import OAI.Combinatorics.CycleDecomposition.BatchRouting namespace OAI universe cycleUniverse1 cycleUniverse2 cycleUniverse3 cycleUniverse4 cycleUniverse5 cycleUniverse6 cycleUniverse7 cycleUniverse8 cycleUniverse9 cycleUniverse10 cycleUniverse11 cycleUniverse12 cycleUniverse13 cycleUniverse14 cycleUniverse15 cycleUniverse16 cycleUniverse17 cycleUniverse18 cycleUniverse19 cycleUniverse20 section open Filter Asymptotics Real open scoped Topology noncomputable section open MeasureTheory ProbabilityTheory Finset section namespace ErdosGallai.Batch noncomputable section open Real Filter Asymptotics lemma routing_length_upper (r h : ℝ) (hr : 2 ≤ r) (hh : 0 < h) (hhr : h ≤ r) : (routingLength r h : ℝ) ≤ 108*(r/h)*(logb 2 r)^2 := by have hr0 : 0 < r := by linarith have hl : 1 ≤ logb 2 r := by simpa using Real.logb_le_logb_of_le (by norm_num : (1:ℝ) < 2) (by norm_num : (0:ℝ) < 2) hr have hR : 1 ≤ r/h := (le_div_iff₀ hh).mpr (by simpa using hhr) have hlog : logb 2 (2*r) = 1 + logb 2 r := by rw [Real.logb_mul (by norm_num) hr0.ne'] norm_num have hg := Nat.ceil_lt_add_one (show 0 ≤ 8*(r/h)*logb 2 (2*r) by rw [hlog]; positivity) have hd := Nat.ceil_lt_add_one (show 0 ≤ logb 2 r by linarith) change (routingG r h : ℝ) < 8*(r/h)*logb 2 (2*r)+1 at hg change (routingDepth r : ℝ) < logb 2 r + 1 at hd rw [hlog] at hg have hprod : 1 ≤ (r/h)*logb 2 r := by nlinarith [mul_nonneg (sub_nonneg.mpr hR) (sub_nonneg.mpr hl)] have hg' : (routingG r h : ℝ) ≤ 18*(r/h)*logb 2 r := by nlinarith have hd' : (1 + routingDepth r : ℝ) ≤ 3*logb 2 r := by linarith have hm := mul_le_mul hg' hd' (by positivity) (by positivity) dsimp [routingLength] push_cast nlinarith lemma eventually_logb_le_power (ε : ℝ) (hε : 0 < ε) : ∀ᶠ D : ℝ in atTop, logb 2 D ≤ D^ε := by have ho := (isLittleO_log_rpow_atTop hε).const_mul_left (1 / log 2) filter_upwards [ho.eventuallyLE, eventually_ge_atTop (1:ℝ)] with D hD h1 simpa [Real.logb, div_eq_mul_inv, mul_comm, Real.norm_eq_abs, abs_of_nonneg (Real.log_nonneg h1), abs_of_nonneg (Real.rpow_nonneg (by linarith) ε), abs_of_pos (show 0 < (log 2)⁻¹ by positivity), abs_of_pos (Real.log_pos (by norm_num : (1:ℝ) < 2))] using hD lemma eventually_constant_le_power (C ε : ℝ) (hε : 0 < ε) : ∀ᶠ D : ℝ in atTop, C ≤ D^ε := (tendsto_rpow_atTop hε).eventually (eventually_ge_atTop C) lemma eventually_const_mul_power_le (C α β : ℝ) (hab : α < β) : ∀ᶠ D : ℝ in atTop, C*D^α ≤ D^β := by filter_upwards [eventually_constant_le_power C (β-α) (by linarith), eventually_gt_atTop (0:ℝ)] with D hc hD calc C*D^α ≤ D^(β-α)*D^α := mul_le_mul_of_nonneg_right hc (Real.rpow_nonneg hD.le _) _ = D^β := by rw [← Real.rpow_add hD]; congr 1; ring theorem eventually_routing_length (c β γ δ : ℝ) (hc : 0 < c) (hβ : 0 < β) (hδ : 0 < δ) : ∀ᶠ D : ℝ in atTop, ∀ r : ℝ, 2 ≤ r → r ≤ D^β → c*D^γ ≤ r → (routingLength r (c*D^γ) : ℝ) ≤ D^(β-γ+δ) := by filter_upwards [eventually_logb_le_power (δ/4) (by positivity), eventually_constant_le_power (108*β^2/c) (δ/2) (by positivity), eventually_gt_atTop (1:ℝ)] with D hlog hconst hD r hr hrD hhr have hD0 : 0 < D := by linarith have hpowγ : 0 < D^γ := Real.rpow_pos_of_pos hD0 _ have hden : 0 < c*D^γ := mul_pos hc hpowγ have hlog0 : 0 ≤ logb 2 r := (Real.logb_pos (by norm_num) (by linarith)).le have hlogR : logb 2 r ≤ β*D^(δ/4) := by have hh := Real.logb_le_logb_of_le (by norm_num : (1:ℝ) < 2) (by linarith : 0 < r) hrD rw [Real.logb_rpow_eq_mul_logb_of_pos hD0] at hh exact hh.trans (mul_le_mul_of_nonneg_left hlog hβ.le) have hratio : r/(c*D^γ) ≤ D^(β-γ)/c := by calc _ ≤ D^β/(c*D^γ) := div_le_div_of_nonneg_right hrD hden.le _ = _ := by rw [Real.rpow_sub hD0]; ring have hsq : (logb 2 r)^2 ≤ β^2*D^(δ/2) := by calc _ ≤ (β*D^(δ/4))^2 := pow_le_pow_left₀ hlog0 hlogR 2 _ = _ := by rw [mul_pow, ← Real.rpow_mul_natCast hD0.le]; congr 2; ring calc (routingLength r (c*D^γ) : ℝ) ≤ 108*(r/(c*D^γ))*(logb 2 r)^2 := routing_length_upper r (c*D^γ) hr hden hhr _ ≤ 108*(D^(β-γ)/c)*(β^2*D^(δ/2)) := by gcongr _ = (108*β^2/c)*D^(β-γ+δ/2) := by rw [Real.rpow_add hD0]; ring _ ≤ D^(δ/2)*D^(β-γ+δ/2) := mul_le_mul_of_nonneg_right hconst (Real.rpow_nonneg hD0.le _) _ = D^(β-γ+δ) := by rw [← Real.rpow_add hD0]; congr 1; ring theorem batch_routing_margin : ∃ D₀ : ℝ, 1 < D₀ ∧ ∀ D ≥ D₀, ∀ r : ℝ, D^(9/10:ℝ) ≤ r → r ≤ D^(51/50:ℝ) → 2 ≤ r ∧ 64*((routingLength r (D^(9/10:ℝ)/4) : ℝ)^2* (D^(1/100:ℝ)+D^(3/10:ℝ))+2*D^(3/10:ℝ)) ≤ D^(9/10:ℝ)/4 := by have hev : ∀ᶠ D : ℝ in atTop, ∀ r : ℝ, D^(9/10:ℝ) ≤ r → r ≤ D^(51/50:ℝ) → 2 ≤ r ∧ 64*((routingLength r (D^(9/10:ℝ)/4) : ℝ)^2* (D^(1/100:ℝ)+D^(3/10:ℝ))+2*D^(3/10:ℝ)) ≤ D^(9/10:ℝ)/4 := by filter_upwards [eventually_routing_length (1/4) (51/50) (9/10) (2/25) (by norm_num) (by norm_num) (by norm_num), eventually_const_mul_power_le 1024 (7/10) (9/10) (by norm_num), eventually_constant_le_power 2 (9/10) (by norm_num), eventually_gt_atTop (1:ℝ)] with D hlen hcost htwo hD r hr hrD have hD0 : 0 < D := by linarith have hr2 : 2 ≤ r := htwo.trans hr have hh : (1/4)*D^(9/10:ℝ) ≤ r := by have hh0 := Real.rpow_nonneg hD0.le (9/10:ℝ) linarith have hL := hlen r hr2 hrD hh norm_num at hL have hL' : (routingLength r (D^(9/10:ℝ)/4) : ℝ) ≤ D^(1/5:ℝ) := by convert hL using 1 ; ring_nf have hsmall : D^(1/100:ℝ) ≤ D^(3/10:ℝ) := Real.rpow_le_rpow_of_exponent_le hD.le (by norm_num) have h37 : D^(3/10:ℝ) ≤ D^(7/10:ℝ) := Real.rpow_le_rpow_of_exponent_le hD.le (by norm_num) have hprod : (routingLength r (D^(9/10:ℝ)/4) : ℝ)^2* (D^(1/100:ℝ)+D^(3/10:ℝ)) ≤ 2*D^(7/10:ℝ) := by calc _ ≤ (D^(1/5:ℝ))^2 * (2*D^(3/10:ℝ)) := by gcongr; linarith _ = _ := by rw [← Real.rpow_mul_natCast hD0.le] norm_num rw [mul_left_comm, ← Real.rpow_add hD0] norm_num refine ⟨hr2, ?_⟩ nlinarith only [hprod, h37, hcost] obtain ⟨A,hA⟩ := eventually_atTop.mp hev refine ⟨max A 2, lt_of_lt_of_le (by norm_num) (le_max_right _ _), ?_⟩ intro D hD exact hA D ((le_max_left _ _).trans hD) lemma eventually_reservoir_capacity (c p : ℝ) (hc : 0 < c) (hp : 0 < p) : ∀ᶠ D : ℝ in atTop, ∀ r : ℝ, 0 ≤ r → r ≤ D^(51/50:ℝ) → (⌈8*r/(p*(c*D^(9/10:ℝ)))⌉₊ : ℝ) ≤ D^(13/100:ℝ) := by filter_upwards [eventually_const_mul_power_le (8/(p*c)+1) (3/25) (13/100) (by norm_num), eventually_gt_atTop (1:ℝ)] with D hbound hD r hr hrD have hD0 : 0 < D := by linarith have hden : 0 < p*(c*D^(9/10:ℝ)) := by positivity have hone : 1 ≤ D^(3/25:ℝ) := Real.one_le_rpow hD.le (by norm_num) have hx : 8*r/(p*(c*D^(9/10:ℝ))) ≤ (8/(p*c))*D^(3/25:ℝ) := by calc _ ≤ 8*D^(51/50:ℝ)/(p*(c*D^(9/10:ℝ))) := by gcongr _ = _ := by have heq : D^(3/25:ℝ) = D^(51/50:ℝ)/D^(9/10:ℝ) := by rw [← Real.rpow_sub hD0]; norm_num rw [heq]; ring have hceil := Nat.ceil_lt_add_one (show 0 ≤ 8*r/(p*(c*D^(9/10:ℝ))) by positivity) nlinarith only [hx, hceil, hone, hbound] theorem residue_routing_margin (c p : ℝ) (hc : 0 < c) (hp : 0 < p) : ∃ D₀ : ℝ, 1 < D₀ ∧ ∀ D ≥ D₀, ∀ r rᵢ : ℝ, 0 ≤ r → r ≤ D^(51/50:ℝ) → 2 ≤ rᵢ → rᵢ ≤ r → D^(37/50:ℝ) ≤ rᵢ → 64*((routingLength rᵢ (D^(37/50:ℝ)) : ℝ)^2* ((⌈8*r/(p*(c*D^(9/10:ℝ)))⌉₊ : ℝ)+1)) ≤ D^(37/50:ℝ) := by have hev : ∀ᶠ D : ℝ in atTop, ∀ r rᵢ : ℝ, 0 ≤ r → r ≤ D^(51/50:ℝ) → 2 ≤ rᵢ → rᵢ ≤ r → D^(37/50:ℝ) ≤ rᵢ → 64*((routingLength rᵢ (D^(37/50:ℝ)) : ℝ)^2* ((⌈8*r/(p*(c*D^(9/10:ℝ)))⌉₊ : ℝ)+1)) ≤ D^(37/50:ℝ) := by filter_upwards [eventually_routing_length 1 (51/50) (37/50) (1/100) (by norm_num) (by norm_num) (by norm_num), eventually_reservoir_capacity c p hc hp, eventually_const_mul_power_le 128 (71/100) (37/50) (by norm_num), eventually_gt_atTop (1:ℝ)] with D hlen hcap hcost hD r rᵢ hr hrD hri2 hrir htau have hD0 : 0 < D := by linarith have hL := hlen rᵢ hri2 (hrir.trans hrD) (by simpa using htau) norm_num at hL have hk := hcap r hr hrD have hone : 1 ≤ D^(13/100:ℝ) := Real.one_le_rpow hD.le (by norm_num) have hprod : (routingLength rᵢ (D^(37/50:ℝ)) : ℝ)^2* ((⌈8*r/(p*(c*D^(9/10:ℝ)))⌉₊ : ℝ)+1) ≤ 2*D^(71/100:ℝ) := by calc _ ≤ (D^(29/100:ℝ))^2 * (2*D^(13/100:ℝ)) := by gcongr; linarith _ = _ := by rw [← Real.rpow_mul_natCast hD0.le] norm_num rw [mul_left_comm, ← Real.rpow_add hD0] norm_num nlinarith only [hprod, hcost] obtain ⟨A,hA⟩ := eventually_atTop.mp hev refine ⟨max A 2, lt_of_lt_of_le (by norm_num) (le_max_right _ _), ?