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import OAI.Computability.Scheduling.SplitPaths
namespace OAI
section
namespace ThreeMachine.Structure
section SamePaths
variable {J A : Type} [Fintype J] [DecidableEq J]
{r : J → J → Prop} {rank : J → ℕ} {atoms : A → Set J}
{p : Layout J} {W : Set J} {P : Set J → Prop}
theorem EdgeData.child_ssubset {a b v ap bp : ℕ} {B V A' B' : Boundary J}
(D : EdgeData r rank atoms p W a b v ap bp B V A' B') :
Window p.time ap bp ⊂ W := by
have hsub : Window p.time ap bp ⊆ W := by
intro x hx
rw [D.parent]
exact ⟨D.start_le.trans_lt hx.1, (hx.2.trans_le D.target_le).trans D.center_lt⟩
have hv : 1 ≤ v ∧ v ≤ Fintype.card J / 3 := by
have := Boundary.at_bounds D.endAt
have := D.start_le
have := D.strict
have := D.target_le
have := D.center_lt
omega
have hc := p.card_slot D.full.1 v hv.1 hv.2
obtain ⟨x, hx⟩ := Finset.card_pos.mp (show 0 < (p.slot v).card by omega)
have ht := (p.mem_slot v x).mp hx
have hxW : x ∈ W := by
rw [D.parent]
exact ⟨by have := D.start_le; have := D.strict; have := D.target_le; omega,
ht ▸ D.center_lt⟩
refine Set.ssubset_iff_subset_ne.mpr ⟨hsub, ?_⟩
intro he
have hh : ap < p.time x ∧ p.time x < bp :=
show x ∈ Window p.time ap bp from he.symm ▸ hxW
have := D.target_le
omega
omit [Fintype J] [DecidableEq J] in
theorem GlobalList.samePriority_final {K : GlobalList J} {B : ℕ} {Q : Set J}
(hrank : ∀ x, rank x < B) (hhigh : ∀ x ∈ W, x ∈ K.Qual → x ∈ Q) :
∀ x ∈ W, x ∈ PriorityCut (K.samePriority rank B Q)
(B + (K.indices.sup id + 1)*B) ↔ x ∈ Q := by
classical
intro x hx
have hr := hrank x
have hk := K.keyValue_bound hrank x
change K.samePriority rank B Q x < B + (K.indices.sup id + 1)*B ↔ x ∈ Q
by_cases hq : x ∈ K.Qual
· have hQ := hhigh x hx hq
simp only [samePriority, ite_eq_left hq, hQ, iff_true]
omega
· by_cases hQ : x ∈ Q <;>
simp only [samePriority, ite_eq_right hq, hQ, ite_true, ite_false, iff_true, iff_false] <;> omega
theorem same_path_normalized (D : NodeData r rank atoms p W)
(htrans : ∀ ⦃x y z⦄, r x y → r y z → r x z)
(hA : AtomSupport atoms r rank) {B v : ℕ} {V : Boundary J}
(hB : 0 < B) (hrank : ∀ x, rank x < B) (hinj : Function.Injective rank)
(hstrict : ∀ x y, r x y → rank x < rank y)
(hv : D.a < v ∧ v < D.b)
(hV : V.At p.time (Fintype.card J / 3) v)
(hcenter : V.Separates r p.time W (D.right.pred r) v)
(hnorm : p.NormalizedOn (Window p.time D.a v) r
(D.list.samePriority rank B (D.right.pred r)))
(hchild : ∀ U, U ⊂ W → Nonempty (NodeData r rank atoms p U) → P U) :
Reached P r atoms W p.time D.a v := by
classical
let E := (Window p.time D.a v).toFinset
have hE : ∀ x, x ∈ E ↔ x ∈ Window p.time D.a v := by intro x; simp [E]
have hEeq : (↑E : Set J) = Window p.time D.a v := Set.ext hE
have hsub : Window p.time D.a v ⊆ W := by
intro x hx
exact (D.window x).mpr ⟨hx.1, hx.2.trans hv.2⟩
let priority := D.list.samePriority rank B (D.right.pred r)
let count := (D.list.indices.sup id + 1) * B
have hfinalAgree : ∀ x ∈ Window p.time D.a v,
