import OAI.Computability.WeisfeilerLeman.Marking namespace OAI universe uV uW uD uP uE uT uL uA uB namespace WLTime.Marking variable {V : Type uV} {W : Type uW} {D : Type uD} [Fintype V] [Fintype W] theorem degree_detect_base (G : SimpleGraph V) (H : SimpleGraph W) (c : V → D) (d : W → D) (code : D → ℕ) (hcode : Function.Injective code) (hpos : ∀ b, 0 < code b) (e : V ≃ W) (hc : ∀ v, c v = d (e v)) (q : ℕ) (hN : 2 ≤ Fintype.card V) (x : V) (y : Vertex W (fun v => code (d v)*(Fintype.card V+1)) q) (hd : Pebble.degree (graph G (fun v => code (c v)*(Fintype.card V+1)) q) (.base x) = Pebble.degree (graph H (fun v => code (d v)*(Fintype.card V+1)) q) y) : ∃ z, y = .base z ∧ c x = d z := by have hcard : Fintype.card V = Fintype.card W := Fintype.card_congr e have hx : 2 < Pebble.degree (graph G (fun v => code (c v)*(Fintype.card V+1)) q) (.base x) := by rw [degree_base] have hm := Nat.mul_le_mul_right (Fintype.card V+1) (hpos (c x)) nlinarith cases y with | base z => refine ⟨z,rfl,hcode ?_⟩ rw [degree_base,degree_base] at hd exact code_of_degree (base_degree_lt G x) (hcard ▸ base_degree_lt H z) hd | mark z i => rw [degree_mark] at hd; omega | pad i => rw [degree_pad] at hd; omega | hub => have hsum : (∑ v : W, code (d v)*(Fintype.card V+1)) = ∑ v : V, code (c v)*(Fintype.card V+1) := by rw [← e.sum_comp (fun v => code (d v)*(Fintype.card V+1))] simp_rw [← hc] have hh := hub_above_base G (fun v => code (c v)*(Fintype.card V+1)) q hN (fun v => Nat.mul_pos (hpos (c v)) (by omega)) x rw [degree_hub] at hd hh rw [← hcard,hsum] at hd omega def basePosition {K : ℕ} {count : V → ℕ} {count' : W → ℕ} {q : ℕ} (P : Pebble.Position K V W) : Pebble.Position K (Vertex V count q) (Vertex W count' q) := fun i => (P i).map (fun xy => (.base xy.1,.base xy.2)) omit [Fintype V] [Fintype W] in @[simp] theorem basePosition_update {K : ℕ} {count : V → ℕ} {count' : W → ℕ} {q : ℕ} (P : Pebble.Position K V W) (i : Fin K) (x : V) (y : W) : (basePosition (count := count) (count' := count') (q := q) (Function.update P i (some (x,y)))) = Function.update (basePosition P) i (some (.base x,.base y)) := by funext j by_cases h : j=i · subst j; simp [basePosition] · simp [basePosition,h] theorem wins_bases (G : SimpleGraph V) (H : SimpleGraph W) (c : V → D) (d : W → D) (code : D → ℕ) (hcode : Function.Injective code) (hpos : ∀ b, 0 < code b) (e₀ : V ≃ W) (hc : ∀ v, c v = d (e₀ v)) (q K : ℕ) (hN : 2 ≤ Fintype.card V) (hK : 2 ≤ K) (h : Pebble.Wins (graph G (fun v => code (c v)*(Fintype.card V+1)) q) (graph H (fun v => code (d v)*(Fintype.card V+1)) q) (fun _ _ => True) (fun _ : Fin K => none)) : Pebble.Wins G H (fun v w => c v = d w) (fun _ : Fin K => none) := by classical let J : Pebble.Invariant G H (fun v w => c v = d w) K := { safe := fun P => Pebble.Wins (graph G (fun v => code (c v)*(Fintype.card V+1)) q) (graph H (fun v => code (d v)*(Fintype.card V+1)) q) (fun _ _ => True) (basePosition P) forget := by intro P Q hQ hPQ refine hQ.forget (fun i => ?