openAI-math-dataset / lean /OAI /Computability /Scheduling /NodeCertificates.lean
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import OAI.Computability.Scheduling.PriorityUpdates
namespace OAI
section
namespace ThreeMachine.Structure
section NodeCertificates
variable {J A : Type} [Fintype J] [DecidableEq J]
structure NodeData (r : J → J → Prop) (rank : J → ℕ) (atoms : A → Set J)
(p : Layout J) (W : Set J) where
full : p.Full r
a : ℕ
b : ℕ
left : Boundary J
right : Boundary J
leftAt : left.At p.time (Fintype.card J / 3) a
rightAt : right.At p.time (Fintype.card J / 3) b
window : ∀ x, x ∈ W ↔ x ∈ Window p.time a b
list : GlobalList J
run : RunData list rank atoms W
upsets : list.Upsets r
second_upset : GlobalUpset r run.second
disjoint : list.InjectionDisjoint W
length : list.indices.card ≤ 5
high : ∀ x ∈ W, x ∈ list.Qual → x ∈ right.pred r
low : ∀ x ∈ W, x ∉ list.Qual → x ∈ left.desc r
past : PastInvariant r p.time list left a
swap : SwapInvariant r p W list rank left a
small : Described atoms W 406
reverseSeed : ReverseSeed r p.time atoms W right b
namespace NodeData
variable {r : J → J → Prop} {rank : J → ℕ} {atoms : A → Set J}
{p q : Layout J} {W : Set J}
def reorder (D : NodeData r rank atoms p W) (hfix : p.FixedOutside q W)
(hq : q.Respects r) : NodeData r rank atoms q W :=
{ D with
full := ⟨D.full.1, hq⟩
leftAt := hfix.boundary D.window (Or.inl le_rfl) D.leftAt
rightAt := hfix.boundary D.window (Or.inr le_rfl) D.rightAt
window := hfix.window D.window
past := D.past.reorder hfix D.window
swap := D.swap.reorder hfix
reverseSeed := D.reverseSeed.reorder (Set.ext D.window) hfix }
theorem cover (D : NodeData r rank atoms p W) :
∀ x ∈ W, x ∈ D.left.desc r ∨ x ∈ D.right.pred r := by
intro x hx
by_cases hq : x ∈ D.list.Qual
· exact Or.inr (D.high x hx hq)
· exact Or.inl (D.low x hx hq)
noncomputable def root (p : Layout J) (hp : p.Full r)
(hA : AtomSupport atoms r rank) : NodeData r rank atoms p Set.univ := by
refine { full := hp, a := 0, b := Fintype.card J / 3 + 1
left := .left, right := .right, leftAt := rfl, rightAt := rfl
window := ?_, list := .one Set.univ, run := RunData.root hA.truth
upsets := ?_, second_upset := ?_, disjoint := ?_, length := ?_
high := ?_, low := ?_, past := ?_, swap := ?_
small := hA.truth.mono (by omega), reverseSeed := ?_ }
· intro x
have := p.time_bounds hp.1 x
simp only [Set.mem_univ, Window, Set.mem_ofPred_eq, true_iff]
omega
· intro i _ x y _ _
trivial
· intro x y _ _
trivial
· intro i hi h2i
simp only [GlobalList.one, Finset.mem_singleton] at hi
omega
· simp [GlobalList.one]
· intro x _ _
trivial
· intro x _ _
trivial
· intro x _ htime
have := (p.time_bounds hp.1 x).1
omega
· intro q _ _ x _ _ y hy
have := (q.time_bounds hp.1 y).1
omega
· refine ⟨Set.univ, ?_, hA.truth.mono (by omega), ?_, ?_⟩
· intro x y _ _
trivial
· intro x _ _
trivial
· intro x _
have := (p.time_bounds hp.1 x).2
omega
end NodeData
structure EdgeData (r : J → J → Prop) (rank : J → ℕ) (atoms : A → Set J)
(p : Layout J) (W : Set J) (a b v ap bp : ℕ)
(B V A' B' : Boundary J) where
full : p.Full r
