import OAI.Computability.WLIdentification.AcceptingBroadcast namespace OAI namespace WLIdentification namespace ProductCircuit variable {r : ℕ} {P E Z T : Type} (C : ProductCircuit r P E Z T) abbrev primaryTruth (p : C.Primary) (a : Fin r → Bool) : Fin (C.primaryDimension p) → Prop := match p with | none => fun _ => False | some p => C.PortTrue p a abbrev primarySet (p : C.Primary) (a : Fin r → Bool) := BufferAlgebra.truthVectors (C.primaryTruth p a) abbrev sourceTruth (l : C.Connection) (a : Fin r → Bool) : Prop := match l with | .original e => C.True (C.source e) a | .test t => C.True (C.testType t) a | .flip _ => False | .broadcast _ _ => False | .self p j => C.primaryTruth p a j | .conflict => False abbrev targetTruth (l : C.Connection) (a : Fin r → Bool) : Prop := match l with | .original e => C.PortTrue (C.target e) a (C.port e) | .test _ => False | .flip _ => False | .broadcast p j => C.PortTrue p a j | .self p j => C.primaryTruth p a j | .conflict => False def rejectConstant : C.Comparison → Bit | .third .conflict => 1 | _ => 0 theorem source_truth_image (l : C.Connection) (a : Fin r → Bool) : C.sourceForm l '' C.primarySet (C.connectionSource l) a = @ite (Set Bit) (C.sourceTruth l a) (Classical.propDecidable _) {0} Set.univ := by classical have hs (p : P) : ⇑(sumForm (C.dimension p)) = fun v => ∑ j, v j := funext (sumForm_apply _) cases l with | original e => rw [hs] have hu := BufferAlgebra.sum_truth (C.PortTrue (C.source e) a) by_cases ht : ∀ j, C.PortTrue (C.source e) a j <;> simpa only [sourceTruth, True, connectionSource, primarySet, primaryTruth, ht, ite_true, ite_false] using hu | test t => rw [hs] have hu := BufferAlgebra.sum_truth (C.PortTrue (C.testType t) a) by_cases ht : ∀ j, C.PortTrue (C.testType t) a j <;> simpa only [sourceTruth, True, connectionSource, primarySet, primaryTruth, ht, ite_true, ite_false] using hu | flip i => simpa only [sourceForm, connectionSource, primarySet, primaryTruth, sourceTruth, ite_false, LinearMap.coe_proj, Function.eval] using BufferAlgebra.projection_truth (fun _ : Fin 1 => False) 0 | broadcast p j => simpa only [sourceForm, connectionSource, primarySet, primaryTruth, sourceTruth, ite_false, LinearMap.coe_proj, Function.eval] using BufferAlgebra.projection_truth (fun _ : Fin 1 => False) 0 | self p j => exact BufferAlgebra.projection_truth (C.primaryTruth p a) j | conflict => simpa only [sourceForm, connectionSource, primarySet, primaryTruth, sourceTruth, ite_false, LinearMap.coe_proj, Function.eval] using BufferAlgebra.projection_truth (fun _ : Fin 1 => False) 0 theorem target_truth_image (l : C.Connection) (a : Fin r → Bool) : C.targetForm l '' C.primarySet (C.connectionTarget l) a = @ite (Set Bit) (C.targetTruth l a) (Classical.propDecidable _) {0} Set.univ := by classical cases l with | original e => exact BufferAlgebra.projection_truth (C.PortTrue (C.target e) a) (C.port e) | test t => simpa only [targetForm, connectionTarget, primarySet, primaryTruth, targetTruth, ite_false, LinearMap.coe_proj, Function.eval] using BufferAlgebra.projection_truth (fun _ : Fin 1 => False) 0 | flip i => simpa only [targetForm, connectionTarget, primarySet, primaryTruth, targetTruth, ite_false, LinearMap.coe_proj, Function.eval] using BufferAlgebra.projection_truth (fun _ : Fin 1 => False) 0 | broadcast p j => exact BufferAlgebra.projection_truth (C.PortTrue p a) j | self p j => exact BufferAlgebra.projection_truth (C.primaryTruth p a) j | conflict => simpa only [targetForm, connectionTarget, primarySet, primaryTruth, targetTruth, ite_false, LinearMap.coe_proj, Function.eval] using BufferAlgebra.projection_truth (fun _ : Fin 1 => False) 0 theorem source_implies_target (h : ¬ C.Accepted) (l : C.Connection) (a : (C.connectionMap l).Point) (ht : C.sourceTruth l ((C.connectionMap l).source a)) : C.targetTruth l ((C.connectionMap l).target a) ∧ C.rejectConstant (.third l) = 0 := by cases l with | original e => exact ⟨PortTrue.edge e a ht, rfl⟩ | test t => exact (h ⟨t, a, ht⟩).elim | flip i => exact ht.elim | broadcast p j => exact ht.elim | self p j => exact ⟨ht, rfl⟩ | conflict => exact ht.elim def rejectDestination (l : C.Connection) (a : Fin r → Bool) : Set Bit := (fun v => C.rejectConstant (.third l) + C.targetForm l v) '' C.primarySet (C.connectionTarget l) (fun i => (C.connectionMap l).mapping i (a i)) theorem rejectDestination_nonempty (l : C.Connection) (a : Fin r → Bool) : (C.rejectDestination l a).Nonempty := (BufferAlgebra.truthVectors_nonempty _).image _ theorem rejectDestination_true (h : ¬ C.Accepted) (l : C.Connection) (a : (C.connectionMap l).Point) (ht : C.sourceTruth l ((C.connectionMap l).source a)) : C.rejectDestination l ((C.connectionMap l).source a) = {0} := by obtain ⟨hd, hb⟩ := C.source_implies_target h l a ht dsimp only [rejectDestination] rw [hb] simp only [zero_add] change C.targetForm l '' C.primarySet (C.connectionTarget l) ((C.connectionMap l).target a) = _ rw [C.target_truth_image l _, ite_eq_left hd] noncomputable def rejectBuffer (l : C.Connection) (a : Fin r → Bool) : Set (Fin 2 → Bit) := by classical exact if C.sourceTruth l a then {0} else BufferAlgebra.correlated (C.rejectDestination l a) theorem rejectBuffer_nonempty (l : C.Connection) (a : Fin r → Bool) : (C.rejectBuffer l a).Nonempty := by classical unfold rejectBuffer split · exact Set.singleton_nonempty _ · exact BufferAlgebra.correlated_nonempty (C.rejectDestination_nonempty l a) theorem rejectBuffer_projection (l : C.Connection) (a : Fin r → Bool) (j : Fin 2) : (fun v => v j) '' C.rejectBuffer l a = C.sourceForm l '' C.primarySet (C.connectionSource l) a := by classical rw [C.source_truth_image] unfold rejectBuffer split · simp · exact BufferAlgebra.correlated_projection (C.rejectDestination_nonempty l a) j theorem rejectBuffer_sum (h : ¬ C.Accepted) (l : C.Connection) (a : (C.connectionMap l).Point) : (fun v => v 0 + v 1) '' C.rejectBuffer l ((C.connectionMap l).source a) = (fun v => C.rejectConstant (.third l) + C.targetForm l v) '' C.primarySet (C.connectionTarget l) ((C.connectionMap l).target a) := by classical change _ = C.rejectDestination l ((C.connectionMap l).source a) unfold rejectBuffer split · rw [C.rejectDestination_true h l a ‹_›] simp · exact