x ∈ PriorityCut priority (B+count) ↔ x ∈ D.right.pred r := by
intro x hx
exact GlobalList.samePriority_final hrank D.high x (hsub hx)
have hfinalSep : V.Separates r p.time (Window p.time D.a v)
(PriorityCut priority (B+count)) v :=
(Boundary.separates_congr (fun x hx => (hfinalAgree x hx).symm)).mp
(hcenter.mono_domain hsub)
have hvbounds : 1 ≤ v ∧ v ≤ Fintype.card J / 3 := by
have := Boundary.at_bounds D.rightAt
omega
have hVactual := Boundary.actual_of_interior hV hvbounds
have hedge {ap bp t : ℕ} {A' B' : Boundary J}
(hap : D.a ≤ ap) (hab : ap < bp) (hbp : bp ≤ v)
(hAA : A'.At p.time (Fintype.card J / 3) ap)
(hBB : B'.At p.time (Fintype.card J / 3) bp)
(hact : ∃ Z, B' = Boundary.actual Z) (ht : t ≤ count)
(hstart : A'.Separates r p.time (Window p.time D.a v)
(PriorityCut priority (B+t)) ap)
(hend : B'.Separates r p.time (Window p.time D.a v)
(PriorityCut priority (B+t)) bp)
(hwalk : CutoffWalk E r p.time priority (PriorityCut priority (B+t)) D.a ap)
(hprev : Reached P r atoms W p.time D.a ap) :
Reached P r atoms W p.time D.a bp := by
obtain ⟨F⟩ := exists_same_edge D htrans hA hB hrank hstrict hv hV hcenter
hap hab hbp hAA hBB hact ht hnorm hstart hend E hE hwalk
exact F.reached hA F.finalSmall hprev
(hchild _ F.child_ssubset ⟨F.toNode htrans hA⟩)
by_cases ha : D.a = 0
· have hL : D.left = Boundary.left := Boundary.at_unique D.leftAt ha
apply hedge le_rfl hv.1 le_rfl D.leftAt hV hVactual le_rfl _ hfinalSep .refl (Or.inl rfl)
rw [hL, ha]
exact Boundary.left_separates
· have habounds : 1 ≤ D.a ∧ D.a ≤ Fintype.card J / 3 := by omega
obtain ⟨Z, hZ⟩ := Boundary.actual_of_interior D.leftAt habounds
have hstartBoundary : D.left.Separates r p.time (Window p.time D.a v)
(PriorityCut priority B) D.a := by
constructor
· intro x hx ht _
have := hx.1
omega
· intro x hx _ hs
apply D.low x (hsub hx)
intro hq
have hs' : priority x < B := hs
dsimp only [priority, GlobalList.samePriority] at hs'
rw [ite_eq_left hq] at hs'
omega
have hstart : Separator E r p.time (PriorityCut priority B) D.a := by
apply (Boundary.actual_separates (hZ ▸ D.leftAt)).mp
simpa only [hEeq, ← hZ] using hstartBoundary
have hclosed : SlotClosed E p.time := by
intro x hx y hy
apply (hE y).mpr
have hh := (hE x).mp hx
simpa only [Window, Set.mem_ofPred, hy] using hh
have hpriority := GlobalList.samePriority_extends hrank hstrict D.upsets
(fun _ _ hxy hy => Boundary.pred_downset htrans D.right hxy hy) D.high
have hnormE : LocalObstruction E r p.time priority :=
normalizedOn_local_obstruction (hEeq.symm ▸ hnorm) hE
obtain ⟨walk⟩ := exists_numeric_walk htrans D.full.2 hclosed
(Or.inr fun x hx => ((hE x).mp hx).1)
(GlobalList.samePriority_injective hrank hinj).injOn
(fun x hx y hy hxy => hpriority x (hsub ((hE x).mp hx)) y (hsub ((hE y).mp hy)) hxy)
hnormE hstart count
have hpos : ∀ i, walk.position i < v := by
intro i
rcases walk.endpoint i with he | ⟨x, hx, ht⟩
· simpa only [he] using hv.1
