_inv sample := rfl
theorem raw_conditional_inside_average {P D O N : Type} [Fintype P] [DecidableEq P]
[Fintype D] [Zero D] [DecidableEq D] [Fintype O] [DecidableEq O] [DecidableEq N]
(J : Finset P) (name : O → Fin 3 → N) (gamma : RawCoefficients J D)
(observed : PositionOutside (zeroSet J gamma) → O × N)
(hpos : 0 < Fintype.card (RawObservationFibre J name gamma observed))
(f : InsideDraw (zeroSet J gamma) O → ℚ) :
average (fun sample : RawObservationFibre J name gamma observed =>
f (insideDraw (zeroSet J gamma) sample.val.2)) = average f := by
let e := rawObservationFibreEquiv J name gamma observed
have hpos' : 0 < Fintype.card (ObservationFibre (zeroSet J gamma) name observed) := by
rwa [Fintype.card_congr e] at hpos
calc
average (fun sample : RawObservationFibre J name gamma observed =>
f (insideDraw (zeroSet J gamma) sample.val.2)) =
average (fun sample : ObservationFibre (zeroSet J gamma) name observed =>
f (insideDraw (zeroSet J gamma) sample.val)) := by
exact average_equiv e (fun sample : ObservationFibre (zeroSet J gamma) name observed =>
f (insideDraw (zeroSet J gamma) sample.val))
_ = average f := conditional_inside_average _ name observed hpos' f
theorem raw_conditional_ratio {P D O N : Type} [Fintype P] [DecidableEq P]
[Fintype D] [Zero D] [DecidableEq D] [Fintype O] [DecidableEq O] [DecidableEq N]
(J : Finset P) (name : O → Fin 3 → N) (gamma : RawCoefficients J D)
(observed : PositionOutside (zeroSet J gamma) → O × N)
(hpos : 0 < Fintype.card (RawObservationFibre J name gamma observed))
(f : InsideDraw (zeroSet J gamma) O → ℚ) :
((∑ sample : RawObservationFibre J name gamma observed,
f (insideDraw (zeroSet J gamma) sample.val.2)) / Fintype.card (RawSample J D O)) /
((Fintype.card (RawObservationFibre J name gamma observed) : ℚ) /
Fintype.card (RawSample J D O)) = average f := by
rw [uniform_conditional_ratio _ hpos]
exact raw_conditional_inside_average J name gamma observed hpos f
theorem raw_conditional_incidence_average {P D O N : Type} [Fintype P] [DecidableEq P]
[Fintype D] [Zero D] [DecidableEq D] [Fintype O] [DecidableEq O] [DecidableEq N]
(J : Finset P) (name : O → Fin 3 → N) (gamma : RawCoefficients J D)
(observed : PositionOutside (zeroSet J gamma) → O × N)
(hpos : 0 < Fintype.card (RawObservationFibre J name gamma observed))
(f : (PositionInside (zeroSet J gamma) → O × N) → ℚ) :
average (fun sample : RawObservationFibre J name gamma observed =>
f (fun j => incidence name (sample.val.2 j.val))) =
average (fun fresh : InsideDraw (zeroSet J gamma) O => f (fun j => incidence name (fresh j))) := by
exact raw_conditional_inside_average J name gamma observed hpos
(fun fresh => f (fun j => incidence name (fresh j)))
theorem raw_conditional_product_incidence {P D O N : Type} [Fintype P] [DecidableEq P]
[Fintype D] [Zero D] [DecidableEq D] [Fintype O] [DecidableEq O] [DecidableEq N]
(J : Finset P) (name : O → Fin 3 → N) (gamma : RawCoefficients J D)
(observed : PositionOutside (zeroSet J gamma) → O × N)
(hpos : 0 < Fintype.card (RawObservationFibre J name gamma observed))
(f : PositionInside (zeroSet J gamma) → O × N → ℚ) :
average (fun sample : RawObservationFibre J name gamma observed =>
∏ j, f j (incidence name (sample.val.2 j.val))) =