BufferAlgebra.correlated_sum _ /-- Rejection produces actual nonempty scalar-image sets, including correlated buffers. This does not assert an unavailable simultaneous global assignment. -/ noncomputable def rejectingImages (h : ¬ C.Accepted) : C.schemas.SpecialImages C.rejectConstant where values p a := match p with | .primary p => C.primarySet p a | .buffer l => C.rejectBuffer l a | .dummy => Set.univ nonempty p a := by cases p with | primary p => exact BufferAlgebra.truthVectors_nonempty _ | buffer l => exact C.rejectBuffer_nonempty l a | dummy => exact ⟨0, Set.mem_univ _⟩ equation e a := by classical cases e with | seed z => change sumForm (C.dimension (C.seedType z)) '' C.primarySet (some (C.seedType z)) ((C.seedMap z).source a) = (fun _ : Fin 1 → Bit => (0 : Bit)) '' Set.univ have ht : C.True (C.seedType z) ((C.seedMap z).source a) := fun j => PortTrue.seed z a j have hs := BufferAlgebra.sum_truth (C.PortTrue (C.seedType z) ((C.seedMap z).source a)) rw [ite_eq_left (show ∀ j, C.PortTrue (C.seedType z) ((C.seedMap z).source a) j from ht)] at hs rw [show ⇑(sumForm (C.dimension (C.seedType z))) = (fun v => ∑ j, v j) from funext (sumForm_apply _)] simpa using hs | first l => change C.sourceForm l '' C.primarySet (C.connectionSource l) ((C.connectionMap l).source a) = (fun v : Fin 2 → Bit => 0 + v 0) '' C.rejectBuffer l ((C.connectionMap l).source a) simpa only [zero_add] using (C.rejectBuffer_projection l ((C.connectionMap l).source a) 0).symm | second l => change C.sourceForm l '' C.primarySet (C.connectionSource l) ((C.connectionMap l).source a) = (fun v : Fin 2 → Bit => 0 + v 1) '' C.rejectBuffer l ((C.connectionMap l).source a) simpa only [zero_add] using (C.rejectBuffer_projection l ((C.connectionMap l).source a) 1).symm | third l => exact C.rejectBuffer_sum h l a end ProductCircuit namespace Marker theorem sum_delta {r : ℕ} (hr : 0 < r) : ∑ i : Fin r, delta i = 1 := by cases r with | zero => omega | succ n => rw [Finset.sum_eq_single (Fin.last n)] · simp [delta] · intro i _ hi have hn : i.val + 1 ≠ n + 1 := by intro he exact hi (Fin.ext (Nat.add_right_cancel he)) exact ite_eq_right hn · simp end Marker namespace ComparisonSchemas variable {r : ℕ} {P E : Type} (S : ComparisonSchemas r P E) theorem linkShift_special (hr : 0 < r) (n : ℕ) (b : E → Bit) (l : S.Link n) (a : (S.layout n).MatchAddress l) : (S.layout n).linkShift (S.specialTwist n b) l a = S.linkConstant n b l := by dsimp only [RingLayout.linkShift, specialTwist] rw [← Finset.sum_mul, Marker.sum_delta hr, one_mul] theorem wireShift_special (hr : 0 < r) (n : ℕ) (b : E → Bit) (e : E) (a : S.DomainAddress e) : S.wireShift n (S.specialTwist n b) e a = b e := by dsimp only [wireShift, firstShift, middleShift, lastShift, RingLayout.linkShift, specialTwist, linkConstant] simp only [mul_zero, Finset.sum_const_zero, zero_add] rw [← Finset.sum_mul, Marker.sum_delta hr, one_mul] end ComparisonSchemas namespace ProductCircuit variable {r : ℕ} {P E Z T : Type} [Fintype P] [Fintype E] [Fintype Z] [Fintype T] (C : ProductCircuit r P E Z T) theorem special_not_isomorphic (hr : 32 ≤ r) (n : ℕ) : ¬ Isomorphic (((C.schemas.layout n).affine (by omega)).graph 0) (((C.schemas.layout n).affine (by omega)).graph (C.schemas.specialTwist n C.rejectConstant)) := by intro hi obtain ⟨h, _, he⟩ := (C.schemas.offsets_iff_real_rowSums (by omega) n _).mp ((((C.schemas.layout n).affine (by omega)).graph_isomorphic_iff _).mp hi) have hc (e : C.Comparison) (a : (C.comparisonMap e).Point) := he e a have hc' (e : C.Comparison) (a : (C.comparisonMap e).Point) : C.schemas.left e (h (C.schemas.source e) (C.schemas.sourceAddress e a)) + C.schemas.right e (h (C.schemas.target e) (C.schemas.targetAddress e a)) = C.rejectConstant e := (hc e a).trans (C.schemas.wireShift_special (by omega) n C.rejectConstant e a) let a := ProductMap.ofAddress (fun _ : Fin r => false) have h₁ := hc' (.first (.self none 0)) a have h₂ := hc' (.second (.self none 0)) a have h₃ := hc' (.third (.self none 0)) a have g₁ := hc' (.first .conflict) a have g₂ := hc' (.second .conflict) a have g₃ := hc' (.third .conflict) a let x := h (.primary none) a (0 : Fin 1) let z : Fin 2 → Bit := h (.buffer (.self none 0)) a let v : Fin 2 → Bit := h (.buffer .conflict) a change x + z 0 = 0 at h₁ change x + z 1 = 0 at h₂ change (z 0 + z 1) + x = 0 at h₃ change x + v 0 = 0 at g₁ change x + v 1 = 0 at g₂ change (v 0 + v 1) + x = 1 at g₃ rw [← CharTwo.add_eq_zero.mp h₁, ← CharTwo.add_eq_zero.mp h₂, CharTwo.add_self_eq_zero, zero_add] at h₃ rw [← CharTwo.add_eq_zero.mp g₁, ← CharTwo.add_eq_zero.mp g₂, CharTwo.add_self_eq_zero, zero_add] at g₃ exact zero_ne_one (h₃.symm.trans g₃) /-- Rejection prevents identification for the full least-closure product circuit, not only for a promised selection of comparison mates. -/ theorem not_identifies_of_rejected (hr : 32 ≤ r) (n : ℕ) (hn : r + 1 < n) (h : ¬ C.Accepted) : ¬ Identifies r (((C.schemas.layout n).affine (by omega)).graph 0) := by intro hi exact C.special_not_isomorphic hr n (hi _ ((C.rejectingImages h).equivalent_special hr hn)) theorem identifies_iff_accepted (hr : 32 ≤ r) (n : ℕ) (hn : r + 1 < n) : Identifies r (((C.schemas.layout n).affine (by omega)).graph 0) ↔ C.Accepted := by constructor · intro hi by_contra hnacc exact C.not_identifies_of_rejected hr n hn hnacc hi · exact C.identifies_of_accepted hr n end ProductCircuit /-- Retained color history always determines the original atomic type. -/ theorem tupleColor_zero_eq {G H : Graph} {k s : ℕ} {v : Fin k → Fin G.order} {w : Fin k → Fin H.order} (h : tupleColor G k s v = tupleColor H k s w) : tupleColor G k 0 v = tupleColor H k 0 w := by induction s with | zero => exact h | succ s ih => exact ih (congrArg Prod.fst h) theorem tupleColor_atomic {G H : Graph} {k s : ℕ} {v : Fin k → Fin G.order} {w : Fin k → Fin H.order} (h : tupleColor G k s v = tupleColor H k s w) : (∀ i j, v i = v j ↔ w i = w j) ∧ (∀ i j, G.edge (v i) (v j) = H.edge (w i) (w j)) := by have h0 := tupleColor_zero_eq h exact ⟨fun i j => decide_eq_decide.mp (congrFun (congrFun (congrArg Prod.fst h0) i) j), fun i j => congrFun (congrFun (congrArg Prod.snd h0) i) j⟩ /-- Restricting a joint color retains an entire replacement vector at once. -/ def restrictTupleColor {j