parent : W = Window p.time a b
endAt : B.At p.time (Fintype.card J / 3) b
centerAt : V.At p.time (Fintype.card J / 3) v
startAt : A'.At p.time (Fintype.card J / 3) ap
targetAt : B'.At p.time (Fintype.card J / 3) bp
targetActual : ∃ Z, B' = Boundary.actual Z
start_le : a ≤ ap
strict : ap < bp
target_le : bp ≤ v
center_lt : v < b
cutoff : Set J
finalCutoff : Set J
finalSmall : Described atoms finalCutoff 1
centerSep : V.Separates r p.time W finalCutoff v
startSep : A'.Separates r p.time (Window p.time a v) cutoff ap
targetSep : B'.Separates r p.time (Window p.time a v) cutoff bp
covers : ∀ x ∈ W, x ∈ cutoff → x ∈ B.pred r
below : ∀ x ∈ W, x ∈ cutoff → x ∈ finalCutoff
list : GlobalList J
run : RunData list rank atoms W
upsets : list.Upsets r
second_upset : GlobalUpset r run.second
disjoint : list.InjectionDisjoint W
labels : ∀ x ∈ W, x ∈ list.Qual ↔ x ∉ cutoff
past : PastInvariant r p.time list A' ap
swap : SwapInvariant r p (Window p.time ap bp) list rank A' ap
globalCutoff : Set J
cutoffSmall : Described atoms globalCutoff 205
cutoffAgrees : ∀ x ∈ W, x ∈ globalCutoff ↔ x ∈ cutoff
lowExtension : Set J
downset : GlobalUpset (fun x y => r y x) lowExtension
lowSmall : Described atoms lowExtension 21
lowAgrees : ∀ x ∈ W, x ∈ lowExtension ↔ x ∈ cutoff
namespace EdgeData
variable {r : J → J → Prop} {rank : J → ℕ} {atoms : A → Set J}
{p : Layout J} {W : Set J} {a b v ap bp : ℕ} {B V A' B' : Boundary J}
noncomputable def toNode
(D : EdgeData r rank atoms p W a b v ap bp B V A' B')
(htrans : ∀ ⦃x y z⦄, r x y → r y z → r x z)
(hA : AtomSupport atoms r rank) :
NodeData r rank atoms p (Window p.time ap bp) := by
let W' := Window p.time ap bp
have hsub : W' ⊆ 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 hE : W' ⊆ Window p.time a v := by
intro x hx
exact ⟨D.start_le.trans_lt hx.1, hx.2.trans_le D.target_le⟩
have hhigh : ∀ x ∈ W', x ∉ D.cutoff → x ∈ B'.pred r := by
intro x hx hn
exact D.targetSep.1 x (hE hx) hx.2 hn
have hlow : ∀ x ∈ W', x ∈ D.cutoff → x ∈ A'.desc r ∩ B.pred r := by
intro x hx hS
exact ⟨D.startSep.2 x (hE hx) hx.1 hS, D.covers x (hsub hx) hS⟩
let K' := D.list.prune W'
let R' := D.run.prune hsub
have hqual : ∀ x ∈ W', x ∈ K'.Qual ↔ x ∉ D.cutoff := by
intro x hx
exact (GlobalList.prune_qual D.list hx).trans (D.labels x (hsub hx))
have hlength : K'.indices.card ≤ 5 := by
obtain ⟨Z, hZ⟩ := D.targetActual
apply GlobalList.pruned_length D.upsets D.disjoint (B := Z)
· intro z hz
have ht : p.time z = bp := (show (Boundary.actual Z).At p.time
(Fintype.card J / 3) bp from hZ ▸ D.targetAt).2.2 z |>.mp hz
rw [D.parent]
exact ⟨by have := D.start_le; have := D.strict; omega,
by have := D.target_le; have := D.center_lt; omega⟩
· intro x hx hq
have h := hhigh x hx ((D.labels x (hsub hx)).mp hq)
simpa only [hZ, Boundary.pred, Set.mem_ofPred_eq] using h
have hpast : PastInvariant r p.time K' A' ap := past_prune D.past
have hh := global_high_identity D.full.2 (p.time_bounds D.full.1)
D.startAt D.targetAt hqual hhigh hpast
have hl := global_low_identity D.full.2 (p.time_bounds D.full.1)
D.startAt D.endAt D.targetAt D.centerAt D.start_le D.strict D.target_le D.center_lt