· exact ht ▸ ((hE x).mp hx).2
apply walk.reached hpos
· intro i bp hab hbp hsep hprev
have hap := (walk.history i).le
have haps : 1 ≤ walk.position i ∧ walk.position i ≤ Fintype.card J / 3 := by
have := hpos i
omega
have hbps : 1 ≤ bp ∧ bp ≤ Fintype.card J / 3 := by omega
exact hedge hap hab hbp (p.triple_at D.full.1 _ haps.1 haps.2)
(p.triple_at D.full.1 _ hbps.1 hbps.2) ⟨_, rfl⟩ (by have := i.isLt; omega)
(separator_at D.full hE haps (walk.separator i))
(separator_at D.full hE hbps hsep) (walk.history i) hprev
· obtain ⟨Q, hQ⟩ := hVactual
apply (Boundary.actual_separates (hQ ▸ hV)).mp
simpa only [hEeq, ← hQ] using hfinalSep
end SamePaths
end ThreeMachine.Structure
namespace ThreeMachine.Structure
section SwitchPaths
variable {J A : Type} [Fintype J] [DecidableEq J]
{r : J → J → Prop} {rank : J → ℕ} {atoms : A → Set J}
{p q : Layout J} {W : Set J} {P : Set J → Prop}
omit [DecidableEq J] in
def SwitchSeed.reorder {L : Boundary J} {a b : ℕ}
(G : SwitchSeed r p.time atoms W L a)
(hW : ∀ x, x ∈ W ↔ x ∈ Window p.time a b) (hfix : p.FixedOutside q W) :
SwitchSeed r q.time atoms W L a := by
refine { G with later := ?_ }
intro x hx
by_cases hxW : x ∈ W
· exact ((hfix.window hW x).mp hxW).1
· rw [hfix.time hxW]
exact G.later x hx
omit [Fintype J] [DecidableEq J] in
theorem switchPriority_final {B : ℕ} {D : Set J} (hrank : ∀ x, rank x < B) :
PriorityCut (switchPriority rank B D) B = Dᶜ := by
classical
ext x
have := hrank x
change (if x ∈ D then B+rank x else rank x) < B ↔ x ∉ D
split_ifs <;> simp_all
theorem switch_path_normalized {a b v B : ℕ} {L R V : Boundary J}
(hp : p.Full r) (htrans : ∀ ⦃x y z⦄, r x y → r y z → r x z)
(hA : AtomSupport atoms r rank) (hrank : ∀ x, rank x < B)
(hinj : Function.Injective rank) (hstrict : ∀ x y, r x y → rank x < rank y)
(hW : ∀ x, x ∈ W ↔ x ∈ Window p.time a b)
(hL : L.At p.time (Fintype.card J / 3) a)
(hR : R.At p.time (Fintype.card J / 3) b)
(hcover : ∀ x ∈ W, x ∈ L.desc r ∨ x ∈ R.pred r)
(G : SwitchSeed r p.time atoms W L a)
(hv : a < v ∧ v < b) (hV : V.At p.time (Fintype.card J / 3) v)
(hcenter : V.Separates r p.time W (L.desc r)ᶜ v)
(hnorm : p.NormalizedOn (Window p.time a v) r (switchPriority rank B (L.desc r)))
(hchild : ∀ U, U ⊂ W → Nonempty (NodeData r rank atoms p U) → P U) :
Reached P r atoms W p.time a v := by
classical
let E := (Window p.time a v).toFinset
have hE : ∀ x, x ∈ E ↔ x ∈ Window p.time a v := by intro x; simp [E]
have hEeq : (↑E : Set J) = Window p.time a v := Set.ext hE
have hsub : Window p.time a v ⊆ W := by
intro x hx
exact (hW x).mpr ⟨hx.1, hx.2.trans hv.2⟩
let priority := switchPriority rank B (L.desc r)
have hfinalSep : V.Separates r p.time (Window p.time a v)
(PriorityCut priority B) v := by
rw [show PriorityCut priority B = (L.desc r)ᶜ from switchPriority_final hrank]
exact hcenter.mono_domain hsub
have hvbounds : 1 ≤ v ∧ v ≤ Fintype.card J / 3 := by
have := Boundary.at_bounds hR
omega
have hVactual := Boundary.actual_of_interior hV hvbounds