k : ℕ} (q : Fin j → Fin k) : (s : ℕ) → TupleColor k s → TupleColor j s | 0, c => (fun i l => c.1 (q i) (q l), fun i l => c.2 (q i) (q l)) | s + 1, c => (restrictTupleColor q s c.1, c.2.map (fun v i => restrictTupleColor q s (v (q i)))) theorem restrictTupleColor_apply (G : Graph) {j k : ℕ} (q : Fin j → Fin k) (hq : Function.Injective q) (s : ℕ) (v : Fin k → Fin G.order) : restrictTupleColor q s (tupleColor G k s v) = tupleColor G j s (v ∘ q) := by induction s generalizing v with | zero => rfl | succ s ih => dsimp only [restrictTupleColor, tupleColor] apply Prod.ext (ih v) dsimp only [Prod.snd] rw [Multiset.map_map] apply Multiset.map_congr rfl intro z _ funext i dsimp only [Function.comp_def] rw [ih, Function.update_comp_eq_of_injective v hq] rfl def padIndex {j k : ℕ} (hj : 0 < j) (_hjk : j ≤ k) (i : Fin k) : Fin j := if hi : i.val < j then ⟨i.val, hi⟩ else ⟨0, hj⟩ @[simp] theorem padIndex_castLE {j k : ℕ} (hj : 0 < j) (hjk : j ≤ k) (i : Fin j) : padIndex hj hjk (Fin.castLE hjk i) = i := by simp [padIndex, i.isLt] def paddedEquiv {j k : ℕ} (hj : 0 < j) (hjk : j ≤ k) (α : Type) : (Fin j → α) ≃ {v : Fin k → α // ∀ i, v i = v (Fin.castLE hjk (padIndex hj hjk i))} where toFun v := ⟨v ∘ padIndex hj hjk, fun i => by simp⟩ invFun v := v.val ∘ Fin.castLE hjk left_inv v := by funext i; simp right_inv v := by apply Subtype.ext funext i exact (v.property i).symm theorem tupleHistogram_dimension_mono {G H : Graph} {j k s : ℕ} (hj : 0 < j) (hjk : j ≤ k) (h : tupleHistogram G k s = tupleHistogram H k s) : tupleHistogram G j s = tupleHistogram H j s := by obtain ⟨E, hE⟩ := tupleRound_bijection h have hp (v : Fin k → Fin G.order) : (∀ i, v i = v (Fin.castLE hjk (padIndex hj hjk i))) ↔ (∀ i, E v i = E v (Fin.castLE hjk (padIndex hj hjk i))) := forall_congr' (fun i => (tupleColor_atomic (hE v)).1 i _) let e := (paddedEquiv hj hjk (Fin G.order)).trans ((E.subtypeEquiv hp).trans (paddedEquiv hj hjk (Fin H.order)).symm) apply histogram_eq_of_equiv e intro v have hh := congrArg (restrictTupleColor (Fin.castLE hjk) s) (hE (v ∘ padIndex hj hjk)) rw [restrictTupleColor_apply _ _ (Fin.castLE_injective _), restrictTupleColor_apply _ _ (Fin.castLE_injective _)] at hh have hv : (v ∘ padIndex hj hjk) ∘ Fin.castLE hjk = v := by funext i; simp rw [hv] at hh exact hh /-- Ordinary neighbor refinement is recoverable from any joint dimension >=2. -/ theorem neighborColor_of_tupleColor {G H : Graph} {k : ℕ} (hk : 2 ≤ k) (s : ℕ) {v : Fin k → Fin G.order} {w : Fin k → Fin H.order} (h : tupleColor G k s v = tupleColor H k s w) (i : Fin k) : neighborColor G s (v i) = neighborColor H s (w i) := by induction s generalizing v w i with | zero => rfl | succ s ih => have hprev := congrArg Prod.fst h obtain ⟨e, he⟩ := exists_colorEquiv (fun z i => tupleColor G k s (Function.update v i z)) (fun z i => tupleColor H k s (Function.update w i z)) (congrArg Prod.snd h) obtain ⟨j, hij⟩ : ∃ j : Fin k, i ≠ j := by by_cases hi : i = ⟨0, by omega⟩ · refine ⟨⟨1, by omega⟩, ?