File size: 3,863 Bytes
92416a2
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import Mathlib
import OAI.Computability.VertexCover.Analysis.DenseSeparatorData
import OAI.Computability.VertexCover.Reduction.RestrictionFrozen

namespace OAI

section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
section
namespace VertexCover.Parameters

theorem h_ge_three (m : ℕ) (hm : 0 < m) : 3 ≤ h m := by
  have hpow : 1 ≤ m^3 := one_le_pow₀ hm
  unfold h
  norm_num only [Nat.reducePow]
  omega

theorem private_variance_threshold (m : ℕ) (hm : 0 < m) : ν m*(h m:ℝ)/4 = 8 := by
  have hn : (m:ℝ) ≠ 0 := by positivity
  simp only [ν, h, Nat.cast_mul, Nat.cast_pow, Nat.cast_ofNat]
  field_simp
  norm_num

end VertexCover.Parameters

namespace VertexCover.LabelCover
open VertexCover.Restriction

theorem dense_privateVariance_lower (Φ : LabelCover) (m : ℕ) (hm : 4 ≤ m)
    (A : Finset (Φ.Vertex (Parameters.d m)))
    (hA : (Φ.graph (Parameters.d m) (Parameters.t m)).IsIndepSet
      (A : Set (Φ.Vertex (Parameters.d m))))
    (hdense : (Fintype.card (Φ.Vertex (Parameters.d m)):ℝ)/(m:ℝ) ≤ A.card) :
    ∃ hV : (Φ.highVectors (Parameters.t m) A).Nonempty,
      ∃ J : Finset (Fin (Parameters.d m)), J.card = Parameters.h m ∧
      ∃ frozen : Φ.Seeds (Parameters.d m),
      ∃ weights : Fin (Parameters.d m) → Fin (Φ.WeightDimension (Parameters.d m)) → ℝ,
        Φ.InWeightCube weights ∧
        8 ≤ Φ.ownTotalVariance J frozen (Φ.outsideSum J frozen weights)
          (Φ.highVectors (Parameters.t m) A) hV := by
  obtain ⟨hV, _hzero, henergy⟩ := Φ.dense_separator_data m hm A hA hdense
  rw [← Φ.restrictionFunction_energy_variance] at henergy
  have hdim := Parameters.dimensions m hm
  obtain ⟨J, hJ, frozen, s, hs⟩ := Φ.restriction_frozen_exists
    hdim.1 (Parameters.h_ge_three m (by omega)) hdim.2.2.1.le
    (Parameters.ν m) (Parameters.positive m (by omega)).1
    (Parameters.restriction_budget m hm) _ hV henergy
  refine ⟨hV, J, hJ, frozen, CompactCube.realWeights s, ?_, ?_⟩
  · intro j k
    exact abs_le.mpr (s j k).2
  · simpa only [Parameters.private_variance_threshold m (by omega)] using hs

theorem graph_soundness_independent (Φ : LabelCover) (m : ℕ) (hm : 4 ≤ m)
    (hval : Φ.value ≤ Parameters.σ m)
    (A : Finset (Φ.Vertex (Parameters.d m)))
    (hA : (Φ.graph (Parameters.d m) (Parameters.t m)).IsIndepSet
      (A : Set (Φ.Vertex (Parameters.d m)))) :
    (A.card:ℝ) < (Fintype.card (Φ.Vertex (Parameters.d m)):ℝ)/(m:ℝ) := by
  by_contra hn
  obtain ⟨hV, J, hJ, frozen, weights, _hw, hlow⟩ :=
    Φ.dense_privateVariance_lower m hm A hA (le_of_not_gt hn)
  have hu := Φ.ownTotalVariance_no_upper m hm hval J hJ frozen
    (Φ.outsideSum J frozen weights) _ hV
  linarith

theorem graph_soundness_cover (Φ : LabelCover) (m : ℕ) (hm : 4 ≤ m)
    (hval : Φ.value ≤ Parameters.σ m)
    (C : Finset (Φ.Vertex (Parameters.d m)))
    (hC : (Φ.graph (Parameters.d m) (Parameters.t m)).IsVertexCover
      (C : Set (Φ.Vertex (Parameters.d m)))) :
    (1-1/(m:ℝ)) * Fintype.card (Φ.Vertex (Parameters.d m)) < (C.card:ℝ) := by
  classical
  have hI : (Φ.graph (Parameters.d m) (Parameters.t m)).IsIndepSet
      (↑(Cᶜ) : Set (Φ.Vertex (Parameters.d m))) := by
    simpa only [Finset.coe_compl] using SimpleGraph.isIndepSet_compl_iff_isVertexCover.mpr hC
  have hi := Φ.graph_soundness_independent m hm hval Cᶜ hI
  rw [Finset.card_compl, Nat.cast_sub (Finset.card_le_univ C)] at hi
  simp only [div_eq_mul_inv, one_mul] at hi ⊢
  nlinarith

end VertexCover.LabelCover


end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end

end OAI