∏ j, average (fun fresh : O × Fin 3 => f j (incidence name fresh)) := by
calc
_ = average (fun fresh : InsideDraw (zeroSet J gamma) O =>
∏ j, f j (incidence name (fresh j))) :=
raw_conditional_inside_average J name gamma observed hpos
(fun fresh => ∏ j, f j (incidence name (fresh j)))
_ = _ := average_coordinate_product (fun j fresh => f j (incidence name fresh))
end
end DFVSGames.Soundness.ConditionalIncidences
end
section
open scoped BigOperators
namespace DFVSGames.Soundness.PartnerMapCoordinates
open PartnerProjection
open ConditionalIncidences (PositionInside PositionOutside RawSlot RawCoefficients average)
open DFVSGames.Integration.BinaryLinear (F2 ofBit toBit)
noncomputable section
variable {P : Type} [DecidableEq P] (rhs : P → Bool) (J : Finset P)
def activeOf (J : Finset P) (j : P) : Bool := decide (j ∈ J)
def inactiveOfOutside (j : PositionOutside J) : PartnerLinear.Inactive (activeOf J) :=
⟨j.val, by simp [activeOf, j.property]⟩
def activeOfInside (j : PositionInside J) : PartnerLinear.Active (activeOf J) :=
⟨j.val, by simp [activeOf, j.property]⟩
def outsideOfInactive (j : PartnerLinear.Inactive (activeOf J)) : PositionOutside J :=
⟨j.val, by simpa [activeOf] using j.property⟩
def insideOfActive (j : PartnerLinear.Active (activeOf J)) : PositionInside J :=
⟨j.val, by simpa [activeOf] using j.property⟩
def tupleToRaw (v : PartnerLinear.PartnerCoordinates (activeOf J)) : RawSlot J → F2
| none => v.1
| some (.inl (j, i)) =>
if i = 0 then (v.2.1 (inactiveOfOutside J j)).1
else (v.2.1 (inactiveOfOutside J j)).2
| some (.inr j) => v.2.2 (activeOfInside J j)
def tupleFromRaw (f : RawSlot J → F2) : PartnerLinear.PartnerCoordinates (activeOf J) :=
(f none,
(fun j => (f (some (.inl (outsideOfInactive J j, 0))),
f (some (.inl (outsideOfInactive J j, 1)))),
fun j => f (some (.inr (insideOfActive J j)))))
def tupleRawEquiv : PartnerLinear.PartnerCoordinates (activeOf J) ≃ₗ[F2] (RawSlot J → F2) where
toFun := tupleToRaw J
invFun := tupleFromRaw J
left_inv v := by
apply Prod.ext
· rfl
· apply Prod.ext
· funext j
apply Prod.ext <;> rfl
· funext j
rfl
right_inv f := by
funext s
rcases s with _ | (⟨j, i⟩ | j)
· rfl
· fin_cases i <;> rfl
· rfl
map_add' x y := by
funext s
rcases s with _ | (⟨j, i⟩ | j)
· rfl
· fin_cases i <;> rfl
· rfl
map_smul' c x := by
funext s
rcases s with _ | (⟨j, i⟩ | j)
· rfl
· fin_cases i <;> rfl
· rfl
def pointEquiv : PartnerPoint rhs (activeOf J) ≃ₗ[F2] (RawSlot J → F2) :=
(PartnerLinear.partnerLinearEquiv rhs (activeOf J)).trans (tupleRawEquiv J)
@[simp] theorem pointEquiv_none (y : PartnerPoint rhs (activeOf J)) :
pointEquiv rhs J y none = ofBit y.homogeneous := rfl
@[simp] theorem pointEquiv_full_first (y : PartnerPoint rhs (activeOf J))
(j : PositionOutside J) :
pointEquiv rhs J y (some (.inl (j, 0))) = ofBit (y.full j.val).first := rfl
@[simp] theorem pointEquiv_full_second (y : PartnerPoint rhs (activeOf J))
(j : PositionOutside J) :
pointEquiv rhs J y (some (.inl (j, 1))) = ofBit (y.full j.val).second := rfl
@[simp] theorem pointEquiv_single (y : PartnerPoint rhs (activeOf J))
(j : PositionInside J) :
pointEquiv rhs J y (some (.inr j)) = ofBit (y.single j.val) := rfl
