Theorem: Regex.VM.lower_inv_exploreεClosure (RegexCorrectness/VM/Auxiliary.lean)

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
h : exploreεClosure nfa pos next currentSave matched saveSlots target stack = (matched', next', saveSlots')
inv : LowerInvExploreεClosure nfa next target stack
⊢ LowerInvεClosure nfa next' #[]
Tactic:
unfold exploreεClosure at h
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h :
  (if target ∈ next then εClosure nfa pos next currentSave matched saveSlots stack
    else
      let next' := next.insert target;
      match hn : nfa[target] with
      | Node.epsilon target' =>
        let_fun isLt := ⋯;
        exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
      | Node.split target₁ target₂ =>
        let_fun isLt := ⋯;
        exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target₁, ⋯⟩
          (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
      | Node.save offset target' =>
        let_fun isLt := ⋯;
        if h : offset < currentSave.size then
          let nextSave := currentSave.set ⟨offset, h⟩ (some pos);
          let stack' := stack.push (StackEntry.restore currentSave);
          exploreεClosure nfa pos next' nextSave matched saveSlots ⟨target', isLt⟩ stack'
        else exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
      | Node.done =>
        let matched' := HOrElse.hOrElse matched fun x => some currentSave;
        let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
        εClosure nfa pos next' currentSave matched' saveSlots' stack
      | Node.char c next =>
        let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
        εClosure nfa pos next' currentSave matched saveSlots' stack
      | Node.sparse cs next =>
        let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
        εClosure nfa pos next' currentSave matched saveSlots' stack
      | Node.fail => εClosure nfa pos next' currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h :
  (if target ∈ next then εClosure nfa pos next currentSave matched saveSlots stack
    else
      let next' := next.insert target;
      match hn : nfa[target] with
      | Node.epsilon target' =>
        let_fun isLt := ⋯;
        exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
      | Node.split target₁ target₂ =>
        let_fun isLt := ⋯;
        exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target₁, ⋯⟩
          (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
      | Node.save offset target' =>
        let_fun isLt := ⋯;
        if h : offset < currentSave.size then
          let nextSave := currentSave.set ⟨offset, h⟩ (some pos);
          let stack' := stack.push (StackEntry.restore currentSave);
          exploreεClosure nfa pos next' nextSave matched saveSlots ⟨target', isLt⟩ stack'
        else exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
      | Node.done =>
        let matched' := HOrElse.hOrElse matched fun x => some currentSave;
        let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
        εClosure nfa pos next' currentSave matched' saveSlots' stack
      | Node.char c next =>
        let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
        εClosure nfa pos next' currentSave matched saveSlots' stack
      | Node.sparse cs next =>
        let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
        εClosure nfa pos next' currentSave matched saveSlots' stack
      | Node.fail => εClosure nfa pos next' currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
split at h
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
h :
  (let next' := next.insert target;
    match hn : nfa[target] with
    | Node.epsilon target' =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.split target₁ target₂ =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target₁, ⋯⟩
        (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
    | Node.save offset target' =>
      let_fun isLt := ⋯;
      if h : offset < currentSave.size then
        let nextSave := currentSave.set ⟨offset, h⟩ (some pos);
        let stack' := stack.push (StackEntry.restore currentSave);
        exploreεClosure nfa pos next' nextSave matched saveSlots ⟨target', isLt⟩ stack'
      else exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.done =>
      let matched' := HOrElse.hOrElse matched fun x => some currentSave;
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched' saveSlots' stack
    | Node.char c next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.sparse cs next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.fail => εClosure nfa pos next' currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
h :
  (let next' := next.insert target;
    match hn : nfa[target] with
    | Node.epsilon target' =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.split target₁ target₂ =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target₁, ⋯⟩
        (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
    | Node.save offset target' =>
      let_fun isLt := ⋯;
      if h : offset < currentSave.size then
        let nextSave := currentSave.set ⟨offset, h⟩ (some pos);
        let stack' := stack.push (StackEntry.restore currentSave);
        exploreεClosure nfa pos next' nextSave matched saveSlots ⟨target', isLt⟩ stack'
      else exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.done =>
      let matched' := HOrElse.hOrElse matched fun x => some currentSave;
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched' saveSlots' stack
    | Node.char c next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.sparse cs next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.fail => εClosure nfa pos next' currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next hmem =>
  have inv' : LowerInvεClosure nfa next stack := by
    intro i j hi hj
    match inv i j hi hj with
    | .inl hnext => exact .inl hnext
    | .inr (.inl htarget) =>
      rw [←htarget] at hmem
      exact .inl hmem
    | .inr (.inr hstack) => exact .inr hstack
  exact lower_inv_εClosure h inv'
State after:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
h :
  (let next' := next.insert target;
    match hn : nfa[target] with
    | Node.epsilon target' =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.split target₁ target₂ =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target₁, ⋯⟩
        (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
    | Node.save offset target' =>
      let_fun isLt := ⋯;
      if h : offset < currentSave.size then
        let nextSave := currentSave.set ⟨offset, h⟩ (some pos);
        let stack' := stack.push (StackEntry.restore currentSave);
        exploreεClosure nfa pos next' nextSave matched saveSlots ⟨target', isLt⟩ stack'
      else exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.done =>
      let matched' := HOrElse.hOrElse matched fun x => some currentSave;