(fun x hx => D.cutoffAgrees x (D.parent ▸ hx))
(fun x hx => D.below x (D.parent ▸ hx))
(D.parent ▸ D.centerSep) D.targetSep hlow
have hsmall : Described atoms W' 406 := global_child_small hA
(R'.qual_small hA hlength) D.cutoffSmall hh hl
have hseedExists := reverse_seed_at_edge htrans D.full.2 (p.time_bounds D.full.1)
D.endAt D.targetAt D.centerAt D.parent rfl rfl D.start_le D.strict D.target_le D.center_lt
hhigh D.covers D.below D.centerSep D.targetSep D.downset D.lowAgrees D.lowSmall
(hA.pred B) (hA.weakDesc B') (hA.weakDesc V)
exact { full := D.full, a := ap, b := bp, left := A', right := B'
leftAt := D.startAt, rightAt := D.targetAt, window := fun _ => Iff.rfl
list := K', run := R', upsets := GlobalList.prune_upsets D.upsets
second_upset := D.second_upset, disjoint := D.disjoint.prune hsub, length := hlength
high := fun x hx hq => hhigh x hx ((hqual x hx).mp hq)
low := fun x hx hn => (hlow x hx (by by_contra h; exact hn ((hqual x hx).mpr h))).1
past := hpast, swap := swap_prune D.swap, small := hsmall, reverseSeed := Classical.choice hseedExists }
end EdgeData
end NodeCertificates
end ThreeMachine.Structure
namespace ThreeMachine.Structure
namespace Boundary
variable {J : Type} {time : J → ℕ} {T s : ℕ}
theorem at_le {B : Boundary J} (hB : B.At time T s) : s ≤ T+1 := by
cases B with
| left => simp only [At] at hB; omega
| right => exact hB.le
| actual Z => exact hB.2.1.trans (by omega)
theorem at_unique {B C : Boundary J} (hB : B.At time T s) (hC : C.At time T s) :
B = C := by
cases B <;> cases C <;> try rfl
all_goals simp only [At] at hB hC
all_goals try omega
congr 1
apply Subtype.ext
ext x
exact (hB.2.2 x).trans (hC.2.2 x).symm
end Boundary
section SameEdges
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}
theorem exists_same_edge (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 t v ap bp : ℕ} {V A' B' : Boundary J}
(hB : 0 < B) (hrank : ∀ x, rank x < B)
(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)
(hap : D.a ≤ ap) (hab : ap < bp) (hbp : bp ≤ v)
(hA' : A'.At p.time (Fintype.card J / 3) ap)
(hB' : B'.At p.time (Fintype.card J / 3) bp)
(hactual : ∃ Z, B' = Boundary.actual Z)
(ht : t ≤ (D.list.indices.sup id + 1) * B)
(hnorm : p.NormalizedOn (Window p.time D.a v) r
(D.list.samePriority rank B (D.right.pred r)))
(hstart : A'.Separates r p.time (Window p.time D.a v)
(PriorityCut (D.list.samePriority rank B (D.right.pred r)) (B+t)) ap)
(hend : B'.Separates r p.time (Window p.time D.a v)
(PriorityCut (D.list.samePriority rank B (D.right.pred r)) (B+t)) bp)
(E : Finset J) (hEwin : ∀ x, x ∈ E ↔ x ∈ Window p.time D.a v)
(hwalk : CutoffWalk E r p.time
(D.list.samePriority rank B (D.right.pred r))
(PriorityCut (D.list.samePriority rank B (D.right.pred r)) (B+t)) D.a ap) :
Nonempty (EdgeData r rank atoms p W D.a D.b v ap bp D.right V A' B') := by
classical
let S := PriorityCut (D.list.samePriority rank B (D.right.pred r)) (B+t)
let K' := D.list.sameUpdate rank B t (D.left.desc r) (D.right.pred r)
let H := D.right.pred r \ (D.list.carry rank (t/B) (t%B)).Qual