_⟩ intro D hD exact hA D ((le_max_left _ _).trans hD) end end ErdosGallai.Batch namespace ErdosGallai.Batch noncomputable section open Finset attribute [local instance] Classical.propDecidable variable {V : Type} [Fintype V] [DecidableEq V] def CutExpansionOn (P : SimpleGraph V) [DecidableRel P.Adj] (W : Finset V) (h : ℝ) : Prop := ∀ A : Finset V, A ⊆ W → h * min (A.card : ℝ) ((W \ A).card : ℝ) ≤ ((P.interedges A (W \ A)).card : ℝ) lemma subtype_image_compl {V : Type} [_contextInstance1 : Fintype V] [_contextInstance2 : DecidableEq V] (W : Finset V) (U : Finset (W : Set V)) : Uᶜ.image Subtype.val = W \ U.image Subtype.val := by ext v simp only [Finset.mem_image, Finset.mem_compl, Finset.mem_sdiff] constructor · rintro ⟨x,hx,rfl⟩ refine ⟨x.property,?_⟩ rintro ⟨y,hy,he⟩ exact hx (Subtype.ext he ▸ hy) · rintro ⟨hv,hvU⟩ refine ⟨⟨v,hv⟩,?_,rfl⟩ intro hx exact hvU ⟨⟨v,hv⟩,hx,rfl⟩ lemma induced_interedges_card (P : SimpleGraph V) [DecidableRel P.Adj] (W : Finset V) (U : Finset (W : Set V)) : (((P.induce (W : Set V)).interedges U Uᶜ).card : ℝ) = ((P.interedges (U.image Subtype.val) (W \ U.image Subtype.val)).card : ℝ) := by classical let f : ↥(W : Set V) × ↥(W : Set V) → V × V := fun e => (e.1.val,e.2.val) have hf : Function.Injective f := by intro a b h apply Prod.ext <;> apply Subtype.ext · exact congrArg Prod.fst h · exact congrArg Prod.snd h have heq : ((P.induce (W : Set V)).interedges U Uᶜ).image f = P.interedges (U.image Subtype.val) (W \ U.image Subtype.val) := by rw [← subtype_image_compl W U] ext e simp only [SimpleGraph.mem_interedges_iff, Finset.mem_image] constructor · rintro ⟨a,⟨ha,hb,hab⟩,rfl⟩ exact ⟨⟨a.1,ha,rfl⟩,⟨a.2,hb,rfl⟩,hab⟩ · rintro ⟨⟨x,hx,hxe⟩,⟨y,hy,hye⟩,he⟩ refine ⟨(x,y),⟨hx,hy,?_⟩,Prod.ext hxe hye⟩ change P.Adj x.val y.val simpa only [hxe,hye] using he rw [← heq, Finset.card_image_of_injective _ hf] lemma cutExpansion_induce (P : SimpleGraph V) [DecidableRel P.Adj] (W : Finset V) (h : ℝ) (hexp : CutExpansionOn P W h) : CutExpansion (P.induce (W : Set V)) h := by classical intro U have hsub : U.image Subtype.val ⊆ W := by rintro v hv obtain ⟨a,ha,rfl⟩ := Finset.mem_image.mp hv exact a.property have h := hexp (U.image Subtype.val) hsub have he : W \ U.image Subtype.val = Uᶜ.image Subtype.val := (subtype_image_compl W U).symm rw [he] at h simp only [Finset.card_image_of_injective _ Subtype.val_injective] at h rw [induced_interedges_card,he] exact h lemma pathInterior_map {A B : Type} [DecidableEq A] [DecidableEq B] {H : SimpleGraph A} {J : SimpleGraph B} (f : H →g J) (hf : Function.Injective f) {a b : A} (p : H.Walk a b) : pathInterior (p.map f) = (pathInterior p).image f := by classical simp only [pathInterior, SimpleGraph.Walk.support_map] rw [Finset.image_sdiff _ _ hf] have hm : (p.support.map f).toFinset = p.support.toFinset.image f := by ext v; simp rw [hm] simp theorem team_routing_on_set {I T : Type} [Fintype I] (G P : SimpleGraph V) [DecidableRel P.Adj] (hPG : P ≤ G) (W : Finset V) (h : ℝ) (hh : 0 < h) (hexp : CutExpansionOn P W h) (hr : 2 ≤ W.card) (x y : I → V) (hx : ∀ i, x i ∈ W) (hy : ∀ i, y i ∈ W) (hxy : ∀ i, x i ≠ y i) (team : I → T) (Z : I → Finset V) (k b z : ℝ) (hk : 1 ≤ k) (hb : 1 ≤ b) (hz : 0 ≤ z) (hload : ∀ v, (endpointLoad univ x y v : ℝ) ≤ k) (hteam : ∀ i, ((univ.filter (fun j => team j = team i)).card : ℝ) ≤ b) (hZ : ∀ i, ((Z i).card : ℝ) ≤ z) (hbudget : 64 * ((routingLength W.card h : ℝ)^2 * (k+b) + z) ≤ h) : ∃ q : ∀ i, G.Walk (x i) (y i), (∀ i, (q i).IsPath ∧ (q i).length ≤ routingLength W.card h ∧ (∀ v ∈ (q i).support, v ∈ W) ∧ (q i).edgeSet ⊆ P.edgeSet ∧ Disjoint (pathInterior (q i)) (Z i)) ∧ Pairwise (fun i j => Disjoint (q i).edgeSet (q j).edgeSet) ∧ (∀ i j, i ≠ j → team i = team j → Disjoint (pathInterior (q i)) (pathInterior (q j))) := by classical let X : I → (W : Set V) := fun i => ⟨x i,hx i⟩ let Y : I → (W : Set V) := fun i => ⟨y i,hy i⟩ let Z' : I → Finset (W : Set V) := fun i => univ.filter (fun v => v.val ∈ Z i) have hl (v : (W : Set V)) : (endpointLoad univ X Y v : ℝ) ≤ k := by simpa only [endpointLoad,X,Y,Subtype.ext_iff] using hload v.val have hz' : ∀ i, ((Z' i).card : ℝ) ≤ z := by intro i apply le_trans _ (hZ i) have hc : (Z' i).card ≤ (Z i).card := by apply Finset.card_le_card_of_injOn Subtype.val · intro v hv; exact (Finset.mem_filter.mp hv).2 · exact Subtype.val_injective.injOn exact_mod_cast hc obtain ⟨q,hq,hd,ht⟩ := routing (P.induce (W : Set V)) h hh (cutExpansion_induce P W h hexp) (by simpa using hr) X Y (fun i he => hxy i (congrArg Subtype.val he)) team Z' k b z hk hb hz hl hteam hz' (by simpa using hbudget) let f : (P.induce (W : Set V)) →g G := { toFun := Subtype.val, map_rel' := fun ha => hPG ha } have hf : Function.Injective f := Subtype.val_injective have hcard : Fintype.card ↥(W : Set V) = W.card := Fintype.card_coe W let Q : ∀ i, G.Walk (x i) (y i) := fun i => (q i).map f refine ⟨Q,?