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched' saveSlots' stack
    | Node.char c next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.sparse cs next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.fail => εClosure nfa pos next' currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
h :
  (let next' := next.insert target;
    match hn : nfa[target] with
    | Node.epsilon target' =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.split target₁ target₂ =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target₁, ⋯⟩
        (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
    | Node.save offset target' =>
      let_fun isLt := ⋯;
      if h : offset < currentSave.size then
        let nextSave := currentSave.set ⟨offset, h⟩ (some pos);
        let stack' := stack.push (StackEntry.restore currentSave);
        exploreεClosure nfa pos next' nextSave matched saveSlots ⟨target', isLt⟩ stack'
      else exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.done =>
      let matched' := HOrElse.hOrElse matched fun x => some currentSave;
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched' saveSlots' stack
    | Node.char c next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.sparse cs next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.fail => εClosure nfa pos next' currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next =>
  simp at h
  split at h
  next target' hn =>
    have isLt := nfa.inBounds' target hn
    have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack := by
      intro i j hi hj
      cases SparseSet.eq_or_mem_of_mem_insert hi with
      | inl htarget =>
        subst htarget
        simp [εStep, Node.εStep, hn] at hj
        exact .inr (.inl (Fin.eq_of_val_eq hj))
      | inr hnext =>
        match inv i j hnext hj with
        | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
        | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
        | .inr (.inr hstack) => exact .inr (.inr hstack)
    exact lower_inv_exploreεClosure h inv'
  next target₁ target₂ hn =>
    have isLt := nfa.inBounds' target hn
    have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target₁, isLt.1⟩ (stack.push (.explore ⟨target₂, isLt.2⟩)) := by
      intro i j hi hj
      cases SparseSet.eq_or_mem_of_mem_insert hi with
      | inl htarget =>
        subst htarget
        simp [εStep, Node.εStep, hn] at hj
        cases hj with
        | inl hj => exact .inr (.inl (Fin.eq_of_val_eq hj))
        | inr hj => exact .inr (.inr ((Array.mem_push ..).mpr (.inr (by simp [hj.symm]))))
      | inr hnext =>
        match inv i j hnext hj with
        | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
        | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
        | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
    exact lower_inv_exploreεClosure h inv'
  next _ target' hn =>
    have isLt := nfa.inBounds' target hn
    split at h
    next =>
      have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ (stack.push (.restore currentSave)) := by
        intro i j hi hj
        cases SparseSet.eq_or_mem_of_mem_insert hi with
        | inl htarget =>
          subst htarget
          simp [εStep, Node.εStep, hn] at hj
          exact .inr (.inl (Fin.eq_of_val_eq hj))
        | inr hnext =>
          match inv i j hnext hj with
          | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
          | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
          | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
      exact lower_inv_exploreεClosure h inv'
    next =>
      have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack := by
        intro i j hi hj
        cases SparseSet.eq_or_mem_of_mem_insert hi with
        | inl htarget =>
          subst htarget
          simp [εStep, Node.εStep, hn] at hj
          exact .inr (.inl (Fin.eq_of_val_eq hj))
        | inr hnext =>
          match inv i j hnext hj with
          | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
          | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
          | .inr (.inr hstack) => exact .inr (.inr hstack)
      exact lower_inv_exploreεClosure h inv'
  next hn =>
    have inv' : LowerInvεClosure nfa (next.insert target) stack := by
      intro i j hi hj
      cases SparseSet.eq_or_mem_of_mem_insert hi with
      | inl htarget =>
        subst htarget
        simp [εStep, Node.εStep, hn] at hj
      | inr hnext =>
        match inv i j hnext hj with
        | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
        | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
        | .inr (.inr hstack) => exact .inr hstack
    exact lower_inv_εClosure h inv'
  next _ _ hn =>
    have inv' : LowerInvεClosure nfa (next.insert target) stack := by
      intro i j hi hj
      cases SparseSet.eq_or_mem_of_mem_insert hi with
      | inl htarget =>
        subst htarget
        simp [εStep, Node.εStep, hn] at hj
      | inr hnext =>
        match inv i j hnext hj with
        | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
        | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
        | .inr (.inr hstack) => exact .inr hstack
    exact lower_inv_εClosure h inv'
  next _ _ hn =>
    have inv' : LowerInvεClosure nfa (next.insert target) stack := by
      intro i j hi hj
      cases SparseSet.eq_or_mem_of_mem_insert hi with
      | inl htarget =>
        subst htarget
        simp [εStep, Node.εStep, hn] at hj
      | inr hnext =>
        match inv i j hnext hj with
        | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
        | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
        | .inr (.inr hstack) => exact .inr hstack
    exact lower_inv_εClosure h inv'
  next hn =>
    have inv' : LowerInvεClosure nfa (next.insert target) stack := by
      intro i j hi hj
      cases SparseSet.eq_or_mem_of_mem_insert hi with
      | inl htarget =>
        subst htarget
        simp [εStep, Node.εStep, hn] at hj
      | inr hnext =>
        match inv i j hnext hj with
        | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
        | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
        | .inr (.inr hstack) => exact .inr hstack
    exact lower_inv_εClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have inv' : LowerInvεClosure nfa next stack := by
  intro i j hi hj
  match inv i j hi hj with
  | .inl hnext => exact .inl hnext
  | .inr (.inl htarget) =>
    rw [←htarget] at hmem
    exact .inl hmem
  | .inr (.inr hstack) => exact .inr hstack
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
inv' : LowerInvεClosure nfa next stack
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
inv' : LowerInvεClosure nfa next stack
⊢ LowerInvεClosure nfa next' #[]
Tactic:
exact lower_inv_εClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next stack
Tactic:
intro i j hi hj
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next ∨ StackEntry.explore j ∈ stack