variable [Fintype P]
def partnerBasis : Module.Basis (RawSlot J) F2 (PartnerPoint rhs (activeOf J)) :=
Module.Basis.ofEquivFun (pointEquiv rhs J)
variable (R : Type) [AddCommGroup R] [Module F2 R]
def mapEquiv : RawCoefficients J R ≃ₗ[F2] (PartnerPoint rhs (activeOf J) →ₗ[F2] R) :=
(partnerBasis rhs J).constr F2
def coefficients (Y : PartnerPoint rhs (activeOf J) →ₗ[F2] R) : RawCoefficients J R :=
(mapEquiv rhs J R).symm Y
theorem map_coefficients (Y : PartnerPoint rhs (activeOf J) →ₗ[F2] R) :
mapEquiv rhs J R (coefficients rhs J R Y) = Y :=
(mapEquiv rhs J R).apply_symm_apply Y
theorem coefficients_map (gamma : RawCoefficients J R) :
coefficients rhs J R (mapEquiv rhs J R gamma) = gamma :=
(mapEquiv rhs J R).symm_apply_apply gamma
theorem mapEquiv_apply (gamma : RawCoefficients J R) (y : PartnerPoint rhs (activeOf J)) :
mapEquiv rhs J R gamma y = ∑ s, pointEquiv rhs J y s • gamma s := by
rw [mapEquiv, Module.Basis.constr_apply_fintype]
simp only [partnerBasis, Module.Basis.equivFun_ofEquivFun]
theorem mapEquiv_expansion (gamma : RawCoefficients J R) (y : PartnerPoint rhs (activeOf J)) :
mapEquiv rhs J R gamma y =
ofBit y.homogeneous • gamma none +
(∑ j : PositionOutside J,
(ofBit (y.full j.val).first • gamma (some (.inl (j, 0))) +
ofBit (y.full j.val).second • gamma (some (.inl (j, 1))))) +
∑ j : PositionInside J, ofBit (y.single j.val) • gamma (some (.inr j)) := by
rw [mapEquiv_apply, Fintype.sum_option, Fintype.sum_sum_type, Fintype.sum_prod_type]
simp only [Fin.sum_univ_two, pointEquiv_none, pointEquiv_full_first,
pointEquiv_full_second, pointEquiv_single]
simp only [add_assoc]
theorem every_map_expansion (Y : PartnerPoint rhs (activeOf J) →ₗ[F2] R)
(y : PartnerPoint rhs (activeOf J)) :
Y y = ∑ s, pointEquiv rhs J y s • coefficients rhs J R Y s := by
rw [← mapEquiv_apply, map_coefficients]
theorem pullback_expansion (gamma : RawCoefficients J R) (slot : P → Slot)
(x : SourcePoint rhs) :
mapEquiv rhs J R gamma (PartnerLinear.projection rhs (activeOf J) slot x) =
ofBit x.homogeneous • gamma none +
(∑ j : PositionOutside J,
(ofBit (x.coordinates j.val).first • gamma (some (.inl (j, 0))) +
ofBit (x.coordinates j.val).second • gamma (some (.inl (j, 1))))) +
∑ j : PositionInside J,
ofBit (retained (slot j.val) (x.coordinates j.val)) • gamma (some (.inr j)) := by
rw [mapEquiv_expansion]
congr 1
· congr 1
apply Finset.sum_congr rfl
intro j _
simp [PartnerLinear.projection_apply, project, activeOf, j.property]
· apply Finset.sum_congr rfl
intro j _
simp [PartnerLinear.projection_apply, project, activeOf, j.property]
instance partnerMapsFintype [Fintype R] :
Fintype (PartnerPoint rhs (activeOf J) →ₗ[F2] R) := by
classical
exact Fintype.ofEquiv (RawCoefficients J R) (mapEquiv rhs J R).toEquiv
theorem uniform_coefficients_maps [Fintype R]
(H : (PartnerPoint rhs (activeOf J) →ₗ[F2] R) → ℚ) :
average (fun gamma : RawCoefficients J R => H (mapEquiv rhs J R gamma)) = average H :=
ConditionalIncidences.average_equiv (mapEquiv rhs J R).toEquiv H
theorem uniform_map_coefficients_product [Fintype R]
(H : RawSlot J → R → ℚ) :
average (fun Y : PartnerPoint rhs (activeOf J) →ₗ[F2] R =>
∏ s, H s (coefficients rhs J R Y s)) = ∏ s, average (H s) := by
calc