_,?_,?_⟩ · intro i refine ⟨(hq i).1.map hf,?_,?_,?_,?_⟩ · simpa only [Q,SimpleGraph.Walk.length_map,hcard] using (hq i).2.1 · intro v hv have hv' : v ∈ (q i).support.map f := by simpa only [Q,SimpleGraph.Walk.support_map] using hv obtain ⟨a,ha,rfl⟩ := List.mem_map.mp hv' exact a.property · intro e he rw [SimpleGraph.Walk.edgeSet_map] at he obtain ⟨d,hd,rfl⟩ := he induction d using Sym2.ind with | _ a b => exact (q i).adj_of_mem_edges hd · rw [show Q i = (q i).map f from rfl, pathInterior_map f hf] apply Finset.disjoint_left.mpr intro v hv hzv obtain ⟨a,ha,rfl⟩ := Finset.mem_image.mp hv exact Finset.disjoint_left.mp (hq i).2.2 ha (by simpa [Z',f] using hzv) · intro i j hij change Disjoint ((q i).map f).edgeSet ((q j).map f).edgeSet rw [SimpleGraph.Walk.edgeSet_map,SimpleGraph.Walk.edgeSet_map, Set.disjoint_image_iff (Sym2.map.injective hf)] apply Set.disjoint_left.mpr intro e he he' exact Finset.disjoint_left.mp (hd i j hij) (by simpa using he) (by simpa using he') · intro i j hij hteam' change Disjoint (pathInterior ((q i).map f)) (pathInterior ((q j).map f)) rw [pathInterior_map f hf,pathInterior_map f hf,Finset.disjoint_image hf] exact ht i j hij hteam' theorem uniform_batch_routing : ∃ D₀ : ℝ, 1 < D₀ ∧ ∀ D ≥ D₀, ∀ (A : Type) [Fintype A] [DecidableEq A], ∀ (G P : SimpleGraph A) [DecidableRel P.Adj], P ≤ G → ∀ W : Finset A, CutExpansionOn P W (D^(9/10:ℝ)/4) → D^(9/10:ℝ) ≤ (W.card : ℝ) → (W.card : ℝ) ≤ D^(51/50:ℝ) → ∀ (I T : Type) [Fintype I] (x y : I → A), (∀ i, x i ∈ W) → (∀ i, y i ∈ W) → (∀ i, x i ≠ y i) → ∀ (team : I → T) (Z : I → Finset A), (∀ v, (endpointLoad univ x y v : ℝ) ≤ D^(1/100:ℝ)) → (∀ i, ((univ.filter (fun j => team j = team i)).card : ℝ) ≤ D^(3/10:ℝ)) → (∀ i, ((Z i).card : ℝ) ≤ 2*D^(3/10:ℝ)) → ∃ q : ∀ i, G.Walk (x i) (y i), (∀ i, (q i).IsPath ∧ (q i).length ≤ routingLength W.card (D^(9/10:ℝ)/4) ∧ (∀ v ∈ (q i).support, v ∈ W) ∧ (q i).edgeSet ⊆ P.edgeSet ∧ Disjoint (pathInterior (q i)) (Z i)) ∧ Pairwise (fun i j => Disjoint (q i).edgeSet (q j).edgeSet) ∧ (∀ i j, i ≠ j → team i = team j → Disjoint (pathInterior (q i)) (pathInterior (q j))) := by obtain ⟨D₀,hD₀,hm⟩ := batch_routing_margin refine ⟨D₀,hD₀,?_⟩ intro D hD A _ _ G P _ hPG W hexp hr₁ hr₂ I T _ x y hx hy hxy team Z hl ht hZ have hD1 : 1 < D := hD₀.trans_le hD have hD0 : 0 < D := lt_trans zero_lt_one hD1 obtain ⟨hr,hbudget⟩ := hm D hD W.card hr₁ hr₂ apply team_routing_on_set G P hPG W _ (by positivity) hexp (by exact_mod_cast hr) x y hx hy hxy team Z _ _ _ _ _ (by positivity) hl ht hZ hbudget · exact Real.one_le_rpow hD1.le (by norm_num) · exact Real.one_le_rpow hD1.le (by norm_num) end end ErdosGallai.Batch namespace ErdosGallai.Batch open SimpleGraph variable {V : Type cycleUniverse1} {G : SimpleGraph V} structure CycleVisit (G : SimpleGraph V) where start : V finish : V walk : G.Walk start finish inductive VisitChain (G : SimpleGraph V) : V → V → Type _ | single {u v : V} (p : G.Walk u v) : VisitChain G u v | cons {u v w z : V} (p : G.Walk u v) (h : G.Adj v w) (q : VisitChain G w z) : VisitChain G u z namespace VisitChain variable {u v : V} def walk : {u v : V} → VisitChain G u v → G.Walk u v | _, _, .single p => p | _, _, .cons p h q => p.append (.cons h q.walk) def visits : {u v : V} → VisitChain G u v → List (CycleVisit G) | u, v, .single p => [⟨u,v,p⟩] | u, _, .cons (v := v) p _ q => ⟨u,v,p⟩ :: q.visits def links : {u v : V} → VisitChain G u v → Set (Sym2 V) | _, _, .single _ => ∅ | _, _, .cons (v := v) (w := w) _ _ q => {s(v,w)} ∪ q.links def switchEdges (q : VisitChain G u v) : Set (Sym2 V) := ⋃ p ∈ q.visits, p.walk.edgeSet lemma mem_support_iff (q : VisitChain G u v) (x : V) : x ∈ q.walk.support ↔ ∃ p ∈ q.visits, x ∈ p.walk.support := by induction q with | single p => simp [walk, visits] | cons p h q ih => simp only [walk, Walk.mem_support_append_iff, Walk.support_cons, List.mem_cons, ih, visits, List.mem_cons] constructor · rintro (hp | rfl | ⟨r,hr,hx⟩) · exact ⟨_, Or.inl rfl, hp⟩ · exact ⟨_, Or.inl