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next ∨ StackEntry.explore j ∈ stack
Tactic:
match inv i j hi hj with
| .inl hnext => exact .inl hnext
| .inr (.inl htarget) =>
  rw [←htarget] at hmem
  exact .inl hmem
| .inr (.inr hstack) => exact .inr hstack
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next
hj : ↑j ∈ nfa.εStep ↑i
hnext : j ∈ next
⊢ j ∈ next ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl hnext
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next
hj : ↑j ∈ nfa.εStep ↑i
htarget : j = target
⊢ j ∈ next ∨ StackEntry.explore j ∈ stack
Tactic:
rw [←htarget] at hmem
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hmem : j ∈ next
hi : i ∈ next
hj : ↑j ∈ nfa.εStep ↑i
htarget : j = target
⊢ j ∈ next ∨ StackEntry.explore j ∈ stack

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hmem : j ∈ next
hi : i ∈ next
hj : ↑j ∈ nfa.εStep ↑i
htarget : j = target
⊢ j ∈ next ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl hmem
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
hmem : target ∈ next
h : εClosure nfa pos next currentSave matched saveSlots stack = (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next
hj : ↑j ∈ nfa.εStep ↑i
hstack : StackEntry.explore j ∈ stack
⊢ j ∈ next ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inr hstack
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
h :
  (let next' := next.insert target;
    match hn : nfa[target] with
    | Node.epsilon target' =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.split target₁ target₂ =>
      let_fun isLt := ⋯;
      exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target₁, ⋯⟩
        (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
    | Node.save offset target' =>
      let_fun isLt := ⋯;
      if h : offset < currentSave.size then
        let nextSave := currentSave.set ⟨offset, h⟩ (some pos);
        let stack' := stack.push (StackEntry.restore currentSave);
        exploreεClosure nfa pos next' nextSave matched saveSlots ⟨target', isLt⟩ stack'
      else exploreεClosure nfa pos next' currentSave matched saveSlots ⟨target', isLt⟩ stack
    | Node.done =>
      let matched' := HOrElse.hOrElse matched fun x => some currentSave;
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched' saveSlots' stack
    | Node.char c next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.sparse cs next =>
      let saveSlots' := saveSlots.set ↑target ⋯ currentSave;
      εClosure nfa pos next' currentSave matched saveSlots' stack
    | Node.fail => εClosure nfa pos next' currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
simp at h
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
h :
  (match hn : nfa[↑target] with
    | Node.epsilon target' =>
      exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack
    | Node.split target₁ target₂ =>
      exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
        (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
    | Node.save offset target' =>
      if h : offset < currentSave.size then
        exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset, ⋯⟩ (some pos)) matched saveSlots
          ⟨target', ⋯⟩ (stack.push (StackEntry.restore currentSave))
      else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack
    | Node.done =>
      εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
        (saveSlots.set ↑target ⋯ currentSave) stack
    | Node.char c next_1 =>
      εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack
    | Node.sparse cs next_1 =>
      εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack
    | Node.fail => εClosure nfa pos (next.insert target) currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
h :
  (match hn : nfa[↑target] with
    | Node.epsilon target' =>
      exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack
    | Node.split target₁ target₂ =>
      exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
        (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
    | Node.save offset target' =>
      if h : offset < currentSave.size then
        exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset, ⋯⟩ (some pos)) matched saveSlots
          ⟨target', ⋯⟩ (stack.push (StackEntry.restore currentSave))
      else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack
    | Node.done =>
      εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
        (saveSlots.set ↑target ⋯ currentSave) stack
    | Node.char c next_1 =>
      εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack
    | Node.sparse cs next_1 =>
      εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack
    | Node.fail => εClosure nfa pos (next.insert target) currentSave matched saveSlots stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
split at h
State after:
case h_1
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target'✝ : ℕ
heq✝ : nfa[↑target] = Node.epsilon target'✝
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target'✝, ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_2
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁✝ target₂✝ : ℕ
heq✝ : nfa[↑target] = Node.split target₁✝ target₂✝
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁✝, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂✝, ⋯⟩)) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_3
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target'✝ : ℕ
heq✝ : nfa[↑target] = Node.save offset✝ target'✝
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target'✝, ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target'✝, ⋯⟩ stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_4
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case h_1
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target'✝ : ℕ
heq✝ : nfa[↑target] = Node.epsilon target'✝
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target'✝, ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_2
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁✝ target₂✝ : ℕ
heq✝ : nfa[↑target] = Node.split target₁✝ target₂✝
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁✝, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂✝, ⋯⟩)) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_3
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target'✝ : ℕ
heq✝ : nfa[↑target] = Node.save offset✝ target'✝
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target'✝, ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target'✝, ⋯⟩ stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_4
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next target' hn =>
  have isLt := nfa.inBounds' target hn
  have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack := by
    intro i j hi hj
    cases SparseSet.eq_or_mem_of_mem_insert hi with
    | inl htarget =>
      subst htarget
      simp [εStep, Node.εStep, hn] at hj
      exact .inr (.inl (Fin.eq_of_val_eq hj))
    | inr hnext =>
      match inv i j hnext hj with
      | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
      | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
      | .inr (.inr hstack) => exact .inr (.inr hstack)
  exact lower_inv_exploreεClosure h inv'
State after:
case h_2
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁✝ target₂✝ : ℕ
heq✝ : nfa[↑target] = Node.split target₁✝ target₂✝
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁✝, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂✝, ⋯⟩)) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_3
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target'✝ : ℕ
heq✝ : nfa[↑target] = Node.save offset✝ target'✝