_) rcases hPQ i with hi | hi · exact Or.inl (by simp [basePosition,hi]) · exact Or.inr (by simp [basePosition,hi]) atomic := by intro P hP constructor · intro i x y hi have hdi := hP.degree_eq hK (i := i) (x := .base x) (y := .base y) (by simp [basePosition,hi]) obtain ⟨z,hz,hcz⟩ := degree_detect_base G H c d code hcode hpos e₀ hc q hN x (.base y) hdi cases Vertex.base.inj hz exact hcz · intro i j x y u v hi hj have hh := hP.atomic.2 i j (.base x) (.base y) (.base u) (.base v) (by simp [basePosition,hi]) (by simp [basePosition,hj]) simpa only [Vertex.base.injEq,graph,Adj] using hh extend := by intro P hP i hi obtain ⟨e,he⟩ := hP.extend i (by simp [basePosition,hi]) have hb (x : V) : ∃ y, e (.base x) = .base y ∧ c x = d y := by exact degree_detect_base G H c d code hcode hpos e₀ hc q hN x (e (.base x)) ((he (.base x)).degree_eq hK (Function.update_self _ _ _)) choose f hf hcf using hb have hinj : Function.Injective f := by intro x y hxy exact Vertex.base.inj (e.injective (by rw [hf,hf,hxy])) let eb : V ≃ W := Equiv.ofBijective f ((Fintype.bijective_iff_injective_and_card f).mpr ⟨hinj,Fintype.card_congr e₀⟩) refine ⟨eb,fun x => ?_⟩ rw [basePosition_update] simpa only [hf,eb,Equiv.ofBijective_apply] using he (.base x) } refine ⟨J,?_⟩ unfold J basePosition exact h end WLTime.Marking namespace WLTime.Compression namespace ConsistencyData variable {r m : ℕ} {P : Type uP} {E : Type uE} [Fintype P] [Fintype E] (I : ConsistencyData (r+1) m P E) noncomputable def baseEquiv (K : ℕ) (hr : 1 ≤ r) : I.Vertex K 0 ≃ I.Vertex K 1 := Equiv.sigmaCongrRight (fun b => I.translate K b.val (Classical.choice (I.legal_nonempty K hr 1 b.val))) omit [Fintype P] [Fintype E] in @[simp] theorem baseEquiv_block (K : ℕ) (hr : 1 ≤ r) (x : I.Vertex K 0) : (I.baseEquiv K hr x).1 = x.1 := rfl noncomputable def blockCode (K : ℕ) (b : I.Block K) : ℕ := (Fintype.equivFin (I.Block K) b).val + 1 theorem blockCode_injective (K : ℕ) : Function.Injective (I.blockCode K) := by intro b c h apply (Fintype.equivFin (I.Block K)).injective apply Fin.ext simpa only [blockCode,Nat.add_right_cancel_iff] using h theorem blockCode_pos (K : ℕ) (b : I.Block K) : 0 < I.blockCode K b := Nat.zero_lt_succ _ noncomputable def markCount (K : ℕ) (b : I.Block K) : ℕ := I.blockCode K b * (Fintype.card (I.Vertex K 0)+1) abbrev MarkedVertex (K : ℕ) (ε : F₂) (q : ℕ) := Marking.Vertex (I.Vertex K ε) (fun v => I.markCount K v.1) q noncomputable def markedGraph (K : ℕ) (ε : F₂) (q : ℕ) : SimpleGraph (I.MarkedVertex K ε q) := Marking.graph (I.valuationGraph K ε) (fun v => I.markCount K v.1) q theorem marked_diameter_two (K : ℕ) (ε : F₂) (q : ℕ) (x y : I.MarkedVertex K ε q) : x=y ∨ (I.markedGraph K ε q).Adj x y ∨ ∃ z, (I.markedGraph K ε q).Adj x z ∧ (I.markedGraph