have hagree : ∀ x ∈ W, x ∈ S ↔ x ∈ H :=
GlobalList.samePriority_cut hB hrank D.high ht
have hlabels : ∀ x ∈ W, x ∈ K'.Qual ↔ x ∉ S :=
GlobalList.sameUpdate_agreement hB hrank D.high D.cover ht
have hsub : Window p.time ap bp ⊆ W := by
intro x hx
exact (D.window x).mpr ⟨hap.trans_lt hx.1, (hx.2.trans_le hbp).trans hv.2⟩
have hE : Window p.time ap bp ⊆ Window p.time D.a v := by
intro x hx
exact ⟨hap.trans_lt hx.1, hx.2.trans_le hbp⟩
have hqual : ∀ x ∈ Window p.time ap bp, x ∉ A'.desc r → x ∈ K'.Qual := by
intro x hx hn
apply (hlabels x (hsub hx)).mpr
intro hS
exact hn (hstart.2 x (hE hx) hx.1 hS)
have hswap : SwapInvariant r p (Window p.time ap bp) K' rank A' ap := by
rcases hap.eq_or_lt with he | hl
· have hAA : A' = D.left := Boundary.at_unique hA' (he ▸ D.leftAt)
subst ap
subst A'
exact sameUpdate_swap_inherited D.full D.leftAt D.window hsub D.swap hqual
· apply swap_from_normalized (fun _ => Iff.rfl) (fun _ => Iff.rfl) hl hbp hab hnorm hqual
intro x hx hxK y hya hyK hkey
have hyW : y ∈ W := (D.window y).mpr ⟨by omega,
by have := hv.2; omega⟩
exact (GlobalList.sameUpdate_key hrank D.high (hsub hx) hyW hxK hyK).mp hkey
have hapos : D.a ≤ Fintype.card J / 3 := by
have := Boundary.at_le D.rightAt
omega
have hEeq : (↑E : Set J) = Window p.time D.a v := Set.ext hEwin
have hpast : PastInvariant r p.time K' A' ap := by
apply sameUpdate_past D.full htrans D.leftAt hA' D.window
(E := E) hEwin
hv.2 hapos (hab.trans_le hbp) hB hrank hstrict D.upsets D.high D.low
D.past D.swap ht
· apply normalizedOn_local_obstruction
· simpa only [hEeq] using hnorm
· exact hEwin
· simpa only [hEeq] using hstart
· exact hwalk
obtain ⟨Hext, hHup, hHsmall, hHagree⟩ := D.run.carry_low_extension hA D.length
D.upsets D.second_upset hstrict htrans D.right (t/B) (t%B)
refine ⟨{
full := D.full, parent := Set.ext D.window, endAt := D.rightAt
centerAt := hV, startAt := hA', targetAt := hB', targetActual := hactual
start_le := hap, strict := hab, target_le := hbp, center_lt := hv.2
cutoff := S, finalCutoff := D.right.pred r, finalSmall := hA.pred D.right, centerSep := hcenter
startSep := hstart, targetSep := hend
covers := fun x hx hs => ((hagree x hx).mp hs).1
below := fun x hx hs => ((hagree x hx).mp hs).1
list := K', run := (D.run.carry (t/B) (t%B)).append
(D.left.desc r \ D.right.pred r) ((hA.desc D.left).diff (hA.pred D.right))
upsets := GlobalList.sameUpdate_upsets D.upsets
(Boundary.desc_upset htrans D.left) (fun _ _ hxy hx => Boundary.pred_downset htrans D.right hxy hx) hstrict
second_upset := D.second_upset
disjoint := GlobalList.sameUpdate_disjoint D.disjoint D.high
labels := hlabels, past := hpast, swap := hswap
globalCutoff := H, cutoffSmall := D.run.carry_cutoff_small hA D.length D.right (t/B) (t%B)
cutoffAgrees := fun x hx => (hagree x hx).symm
lowExtension := Hext, downset := hHup, lowSmall := hHsmall
lowAgrees := fun x hx => (hHagree x hx).trans (hagree x hx).symm }⟩
end SameEdges
end ThreeMachine.Structure
namespace ThreeMachine.Structure
section SwitchedEdges
variable {J A : Type} [Fintype J] [DecidableEq J]