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target'✝, ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target'✝, ⋯⟩ stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_4
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case h_2
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁✝ target₂✝ : ℕ
heq✝ : nfa[↑target] = Node.split target₁✝ target₂✝
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁✝, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂✝, ⋯⟩)) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_3
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target'✝ : ℕ
heq✝ : nfa[↑target] = Node.save offset✝ target'✝
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target'✝, ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target'✝, ⋯⟩ stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_4
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next target₁ target₂ hn =>
  have isLt := nfa.inBounds' target hn
  have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target₁, isLt.1⟩ (stack.push (.explore ⟨target₂, isLt.2⟩)) := by
    intro i j hi hj
    cases SparseSet.eq_or_mem_of_mem_insert hi with
    | inl htarget =>
      subst htarget
      simp [εStep, Node.εStep, hn] at hj
      cases hj with
      | inl hj => exact .inr (.inl (Fin.eq_of_val_eq hj))
      | inr hj => exact .inr (.inr ((Array.mem_push ..).mpr (.inr (by simp [hj.symm]))))
    | inr hnext =>
      match inv i j hnext hj with
      | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
      | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
      | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
  exact lower_inv_exploreεClosure h inv'
State after:
case h_3
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target'✝ : ℕ
heq✝ : nfa[↑target] = Node.save offset✝ target'✝
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target'✝, ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target'✝, ⋯⟩ stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_4
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case h_3
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target'✝ : ℕ
heq✝ : nfa[↑target] = Node.save offset✝ target'✝
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target'✝, ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target'✝, ⋯⟩ stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_4
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next _ target' hn =>
  have isLt := nfa.inBounds' target hn
  split at h
  next =>
    have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ (stack.push (.restore currentSave)) := by
      intro i j hi hj
      cases SparseSet.eq_or_mem_of_mem_insert hi with
      | inl htarget =>
        subst htarget
        simp [εStep, Node.εStep, hn] at hj
        exact .inr (.inl (Fin.eq_of_val_eq hj))
      | inr hnext =>
        match inv i j hnext hj with
        | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
        | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
        | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
    exact lower_inv_exploreεClosure h inv'
  next =>
    have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack := by
      intro i j hi hj
      cases SparseSet.eq_or_mem_of_mem_insert hi with
      | inl htarget =>
        subst htarget
        simp [εStep, Node.εStep, hn] at hj
        exact .inr (.inl (Fin.eq_of_val_eq hj))
      | inr hnext =>
        match inv i j hnext hj with
        | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
        | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
        | .inr (.inr hstack) => exact .inr (.inr hstack)
    exact lower_inv_exploreεClosure h inv'
State after:
case h_4
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case h_4
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next hn =>
  have inv' : LowerInvεClosure nfa (next.insert target) stack := by
    intro i j hi hj
    cases SparseSet.eq_or_mem_of_mem_insert hi with
    | inl htarget =>
      subst htarget
      simp [εStep, Node.εStep, hn] at hj
    | inr hnext =>
      match inv i j hnext hj with
      | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
      | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
      | .inr (.inr hstack) => exact .inr hstack
  exact lower_inv_εClosure h inv'
State after:
case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case h_5
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
heq✝ : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next _ _ hn =>
  have inv' : LowerInvεClosure nfa (next.insert target) stack := by
    intro i j hi hj
    cases SparseSet.eq_or_mem_of_mem_insert hi with
    | inl htarget =>
      subst htarget
      simp [εStep, Node.εStep, hn] at hj
    | inr hnext =>
      match inv i j hnext hj with
      | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
      | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
      | .inr (.inr hstack) => exact .inr hstack
  exact lower_inv_εClosure h inv'
State after:
case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case h_6
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
heq✝ : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next _ _ hn =>
  have inv' : LowerInvεClosure nfa (next.insert target) stack := by
    intro i j hi hj
    cases SparseSet.eq_or_mem_of_mem_insert hi with
    | inl htarget =>
      subst htarget
      simp [εStep, Node.εStep, hn] at hj
    | inr hnext =>
      match inv i j hnext hj with
      | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
      | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
      | .inr (.inr hstack) => exact .inr hstack
  exact lower_inv_εClosure h inv'
State after:
case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case h_7
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
heq✝ : nfa[↑target] = Node.fail
h : εClosure nfa pos (next.insert target) currentSave matched saveSlots stack = (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next hn =>
  have inv' : LowerInvεClosure nfa (next.insert target) stack := by
    intro i j hi hj
    cases SparseSet.eq_or_mem_of_mem_insert hi with
    | inl htarget =>
      subst htarget
      simp [εStep, Node.εStep, hn] at hj
    | inr hnext =>
      match inv i j hnext hj with
      | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
      | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
      | .inr (.inr hstack) => exact .inr hstack
  exact lower_inv_εClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have isLt := nfa.inBounds' target hn
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack := by
  intro i j hi hj
  cases SparseSet.eq_or_mem_of_mem_insert hi with
  | inl htarget =>
    subst htarget
    simp [εStep, Node.εStep, hn] at hj
    exact .inr (.inl (Fin.eq_of_val_eq hj))
  | inr hnext =>
    match inv i j hnext hj with
    | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
    | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
    | .inr (.inr hstack) => exact .inr (.inr hstack)
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack
⊢ LowerInvεClosure nfa next' #[]
Tactic:
exact lower_inv_exploreεClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
⊢ LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack
Tactic:
intro i j hi hj
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
cases SparseSet.eq_or_mem_of_mem_insert hi with
| inl htarget =>
  subst htarget
  simp [εStep, Node.εStep, hn] at hj
  exact .inr (.inl (Fin.eq_of_val_eq hj))
| inr hnext =>
  match inv i j hnext hj with
  | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
  | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
  | .inr (.inr hstack) => exact .inr (.inr hstack)
State after:
no goals