rfl, p.end_mem_support⟩ · exact ⟨r, Or.inr hr, hx⟩ · rintro ⟨r, rfl | hr, hx⟩ · exact Or.inl hx · exact Or.inr (Or.inr ⟨r,hr,hx⟩) lemma isPath_of_separated (q : VisitChain G u v) (hp : ∀ p ∈ q.visits, p.walk.IsPath) (hd : q.visits.Pairwise (fun p r => p.walk.support.Disjoint r.walk.support)) : q.walk.IsPath := by induction q with | single p => exact hp ⟨_,_,p⟩ (by simp [visits]) | cons p h q ih => have hpd := (List.pairwise_cons.mp hd).1 have hqt := ih (fun r hr => hp r (by simp [visits, hr])) (List.pairwise_cons.mp hd).2 have hpt := hp ⟨_,_,p⟩ (by simp [visits]) have hdisj : p.support.Disjoint q.walk.support := by rw [List.disjoint_left] intro x hx hqx obtain ⟨r,hr,hxr⟩ := q.mem_support_iff x |>.mp hqx exact hpd r hr hx hxr apply Walk.IsPath.mk' simpa only [walk, Walk.support_append, Walk.support_cons, List.tail_cons] using (List.nodup_append').mpr ⟨hpt.support_nodup, hqt.support_nodup, hdisj⟩ lemma length_visits_le (q : VisitChain G u v) : q.visits.length ≤ q.walk.length + 1 := by induction q with | single p => simp [visits, walk] | cons p h q ih => simp only [visits, List.length_cons, walk, Walk.length_append, Walk.length_cons]; omega lemma edgeSet_eq (q : VisitChain G u v) : q.walk.edgeSet = q.links ∪ q.switchEdges := by induction q with | single p => simp [walk, links, switchEdges, visits] | cons p h q ih => simp only [walk, Walk.edgeSet_append, Walk.edgeSet_cons, ih, links, switchEdges, visits] ext e simp only [Set.mem_union, Set.mem_singleton_iff, Set.mem_insert_iff, Set.mem_iUnion, List.mem_cons, exists_prop, or_and_right, exists_or, exists_eq_left] tauto theorem close_cycle (q : VisitChain G u v) (hc : G.Adj v u) (hp : ∀ p ∈ q.visits, p.walk.IsPath) (hd : q.visits.Pairwise (fun p r => p.walk.support.Disjoint r.walk.support)) (hn : 3 ≤ q.visits.length) : (Walk.cons hc q.walk).IsCycle ∧ (Walk.cons hc q.walk).edgeSet = {s(v,u)} ∪ q.links ∪ q.switchEdges ∧ 3 ≤ (Walk.cons hc q.walk).length := by have hpath := q.isPath_of_separated hp hd have hlength := q.length_visits_le have he : s(v,u) ∉ q.walk.edges := by intro he have hh := hpath.length_eq_one_of_mem_edges (Sym2.eq_swap ▸ he) omega refine ⟨Path.cons_isCycle ⟨q.walk,hpath⟩ hc he, ?_, ?_⟩ · rw [Walk.edgeSet_cons, q.edgeSet_eq] ext e simp only [Set.mem_union, Set.mem_insert_iff, Set.mem_singleton_iff] tauto · simp only [Walk.length_cons] omega end VisitChain namespace CycleVisit def ends (p : CycleVisit G) : Set V := {p.start, p.finish} def interior (p : CycleVisit G) : Set V := {x | x ∈ p.walk.support} \ p.ends lemma separated_of_interiors (p q : CycleVisit G) (he : Disjoint p.ends q.ends) (hpq : Disjoint p.interior q.ends) (hqp : Disjoint q.interior p.ends) (hi : Disjoint p.interior q.interior) : p.walk.support.Disjoint q.walk.support := by rw [List.disjoint_left] intro x hx hy by_cases hpx : x ∈ p.ends · by_cases hqx : x ∈ q.ends · exact Set.disjoint_left.mp he hpx hqx · exact Set.disjoint_left.mp hqp ⟨hy,hqx⟩ hpx · by_cases hqx : x ∈ q.ends · exact Set.disjoint_left.mp hpq ⟨hx,hpx⟩ hqx · exact Set.disjoint_left.mp hi ⟨hx,hpx⟩ ⟨hy,hqx⟩ end CycleVisit theorem quotient_cycle_inflation {u v : V} (q : VisitChain G u v) (hc : G.Adj v u) (hp : ∀ p ∈ q.visits, p.walk.IsPath) (he : q.visits.Pairwise (fun p r => Disjoint p.ends r.ends)) (hf : ∀ p ∈ q.visits, ∀ r ∈ q.visits, Disjoint p.interior r.ends) (hi : q.visits.Pairwise (fun p r => Disjoint p.interior r.interior)) (hn : 3 ≤ q.visits.length) : (Walk.cons hc q.walk).IsCycle ∧ (Walk.cons hc q.walk).edgeSet = {s(v,u)} ∪ q.links ∪ q.switchEdges ∧ 3 ≤ (Walk.cons hc q.walk).length := by apply q.close_cycle hc hp _ hn have hh := he.and hi apply hh.imp_of_mem intro p r hpm hrm hpr exact p.separated_of_interiors r hpr.1 (hf p hpm r hrm) (hf r hrm p hpm) hpr.2 namespace VisitChain variable {W : Type cycleUniverse2} {Q : SimpleGraph W} def of_walk (s t : W → V) (q : ∀ z, G.Walk (s z) (t z)) : {a b : W} → (p : Q.Walk a b) → (∀ d ∈ p.darts, G.Adj (t d.fst) (s d.snd)) → VisitChain G (s a) (t b) | _, _, .nil, _ => .single (q _) | a, b, .cons (v := c) h p, hr => .cons (q a) (hr ⟨(a,c),h⟩ (by simp)) (of_walk s t q p (by intro d hd; exact hr d (by simp [hd]))) lemma of_walk_visits (s t : W → V) (q : ∀ z, G.Walk (s z) (t z)) {a b : W} (p : Q.Walk