_⟩ rw [hi] intro he have := congrArg Fin.val he change (0 : ℕ) = 1 at this omega · exact ⟨⟨0, by omega⟩, hi⟩ change (neighborColor G s (v i), _) = (neighborColor H s (w i), _) apply Prod.ext (ih hprev i) apply filteredHistogram_eq_of_equiv e · intro z have hz := (tupleColor_atomic (congrFun (he z) j)).2 i j simp only [Function.update_of_ne hij, Function.update_self] at hz rw [hz] · intro z simpa only [Function.update_self] using ih (congrFun (he z) j) j theorem neighborHistogram_of_tupleHistogram {G H : Graph} {k s : ℕ} (hk : 2 ≤ k) (h : tupleHistogram G k s = tupleHistogram H k s) : neighborHistogram G s = neighborHistogram H s := by obtain ⟨E, hE⟩ := tupleRound_bijection h let i : Fin k := ⟨0, by omega⟩ have hp (v : Fin k → Fin G.order) : (∀ j, v j = v i) ↔ ∀ j, E v j = E v i := forall_congr' (fun j => (tupleColor_atomic (hE v)).1 j i) let e := (diagonalEquiv i (Fin G.order)).trans ((E.subtypeEquiv hp).trans (diagonalEquiv i (Fin H.order)).symm) exact histogram_eq_of_equiv e _ _ (fun v => neighborColor_of_tupleColor hk s (hE (fun _ => v)) i) theorem equivalent_dimension_mono {G H : Graph} {j k : ℕ} (hj : 0 < j) (hjk : j ≤ k) (h : Equivalent k G H) : Equivalent j G H := by by_cases he : j = k · simpa only [he] using h have hk : 2 ≤ k := by omega have hne : k ≠ 1 := by omega rw [Equivalent, ite_eq_right hne] at h unfold Equivalent split_ifs with hj1 · intro s; exact neighborHistogram_of_tupleHistogram hk (h s) · intro s; exact tupleHistogram_dimension_mono hj hjk (h s) theorem identifies_dimension_mono {G : Graph} {j k : ℕ} (hj : 0 < j) (hjk : j ≤ k) (h : Identifies j G) : Identifies k G := fun H hH => h H (equivalent_dimension_mono hj hjk hH) /-- A finite graph has a positive identifying dimension without any restriction on the order of its candidate mate. -/ theorem identifies_order (G : Graph) : Identifies (max 2 G.order) G := by intro H he obtain ⟨e, _⟩ := equivalent_degreeBijection (le_max_left _ _) he by_cases hn : 0 < G.order · obtain ⟨f, hf, ha, _⟩ := equivalent_local_match (le_max_left _ _) he (le_max_right _ _) hn (fun i => i) have hfi : Function.Injective f := fun i j h => (hf i j).mpr h have hfb : Function.Bijective f := (Fintype.bijective_iff_injective_and_card f).mpr ⟨hfi, Fintype.card_congr e⟩ exact ⟨Equiv.ofBijective f hfb, ha⟩ · exact ⟨e, fun u _ => by have := u.isLt; omega⟩ theorem positive_identifying_nonempty (G : Graph) : {k : ℕ | 0 < k ∧ Identifies k G}.Nonempty := ⟨max 2 G.order, by have := le_max_left 2 G.order; omega, identifies_order G⟩ theorem WLdim_spec (G : Graph) : 0 < WLdim G ∧ Identifies (WLdim G) G := Nat.sInf_mem (positive_identifying_nonempty G) theorem WLdim_le_iff {G : Graph} {k : ℕ} (hk : 0 < k) : WLdim G ≤ k ↔ Identifies k G := by constructor · intro h; exact identifies_dimension_mono (WLdim_spec G).1 h (WLdim_spec G).2 · intro h; exact Nat.sInf_le ⟨hk, h⟩ namespace ProductCircuit variable {r : ℕ} {P E Z T : Type} [Fintype P] [Fintype E] [Fintype Z] [Fintype T] (C : ProductCircuit r P E Z T) theorem dimension_iff_accepted (hr : 32 ≤ r) (n : ℕ) (hn : r + 1 < n) : WLdim (((C.schemas.layout n).affine (by omega)).graph 0) ≤ r ↔ C.Accepted := by rw [WLdim_le_iff (by omega), C.identifies_iff_accepted hr n hn] end ProductCircuit end WLIdentification end OAI