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
htarget : i = target
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
subst htarget
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target' : ℕ
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target' : ℕ
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
simp [εStep, Node.εStep, hn] at hj
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target' : ℕ
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target'
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target' : ℕ
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target'
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inr (.inl (Fin.eq_of_val_eq hj))
State after:
no goals

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
match inv i j hnext hj with
| .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
| .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
| .inr (.inr hstack) => exact .inr (.inr hstack)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext✝ : i ∈ next
hnext : j ∈ next
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (SparseSet.mem_insert_of_mem hnext)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
htarget : j = target
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (htarget ▸ SparseSet.mem_insert)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target' : ℕ
hn : nfa[↑target] = Node.epsilon target'
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
isLt : (Node.epsilon target').inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
hstack : StackEntry.explore j ∈ stack
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inr (.inr hstack)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have isLt := nfa.inBounds' target hn
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target₁, isLt.1⟩ (stack.push (.explore ⟨target₂, isLt.2⟩)) := by
  intro i j hi hj
  cases SparseSet.eq_or_mem_of_mem_insert hi with
  | inl htarget =>
    subst htarget
    simp [εStep, Node.εStep, hn] at hj
    cases hj with
    | inl hj => exact .inr (.inl (Fin.eq_of_val_eq hj))
    | inr hj => exact .inr (.inr ((Array.mem_push ..).mpr (.inr (by simp [hj.symm]))))
  | inr hnext =>
    match inv i j hnext hj with
    | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
    | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
    | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target₁, ⋯⟩ (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target₁, ⋯⟩ (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
⊢ LowerInvεClosure nfa next' #[]
Tactic:
exact lower_inv_exploreεClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
⊢ LowerInvExploreεClosure nfa (next.insert target) ⟨target₁, ⋯⟩ (stack.push (StackEntry.explore ⟨target₂, ⋯⟩))
Tactic:
intro i j hi hj
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
cases SparseSet.eq_or_mem_of_mem_insert hi with
| inl htarget =>
  subst htarget
  simp [εStep, Node.εStep, hn] at hj
  cases hj with
  | inl hj => exact .inr (.inl (Fin.eq_of_val_eq hj))
  | inr hj => exact .inr (.inr ((Array.mem_push ..).mpr (.inr (by simp [hj.symm]))))
| inr hnext =>
  match inv i j hnext hj with
  | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
  | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
  | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
State after:
no goals

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
htarget : i = target
⊢ j ∈ next.insert target ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
subst htarget
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target₁ target₂ : ℕ
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target₁ target₂ : ℕ
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
simp [εStep, Node.εStep, hn] at hj
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target₁ target₂ : ℕ
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target₁ ∨ ↑j = target₂
⊢ j ∈ next.insert i ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target₁ target₂ : ℕ
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target₁ ∨ ↑j = target₂
⊢ j ∈ next.insert i ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
cases hj with
| inl hj => exact .inr (.inl (Fin.eq_of_val_eq hj))
| inr hj => exact .inr (.inr ((Array.mem_push ..).mpr (.inr (by simp [hj.symm]))))
State after:
no goals

State before:
case inl.inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target₁ target₂ : ℕ
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target₁
⊢ j ∈ next.insert i ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
exact .inr (.inl (Fin.eq_of_val_eq hj))
State after:
no goals

State before:
case inl.inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target₁ target₂ : ℕ
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target₂
⊢ j ∈ next.insert i ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
exact .inr (.inr ((Array.mem_push ..).mpr (.inr (by simp [hj.symm]))))
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target₁ target₂ : ℕ
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target₂
⊢ StackEntry.explore j = StackEntry.explore ⟨target₂, ⋯⟩
Tactic:
simp [hj.symm]
State after:
no goals