structure SwitchSeed (r : J → J → Prop) (time : J → ℕ) (atoms : A → Set J)
(W : Set J) (B : Boundary J) (a : ℕ) where
predicate : Set J
upset : GlobalUpset r predicate
small : Described atoms predicate 24
cover : ∀ x ∈ W, x ∉ B.desc r → x ∈ predicate
later : ∀ x ∈ predicate, a < time x
variable {r : J → J → Prop} {rank : J → ℕ} {atoms : A → Set J}
{p : Layout J} {W : Set J}
def ReverseSeed.toSwitch {B : Boundary J} {b : ℕ}
(D : ReverseSeed r p.time atoms W B b) (hfull : 3 ∣ Fintype.card J)
(hb : b ≤ Fintype.card J / 3 + 1) :
SwitchSeed (fun x y => r y x) p.reverse.time atoms W B.reverse
(Fintype.card J / 3 + 1 - b) := by
refine { predicate := D.predicate, upset := D.downset, small := D.small
cover := ?_, later := ?_ }
· simpa only [Boundary.desc_reverse] using D.cover
· intro x hx
rw [Layout.reverse_time p hfull]
have := D.earlier x hx
have := p.time_bounds hfull x
omega
theorem exists_switch_edge {a b v ap bp B t : ℕ} {L R V A' B' : 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)
(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)
(hap : a ≤ ap) (hab : ap < bp) (hbp : bp ≤ v)
(hA' : A'.At p.time (Fintype.card J / 3) ap)
(hB' : B'.At p.time (Fintype.card J / 3) bp)
(hactual : ∃ Z, B' = Boundary.actual Z) (ht : t ≤ B)
(hnorm : p.NormalizedOn (Window p.time a v) r (switchPriority rank B (L.desc r)))
(hstart : A'.Separates r p.time (Window p.time a v)
(PriorityCut (switchPriority rank B (L.desc r)) t) ap)
(hend : B'.Separates r p.time (Window p.time a v)
(PriorityCut (switchPriority rank B (L.desc r)) t) bp) :
Nonempty (EdgeData r rank atoms p W a b v ap bp R V A' B') := by
classical
let S := PriorityCut (switchPriority rank B (L.desc r)) t
let K' := GlobalList.pair (G.predicate ∩ RankTail rank t) (L.desc r)
have hlabels : ∀ x ∈ W, x ∈ K'.Qual ↔ x ∉ S :=
GlobalList.switchPair_agreement ht G.cover
have hcut : S = (L.desc r)ᶜ \ RankTail rank t := switchPriority_cut ht
have hsup : GlobalUpset r (L.desc r) := Boundary.desc_upset htrans L
have hK : K'.Upsets r := GlobalList.pair_upsets
(fun _ _ hxy hx => ⟨G.upset hxy hx.1, rankTail_upset hstrict t hxy hx.2⟩) hsup
have hnonearly : ∀ x ∈ K'.Qual, a < p.time x := by
intro x hx
rw [GlobalList.qual_pair] at hx
rcases hx with hx | hx
· exact G.later x hx.1
· exact Boundary.desc_time hp.2 (p.time_bounds hp.1) hL hx
have hsub : Window p.time ap bp ⊆ W := by
intro x hx
exact (hW x).mpr ⟨hap.trans_lt hx.1, (hx.2.trans_le hbp).trans hv.2⟩
have hE : Window p.time ap bp ⊆ Window p.time a v := by
intro x hx
exact ⟨hap.trans_lt hx.1, hx.2.trans_le hbp⟩
have hqual : ∀ x ∈ Window p.time ap bp, x ∉ A'.desc r → x ∈ K'.Qual := by
intro x hx hn
apply (hlabels x (hsub hx)).mpr
intro hS
exact hn (hstart.2 x (hE hx) hx.1 hS)
have hpast : PastInvariant r p.time K' A' ap := by
intro x hx ht'
have hax := hnonearly x hx
have hxE : x ∈ Window p.time a v := ⟨hax, ht'.trans_lt (hab.trans_le hbp)⟩
rcases ht'.eq_or_lt with he | hl
· exact (Boundary.mem_weak_at_time (p.time_bounds hp.1) hA' he).1
· have hxW : x ∈ W := (hW x).mpr ⟨hax, hxE.2.trans hv.2⟩
exact A'.pred_subset_weakPred r (hstart.1 x hxE hl ((hlabels x hxW).mp hx))
