File size: 7,744 Bytes
e63eb7f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import OAI.Combinatorics.EditApproximation.Numerics.VectorOptimizerWork
import OAI.Combinatorics.EditApproximation.Geometry.WideActions
import OAI.Combinatorics.EditApproximation.Geometry.BandDimension
import OAI.Combinatorics.EditApproximation.Definitions


namespace OAI

/-! Literal finite enumeration with counters. Each callback is evaluated
once and its returned work is charged; list cells and copied output cells
are charged separately. -/

namespace EditApproximation



theorem arithmeticMapWithWork_value {α β : Type*} (f : α → β × ℕ) (values : List α) :
    (arithmeticMapWithWork f values).1 = values.map (fun a => (f a).1) := by
  induction values with
  | nil => rfl
  | cons a rest ih => simp only [arithmeticMapWithWork, ih, List.map_cons]

theorem arithmeticMapWithWork_cost {α β : Type*} (f : α → β × ℕ) (values : List α)
    (C : ℕ) (hC : ∀ a ∈ values, (f a).2 ≤ C) :
    (arithmeticMapWithWork f values).2 ≤ values.length * (C + 3) := by
  induction values with
  | nil => simp only [arithmeticMapWithWork, List.length_nil, Nat.zero_mul, le_refl]
  | cons a rest ih =>
    have ha := hC a List.mem_cons_self
    have htail := ih (fun b hb => hC b (List.mem_cons_of_mem a hb))
    simp only [arithmeticMapWithWork, List.length_cons]
    nlinarith only [ha, htail]



theorem arithmeticFlatMapWithWork_value {α β : Type*} (f : α → List β × ℕ) (values : List α) :
    (arithmeticFlatMapWithWork f values).1 = values.flatMap (fun a => (f a).1) := by
  induction values with
  | nil => rfl
  | cons a rest ih => simp only [arithmeticFlatMapWithWork, ih, List.flatMap_cons]

theorem arithmeticFlatMapWithWork_cost {α β : Type*} (f : α → List β × ℕ) (values : List α)
    (C L : ℕ) (hC : ∀ a ∈ values, (f a).2 ≤ C) (hL : ∀ a ∈ values, (f a).1.length ≤ L) :
    (arithmeticFlatMapWithWork f values).2 ≤ values.length * (C + L + 3) := by
  induction values with
  | nil => simp only [arithmeticFlatMapWithWork, List.length_nil, Nat.zero_mul, le_refl]
  | cons a rest ih =>
    have ha := hC a List.mem_cons_self
    have hla := hL a List.mem_cons_self
    have htail := ih (fun b hb => hC b (List.mem_cons_of_mem a hb))
      (fun b hb => hL b (List.mem_cons_of_mem a hb))
    simp only [arithmeticFlatMapWithWork, List.length_cons]
    nlinarith only [ha, hla, htail]

/-- Each complete assignment is stored in an array, so later coordinate
access is constant time. The recursive tail is constructed once. -/


theorem materializedAssignmentsWithWork_value {α : Type*} (M : ℕ) (choices : Fin M → List α) :
    ((materializedAssignmentsWithWork M choices).1.map Vector.get) = finiteAssignments M choices := by
  have hget {m : ℕ} (f : Fin m → α) : (Vector.ofFn f).get = f := funext (vector_get_ofFn f)
  induction M with
  | zero => simp only [materializedAssignmentsWithWork, finiteAssignments, List.map_cons,
      List.map_nil, hget]
  | succ M ih =>
    simp only [materializedAssignmentsWithWork, arithmeticFlatMapWithWork_value,
      arithmeticMapWithWork_value, List.map_flatMap, List.map_map, Function.comp_def, hget]
    unfold finiteAssignments
    apply List.flatMap_congr
    intro head _
    rw [← ih (fun i => choices i.succ), List.map_map]
    rfl