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
⊢ j ∈ next.insert target ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
match inv i j hnext hj with
| .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
| .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
| .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext✝ : i ∈ next
hnext : j ∈ next
⊢ j ∈ next.insert target ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
exact .inl (SparseSet.mem_insert_of_mem hnext)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
htarget : j = target
⊢ j ∈ next.insert target ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
exact .inl (htarget ▸ SparseSet.mem_insert)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
target₁ target₂ : ℕ
hn : nfa[↑target] = Node.split target₁ target₂
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target₁, ⋯⟩
      (stack.push (StackEntry.explore ⟨target₂, ⋯⟩)) =
    (matched', next', saveSlots')
isLt : (Node.split target₁ target₂).inBounds nfa.nodes.size
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
hstack : StackEntry.explore j ∈ stack
⊢ j ∈ next.insert target ∨ j = ⟨target₁, ⋯⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.explore ⟨target₂, ⋯⟩)
Tactic:
exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target', ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have isLt := nfa.inBounds' target hn
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target', ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack) =
    (matched', next', saveSlots')
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
h :
  (if h : offset✝ < currentSave.size then
      exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots
        ⟨target', ⋯⟩ (stack.push (StackEntry.restore currentSave))
    else exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack) =
    (matched', next', saveSlots')
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
⊢ LowerInvεClosure nfa next' #[]
Tactic:
split at h
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next =>
  have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ (stack.push (.restore currentSave)) := by
    intro i j hi hj
    cases SparseSet.eq_or_mem_of_mem_insert hi with
    | inl htarget =>
      subst htarget
      simp [εStep, Node.εStep, hn] at hj
      exact .inr (.inl (Fin.eq_of_val_eq hj))
    | inr hnext =>
      match inv i j hnext hj with
      | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
      | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
      | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
  exact lower_inv_exploreεClosure h inv'
State after:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
next =>
  have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack := by
    intro i j hi hj
    cases SparseSet.eq_or_mem_of_mem_insert hi with
    | inl htarget =>
      subst htarget
      simp [εStep, Node.εStep, hn] at hj
      exact .inr (.inl (Fin.eq_of_val_eq hj))
    | inr hnext =>
      match inv i j hnext hj with
      | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
      | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
      | .inr (.inr hstack) => exact .inr (.inr hstack)
  exact lower_inv_exploreεClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ (stack.push (.restore currentSave)) := by
  intro i j hi hj
  cases SparseSet.eq_or_mem_of_mem_insert hi with
  | inl htarget =>
    subst htarget
    simp [εStep, Node.εStep, hn] at hj
    exact .inr (.inl (Fin.eq_of_val_eq hj))
  | inr hnext =>
    match inv i j hnext hj with
    | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
    | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
    | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ (stack.push (StackEntry.restore currentSave))
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ (stack.push (StackEntry.restore currentSave))
⊢ LowerInvεClosure nfa next' #[]
Tactic:
exact lower_inv_exploreεClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
⊢ LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ (stack.push (StackEntry.restore currentSave))
Tactic:
intro i j hi hj
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)
Tactic:
cases SparseSet.eq_or_mem_of_mem_insert hi with
| inl htarget =>
  subst htarget
  simp [εStep, Node.εStep, hn] at hj
  exact .inr (.inl (Fin.eq_of_val_eq hj))
| inr hnext =>
  match inv i j hnext hj with
  | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
  | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
  | .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
State after:
no goals

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
htarget : i = target
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)
Tactic:
subst htarget
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
offset✝ target' : ℕ
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝¹ : offset✝ < currentSave.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.save offset✝ target'
h :
  exploreεClosure nfa pos (next.insert i) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
offset✝ target' : ℕ
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝¹ : offset✝ < currentSave.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.save offset✝ target'
h :
  exploreεClosure nfa pos (next.insert i) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)
Tactic:
simp [εStep, Node.εStep, hn] at hj
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
offset✝ target' : ℕ
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝¹ : offset✝ < currentSave.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.save offset✝ target'
h :
  exploreεClosure nfa pos (next.insert i) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target'
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
offset✝ target' : ℕ
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝¹ : offset✝ < currentSave.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.save offset✝ target'
h :
  exploreεClosure nfa pos (next.insert i) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target'
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)
Tactic:
exact .inr (.inl (Fin.eq_of_val_eq hj))
State after:
no goals