have hedge {ap bp t : ℕ} {A' B' : Boundary J}
(hap : a ≤ ap) (hab : ap < bp) (hbp : bp ≤ v)
(hAA : A'.At p.time (Fintype.card J / 3) ap)
(hBB : B'.At p.time (Fintype.card J / 3) bp)
(hact : ∃ Z, B' = Boundary.actual Z) (ht : t ≤ B)
(hstart : A'.Separates r p.time (Window p.time a v) (PriorityCut priority t) ap)
(hend : B'.Separates r p.time (Window p.time a v) (PriorityCut priority t) bp)
(hprev : Reached P r atoms W p.time a ap) :
Reached P r atoms W p.time a bp := by
obtain ⟨F⟩ := exists_switch_edge hp htrans hA hrank hstrict hW hL hR hcover G
hv hV hcenter hap hab hbp hAA hBB hact ht hnorm hstart hend
exact F.reached hA F.finalSmall hprev
(hchild _ F.child_ssubset ⟨F.toNode htrans hA⟩)
by_cases ha : a = 0
· have hLL : L = Boundary.left := Boundary.at_unique hL ha
apply hedge le_rfl hv.1 le_rfl hL hV hVactual le_rfl _ hfinalSep (Or.inl rfl)
rw [hLL, ha]
exact Boundary.left_separates
· have habounds : 1 ≤ a ∧ a ≤ Fintype.card J / 3 := by omega
have hstart : Separator E r p.time (PriorityCut priority 0) a := by
constructor
· intro x hx ht _
have := ((hE x).mp hx).1
omega
· intro x _ _ hs
exact (Nat.not_lt_zero _ hs).elim
have hclosed : SlotClosed E p.time := by
intro x hx y hy
apply (hE y).mpr
have hh := (hE x).mp hx
simpa only [Window, Set.mem_ofPred, hy] using hh
have hpriority := switchPriority_extends hrank hstrict (Boundary.desc_upset htrans L)
have hnormE : LocalObstruction E r p.time priority :=
normalizedOn_local_obstruction (hEeq.symm ▸ hnorm) hE
obtain ⟨walk⟩ := exists_numeric_walk htrans hp.2 hclosed
(Or.inr fun x hx => ((hE x).mp hx).1)
(switchPriority_injective hrank hinj).injOn
(fun x _ y _ hxy => hpriority x y hxy) hnormE hstart B
have hpos : ∀ i, walk.position i < v := by
intro i
rcases walk.endpoint i with he | ⟨x, hx, ht⟩
· simpa only [he] using hv.1
· exact ht ▸ ((hE x).mp hx).2
apply walk.reached hpos
· intro i bp hab hbp hsep hprev
have hap := (walk.history i).le
have haps : 1 ≤ walk.position i ∧ walk.position i ≤ Fintype.card J / 3 := by
have := hpos i
omega
have hbps : 1 ≤ bp ∧ bp ≤ Fintype.card J / 3 := by omega
exact hedge (t := i.val) hap hab hbp (p.triple_at hp.1 _ haps.1 haps.2)
(p.triple_at hp.1 _ hbps.1 hbps.2) ⟨_, rfl⟩ (by have := i.isLt; omega)
(separator_at hp hE haps (by simpa only [Nat.zero_add] using walk.separator i))
(separator_at hp hE hbps (by simpa only [Nat.zero_add] using hsep)) hprev
· obtain ⟨Q, hQ⟩ := hVactual
apply (Boundary.actual_separates (hQ ▸ hV)).mp
simpa only [Nat.zero_add, hEeq, ← hQ] using hfinalSep
end SwitchPaths
end ThreeMachine.Structure
namespace ThreeMachine.Structure
section SideNormalization
variable {J A : Type} [Fintype J] [DecidableEq J]
{r : J → J → Prop} {rank : J → ℕ} {atoms : A → Set J}
{p : Layout J} {W : Set J} {P : Set J → Prop}
theorem same_path (D : NodeData r rank atoms p W)
(htrans : ∀ ⦃x y z⦄, r x y → r y z → r x z)
(hA : AtomSupport atoms r rank) {B v : ℕ} {V : Boundary J}
