File size: 8,020 Bytes
760f90e
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
import Mathlib.Data.List.FinRange
import OAI.Computability.UniqueGames.Machines.FinalCNFMachineLemmas
import OAI.Computability.UniqueGames.Machines.FinalCNFRowPlanLemmas

namespace OAI

/-!
Exact row enumeration and input/output stream identities for the concrete
final-CNF machine. Rows occur in stored order, including repeated rows.
-/

namespace UniqueGamesTheorem.Foundations.Complexity.FinalCNFMachine.Program

open PCP PCP.AlphabetTable FinalCNFTableAdapter

/-- The actual unprocessed suffix of the finite table's stored row indices. -/
def remainingEvents (table : GraphTables.Table) (r : Nat) : List (Fin table.darts) :=
  (List.finRange table.darts).drop r

def processedEvents (table : GraphTables.Table) (r : Nat) : List (Fin table.darts) :=
  (List.finRange table.darts).take r

def inputStream (table : GraphTables.Table) (events : List (Fin table.darts)) : List Bool :=
  events.flatMap (fun e => encodeWords (GraphTables.rowWords table.rows[e]))

def outputStream (plan : Plan) (table : GraphTables.Table)
    (events : List (Fin table.darts)) : List Bool :=
  events.flatMap (fun e => plan.flatMap (Emitter.commandBits (rowOperands table e)
    (rowRelation table e)))

@[simp] theorem remainingEvents_zero (table : GraphTables.Table) :
    remainingEvents table 0 = List.finRange table.darts := by
  simp [remainingEvents]

@[simp] theorem remainingEvents_length (table : GraphTables.Table) (r : Nat) :
    (remainingEvents table r).length = table.darts - r := by
  simp [remainingEvents]

@[simp] theorem remainingEvents_done (table : GraphTables.Table) :
    remainingEvents table table.darts = [] := by
  simp [remainingEvents]

theorem remainingEvents_cons (table : GraphTables.Table) (r : Nat) (h : r < table.darts) :
    remainingEvents table r = ⟨r, h⟩ :: remainingEvents table (r + 1) := by
  unfold remainingEvents
  rw [List.drop_eq_getElem_cons (l := List.finRange table.darts) (i := r)
    (by simpa using h)]
  simp

@[simp] theorem processedEvents_zero (table : GraphTables.Table) :
    processedEvents table 0 = [] := by simp [processedEvents]

@[simp] theorem processedEvents_done (table : GraphTables.Table) :
    processedEvents table table.darts = List.finRange table.darts := by
  simp [processedEvents]

theorem processedEvents_succ (table : GraphTables.Table) (r : Nat) (h : r < table.darts) :
    processedEvents table (r + 1) = processedEvents table r ++ [⟨r, h⟩] := by
  unfold processedEvents
  rw [List.take_succ_eq_append_getElem (l := List.finRange table.darts) (i := r)
    (by simpa using h)]
  simp

theorem processed_append_remaining (table : GraphTables.Table) (r : Nat) :
    processedEvents table r ++ remainingEvents table r = List.finRange table.darts := by
  exact List.take_append_drop r (List.finRange table.darts)

@[simp] theorem inputStream_nil (table : GraphTables.Table) : inputStream table [] = [] := rfl

@[simp] theorem inputStream_cons (table : GraphTables.Table) (e : Fin table.darts)
    (events : List (Fin table.darts)) :
    inputStream table (e :: events) =
      encodeWords (GraphTables.rowWords table.rows[e]) ++ inputStream table events := rfl

@[simp] theorem inputStream_append (table : GraphTables.Table)
    (first rest : List (Fin table.darts)) :
    inputStream table (first ++ rest) = inputStream table first ++ inputStream table rest := by
  simp only [inputStream, List.flatMap_append]

@[simp] theorem outputStream_nil (plan : Plan) (table : GraphTables.Table) :
    outputStream plan table [] = [] := rfl

@[simp] theorem outputStream_cons (plan : Plan) (table : GraphTables.Table)
    (e : Fin table.darts) (events : List (Fin table.darts)) :
    outputStream plan table (e :: events) =
      plan.flatMap (Emitter.commandBits (rowOperands table e) (rowRelation table e)) ++
        outputStream plan table events := rfl