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)
Tactic:
match inv i j hnext hj with
| .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
| .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
| .inr (.inr hstack) => exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext✝ : i ∈ next
hnext : j ∈ next
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)
Tactic:
exact .inl (SparseSet.mem_insert_of_mem hnext)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
htarget : j = target
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)
Tactic:
exact .inl (htarget ▸ SparseSet.mem_insert)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) (currentSave.set ⟨offset✝, ⋯⟩ (some pos)) matched saveSlots ⟨target', ⋯⟩
      (stack.push (StackEntry.restore currentSave)) =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
hstack : StackEntry.explore j ∈ stack
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack.push (StackEntry.restore currentSave)
Tactic:
exact .inr (.inr ((Array.mem_push ..).mpr (.inl hstack)))
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack := by
  intro i j hi hj
  cases SparseSet.eq_or_mem_of_mem_insert hi with
  | inl htarget =>
    subst htarget
    simp [εStep, Node.εStep, hn] at hj
    exact .inr (.inl (Fin.eq_of_val_eq hj))
  | inr hnext =>
    match inv i j hnext hj with
    | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
    | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
    | .inr (.inr hstack) => exact .inr (.inr hstack)
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
inv' : LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack
⊢ LowerInvεClosure nfa next' #[]
Tactic:
exact lower_inv_exploreεClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
⊢ LowerInvExploreεClosure nfa (next.insert target) ⟨target', isLt⟩ stack
Tactic:
intro i j hi hj
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
cases SparseSet.eq_or_mem_of_mem_insert hi with
| inl htarget =>
  subst htarget
  simp [εStep, Node.εStep, hn] at hj
  exact .inr (.inl (Fin.eq_of_val_eq hj))
| inr hnext =>
  match inv i j hnext hj with
  | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
  | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
  | .inr (.inr hstack) => exact .inr (.inr hstack)
State after:
no goals

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
htarget : i = target
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
subst htarget
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
offset✝ target' : ℕ
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝¹ : ¬offset✝ < currentSave.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.save offset✝ target'
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
offset✝ target' : ℕ
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝¹ : ¬offset✝ < currentSave.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.save offset✝ target'
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
simp [εStep, Node.εStep, hn] at hj
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
offset✝ target' : ℕ
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝¹ : ¬offset✝ < currentSave.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.save offset✝ target'
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target'
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
offset✝ target' : ℕ
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝¹ : ¬offset✝ < currentSave.size
i j : Fin nfa.nodes.size
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.save offset✝ target'
h :
  exploreεClosure nfa pos (next.insert i) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
hj : ↑j = target'
⊢ j ∈ next.insert i ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inr (.inl (Fin.eq_of_val_eq hj))
State after:
no goals

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
match inv i j hnext hj with
| .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
| .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
| .inr (.inr hstack) => exact .inr (.inr hstack)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext✝ : i ∈ next
hnext : j ∈ next
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (SparseSet.mem_insert_of_mem hnext)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
htarget : j = target
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (htarget ▸ SparseSet.mem_insert)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝¹ : target ∉ next
offset✝ target' : ℕ
hn : nfa[↑target] = Node.save offset✝ target'
isLt : (Node.save offset✝ target').inBounds nfa.nodes.size
h✝ : ¬offset✝ < currentSave.size
h :
  exploreεClosure nfa pos (next.insert target) currentSave matched saveSlots ⟨target', ⋯⟩ stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
hstack : StackEntry.explore j ∈ stack
⊢ j ∈ next.insert target ∨ j = ⟨target', isLt⟩ ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inr (.inr hstack)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have inv' : LowerInvεClosure nfa (next.insert target) stack := by
  intro i j hi hj
  cases SparseSet.eq_or_mem_of_mem_insert hi with
  | inl htarget =>
    subst htarget
    simp [εStep, Node.εStep, hn] at hj
  | inr hnext =>
    match inv i j hnext hj with
    | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
    | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
    | .inr (.inr hstack) => exact .inr hstack
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
inv' : LowerInvεClosure nfa (next.insert target) stack
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
inv' : LowerInvεClosure nfa (next.insert target) stack
⊢ LowerInvεClosure nfa next' #[]
Tactic:
exact lower_inv_εClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa (next.insert target) stack
Tactic:
intro i j hi hj
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
cases SparseSet.eq_or_mem_of_mem_insert hi with
| inl htarget =>
  subst htarget
  simp [εStep, Node.εStep, hn] at hj
| inr hnext =>
  match inv i j hnext hj with
  | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
  | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
  | .inr (.inr hstack) => exact .inr hstack
State after:
no goals

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
htarget : i = target
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
subst htarget
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.done
h :
  εClosure nfa pos (next.insert i) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑i ⋯ currentSave) stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ StackEntry.explore j ∈ stack

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.done
h :
  εClosure nfa pos (next.insert i) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑i ⋯ currentSave) stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ StackEntry.explore j ∈ stack
Tactic:
simp [εStep, Node.εStep, hn] at hj
State after:
no goals

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
match inv i j hnext hj with
| .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
| .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
| .inr (.inr hstack) => exact .inr hstack
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext✝ : i ∈ next
hnext : j ∈ next
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (SparseSet.mem_insert_of_mem hnext)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
htarget : j = target
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (htarget ▸ SparseSet.mem_insert)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
hn : nfa[↑target] = Node.done
h :
  εClosure nfa pos (next.insert target) currentSave (HOrElse.hOrElse matched fun x => some currentSave)
      (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
hstack : StackEntry.explore j ∈ stack
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inr hstack
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have inv' : LowerInvεClosure nfa (next.insert target) stack := by
  intro i j hi hj
  cases SparseSet.eq_or_mem_of_mem_insert hi with
  | inl htarget =>
    subst htarget
    simp [εStep, Node.εStep, hn] at hj
  | inr hnext =>
    match inv i j hnext hj with
    | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
    | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
    | .inr (.inr hstack) => exact .inr hstack
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
inv' : LowerInvεClosure nfa (next.insert target) stack
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
inv' : LowerInvεClosure nfa (next.insert target) stack
⊢ LowerInvεClosure nfa next' #[]
Tactic:
exact lower_inv_εClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa (next.insert target) stack
Tactic:
intro i j hi hj
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
cases SparseSet.eq_or_mem_of_mem_insert hi with
| inl htarget =>
  subst htarget
  simp [εStep, Node.εStep, hn] at hj
| inr hnext =>
  match inv i j hnext hj with
  | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
  | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
  | .inr (.inr hstack) => exact .inr hstack
State after:
no goals