(hB : 0 < B) (hrank : ∀ x, rank x < B) (hinj : Function.Injective rank)
(hstrict : ∀ x y, r x y → rank x < rank y)
(hv : D.a < v ∧ v < D.b)
(hV : V.At p.time (Fintype.card J / 3) v)
(hcenter : V.Separates r p.time W (D.right.pred r) v)
(hchild : ∀ q U, U ⊂ W → Nonempty (NodeData r rank atoms q U) → P U) :
Reached P r atoms W p.time D.a v := by
let E := Window p.time D.a v
have hsub : E ⊆ W := fun x hx => (D.window x).mpr ⟨hx.1, hx.2.trans hv.2⟩
obtain ⟨q, hfix, hnorm⟩ := exists_normalizedOn p E r
(D.list.samePriority rank B (D.right.pred r)) D.full.2
let Dq := D.reorder (hfix.mono hsub) hnorm.1
have hE : E = Window q.time D.a v := Set.ext (hfix.window (fun _ => Iff.rfl))
have hVq := hfix.boundary (fun _ => Iff.rfl) (Or.inr le_rfl) hV
have hcenterq := hcenter.reorder hfix (fun _ => Iff.rfl) (Or.inr le_rfl)
have hnormq : q.NormalizedOn (Window q.time Dq.a v) r
(Dq.list.samePriority rank B (Dq.right.pred r)) := by
change q.NormalizedOn (Window q.time D.a v) r
(D.list.samePriority rank B (D.right.pred r))
exact hE ▸ hnorm
have hreach := same_path_normalized Dq htrans hA hB hrank hinj hstrict hv hVq
hcenterq hnormq (hchild q)
exact hreach.congr_time
(fun x => (hfix.before_iff (fun _ => Iff.rfl) (Or.inr le_rfl) x).symm)
(fun x => (hfix.after_iff (fun _ => Iff.rfl) (Or.inr le_rfl) x).symm)
theorem switch_path {a b v B : ℕ} {L R V : Boundary J}
(hp : p.Full r) (htrans : ∀ ⦃x y z⦄, r x y → r y z → r x z)
(hA : AtomSupport atoms r rank) (hrank : ∀ x, rank x < B)
(hinj : Function.Injective rank) (hstrict : ∀ x y, r x y → rank x < rank y)
(hW : ∀ x, x ∈ W ↔ x ∈ Window p.time a b)
(hL : L.At p.time (Fintype.card J / 3) a)
(hR : R.At p.time (Fintype.card J / 3) b)
(hcover : ∀ x ∈ W, x ∈ L.desc r ∨ x ∈ R.pred r)
(G : SwitchSeed r p.time atoms W L a)
(hv : a < v ∧ v < b) (hV : V.At p.time (Fintype.card J / 3) v)
(hcenter : V.Separates r p.time W (L.desc r)ᶜ v)
(hchild : ∀ q U, U ⊂ W → Nonempty (NodeData r rank atoms q U) → P U) :
Reached P r atoms W p.time a v := by
let E := Window p.time a v
have hsub : E ⊆ W := fun x hx => (hW x).mpr ⟨hx.1, hx.2.trans hv.2⟩
obtain ⟨q, hfix, hnorm⟩ := exists_normalizedOn p E r
(switchPriority rank B (L.desc r)) hp.2
have hE : E = Window q.time a v := Set.ext (hfix.window (fun _ => Iff.rfl))
have hfixW := hfix.mono hsub
have hWq := hfixW.window hW
have hLq := hfixW.boundary hW (Or.inl le_rfl) hL
have hRq := hfixW.boundary hW (Or.inr le_rfl) hR
have hVq := hfix.boundary (fun _ => Iff.rfl) (Or.inr le_rfl) hV
have hcenterq := hcenter.reorder hfix (fun _ => Iff.rfl) (Or.inr le_rfl)
have hnormq : q.NormalizedOn (Window q.time a v) r
(switchPriority rank B (L.desc r)) := by simpa only [hE] using hnorm
have hreach := switch_path_normalized ⟨hp.1, hnorm.1⟩ htrans hA hrank hinj hstrict
hWq hLq hRq hcover (G.reorder hW hfixW) hv hVq hcenterq hnormq (hchild q)
exact hreach.congr_time
(fun x => (hfix.before_iff (fun _ => Iff.rfl) (Or.inr le_rfl) x).symm)