_ = average (fun gamma : RawCoefficients J R => ∏ s, H s (gamma s)) :=
ConditionalIncidences.average_equiv (mapEquiv rhs J R).symm.toEquiv
(fun gamma => ∏ s, H s (gamma s))
_ = _ := ConditionalIncidences.average_coordinate_product H
end
end DFVSGames.Soundness.PartnerMapCoordinates
end
namespace DFVSGames.Soundness.IncidenceExtraction
abbrev Triple := Fin 3 → Bool
def xorTriple (x : Triple) : Bool := (x 0 ^^ x 1) ^^ x 2
structure Incidence (Occurrence Name : Type) where
name : Occurrence → Fin 3 → Name
rhs : Occurrence → Bool
def Incidence.accepts {Occurrence Name : Type}
(g : Incidence Occurrence Name) (o : Occurrence) (i : Fin 3)
(a : Triple) (b : Bool) : Prop :=
xorTriple a = g.rhs o ∧ a i = b
def Incidence.namedAccepts {Occurrence Name : Type}
(g : Incidence Occurrence Name) (o : Occurrence) (n : Name)
(a : Triple) (b : Bool) : Prop :=
∃ i, g.name o i = n ∧ g.accepts o i a b
theorem Incidence.accepts_implies_namedAccepts {Occurrence Name : Type}
(g : Incidence Occurrence Name) (o : Occurrence) (i : Fin 3)
(a : Triple) (b : Bool) (h : g.accepts o i a b) :
g.namedAccepts o (g.name o i) a b :=
⟨i, rfl, h⟩
theorem Incidence.namedAccepts_iff_accepts {Occurrence Name : Type}
(g : Incidence Occurrence Name)
(distinct : ∀ o i j, g.name o i = g.name o j → i = j)
(o : Occurrence) (i : Fin 3) (a : Triple) (b : Bool) :
g.namedAccepts o (g.name o i) a b ↔ g.accepts o i a b := by
constructor
· rintro ⟨j, hname, h⟩
have hji := distinct o j i hname
simpa [hji] using h
· exact g.accepts_implies_namedAccepts o i a b
structure FullPoint (Position : Type) where
homogeneous : Bool
coords : Position → Triple
def FullPoint.valid {Position Occurrence Name : Type}
(g : Incidence Occurrence Name) (u : Position → Occurrence)
(e : FullPoint Position) : Prop :=
∀ j, xorTriple (e.coords j) = (g.rhs (u j) && e.homogeneous)
structure PartnerPoint (Position : Type) where
homogeneous : Bool
single : Position → Bool
def AugmentedAccepts {Position Occurrence Name : Type}
(g : Incidence Occurrence Name) (u : Position → Occurrence)
(active : Position → Prop) (slot : Position → Fin 3)
(eA : FullPoint Position) (eB : PartnerPoint Position) : Prop :=
eA.valid g u ∧ eA.homogeneous = true ∧ eB.homogeneous = true ∧
∀ j, active j → eA.coords j (slot j) = eB.single j
def RepeatedAccepts {Position Occurrence Name : Type}
(g : Incidence Occurrence Name) (u : Position → Occurrence)
(slot : Position → Fin 3) (inside : Position → Prop)
(answerA : Position → Triple) (answerB : Position → Bool) : Prop :=
∀ j, inside j → g.accepts (u j) (slot j) (answerA j) (answerB j)
theorem augmented_accepts_implies_repeated_accepts
{Position Occurrence Name : Type}
(g : Incidence Occurrence Name) (u : Position → Occurrence)
(active inside : Position → Prop) (slot : Position → Fin 3)
(eA : FullPoint Position) (eB : PartnerPoint Position)
(hinside : ∀ j, inside j → active j)
(haccept : AugmentedAccepts g u active slot eA eB) :
RepeatedAccepts g u slot inside eA.coords eB.single := by
obtain ⟨hvalid, hone, _, hagree⟩ := haccept
intro j hj
constructor
· have heq := hvalid j
simpa [hone] using heq
· exact hagree j (hinside j hj)
theorem augmented_accepts_implies_named_repeated_accepts