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
htarget : i = target
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
subst htarget
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
c✝ : Char
next✝ : ℕ
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert i) currentSave matched (saveSlots.set ↑i ⋯ currentSave) stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ StackEntry.explore j ∈ stack

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
c✝ : Char
next✝ : ℕ
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert i) currentSave matched (saveSlots.set ↑i ⋯ currentSave) stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ StackEntry.explore j ∈ stack
Tactic:
simp [εStep, Node.εStep, hn] at hj
State after:
no goals

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
match inv i j hnext hj with
| .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
| .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
| .inr (.inr hstack) => exact .inr hstack
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext✝ : i ∈ next
hnext : j ∈ next
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (SparseSet.mem_insert_of_mem hnext)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
htarget : j = target
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (htarget ▸ SparseSet.mem_insert)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
c✝ : Char
next✝ : ℕ
hn : nfa[↑target] = Node.char c✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
hstack : StackEntry.explore j ∈ stack
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inr hstack
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa next' #[]
Tactic:
have inv' : LowerInvεClosure nfa (next.insert target) stack := by
  intro i j hi hj
  cases SparseSet.eq_or_mem_of_mem_insert hi with
  | inl htarget =>
    subst htarget
    simp [εStep, Node.εStep, hn] at hj
  | inr hnext =>
    match inv i j hnext hj with
    | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
    | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
    | .inr (.inr hstack) => exact .inr hstack
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
inv' : LowerInvεClosure nfa (next.insert target) stack
⊢ LowerInvεClosure nfa next' #[]

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
inv' : LowerInvεClosure nfa (next.insert target) stack
⊢ LowerInvεClosure nfa next' #[]
Tactic:
exact lower_inv_εClosure h inv'
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
⊢ LowerInvεClosure nfa (next.insert target) stack
Tactic:
intro i j hi hj
State after:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
cases SparseSet.eq_or_mem_of_mem_insert hi with
| inl htarget =>
  subst htarget
  simp [εStep, Node.εStep, hn] at hj
| inr hnext =>
  match inv i j hnext hj with
  | .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
  | .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
  | .inr (.inr hstack) => exact .inr hstack
State after:
no goals

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
htarget : i = target
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
subst htarget
State after:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
cs✝ : Data.Classes
next✝ : ℕ
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert i) currentSave matched (saveSlots.set ↑i ⋯ currentSave) stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ StackEntry.explore j ∈ stack

State before:
case inl
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
cs✝ : Data.Classes
next✝ : ℕ
i j : Fin nfa.nodes.size
hj : ↑j ∈ nfa.εStep ↑i
inv : LowerInvExploreεClosure nfa next i stack
h✝ : i ∉ next
hn : nfa[↑i] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert i) currentSave matched (saveSlots.set ↑i ⋯ currentSave) stack =
    (matched', next', saveSlots')
hi : i ∈ next.insert i
⊢ j ∈ next.insert i ∨ StackEntry.explore j ∈ stack
Tactic:
simp [εStep, Node.εStep, hn] at hj
State after:
no goals

State before:
case inr
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
match inv i j hnext hj with
| .inl hnext => exact .inl (SparseSet.mem_insert_of_mem hnext)
| .inr (.inl htarget) => exact .inl (htarget ▸ SparseSet.mem_insert)
| .inr (.inr hstack) => exact .inr hstack
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext✝ : i ∈ next
hnext : j ∈ next
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (SparseSet.mem_insert_of_mem hnext)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
htarget : j = target
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inl (htarget ▸ SparseSet.mem_insert)
State after:
no goals

State before:
nfa : NFA
pos : String.Pos
next : SparseSet nfa.nodes.size
currentSave : Array (Option String.Pos)
matched : Option (Array (Option String.Pos))
saveSlots : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
target : Fin nfa.nodes.size
stack : Array (StackEntry nfa.nodes.size)
matched' : Option (Array (Option String.Pos))
next' : SparseSet nfa.nodes.size
saveSlots' : Data.Vec (Array (Option String.Pos)) nfa.nodes.size
inv : LowerInvExploreεClosure nfa next target stack
h✝ : target ∉ next
cs✝ : Data.Classes
next✝ : ℕ
hn : nfa[↑target] = Node.sparse cs✝ next✝
h :
  εClosure nfa pos (next.insert target) currentSave matched (saveSlots.set ↑target ⋯ currentSave) stack =
    (matched', next', saveSlots')
i j : Fin nfa.nodes.size
hi : i ∈ next.insert target
hj : ↑j ∈ nfa.εStep ↑i
hnext : i ∈ next
hstack : StackEntry.explore j ∈ stack
⊢ j ∈ next.insert target ∨ StackEntry.explore j ∈ stack
Tactic:
exact .inr hstack
State after:
no goals