(fun x => (hfix.after_iff (fun _ => Iff.rfl) (Or.inr le_rfl) x).symm)
end SideNormalization
end ThreeMachine.Structure
namespace ThreeMachine.Structure
section ReversePaths
variable {J A : Type} [Fintype J] {r : J → J → Prop}
{atoms : A → Set J} {p : Layout J} {W S : Set J}
theorem Boundary.Separates.reverse {B : Boundary J} {s : ℕ}
(hfull : 3 ∣ Fintype.card J) (hs : s ≤ Fintype.card J / 3 + 1)
(h : B.Separates r p.time W S s) :
B.reverse.Separates (fun x y => r y x) p.reverse.time W Sᶜ
(Fintype.card J / 3 + 1 - s) := by
constructor
· intro x hx ht hn
have hxbound := p.time_bounds hfull x
rw [p.reverse_time hfull] at ht
have hl : s < p.time x := by omega
have hxS : x ∈ S := by simpa only [Set.mem_compl_iff, not_not] using hn
simpa only [Boundary.pred_reverse] using h.2 x hx hl hxS
· intro x hx ht hn
have hxbound := p.time_bounds hfull x
rw [p.reverse_time hfull] at ht
have hl : p.time x < s := by omega
simpa only [Boundary.desc_reverse] using h.1 x hx hl hn
theorem SplitVertex.AtTime.reverse {u : SplitVertex r atoms W} {s : ℕ}
(hfull : 3 ∣ Fintype.card J) (hs : s ≤ Fintype.card J / 3 + 1)
(h : u.AtTime p.time s) :
u.reverse.AtTime p.reverse.time (Fintype.card J / 3 + 1 - s) := by
constructor
· intro x
change x ∈ u.right ↔ _
rw [h.2.2 x, p.reverse_time hfull]
have := p.time_bounds hfull x
apply and_congr_right
intro _
omega
· constructor
· intro x
change x ∈ u.middle.val ↔ _
rw [h.2.1 x, p.reverse_time hfull]
have := p.time_bounds hfull x
apply and_congr_right
intro _
omega
· intro x
change x ∈ u.left ↔ _
rw [h.1 x, p.reverse_time hfull]
have := p.time_bounds hfull x
apply and_congr_right
intro _
omega
theorem window_reverse {a b : ℕ} (hfull : 3 ∣ Fintype.card J)
(ha : a ≤ Fintype.card J / 3 + 1) (hb : b ≤ Fintype.card J / 3 + 1) :
Window p.reverse.time (Fintype.card J / 3 + 1 - b) (Fintype.card J / 3 + 1 - a) =
Window p.time a b := by
ext x
change (_ < p.reverse.time x ∧ p.reverse.time x < _) ↔ _ < p.time x ∧ p.time x < _
rw [p.reverse_time hfull]
have := p.time_bounds hfull x
omega
end ReversePaths
end ThreeMachine.Structure
namespace ThreeMachine.Structure
section Completeness
variable {J A : Type} [Fintype J] [DecidableEq J] {atoms : A → Set J}
theorem node_complete (n : ℕ) :
∀ (r : J → J → Prop) (rank reverseRank : J → ℕ) (p : Layout J) (W : Set J) (B : ℕ),
(∀ ⦃x y z⦄, r x y → r y z → r x z) →
AtomSupport atoms r rank → AtomSupport atoms (fun x y => r y x) reverseRank →
0 < B → (∀ x, rank x < B) → (∀ x, reverseRank x < B) →
Function.Injective rank → Function.Injective reverseRank →
(∀ x y, r x y → rank x < rank y) →
(∀ x y, r y x → reverseRank x < reverseRank y) →
NodeData r rank atoms p W → W.ncard ≤ n → AcceptedAt r atoms n W := by
induction n with
| zero =>
intro r rank reverseRank p W B _ _ _ _ _ _ _ _ _ _ D hcard
have hW : W = ∅ := (Set.ncard_eq_zero (Set.toFinite W)).mp (Nat.eq_zero_of_le_zero hcard)
exact ⟨D.small.mono (by omega), hW⟩
| succ n ih =>