{Position RepeatPosition Occurrence Name : Type}
(g : Incidence Occurrence Name) (u : Position → Occurrence)
(active : Position → Prop) (slot : Position → Fin 3)
(embed : RepeatPosition → Position)
(eA : FullPoint Position) (eB : PartnerPoint Position)
(hinside : ∀ r, active (embed r))
(haccept : AugmentedAccepts g u active slot eA eB) :
∀ r, g.namedAccepts (u (embed r))
(g.name (u (embed r)) (slot (embed r)))
(eA.coords (embed r)) (eB.single (embed r)) := by
intro r
apply g.accepts_implies_namedAccepts
obtain ⟨hvalid, hone, _, hagree⟩ := haccept
constructor
· have heq := hvalid (embed r)
simpa [hone] using heq
· exact hagree (embed r) (hinside r)
structure Game (QA QB A B : Type) where
accepts : QA → QB → A → B → Prop
structure Strategies (QA QB A B : Type) where
first : QA → A
second : QB → B
def Strategies.wins {QA QB A B : Type} (s : Strategies QA QB A B)
(g : Game QA QB A B) (qa : QA) (qb : QB) : Prop :=
g.accepts qa qb (s.first qa) (s.second qb)
structure LocalSimulation
{InnerQA InnerQB InnerA InnerB OuterQA OuterQB OuterA OuterB : Type}
(inner : Game InnerQA InnerQB InnerA InnerB)
(outer : Game OuterQA OuterQB OuterA OuterB) where
questionA : InnerQA → OuterQA
questionB : InnerQB → OuterQB
answerA : InnerQA → OuterA → InnerA
answerB : InnerQB → OuterB → InnerB
sound : ∀ qa qb a b,
outer.accepts (questionA qa) (questionB qb) a b →
inner.accepts qa qb (answerA qa a) (answerB qb b)
def LocalSimulation.induced
{InnerQA InnerQB InnerA InnerB OuterQA OuterQB OuterA OuterB : Type}
{inner : Game InnerQA InnerQB InnerA InnerB}
{outer : Game OuterQA OuterQB OuterA OuterB}
(r : LocalSimulation inner outer)
(s : Strategies OuterQA OuterQB OuterA OuterB) :
Strategies InnerQA InnerQB InnerA InnerB where
first qa := r.answerA qa (s.first (r.questionA qa))
second qb := r.answerB qb (s.second (r.questionB qb))
theorem LocalSimulation.induced_wins
{InnerQA InnerQB InnerA InnerB OuterQA OuterQB OuterA OuterB : Type}
{inner : Game InnerQA InnerQB InnerA InnerB}
{outer : Game OuterQA OuterQB OuterA OuterB}
(r : LocalSimulation inner outer)
(s : Strategies OuterQA OuterQB OuterA OuterB)
(qa : InnerQA) (qb : InnerQB)
(hwins : s.wins outer (r.questionA qa) (r.questionB qb)) :
(r.induced s).wins inner qa qb :=
r.sound qa qb (s.first (r.questionA qa)) (s.second (r.questionB qb)) hwins
theorem LocalSimulation.seeded_induced_wins
{InnerQA InnerQB InnerA InnerB OuterQA OuterQB OuterA OuterB Seed : Type}
{inner : Game InnerQA InnerQB InnerA InnerB}
{outer : Game OuterQA OuterQB OuterA OuterB}
(r : LocalSimulation inner outer)
(strategy : Seed → Strategies OuterQA OuterQB OuterA OuterB)
(seed : Seed) (qa : InnerQA) (qb : InnerQB)
(hwins : (strategy seed).wins outer (r.questionA qa) (r.questionB qb)) :
(r.induced (strategy seed)).wins inner qa qb :=
r.induced_wins (strategy seed) qa qb hwins
end DFVSGames.Soundness.IncidenceExtraction
namespace DFVSGames.Soundness.ConcreteExtraction
open PartnerProjection IncidenceExtraction
def slotIndex : PartnerProjection.Slot → Fin 3
| .first => 0
| .second => 1
| .third => 2
def tripleCoordinates (x : PartnerProjection.Triple) : IncidenceExtraction.Triple :=
fun i => if i = 0 then x.first else if i = 1 then x.second else x.third