a b) (hr : ∀ d ∈ p.darts, G.Adj (t d.fst) (s d.snd)) : (of_walk s t q p hr).visits = p.support.map (fun z => (⟨s z,t z,q z⟩ : CycleVisit G)) := by induction p with | nil => rfl | cons h p ih => simp [of_walk, visits, ih] lemma of_walk_links (s t : W → V) (q : ∀ z, G.Walk (s z) (t z)) {a b : W} (p : Q.Walk a b) (hr : ∀ d ∈ p.darts, G.Adj (t d.fst) (s d.snd)) : (of_walk s t q p hr).links = {e | ∃ d ∈ p.darts, e = s(t d.fst,s d.snd)} := by induction p with | nil => ext e; simp [of_walk, links] | cons h p ih => ext e simp [of_walk, links, ih, ] lemma of_walk_switchEdges (s t : W → V) (q : ∀ z, G.Walk (s z) (t z)) {a b : W} (p : Q.Walk a b) (hr : ∀ d ∈ p.darts, G.Adj (t d.fst) (s d.snd)) : (of_walk s t q p hr).switchEdges = ⋃ z ∈ p.support, (q z).edgeSet := by rw [switchEdges, of_walk_visits] ext e simp only [Set.mem_iUnion, List.mem_map, exists_prop] constructor · rintro ⟨r,⟨z,hz,rfl⟩,he⟩ exact ⟨z,hz,he⟩ · rintro ⟨z,hz,he⟩ exact ⟨⟨s z,t z,q z⟩,⟨z,hz,rfl⟩,he⟩ end VisitChain theorem lift_quotient_cycle {W : Type cycleUniverse3} {Q : SimpleGraph W} (s t : W → V) (q : ∀ z, G.Walk (s z) (t z)) {a : W} (p : Q.Walk a a) (hp : p.IsCycle) (hr : ∀ d ∈ p.dropLast.darts, G.Adj (t d.fst) (s d.snd)) (hc : G.Adj (t p.penultimate) (s a)) (hq : ∀ z ∈ p.dropLast.support, (q z).IsPath) (hsep : ∀ z ∈ p.dropLast.support, ∀ w ∈ p.dropLast.support, z ≠ w → (q z).support.Disjoint (q w).support) : ∃ c : G.Walk (t p.penultimate) (t p.penultimate), c.IsCycle ∧ c.edgeSet = {s(t p.penultimate,s a)} ∪ {e | ∃ d ∈ p.dropLast.darts, e = s(t d.fst,s d.snd)} ∪ (⋃ z ∈ p.dropLast.support, (q z).edgeSet) := by let chain := VisitChain.of_walk s t q p.dropLast hr have hv : chain.visits = p.dropLast.support.map (fun z => (⟨s z,t z,q z⟩ : CycleVisit G)) := VisitChain.of_walk_visits s t q p.dropLast hr have hpaths : ∀ v ∈ chain.visits, v.walk.IsPath := by intro v hvv rw [hv] at hvv obtain ⟨z,hz,rfl⟩ := List.mem_map.mp hvv exact hq z hz have hpair : chain.visits.Pairwise (fun v w => v.walk.support.Disjoint w.walk.support) := by rw [hv, List.pairwise_map] apply (List.pairwise_iff_getElem).mpr intro i j hi hj hij have hne : p.dropLast.support[i] ≠ p.dropLast.support[j] := by intro he have hij' := hp.isPath_dropLast.support_nodup.getElem_inj_iff.mp he omega exact hsep _ (List.getElem_mem _) _ (List.getElem_mem _) hne have hn : 3 ≤ chain.visits.length := by rw [hv, List.length_map, Walk.length_support, Walk.length_dropLast] have := hp.three_le_length omega obtain ⟨hcycle,hedges,_⟩ := chain.close_cycle hc hpaths hpair hn refine ⟨Walk.cons hc chain.walk,hcycle,?_⟩ rw [hedges, VisitChain.of_walk_links, VisitChain.of_walk_switchEdges] noncomputable section attribute [local instance] Classical.propDecidable theorem orient_edge_representatives {W : Type cycleUniverse4} {Q : SimpleGraph W} (projMap : V → W) (S : Set (Sym2 V)) (hSG : S ⊆ G.edgeSet) (hrep : ∀ e ∈ Q.edgeSet, ∃ f ∈ S, Sym2.map projMap f = e) : ∃ R : Q.Dart → G.Dart, ∀ d, (R d).edge ∈ S ∧ projMap (R d).fst = d.fst ∧ projMap (R d).snd = d.snd := by have hex : ∀ d : Q.Dart, ∃ r : G.Dart, r.edge ∈ S ∧ projMap r.fst = d.fst ∧ projMap r.snd = d.snd := by intro d obtain ⟨f,hf,hmap⟩ := hrep d.edge d.edge_mem induction f using Sym2.ind with | _ x y => have hadj : G.Adj x y := hSG hf change s(projMap x,projMap y) = s(d.fst,d.snd) at hmap rcases Sym2.eq_iff.mp hmap with he | he · exact ⟨⟨(x,y),hadj⟩,hf,he.1,he.2⟩ · refine ⟨⟨(y,x),hadj.symm⟩,?_,he.2,he.1⟩ change s(y,x) ∈ S simpa only [Sym2.eq_swap] using hf exact Classical.axiomOfChoice hex def portFrom {A : Type cycleUniverse5} {W : Type cycleUniverse6} (L : List A) (f : A → W) (g : A → V) (v₀ : V) (z : W) : V := if h : ∃ d ∈ L, f d = z then g h.choose else v₀ lemma portFrom_on {A : Type cycleUniverse7} {W : Type cycleUniverse8} (L : List A) (f : A → W) (g : A → V) (v₀ : V) (hn : (L.map f).Nodup) {d : A} (hd : d ∈ L) : portFrom L f g v₀ (f d) = g d := by have hex : ∃ e ∈ L, f e = f d := ⟨d,hd,rfl⟩ rw [portFrom, dite_eq_left hex] congr 1 exact List.inj_on_of_nodup_map hn hex.choose_spec.1 hd hex.choose_spec.2 theorem choose_cycle_ports {W : Type cycleUniverse9} {Q : SimpleGraph W} (projMap : V → W) (R : Q.Dart → G.Dart) (hprojMap : ∀ d, projMap (R d).fst = d.fst ∧ projMap (R d).snd = d.snd) {a : W} (p : Q.Walk a a) (hp : p.IsCycle) (v₀ : V) : ∃ s t : W → V, (∀ d ∈ p.darts, t d.fst = (R d).fst ∧ s d.snd = (R d).snd) ∧ (∀ z ∈ p.dropLast.support, projMap (s z) = z ∧ projMap (t z) = z) := by let s := portFrom p.darts (fun d => d.snd) (fun d => (R d).snd) v₀ let t := portFrom p.darts (fun d => d.fst) (fun d => (R d).fst) v₀ have hnf : (p.darts.map (fun d => d.fst)).Nodup := by rw [Walk.map_fst_darts] exact hp.nodup_dropLast_support have hns : (p.darts.map (fun d => d.snd)).Nodup := by rw [Walk.map_snd_darts] exact hp.support_nodup have ht : ∀ d ∈ p.darts, t d.fst = (R d).fst := fun d hd => portFrom_on _ _ _ _ hnf hd have hs : ∀ d ∈ p.darts, s d.snd = (R d).snd := fun d hd => portFrom_on _ _ _ _ hns hd refine ⟨s,t,fun d hd => ⟨ht d hd,hs d hd⟩,?_⟩ intro z hz have hz' : z ∈ p.support.dropLast := by rw [← p.support_dropLast hp.not_nil] exact hz have hzt : z ∈ p.support.tail := p.tail_support_perm_dropLast_support.mem_iff.mpr hz' have hzf : z ∈ p.darts.map (fun d => d.fst) := by rwa [Walk.map_fst_darts] have hzs : z ∈ p.darts.map (fun d => d.snd) := by rwa [Walk.map_snd_darts] obtain ⟨d,hd,he⟩ := List.mem_map.mp hzf obtain ⟨e,he',hee⟩ := List.mem_map.mp hzs exact ⟨by rw [← hee,hs e he']; exact (hprojMap e).2, by rw [← he,ht d hd]; exact (hprojMap d).1⟩ lemma last_dart_mem {W : Type cycleUniverse10} {Q : SimpleGraph W} {a b : W} (p : Q.Walk a b) (hp : ¬p.Nil) : (⟨(p.penultimate,b),p.adj_penultimate hp⟩ : Q.Dart) ∈ p.darts := by have he := congrArg Walk.darts (p.concat_dropLast (p.adj_penultimate hp)) rw [Walk.darts_concat] at he rw [← he] simp lemma cycle_darts_split {W : Type cycleUniverse11} {Q : SimpleGraph W} {a b : W} (p : Q.Walk a b) (hp : ¬p.Nil) : p.darts = p.dropLast.darts ++ [⟨(p.penultimate,b),p.adj_penultimate hp⟩] := by have he := congrArg Walk.darts (p.concat_dropLast (p.adj_penultimate hp)) simpa only [Walk.darts_concat, List.concat_eq_append] using he.symm theorem inflate_represented_cycle {W : Type cycleUniverse12} {Q : SimpleGraph W} (R : Q.Dart → G.Dart) (s t : W → V) {a : W} (p : Q.Walk a a) (hp : p.IsCycle) (hports : ∀ d ∈ p.darts, t d.fst = (R d).fst ∧ s d.snd = (R d).snd) (q : ∀ z, G.Walk (s z) (t z)) (hq : ∀ z ∈ p.dropLast.support, (q z).IsPath) (hsep : ∀ z ∈ p.dropLast.support, ∀ w ∈ p.dropLast.support, z ≠ w → (q z).support.Disjoint (q w).support) : ∃ (v : V) (c : G.Walk v v), c.IsCycle ∧ c.edgeSet = {e | ∃ d ∈ p.darts, e = (R d).edge} ∪ (⋃ z ∈ p.dropLast.support, (q z).edgeSet) := by let last : Q.Dart := ⟨(p.penultimate,a),p.adj_penultimate hp.not_nil⟩ have hlast : last ∈ p.darts := last_dart_mem p hp.not_nil have hsub : p.dropLast.darts ⊆ p.darts := by rw [Walk.darts_dropLast]; exact List.dropLast_subset _ have hed : ∀ d ∈ p.darts, s(t d.fst,s d.snd) = (R d).edge := by intro d hd rw [(hports d hd).1,(hports d hd).2] rfl have hadj : ∀ d ∈ p.darts, G.Adj (t d.fst) (s d.snd) := by intro d hd rw [(hports d hd).1,(hports d hd).2] exact (R d).adj obtain ⟨c,hc,he⟩ := lift_quotient_cycle s t q p hp (fun d hd => hadj d (hsub hd)) (hadj last hlast) hq hsep refine ⟨_,c,hc,?_⟩ rw [he] have hlinks : {s(t p.penultimate,s a)} ∪ {e | ∃ d ∈ p.dropLast.darts, e = s(t d.fst,s d.snd)} = {e | ∃ d ∈ p.darts, e = (R d).edge} := by ext e simp only [Set.mem_union, Set.mem_singleton_iff, Set.mem_ofPred_eq] constructor · rintro (rfl | ⟨d,hd,rfl⟩) · exact ⟨last,hlast,hed last hlast⟩ · exact ⟨d,hsub hd,hed d (hsub hd)⟩ · rintro ⟨d,hd,rfl⟩ rw [cycle_darts_split p hp.not_nil] at hd simp only [List.mem_append,List.mem_singleton] at hd rcases hd with hd | rfl · exact Or.inr ⟨d,hd,(hed d (hsub hd)).symm⟩ · exact Or.inl (hed last hlast).symm rw [hlinks] theorem interiors_disjoint_across_routers {I : Type cycleUniverse13} {R : Type cycleUniverse14} (U : R → Set V) (hi : Pairwise (fun r s => Disjoint (U r) (U s))) (router : I → R) (A : I → Set V) (hA : ∀ i, A i ⊆ U (router i)) (hteam : ∀ i j, i ≠ j → router i = router j → Disjoint (A i) (A j)) : Pairwise (fun i j => Disjoint (A i) (A j)) := by intro i j hij by_cases hr : router i = router j · exact hteam i j hij hr · exact (hi hr).mono (hA i) (hA j) def cyclePortSet {W : Type cycleUniverse15} (S : Set W) (s t : W → V) : Set V := {v | ∃ z ∈ S, v = s z ∨ v = t z} def visitInterior {W : Type cycleUniverse16} (s t : W → V) (q : ∀ z, G.Walk (s z) (t z)) (z : W) : Set V := {x | x ∈ (q z).support ∧ x ≠ s z ∧ x ≠ t z} theorem switch_supports_separated {W : Type cycleUniverse17} (S : Set W) (projMap : V → W) (s t : W → V) (q : ∀ z, G.Walk (s z) (t z)) (hproj : ∀ z ∈ S, projMap (s z) = z ∧ projMap (t z) = z) (havoid : ∀ z ∈ S, Disjoint (visitInterior s t q z) (cyclePortSet S s t)) (hinter : ∀ z ∈ S, ∀ w ∈ S, z ≠ w → Disjoint (visitInterior s t q z) (visitInterior s t q w)) : ∀ z ∈ S, ∀ w ∈ S, z ≠ w → (q z).support.Disjoint (q w).support := by intro z hz w hw hzw rw [List.disjoint_left] intro x hx hy by_cases hxend : x = s z ∨ x = t z · have hxZ : x ∈ cyclePortSet S s t := ⟨z,hz,hxend⟩ by_cases hyend : x = s w ∨ x = t w · have hxprojMap : projMap x = z := by rcases hxend with rfl | rfl <;> simp_all have hyprojMap : projMap x = w := by rcases hyend with rfl | rfl <;> simp_all exact hzw (hxprojMap.symm.trans hyprojMap) · exact Set.disjoint_left.mp (havoid w hw) ⟨hy,fun he => hyend (Or.inl he),fun he => hyend (Or.inr he)⟩ hxZ · have hxI : x ∈ visitInterior s t q z := ⟨hx,fun he => hxend (Or.inl he),fun he => hxend (Or.inr he)⟩ by_cases hyend : x = s w ∨ x = t w · exact Set.disjoint_left.mp (havoid z hz) hxI ⟨w,hw,hyend⟩ · exact Set.disjoint_left.mp (hinter z hz w hw hzw) hxI ⟨hy,fun he => hyend (Or.inl he),fun he => hyend (Or.inr he)⟩ theorem cyclePortSet_eq_representative_vertices {W : Type cycleUniverse18} {Q : SimpleGraph W} (R : Q.Dart → G.Dart) (s t : W → V) {a : W} (p : Q.Walk a a) (hp : p.IsCycle) (hports : ∀ d ∈ p.darts, t d.fst = (R d).fst ∧ s d.snd = (R d).snd) : cyclePortSet {z | z ∈ p.dropLast.support} s t = {v | ∃ d ∈ p.darts, v = (R d).fst ∨ v = (R d).snd} := by have hmF : p.darts.map (fun d => d.fst) = p.dropLast.support := by rw [Walk.map_fst_darts, p.support_dropLast hp.not_nil] have hmS : ∀ z, z ∈ p.darts.map (fun d => d.snd) ↔ z ∈ p.dropLast.support := by intro z rw [Walk.map_snd_darts, p.support_dropLast hp.not_nil] exact p.tail_support_perm_dropLast_support.mem_iff ext v constructor · rintro ⟨z,hz,hv | hv⟩ · obtain ⟨d,hd,hds⟩ := List.mem_map.mp ((hmS z).mpr hz) exact ⟨d,hd,Or.inr (hv.trans (by rw [← hds]; exact (hports d hd).2))⟩ · have hz' : z ∈ p.darts.map (fun d => d.fst) := by rwa [hmF] obtain ⟨d,hd,hdf⟩ := List.mem_map.mp hz' exact ⟨d,hd,Or.inl (hv.trans (by rw [← hdf]; exact (hports d hd).1))⟩ · rintro ⟨d,hd,hv | hv⟩ · refine ⟨d.fst,?_,Or.inr (hv.trans (hports d hd).1.symm)⟩ rw [← hmF] exact List.mem_map.mpr ⟨d,hd,rfl⟩ · exact ⟨d.snd,(hmS _).mp (List.mem_map.mpr ⟨d,hd,rfl⟩), Or.inl (hv.trans (hports d hd).2.symm)⟩ theorem complete_batch_cycle {W : Type cycleUniverse19} {Ridx : Type cycleUniverse20} {Q : SimpleGraph W} (projMap : V → W) (R : Q.Dart → G.Dart) (_hprojMap : ∀ d, projMap (R d).fst = d.fst ∧ projMap (R d).snd = d.snd) {a : W} (p : Q.Walk a a) (hp : p.IsCycle) (s t : W → V) (hports : ∀ d ∈ p.darts, t d.fst = (R d).fst ∧ s d.snd = (R d).snd) (hproj : ∀ z ∈ p.dropLast.support, projMap (s z) = z ∧ projMap (t z) = z) (q : ∀ z, G.Walk (s z) (t z)) (hq : ∀ z ∈ p.dropLast.support, (q z).IsPath) (U : Ridx → Set V) (hU : Pairwise (fun i j => Disjoint (U i) (U j))) (router : {z // z ∈ p.dropLast.support} → Ridx) (hroute : ∀ z : {z // z ∈ p.dropLast.support}, visitInterior s t q z ⊆ U (router z)) (hteam : ∀ z w : {z // z ∈ p.dropLast.support}, z ≠ w → router z = router w → Disjoint (visitInterior s t q z) (visitInterior s t q w)) (havoid : ∀ z ∈ p.dropLast.support, Disjoint (visitInterior s t q z) {v | ∃ d ∈ p.darts, v = (R d).fst ∨ v = (R d).snd}) : ∃ (v : V) (c : G.Walk v v), c.IsCycle ∧ c.edgeSet = {e | ∃ d ∈ p.darts, e = (R d).edge} ∪ (⋃ z ∈ p.dropLast.support, (q z).edgeSet) := by have hinter := interiors_disjoint_across_routers U hU router (fun z => visitInterior s t q z) hroute hteam apply inflate_represented_cycle R s t p hp hports q hq apply switch_supports_separated {z | z ∈ p.dropLast.support} projMap s t q hproj · intro z hz rw [cyclePortSet_eq_representative_vertices R s t p hp hports] exact havoid z hz · intro z hz w hw hzw exact hinter (show (⟨z,hz⟩ : {z // z ∈ p.dropLast.support}) ≠ ⟨w,hw⟩ from fun he => hzw (congrArg Subtype.val he)) end end ErdosGallai.Batch end end end end OAI