intro r rank reverseRank p W B htrans hA hAR hB hrank hrankR hinj hinjR hstrict hstrictR D hcard
have hsmall : Described atoms W 10000 := D.small.mono (by omega)
by_cases hWempty : W = ∅
· exact ⟨hsmall, Or.inl hWempty⟩
have hne : W.Nonempty := Set.nonempty_iff_ne_empty.mpr hWempty
obtain ⟨q, hfix, hq, v, V, hav, hvb, hV, hcenter⟩ := exists_node_center D htrans hne
let Dq := D.reorder hfix hq
have hchild : ∀ q U, U ⊂ W → Nonempty (NodeData r rank atoms q U) →
AcceptedAt r atoms n U := by
intro q U hU hDU
obtain ⟨DU⟩ := hDU
have hlt := Set.ncard_lt_ncard hU
exact ih r rank reverseRank q U B htrans hA hAR hB hrank hrankR
hinj hinjR hstrict hstrictR DU (by omega)
have hchildR : ∀ q U, U ⊂ W →
Nonempty (NodeData (fun x y => r y x) reverseRank atoms q U) →
AcceptedAt (fun x y => r y x) atoms n U := by
intro q U hU hDU
obtain ⟨DU⟩ := hDU
have hlt := Set.ncard_lt_ncard hU
exact ih (fun x y => r y x) reverseRank rank q U B
(fun {_ _ _} hxy hyz => htrans hyz hxy) hAR hA hB hrankR hrank
hinjR hinj hstrictR hstrict DU (by omega)
have hleft := same_path Dq htrans hA hB hrank hinj hstrict ⟨hav, hvb⟩ hV hcenter hchild
let T := Fintype.card J / 3
have ha : D.a ≤ T+1 := Boundary.at_bounds D.leftAt
have hb : D.b ≤ T+1 := Boundary.at_bounds D.rightAt
have hv : v ≤ T+1 := by omega
have hfrom : T+1-D.b < T+1-v := by omega
have hto : T+1-v < T+1-D.a := by omega
have hWr : ∀ x, x ∈ W ↔ x ∈ Window q.reverse.time (T+1-D.b) (T+1-D.a) := by
rw [window_reverse D.full.1 ha hb]
exact Dq.window
have hcoverr : ∀ x ∈ W, x ∈ Dq.right.reverse.desc (fun x y => r y x) ∨
x ∈ Dq.left.reverse.pred (fun x y => r y x) := by
intro x hx
simpa only [Boundary.desc_reverse, Boundary.pred_reverse, or_comm] using Dq.cover x hx
have hcenterr : V.reverse.Separates (fun x y => r y x) q.reverse.time W
(Dq.right.reverse.desc (fun x y => r y x))ᶜ (T+1-v) := by
rw [Boundary.desc_reverse]
exact hcenter.reverse D.full.1 hv
have hright := switch_path (Layout.reverse_full Dq.full) (fun {_ _ _} hxy hyz => htrans hyz hxy)
hAR hrankR hinjR hstrictR hWr (Boundary.at_reverse D.full.1 Dq.rightAt)
(Boundary.at_reverse D.full.1 Dq.leftAt) hcoverr
(Dq.reverseSeed.toSwitch D.full.1 hb) ⟨hfrom, hto⟩
(Boundary.at_reverse D.full.1 hV) hcenterr hchildR
rcases hleft with he | ⟨ul, vl, hul, hpl, hvl⟩
· change v = D.a at he
omega
rcases hright with he | ⟨ur, vr, hur, hpr, hvr⟩
· change T+1-v = T+1-D.b at he
omega
have hvback : T+1-(T+1-v) = v := by omega
have hvr' : vr.reverse.AtTime q.time v := by
have hh := hvr.reverse D.full.1 (Nat.sub_le (T+1) v)
change vr.reverse.AtTime q.reverse.reverse.time (T+1-(T+1-v)) at hh
rw [hvback] at hh
simpa only [Layout.reverse_reverse] using hh
have hsame : vl = vr.reverse := hvl.unique hvr'
have hpr' := SplitVertex.path_reverse (fun _ h => AcceptedAt.reverse h) hpr
refine ⟨hsmall, Or.inr ⟨ul, ur.reverse, hul, ?_, AcceptedAt.reverse hur⟩⟩
exact hpl.trans (hsame.symm ▸ hpr')
end Completeness
end ThreeMachine.Structure
end
end OAI