theorem parity_coordinates (x : PartnerProjection.Triple) :
IncidenceExtraction.xorTriple (tripleCoordinates x) = PartnerProjection.parity x := rfl
theorem retained_coordinates (x : PartnerProjection.Triple) (i : PartnerProjection.Slot) :
tripleCoordinates x (slotIndex i) = PartnerProjection.retained i x := by
cases i <;> rfl
def fullPoint {P : Type} {rhs : P → Bool}
(x : PartnerProjection.SourcePoint rhs) : IncidenceExtraction.FullPoint P :=
⟨x.homogeneous, fun j => tripleCoordinates (x.coordinates j)⟩
def partnerPoint {P : Type} {rhs active : P → Bool}
(x : PartnerProjection.PartnerPoint rhs active) : IncidenceExtraction.PartnerPoint P :=
⟨x.homogeneous, x.single⟩
theorem actual_projection_accepts
{P O N : Type} (g : IncidenceExtraction.Incidence O N) (u : P → O)
(active : P → Bool) (slot : P → PartnerProjection.Slot)
(x : PartnerProjection.SourcePoint (fun j => g.rhs (u j)))
(y : PartnerProjection.PartnerPoint (fun j => g.rhs (u j)) active)
(hone : x.homogeneous = true)
(hproject : PartnerProjection.project (fun j => g.rhs (u j)) active slot x = y) :
IncidenceExtraction.AugmentedAccepts g u (fun j => active j = true)
(fun j => slotIndex (slot j)) (fullPoint x) (partnerPoint y) := by
subst y
constructor
· intro j
exact x.valid j
constructor
· exact hone
constructor
· exact hone
intro j hj
change tripleCoordinates (x.coordinates j) (slotIndex (slot j)) =
(if active j then PartnerProjection.retained (slot j) (x.coordinates j) else false)
rw [hj]
exact retained_coordinates _ _
theorem actual_projection_implies_named_repetition
{P R O N : Type} (g : IncidenceExtraction.Incidence O N) (u : P → O)
(active : P → Bool) (slot : P → PartnerProjection.Slot) (embed : R → P)
(x : PartnerProjection.SourcePoint (fun j => g.rhs (u j)))
(y : PartnerProjection.PartnerPoint (fun j => g.rhs (u j)) active)
(hinside : ∀ r, active (embed r) = true)
(hone : x.homogeneous = true)
(hproject : PartnerProjection.project (fun j => g.rhs (u j)) active slot x = y) :
∀ r, g.namedAccepts (u (embed r))
(g.name (u (embed r)) (slotIndex (slot (embed r))))
(tripleCoordinates (x.coordinates (embed r))) (y.single (embed r)) := by
exact IncidenceExtraction.augmented_accepts_implies_named_repeated_accepts g u
(fun j => active j = true) (fun j => slotIndex (slot j)) embed
(fullPoint x) (partnerPoint y) hinside
(actual_projection_accepts g u active slot x y hone hproject)
end DFVSGames.Soundness.ConcreteExtraction
namespace DFVSGames.Reduction.ActualHomogeneous
open Integration.BinaryLinear
open scoped BigOperators
abbrev E (k : Nat) := F2 × (Fin k → F2 × F2)
abbrev Ambient (k : Nat) := F2 × (Fin k → Fin 3 → F2)
variable {k : Nat}
def tau : E k →ₗ[F2] F2 := LinearMap.fst F2 _ _
def hBasis (k : Nat) : E k := (1, 0)
def firstBasis (j : Fin k) : E k := (0, Pi.single j (1, 0))
def secondBasis (j : Fin k) : E k := (0, Pi.single j (0, 1))
def coordinateBasis (j : Fin k) (i : Fin 2) : E k :=
if i = 0 then firstBasis j else secondBasis j
@[simp] theorem tau_hBasis : tau (hBasis k) = 1 := rfl
@[simp] theorem tau_firstBasis (j : Fin k) : tau (firstBasis j) = 0 := rfl
@[simp] theorem tau_secondBasis (j : Fin k) : tau (secondBasis j) = 0 := rfl
theorem pair_fst_ite (p : Prop) [Decidable p] (a b : F2 × F2) :