have hswap : SwapInvariant r p (Window p.time ap bp) K' rank A' ap := by
rcases hap.eq_or_lt with he | hl
· intro q hfix _ x _ _ y hy hyK
have hnW : y ∉ Window p.time ap bp := by
intro hyW
have h := (hfix.window (fun _ => Iff.rfl) y).mp hyW
have := h.1
omega
have hya : p.time y = a := by rw [← hfix.time hnW, hy]; omega
have := hnonearly y hyK
omega
· apply swap_from_normalized (fun _ => Iff.rfl) (fun _ => Iff.rfl) hl hbp hab hnorm hqual
intro x _ _ y _ _ hkey
exact (GlobalList.switchPair_key hrank x y).mp hkey
have hSsmall : Described atoms S 2 := by
rw [hcut]
exact (hA.desc L).compl.diff (hA.rankTail t)
have hSdown : GlobalUpset (fun x y => r y x) S := by
rw [hcut]
intro x y hyx hx
exact ⟨fun hyD => hx.1 (hsup hyx hyD), fun hyr =>
hx.2 (rankTail_upset hstrict t hyx hyr)⟩
refine ⟨{
full := hp, parent := Set.ext hW, endAt := hR, centerAt := hV
startAt := hA', targetAt := hB', targetActual := hactual
start_le := hap, strict := hab, target_le := hbp, center_lt := hv.2
cutoff := S, finalCutoff := (L.desc r)ᶜ, finalSmall := (hA.desc L).compl, centerSep := hcenter
startSep := hstart, targetSep := hend, covers := ?_, below := ?_
list := K', run := RunData.switched G.small (hA.desc L) G.cover t
upsets := hK, second_upset := hsup, disjoint := ?_, labels := hlabels
past := hpast, swap := hswap, globalCutoff := S
cutoffSmall := hSsmall.mono (by omega), cutoffAgrees := fun _ _ => Iff.rfl
lowExtension := S, downset := hSdown, lowSmall := hSsmall.mono (by omega)
lowAgrees := fun _ _ => Iff.rfl }⟩
· intro x hx hS
rw [hcut] at hS
exact (hcover x hx).resolve_left hS.1
· intro x _ hS
rw [hcut] at hS
exact hS.1
· intro i hi h2i
simp only [K', GlobalList.pair, Finset.mem_insert, Finset.mem_singleton] at hi
omega
end SwitchedEdges
end ThreeMachine.Structure
namespace ThreeMachine.Structure
section Centers
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}
omit [DecidableEq J] in
theorem window_first_slot {a b : ℕ} (hp : p.Full r)
(hne : (Window p.time a b).Nonempty) :
∃ x ∈ Window p.time a b, p.time x = a+1 := by
obtain ⟨y, hy⟩ := hne
change a < p.time y ∧ p.time y < b at hy
have hybound := p.time_bounds hp.1 y
have hb : a+1 ≤ Fintype.card J / 3 := by omega
have hc := p.card_slot hp.1 (a+1) (by omega) hb
have hn : (p.slot (a+1)).Nonempty := Finset.card_pos.mp (by omega)
obtain ⟨x, hx⟩ := hn
have hx' := (p.mem_slot (a+1) x).mp hx
exact ⟨x, ⟨by omega, by omega⟩, hx'⟩
theorem exists_node_center (D : NodeData r rank atoms p W)
(htrans : ∀ ⦃x y z⦄, r x y → r y z → r x z) (hne : W.Nonempty) :
∃ q : Layout J, ∃ _hfix : p.FixedOutside q W, q.Respects r ∧
∃ (v : ℕ) (V : Boundary J), D.a < v ∧ v < D.b ∧
V.At q.time (Fintype.card J / 3) v ∧
V.Separates r q.time W (D.right.pred r) v := by
classical
let priority := fun x : J => if x ∈ D.right.pred r then (p x).val
else Fintype.card J + (p x).val
obtain ⟨q, hfix, hnorm⟩ := exists_normalizedOn p W r priority D.full.2
let Dq := D.reorder hfix hnorm.1
have hwindow : ∀ x, x ∈ W ↔ x ∈ Window q.time D.a D.b := Dq.window
let E := W.toFinset
have hE : ∀ x, x ∈ E ↔ x ∈ W := by intro x; simp [E]