K ε q).Adj z y := Marking.diameter_two _ x y noncomputable def markedEquiv (K : ℕ) (hr : 1 ≤ r) (q : ℕ) : I.MarkedVertex K 0 q ≃ I.MarkedVertex K 1 q := Marking.liftEquiv (I.baseEquiv K hr) (fun _ => rfl) theorem card_marked_eq (K : ℕ) (hr : 1 ≤ r) (q : ℕ) : Fintype.card (I.MarkedVertex K 0 q) = Fintype.card (I.MarkedVertex K 1 q) := Fintype.card_congr (I.markedEquiv K hr q) theorem two_le_card_base [Nonempty P] (K : ℕ) (hm : 2 ≤ m) : 2 ≤ Fintype.card (I.Vertex K 0) := by classical let p : P := Classical.choice inferInstance let z : Fin m := ⟨0,by omega⟩ let f : Fin m → I.Vertex K 0 := fun a => ⟨⟨.site 0 (.inl p) a z,True.intro,True.intro⟩,I.zeroValuation K _⟩ have hf : Function.Injective f := by intro a b h have he := congrArg (fun x : I.Vertex K 0 => x.1.val) h exact (BlockName.site.inj he).2.2.1 have hc := Fintype.card_le_of_injective f hf simp only [Fintype.card_fin] at hc omega theorem marked_wins_iff_ac [Nonempty P] (hr : 2 ≤ r) (hm : 2 ≤ m) (q : ℕ) : Pebble.Wins (I.markedGraph (r+2) 0 q) (I.markedGraph (r+2) 1 q) (fun _ _ => True) (fun _ : Fin (r+2) => none) ↔ I.ArcConsistent := by classical constructor · intro h apply (I.colored_wins_iff_ac hr).mp exact Marking.wins_bases (I.valuationGraph (r+2) 0) (I.valuationGraph (r+2) 1) Sigma.fst Sigma.fst (I.blockCode (r+2)) (I.blockCode_injective (r+2)) (I.blockCode_pos (r+2)) (I.baseEquiv (r+2) (by omega)) (fun _ => rfl) q (r+2) (I.two_le_card_base (r+2) hm) (by omega) h · intro h obtain ⟨Q⟩ := I.arcConsistent_iff.mp h exact (Marking.liftSystem Sigma.fst Sigma.fst (I.markCount (r+2)) q (r+2) (I.valuationSystem Q (r+2) (by omega) hr le_rfl)).wins_empty end ConsistencyData end WLTime.Compression namespace WLTime.Compression noncomputable def BlockName.equivProduct {r : ℕ} {T : Type uT} {L : Type uL} {A : Type uA} : BlockName r T L A ≃ Fin (r+1) × (T ⊕ L) × A × A where toFun | .site i t a b => (i,.inl t,a,b) | .square i l a b => (i,.inr l,a,b) invFun | (i,.inl t,a,b) => .site i t a b | (i,.inr l,a,b) => .square i l a b left_inv x := by cases x <;> rfl right_inv x := by rcases x with ⟨i,t | l,a,b⟩ <;> rfl theorem BlockName.card {r : ℕ} {T : Type uT} {L : Type uL} {A : Type uA} [Fintype T] [Fintype L] [Fintype A] : Fintype.card (BlockName r T L A) = (r+1)*(Fintype.card T+Fintype.card L)*(Fintype.card A)^2 := by rw [Fintype.card_congr BlockName.equivProduct] simp only [Fintype.card_prod,Fintype.card_sum,Fintype.card_fin] ring namespace ConsistencyData variable {r m : ℕ} {P : Type uP} {E : Type uE} [Fintype P] [Fintype E] (I : ConsistencyData (r+1) m P E) noncomputable def blockCoefficient (_I : ConsistencyData (r+1) m P E) (K : ℕ) : ℕ := (r+1)*(Fintype.card P+Fintype.card E*(8*K+1)) theorem card_blocks_le (K : ℕ) : Fintype.card (I.Block K) ≤ I.blockCoefficient K*m^2 := by classical calc _ ≤ Fintype.card (RawBlock (r := r) (m := m) (P := P) (E := E) K) := Fintype.card_subtype_le _ _ = _ := by rw [BlockName.card] simp only [TypeNode,TypeLink,Fintype.card_sum,Fintype.card_prod,Fintype.card_fin, blockCoefficient] ring omit [Fintype P] [Fintype E] in theorem footprint_card_le (K : ℕ) (b : RawBlock (r := r) (m := m) (P := P) (E := E) K) : (I.footprint K b).card ≤ 4 := by classical cases b <;> simp only [footprint] · simp · exact (Finset.card_insert_le _ _).trans (Nat.succ_le_succ ((Finset.card_insert_le _ _).trans (Nat.succ_le_succ ((Finset.card_insert_le _ _).trans (by simp))))) omit [Fintype P] [Fintype E] in theorem card_readValue_le (K D : ℕ) (hD : 2 ≤ D) (hp : ∀ p, 2^(I.dim p) ≤ D) (n : RawName (r := r) (m := m) (P := P) (E := E) K) : Fintype.card (I.ReadValue K n) ≤ D := by cases n with | horizontal i t a b => cases t with | inl p => simpa [ReadValue,Value,F₂,ZMod.card] using hp p | inr ej => simpa [ReadValue,Value,F₂,ZMod.card] using hD | vertical => simpa [ReadValue,F₂,ZMod.card] using hD theorem card_legal_le (K D : ℕ) (hD : 2 ≤ D) (hp : ∀ p, 2^(I.dim p) ≤ D) (ε : F₂) (b : I.Block K) : Fintype.card (I.Legal K ε b.val) ≤ D^4 := by classical let f : I.Legal K ε b.val → ((n : {n // n ∈ I.footprint K b.val}) → I.ReadValue K n.val) := fun R n => R.val.val n.val have hf : Function.Injective f := by intro R S h apply Subtype.ext apply Subtype.ext funext n by_cases hn : n ∈ I.footprint K b.val · exact congrFun h ⟨n,hn⟩ · exact (R.val.property n hn).trans (S.val.property n hn).symm calc _ ≤ Fintype.card ((n : {n // n ∈ I.footprint K b.val}) → I.ReadValue K n.val) := Fintype.card_le_of_injective f hf _ = ∏ n : {n // n ∈ I.footprint K b.val}, Fintype.card (I.ReadValue K n.val) := Fintype.card_pi _ ≤ ∏ _n : {n // n ∈ I.footprint K b.val}, D := Finset.prod_le_prod (fun n _ => I.card_readValue_le K D hD hp n.val) _ = D^(I.footprint K b.val).card := by simp _ ≤ D^4 := Nat.pow_le_pow_right (by omega) (I.footprint_card_le K b.val) theorem card_bases_le (K D : ℕ) (hD : 2 ≤ D) (hp : ∀ p, 2^(I.dim p) ≤ D) (ε : F₂) : Fintype.card (I.Vertex K ε) ≤ I.blockCoefficient K*D^4*m^2 := by classical calc _ = ∑ b : I.Block K, Fintype.card (I.Legal K ε b.val) := Fintype.card_sigma _ ≤ ∑ _b : I.Block K, D^4 := Finset.sum_le_sum (fun b _ => I.card_legal_le K D hD hp ε b) _ = Fintype.card (I.Block K)*D^4 := by simp _ ≤ (I.blockCoefficient K*m^2)*D^4 := Nat.mul_le_mul_right _ (I.card_blocks_le K) _ = _ := by ring theorem card_blocks_le_bases (K : ℕ) : Fintype.card (I.Block K) ≤ Fintype.card (I.Vertex K 0) := by exact Fintype.card_le_of_injective (fun b : I.Block K => (⟨b,I.zeroValuation K b.val⟩ : I.Vertex K 0)) (fun _ _ h => congrArg Sigma.fst h) theorem marked_order_cubic (K q : ℕ) : Fintype.card (I.MarkedVertex K 0 q) ≤ (Fintype.card (I.Vertex K 0)+1)^3+q := by classical rw [Marking.card_vertices] have hmark (v : I.Vertex K 0) : I.markCount K v.1 ≤ Fintype.card (I.Vertex K 0)*(Fintype.card (I.Vertex K 0)+1) := by apply Nat.mul_le_mul_right exact (Nat.succ_le_iff.mpr (Fintype.equivFin (I.Block K) v.1).isLt).trans (I.card_blocks_le_bases K) have hs := Finset.sum_le_sum (fun v (_ : v ∈ (Finset.univ : Finset (I.Vertex K 0))) => hmark v) simp only [Finset.sum_const,Finset.card_univ,smul_eq_mul] at hs nlinarith theorem marked_order_six (K D : ℕ) (hm : 1 ≤ m) (hD : 2 ≤ D) (hp : ∀ p, 2^(I.dim p) ≤ D) (q : ℕ) : Fintype.card (I.MarkedVertex K 0 q) ≤ (I.blockCoefficient K*D^4+1)^3*m^6+q := by have hN := I.card_bases_le K D hD hp 0 have hm2 : 1 ≤ m^2 := Nat.one_le_pow _ _ hm calc _ ≤ (Fintype.card (I.Vertex K 0)+1)^3+q := I.marked_order_cubic K q _ ≤ (I.blockCoefficient K*D^4*m^2+1)^3+q := by gcongr _ ≤ ((I.blockCoefficient K*D^4+1)*m^2)^3+q := by gcongr; nlinarith _ = _ := by ring end ConsistencyData end WLTime.Compression namespace WLTime noncomputable def Graph.ofSimple {V : Type uV} {n : ℕ} (G : SimpleGraph V) (e : V ≃ Fin n) : Graph n := by classical exact ⟨fun x y => decide (G.Adj (e.symm x) (e.symm y)), (by intro x y; simp only [decide_eq_decide]; exact G.adj_comm _ _),fun x => by simp⟩ def Graph.simple {n : ℕ} (G : Graph n) : SimpleGraph (Fin n) where Adj x y := G.adj x y = true symm := ⟨fun x y h => (G.property.1 y x).trans h⟩ loopless := ⟨fun x h => Bool.false_ne_true ((G.property.2 x).symm.trans h)⟩ @[simp] theorem Graph.ofSimple_adj {V : Type uV} {n : ℕ} (G : SimpleGraph V) (e : V ≃ Fin n) (x y : V) : ((Graph.ofSimple G e).simple).Adj (e x) (e y) ↔ G.Adj x y := by simp [Graph.ofSimple,Graph.simple,Graph.adj] @[simp] theorem Graph.ofSimple_diameter {V : Type uV} {n : ℕ} (G : SimpleGraph V) (e : V ≃ Fin n) (hn : 0 < n) (h : ∀ x y, x=y ∨ G.Adj x y ∨ ∃ z, G.Adj x z ∧ G.Adj z y) : (Graph.ofSimple G e).diameterTwo := by refine ⟨hn,fun x y => ?_⟩ rcases h (e.symm x) (e.symm y) with he | he | ⟨z,hz,hz'⟩ · exact Or.inl (e.symm.injective he) · exact Or.inr (Or.inl (by simpa [Graph.ofSimple,Graph.adj] using he)) · exact Or.inr (Or.inr ⟨e z,by simpa [Graph.ofSimple,Graph.adj] using hz, by simpa [Graph.ofSimple,Graph.adj] using hz'⟩) theorem pebble_iff_wins {n K : ℕ} (G H : Graph n) (P : Position K n) : Pebble.Wins G.simple H.simple (fun _ _ => True) P ↔ Wins G H P := by constructor · rintro ⟨I,hI⟩ let J : GameInvariant G H K := { safe := I.safe forget := I.forget atomic := by intro Q hQ i j x y u v hi hj obtain ⟨he,ha⟩ := (I.atomic hQ).2 i j x y u v hi hj refine ⟨he,?_⟩ change (G.adj x u = true ↔ H.adj y v = true) at ha cases hg : G.adj x u <;> cases hh : H.adj y v <;> simp_all extend := I.extend } exact ⟨J,hI⟩ · rintro ⟨I,hI⟩ let J : Pebble.Invariant G.simple H.simple (fun _ _ => True) K := { safe := I.safe forget := I.forget atomic := by intro Q hQ refine ⟨fun _ _ _ _ => True.intro,?