File size: 3,249 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
import Mathlib
import OAI.Computability.VertexCover.Reduction.PrivateTotalEnergyLaw
import OAI.Computability.VertexCover.Reduction.PrivateProjectionBatchLower

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.LabelCover
open MeasureTheory ProbabilityTheory
open VertexCover.Restriction
open EnergyForm.Projection
open scoped BigOperators

theorem restrictionFunction_energy_variance (Φ : LabelCover) {d : ℕ}
    (A : Finset (Φ.Coordinate d → ℝ)) (hA : A.Nonempty) :
    (Φ.restrictionForm d).energy (Φ.restrictionFunction A hA) =
      VertexCover.finiteMean (fun seed : Φ.Seeds d =>
        variance (fun s => Φ.separator A hA (Φ.continuousSum seed s))
          (VertexCover.Cube.blockLaw (Fin d) (Fin (Φ.WeightDimension d)))) := by
  rw [restrictionForm_energy]
  apply congrArg VertexCover.finiteMean
  funext seed
  rw [variance_eq_integral
    (Φ.separator_continuousSum_continuous A hA seed).measurable.aemeasurable,
    Φ.separator_continuousSum_mean_zero]
  simp only [sub_zero, restrictionFunction_apply]
  exact CompactCube.integral_realWeights
    ((Φ.separator_continuousSum_continuous A hA seed).pow 2).measurable.aestronglyMeasurable

theorem restriction_frozen_exists (Φ : LabelCover) {d h : ℕ}
    (hd : 4 ≤ d) (hh : 3 ≤ h) (hhd : h ≤ d) (ν : ℝ) (hν : 0 < ν)
    (hscale : 16*(h:ℝ)+32*(h:ℝ)^2 ≤ ν*d/2)
    (A : Finset (Φ.Coordinate d → ℝ)) (hA : A.Nonempty)
    (henergy : ν*d ≤ (Φ.restrictionForm d).energy (Φ.restrictionFunction A hA)) :
    ∃ J : Finset (Fin d), J.card = h ∧ ∃ frozen : Φ.Seeds d,
      ∃ s : Φ.RestrictionWeights d,
        ν*h/4 ≤ Φ.ownTotalVariance J frozen
          (Φ.outsideSum J frozen (CompactCube.realWeights s)) A hA := by
  classical
  have : Nonempty (Fin Φ.M) := ⟨⟨0, Φ.M_pos⟩⟩
  by_contra hno
  push Not at hno
  have hbound (J : Finset (Fin d)) (hJ : J ∈ batches d h) :
      (∑ j ∈ J, (Φ.restrictionForm d).energy
        (Φ.privateProjection J j (Φ.restrictionFunction A hA))) ≤ ν*h/4 := by
    rw [← Finset.sum_coe_sort J, Φ.privateTotal_energy_law J A hA]
    calc
      _ ≤ VertexCover.finiteMean (fun _ : Φ.Seeds d => ν*h/4) := by
        apply VertexCover.finiteMean_mono
        intro frozen
        have hb := integral_mono (Φ.ownTotalVariance_frozen_integrable J frozen A hA)
          (integrable_const (ν*h/4))
          (fun s => (hno J (mem_batches.mp hJ) frozen s).le)
        simpa using hb
      _ = _ := VertexCover.finiteMean_const _
  have hsum := Finset.sum_le_sum hbound
  have hl := Φ.privateProjection_batch_lower hd hh ν hscale A hA henergy
  simp only [Finset.sum_const, nsmul_eq_mul, card_batches] at hsum
  have hpos : 0 < (d.choose h:ℝ)*ν*h :=
    mul_pos (mul_pos (Nat.cast_pos.mpr (Nat.choose_pos hhd)) hν)
      (Nat.cast_pos.mpr (by omega))
  linarith

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