@[simp] theorem outputStream_append (plan : Plan) (table : GraphTables.Table)
    (first rest : List (Fin table.darts)) :
    outputStream plan table (first ++ rest) =
      outputStream plan table first ++ outputStream plan table rest := by
  simp only [outputStream, List.flatMap_append]

theorem inputStream_remaining_cons (table : GraphTables.Table) (r : Nat)
    (h : r < table.darts) :
    inputStream table (remainingEvents table r) =
      encodeWords (GraphTables.rowWords table.rows[(⟨r, h⟩ : Fin table.darts)]) ++
        inputStream table (remainingEvents table (r + 1)) := by
  rw [remainingEvents_cons table r h, inputStream_cons]

theorem outputStream_remaining_cons (plan : Plan) (table : GraphTables.Table) (r : Nat)
    (h : r < table.darts) :
    outputStream plan table (remainingEvents table r) =
      plan.flatMap (Emitter.commandBits (rowOperands table ⟨r, h⟩)
        (rowRelation table ⟨r, h⟩)) ++
          outputStream plan table (remainingEvents table (r + 1)) := by
  rw [remainingEvents_cons table r h, outputStream_cons]

theorem outputStream_processed_succ (plan : Plan) (table : GraphTables.Table) (r : Nat)
    (h : r < table.darts) :
    outputStream plan table (processedEvents table (r + 1)) =
      outputStream plan table (processedEvents table r) ++
        plan.flatMap (Emitter.commandBits (rowOperands table ⟨r, h⟩)
          (rowRelation table ⟨r, h⟩)) := by
  rw [processedEvents_succ table r h, outputStream_append]
  simp

theorem inputStream_split (table : GraphTables.Table) (r : Nat) :
    inputStream table (List.finRange table.darts) =
      inputStream table (processedEvents table r) ++
        inputStream table (remainingEvents table r) := by
  rw [← inputStream_append, processed_append_remaining]

theorem outputStream_split (plan : Plan) (table : GraphTables.Table) (r : Nat) :
    outputStream plan table (List.finRange table.darts) =
      outputStream plan table (processedEvents table r) ++
        outputStream plan table (remainingEvents table r) := by
  rw [← outputStream_append, processed_append_remaining]

private theorem encodeWords_flatMap_rows {α : Type} (rows : List α) (words : α → List Nat) :
    encodeWords (rows.flatMap words) = rows.flatMap (fun row => encodeWords (words row)) := by
  induction rows with
  | nil => rfl
  | cons row rows ih => simp only [List.flatMap_cons, encodeWords_append, ih]

theorem rowList_eq_finRange_map (table : GraphTables.Table) :
    GraphTables.rowList table = (List.finRange table.darts).map (fun e => table.rows[e]) := by
  rw [← List.ofFn_eq_map, ← Vector.toList_ofFn]
  change table.rows.toList = (Vector.ofFn (fun i => table.rows[i.val])).toList
  rw [Vector.ofFn_getElem]

/-- The stream starts at exactly the row suffix left by the checked header phase. -/
theorem inputStream_all (table : GraphTables.Table) :
    inputStream table (List.finRange table.darts) = tableRowsBits (genericTable table) := by
  rw [tableRowsBits, genericTable_rowList]
  erw [List.flatMap_map]
  have words : (fun row : GraphTables.DartRow table.vertices table.darts =>
      GenericGraphTables.rowWords (genericRow row)) = GraphTables.rowWords :=
    funext genericRow_words
  erw [words]
  rw [rowList_eq_finRange_map, List.flatMap_map, encodeWords_flatMap_rows]
  rfl

theorem inputStream_remaining_zero (table : GraphTables.Table) :
    inputStream table (remainingEvents table 0) = tableRowsBits (genericTable table) := by
  rw [remainingEvents_zero, inputStream_all]

/-- Pushing a row's reversed emission realizes extension of the forward prefix. -/
theorem outputStream_accumulator_succ (plan : Plan) (table : GraphTables.Table)
    (r : Nat) (h : r < table.darts) (header : List Bool) :
    (plan.flatMap (Emitter.commandBits (rowOperands table ⟨r, h⟩)
      (rowRelation table ⟨r, h⟩))).reverse ++
        (header ++ outputStream plan table (processedEvents table r)).reverse =
      (header ++ outputStream plan table (processedEvents table (r + 1))).reverse := by
  rw [outputStream_processed_succ plan table r h]
  simp only [List.reverse_append, List.append_assoc]

end UniqueGamesTheorem.Foundations.Complexity.FinalCNFMachine.Program

end OAI