_⟩ intro i j x y u v hi hj obtain ⟨he,ha⟩ := I.atomic hQ i j x y u v hi hj exact ⟨he,by change (_ = true ↔ _ = true); rw [ha]⟩ extend := I.extend } exact ⟨J,hI⟩ theorem wins_ofSimple_iff {A : Type uA} {B : Type uB} {n K : ℕ} (G : SimpleGraph A) (H : SimpleGraph B) (e : A ≃ Fin n) (f : B ≃ Fin n) : Wins (Graph.ofSimple G e) (Graph.ofSimple H f) (fun _ : Fin K => none) ↔ Pebble.Wins G H (fun _ _ => True) (fun _ : Fin K => none) := by rw [← pebble_iff_wins] constructor · intro h have hh := h.transport (G' := G) (H' := H) e.symm f.symm (fun x y => by simp [Graph.ofSimple,Graph.simple,Graph.adj]) (fun x y => by simp [Graph.ofSimple,Graph.simple,Graph.adj]) simpa only [Pebble.Position.map_none] using hh · intro h have hh := h.transport e f (fun x y => (Graph.ofSimple_adj G e x y).symm) (fun x y => (Graph.ofSimple_adj H f x y).symm) simpa only [Pebble.Position.map_none] using hh end WLTime namespace WLTime.Compression namespace ConsistencyData variable {r m : ℕ} {P : Type uP} {E : Type uE} [Fintype P] [Fintype E] (I : ConsistencyData (r+1) m P E) theorem marked_padding_order (K q : ℕ) : Fintype.card (I.MarkedVertex K 0 q) = Fintype.card (I.MarkedVertex K 0 0)+q := by rw [Marking.card_vertices,Marking.card_vertices] theorem matrix_compression [Nonempty P] (hr : 2 ≤ r) (hm : 2 ≤ m) (n : ℕ) (hn : Fintype.card (I.MarkedVertex (r+2) 0 0) ≤ n) : ∃ G H : Graph n, G.diameterTwo ∧ H.diameterTwo ∧ (Equivalent .joint (r+1) G H ↔ I.ArcConsistent) ∧ (Equivalent .separate (r+2) G H ↔ I.ArcConsistent) := by classical let q := n-Fintype.card (I.MarkedVertex (r+2) 0 0) have hcard : Fintype.card (I.MarkedVertex (r+2) 0 q) = n := by rw [I.marked_padding_order] exact Nat.add_sub_of_le hn let e : I.MarkedVertex (r+2) 0 q ≃ Fin n := (Fintype.equivFin _).trans (finCongr hcard) let f : I.MarkedVertex (r+2) 1 q ≃ Fin n := (I.markedEquiv (r+2) (by omega) q).symm.trans e have hnpos : 0 < n := hcard ▸ Fintype.card_pos_iff.mpr ⟨Marking.Vertex.hub⟩ let G := Graph.ofSimple (I.markedGraph (r+2) 0 q) e let H := Graph.ofSimple (I.markedGraph (r+2) 1 q) f refine ⟨G,H,Graph.ofSimple_diameter _ _ hnpos (I.marked_diameter_two _ _ _), Graph.ofSimple_diameter _ _ hnpos (I.marked_diameter_two _ _ _),?_,?_⟩ · exact (joint_equivalent_iff_wins hnpos (by omega)).trans ((wins_ofSimple_iff _ _ e f).trans (I.marked_wins_iff_ac hr hm q)) · exact (separate_equivalent_iff_wins hnpos).trans ((wins_ofSimple_iff _ _ e f).trans (I.marked_wins_iff_ac hr hm q)) theorem matrix_compression_six [Nonempty P] (hr : 2 ≤ r) (hm : 2 ≤ m) (D : ℕ) (hD : 2 ≤ D) (hp : ∀ p, 2^(I.dim p) ≤ D) (n : ℕ) (hn : (I.blockCoefficient (r+2)*D^4+1)^3*m^6 ≤ n) : ∃ G H : Graph n, G.diameterTwo ∧ H.diameterTwo ∧ (Equivalent .joint (r+1) G H ↔ I.ArcConsistent) ∧ (Equivalent .separate (r+2) G H ↔ I.ArcConsistent) := by apply I.matrix_compression hr hm n have h := I.marked_order_six (r+2) D (by omega) hD hp 0 simp only [Nat.add_zero] at h exact h.trans hn end ConsistencyData end WLTime.Compression end OAI