have hEeq : (↑E : Set J) = W := Set.ext hE
have hclosed : SlotClosed E q.time := by
intro x hx y hxy
apply (hE y).mpr
have h := (hwindow x).mp ((hE x).mp hx)
exact (hwindow y).mpr (by simpa only [Window, Set.mem_ofPred, ← hxy] using h)
have hideal : IdealOn E r (D.right.pred r) := by
intro x _ y _ hxy hy
exact Boundary.pred_downset htrans D.right hxy hy
have hprefix : PrefixOn E priority (D.right.pred r) := by
intro x _ hx y _ hy
simp only [priority, ite_eq_left hx, ite_eq_right hy]
have := (p x).isLt
omega
have hne' : (Window q.time D.a D.b).Nonempty := by
obtain ⟨x, hx⟩ := hne
exact ⟨x, (hwindow x).mp hx⟩
obtain ⟨x, hx, hxa⟩ := window_first_slot Dq.full hne'
have hnormE : LocalObstruction E r q.time priority := by
apply normalizedOn_local_obstruction
· simpa only [hEeq] using hnorm
· intro x
exact (hE x).trans (hwindow x)
have hfirst : EarlierHigh E r q.time (D.right.pred r) (D.a+1) := by
intro x hx htime _
have := ((hwindow x).mp ((hE x).mp hx)).1
omega
obtain ⟨v, _, hpath, hsep⟩ := walk_to_separator htrans hnorm.1 hclosed
(Or.inl ⟨x, (hE x).mpr ((hwindow x).mpr hx), hxa⟩) hideal hprefix hnormE hfirst
have hv : ∃ z ∈ W, q.time z = v := by
rcases hpath.endpoint with he | ⟨z, hz, he⟩
· exact ⟨x, (hwindow x).mpr hx, hxa.trans he.symm⟩
· exact ⟨z, (hE z).mp hz, he⟩
obtain ⟨z, hz, hzv⟩ := hv
have hvwin := (hwindow z).mp hz
have hvlo := hvwin.1
have hvhi := hvwin.2
have hvbound := q.time_bounds D.full.1 z
have hva : D.a < v := by omega
have hvb : v < D.b := by omega
have hvpos : 1 ≤ v := by omega
have hvle : v ≤ Fintype.card J / 3 := by omega
let V := Boundary.actual (q.triple D.full.1 v hvpos hvle)
have hV : V.At q.time (Fintype.card J / 3) v := q.triple_at D.full.1 v hvpos hvle
refine ⟨q, hfix, hnorm.1, v, V, hva, hvb, hV, ?_⟩
simpa only [hEeq] using (Boundary.actual_separates hV).mpr hsep
omit [DecidableEq J] in
theorem Layout.FixedOutside.before_iff {U : Set J} {a b s : ℕ}
(hfix : p.FixedOutside q U) (hU : ∀ x, x ∈ U ↔ x ∈ Window p.time a b)
(hs : s ≤ a ∨ b ≤ s) (x : J) : p.time x < s ↔ q.time x < s := by
by_cases hx : x ∈ U
· have hp := (hU x).mp hx
have hq := (hfix.window hU x).mp hx
rcases hs with hs | hs <;> dsimp [Window] at hp hq <;> omega
· rw [hfix.time hx]
omit [DecidableEq J] in
theorem Layout.FixedOutside.after_iff {U : Set J} {a b s : ℕ}
(hfix : p.FixedOutside q U) (hU : ∀ x, x ∈ U ↔ x ∈ Window p.time a b)
(hs : s ≤ a ∨ b ≤ s) (x : J) : s < p.time x ↔ s < q.time x := by
by_cases hx : x ∈ U
· have hp := (hU x).mp hx
have hq := (hfix.window hU x).mp hx
rcases hs with hs | hs <;> dsimp [Window] at hp hq <;> omega
· rw [hfix.time hx]
omit [DecidableEq J] in
theorem Boundary.Separates.reorder {U S : Set J} {a b s : ℕ} {V : Boundary J}
(hsep : V.Separates r p.time W S s) (hfix : p.FixedOutside q U)
(hU : ∀ x, x ∈ U ↔ x ∈ Window p.time a b) (hs : s ≤ a ∨ b ≤ s) :
V.Separates r q.time W S s := by
constructor
· intro x hx htime hn
exact hsep.1 x hx ((hfix.before_iff hU hs x).mpr htime) hn
· intro x hx htime hS
exact hsep.2 x hx ((hfix.after_iff hU hs x).mpr htime) hS
end Centers
end ThreeMachine.Structure
end
end OAI