theorem materializedAssignmentsWithWork_cost {α : Type*} (M K : ℕ)
    (choices : Fin M → List α) (hchoices : ∀ i, (choices i).length ≤ K) :
    (materializedAssignmentsWithWork M choices).2 ≤
      (M + 1) * (6 * M + 10) * (K + 1) ^ (M + 1) := by
  induction M with
  | zero =>
    simp only [materializedAssignmentsWithWork, Nat.zero_add, Nat.mul_zero, pow_one, Nat.one_mul]
    omega
  | succ M ih =>
    let previous := materializedAssignmentsWithWork M (fun i => choices i.succ)
    have hprevious := ih (fun i => choices i.succ) (fun i => hchoices i.succ)
    have hlength : previous.1.length ≤ K ^ M := by
      have heq := congrArg List.length
        (materializedAssignmentsWithWork_value M (fun i => choices i.succ))
      simp only [List.length_map] at heq
      exact heq.trans_le (finiteAssignments_length_le M K _ (fun i => hchoices i.succ))
    have hmap (head : α) :
        (arithmeticMapWithWork (fun tail : Vector α M =>
          (Vector.ofFn (Fin.cons head tail.get), 3 * (M + 1))) previous.1).2 ≤
            previous.1.length * (3 * (M + 1) + 3) :=
      arithmeticMapWithWork_cost _ _ _ (fun _ _ => le_rfl)
    have hmaplength (head : α) :
        (arithmeticMapWithWork (fun tail : Vector α M =>
          (Vector.ofFn (Fin.cons head tail.get), 3 * (M + 1))) previous.1).1.length ≤
            previous.1.length := by
      rw [arithmeticMapWithWork_value, List.length_map]
    have hflat := arithmeticFlatMapWithWork_cost (fun head =>
      arithmeticMapWithWork (fun tail : Vector α M =>
        (Vector.ofFn (Fin.cons head tail.get), 3 * (M + 1))) previous.1) (choices 0)
      (previous.1.length * (3 * (M + 1) + 3)) previous.1.length
      (fun head _ => hmap head) (fun head _ => hmaplength head)
    have hchoice := hchoices 0
    have hL : previous.1.length ≤ (K + 1) ^ M :=
      hlength.trans (Nat.pow_le_pow_left (by omega) M)
    have hscale : K * (K + 1) ^ M ≤ (K + 1) ^ (M + 1) := by
      rw [pow_succ]
      nlinarith
    have hZ : K + 1 ≤ (K + 1) ^ (M + 1) := Nat.le_pow (by omega)
    have hexp : (K + 1) ^ (M + 1) ≤ (K + 1) ^ (M + 2) :=
      Nat.pow_le_pow_right (by omega) (by omega)
    have hexpanded :
        (arithmeticFlatMapWithWork (fun head =>
          arithmeticMapWithWork (fun tail : Vector α M =>
            (Vector.ofFn (Fin.cons head tail.get), 3 * (M + 1))) previous.1) (choices 0)).2 ≤
          (3 * M + 11) * (K + 1) ^ (M + 1) := by
      apply hflat.trans
      calc
        _ ≤ K * ((K + 1) ^ M * (3 * (M + 1) + 3) + (K + 1) ^ M + 3) :=
          Nat.mul_le_mul hchoice (by nlinarith only [hL])
        _ = (3 * M + 7) * (K * (K + 1) ^ M) + 3 * K := by ring
        _ ≤ (3 * M + 7) * (K + 1) ^ (M + 1) + 3 * K :=
          Nat.add_le_add_right (Nat.mul_le_mul_left _ hscale) _
        _ ≤ _ := by nlinarith only [hZ]
    change previous.2 + _ + 1 ≤ _
    have hcoefficient :
        (M + 1) * (6 * M + 10) + (3 * M + 11) + 1 ≤ (M + 2) * (6 * (M + 1) + 10) := by
      nlinarith
    have hone : 1 ≤ (K + 1) ^ (M + 1) := Nat.one_le_pow _ _ (by omega)
    calc
      _ ≤ ((M + 1) * (6 * M + 10) + (3 * M + 11) + 1) * (K + 1) ^ (M + 1) := by
        dsimp only [previous] at *
        nlinarith only [hprevious, hexpanded, hone]
      _ ≤ (M + 2) * (6 * (M + 1) + 10) * (K + 1) ^ (M + 2) :=
        Nat.mul_le_mul hcoefficient hexp
      _ = _ := by rfl

def materializedWideActionsWithWork {nx ny : ℕ} (M : ℕ) (parent : TargetInterval nx)
    (r : TargetInterval ny) (b P : ℕ) : List (Vector (TargetInterval ny) M) × ℕ :=
  materializedAssignmentsWithWork M (wideChildStateList parent r b P)

theorem materializedWideActionsWithWork_value {nx ny : ℕ} (M : ℕ) (parent : TargetInterval nx)
    (r : TargetInterval ny) (b P : ℕ) :
    ((materializedWideActionsWithWork M parent r b P).1.map Vector.get) =
      wideActionList M parent r b P :=
  materializedAssignmentsWithWork_value M _

/-- Cartesian-product construction after the endpoint lists are present.
Each returned action supports direct indexed reads from its stored array. -/
theorem materializedWideActionsWithWork_cost {nx ny : ℕ} (M : ℕ) (parent : TargetInterval nx)
    (r : TargetInterval ny) (b P : ℕ) (hP : 0 < P) :
    (materializedWideActionsWithWork M parent r b P).2 ≤
      (M + 1) * (6 * M + 10) * ((40 * P + 2) ^ 2 + 1) ^ (M + 1) :=
  materializedAssignmentsWithWork_cost M ((40 * P + 2) ^ 2) _
    (wideChildStateList_length_le parent r hP)

end EditApproximation

end OAI