(if p then a else b).1 = if p then a.1 else b.1 := by split_ifs <;> rfl
theorem pair_snd_ite (p : Prop) [Decidable p] (a b : F2 × F2) :
(if p then a else b).2 = if p then a.2 else b.2 := by split_ifs <;> rfl
theorem coordinate_decomposition (x : E k) :
x = x.1 • hBasis k + ∑ j : Fin k,
((x.2 j).1 • firstBasis j + (x.2 j).2 • secondBasis j) := by
apply Prod.ext
· simp [hBasis, firstBasis, secondBasis, Prod.fst_sum]
· funext j
apply Prod.ext <;>
simp [hBasis, firstBasis, secondBasis, Pi.single_apply,
Prod.snd_sum, Prod.fst_sum, Finset.sum_apply, pair_fst_ite, pair_snd_ite]
theorem linearMap_expansion {R : Type*} [AddCommGroup R] [Module F2 R]
(X : E k →ₗ[F2] R) (x : E k) :
X x = x.1 • X (hBasis k) + ∑ j : Fin k,
((x.2 j).1 • X (firstBasis j) + (x.2 j).2 • X (secondBasis j)) := by
conv_lhs => rw [coordinate_decomposition x]
simp
def homogeneous (b : Fin k → F2) : Submodule F2 (Ambient k) where
carrier := {x | ∀ j, x.2 j 0 + x.2 j 1 + x.2 j 2 = b j * x.1}
zero_mem' := by simp
add_mem' := by
intro x y hx hy j
change (x.2 j 0 + y.2 j 0) + (x.2 j 1 + y.2 j 1) +
(x.2 j 2 + y.2 j 2) = b j * (x.1 + y.1)
calc
_ = (x.2 j 0 + x.2 j 1 + x.2 j 2) +
(y.2 j 0 + y.2 j 1 + y.2 j 2) := by ring
_ = b j * x.1 + b j * y.1 := by rw [hx j, hy j]
_ = _ := by ring
smul_mem' := by
intro c x hx j
change c * x.2 j 0 + c * x.2 j 1 + c * x.2 j 2 = b j * (c * x.1)
calc
_ = c * (x.2 j 0 + x.2 j 1 + x.2 j 2) := by ring
_ = c * (b j * x.1) := by rw [hx j]
_ = _ := by ring
def embed (b : Fin k → F2) : E k →ₗ[F2] Ambient k where
toFun x := (x.1, fun j => ![(x.2 j).1, (x.2 j).2,
b j * x.1 + (x.2 j).1 + (x.2 j).2])
map_add' x y := by
apply Prod.ext
· rfl
· funext j i
fin_cases i <;> simp ; ring
map_smul' c x := by
apply Prod.ext
· rfl
· funext j i
fin_cases i <;> simp [smul_eq_mul] ; ring
theorem embed_mem (b : Fin k → F2) (x : E k) : embed b x ∈ homogeneous b := by
intro j
change (x.2 j).1 + (x.2 j).2 + (b j * x.1 + (x.2 j).1 + (x.2 j).2) = b j * x.1
have h1 := CharTwo.add_self_eq_zero ((x.2 j).1)
have h2 := CharTwo.add_self_eq_zero ((x.2 j).2)
calc
_ = b j * x.1 + (((x.2 j).1 + (x.2 j).1) + ((x.2 j).2 + (x.2 j).2)) := by ring
_ = _ := by rw [h1, h2]; simp
def equivalence (b : Fin k → F2) : E k ≃ₗ[F2] homogeneous b where
toFun x := ⟨embed b x, embed_mem b x⟩
invFun x := (x.1.1, fun j => (x.1.2 j 0, x.1.2 j 1))
left_inv x := by rfl
right_inv x := by
apply Subtype.ext
apply Prod.ext
· rfl
· funext j i
fin_cases i
· rfl
· rfl
· change b j * x.1.1 + x.1.2 j 0 + x.1.2 j 1 = x.1.2 j 2
rw [← x.property j]
have h1 := CharTwo.add_self_eq_zero (x.1.2 j 0)
have h2 := CharTwo.add_self_eq_zero (x.1.2 j 1)
calc
_ = x.1.2 j 2 + ((x.1.2 j 0 + x.1.2 j 0) + (x.1.2 j 1 + x.1.2 j 1)) := by ring
_ = _ := by rw [h1, h2]; simp
map_add' x y := Subtype.ext ((embed b).map_add x y)
map_smul' c x := Subtype.ext ((embed b).map_smul c x)
theorem finrank_E (k : Nat) : Module.finrank F2 (E k) = 1 + 2 * k := by
simp [E, Module.finrank_prod, Module.finrank_pi_fintype, Nat.mul_comm]
theorem finrank_homogeneous (b : Fin k → F2) :
Module.finrank F2 (homogeneous b) = 1 + 2 * k := by
rw [← (equivalence b).finrank_eq, finrank_E]
end DFVSGames.Reduction.ActualHomogeneous
end OAI