File size: 8,216 Bytes
f61e547
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
173
174
175
176
177
178
179
180
181
182
183
import Mathlib

namespace OAI

noncomputable section

open Real

namespace Problem367

theorem log_sq_le_four_mul {I : ℝ} (hI : 1 ≤ I) :
    (Real.log I) ^ 2 ≤ 4 * I := by
  have hI0 : 0 ≤ I := le_trans zero_le_one hI
  have hlog0 : 0 ≤ Real.log I := Real.log_nonneg hI
  have hsqrt : 0 < Real.sqrt I := Real.sqrt_pos.2 (lt_of_lt_of_le zero_lt_one hI)
  have hlog := Real.log_le_sub_one_of_pos hsqrt
  rw [Real.log_sqrt hI0] at hlog
  have hle : Real.log I ≤ 2 * Real.sqrt I := by linarith
  nlinarith [Real.sq_sqrt hI0, sq_nonneg (2 * Real.sqrt I - Real.log I)]

theorem log_three_halves_le_four_mul {I : ℝ} (hI : 1 ≤ I) :
    (Real.log I) ^ ((3 : ℝ) / 2) ≤ 4 * I := by
  have hlog0 : 0 ≤ Real.log I := Real.log_nonneg hI
  by_cases hlog1 : Real.log I ≤ 1
  · have hpow : (Real.log I) ^ ((3 : ℝ) / 2) ≤ 1 :=
      Real.rpow_le_one hlog0 hlog1 (by norm_num)
    linarith
  · have hpow := Real.rpow_le_rpow_of_exponent_le (le_of_not_ge hlog1)
      (show (3 : ℝ) / 2 ≤ 2 by norm_num)
    exact hpow.trans (by simpa using log_sq_le_four_mul hI)

theorem sqrt_mul_sqrt_le_of_le_mul {S V C : ℝ}
    (_hS : 0 ≤ S) (hV : 0 ≤ V) (hC : 1 ≤ C) (hSV : S ≤ C * V) :
    Real.sqrt V * Real.sqrt S ≤ C * V := by
  have hC0 : 0 ≤ C := le_trans zero_le_one hC
  calc
    Real.sqrt V * Real.sqrt S = Real.sqrt (V * S) := (Real.sqrt_mul hV S).symm
    _ ≤ Real.sqrt (V * (C * V)) :=
      Real.sqrt_le_sqrt (mul_le_mul_of_nonneg_left hSV hV)
    _ = Real.sqrt C * V := by
      rw [Real.sqrt_mul hV, Real.sqrt_mul hC0]
      calc
        Real.sqrt V * (Real.sqrt C * Real.sqrt V) = Real.sqrt C * (Real.sqrt V)^2 := by ring
        _ = Real.sqrt C * V := by rw [Real.sq_sqrt hV]
    _ ≤ C * V := by
      gcongr
      exact Real.sqrt_le_self_iff.2 (Or.inr hC)

theorem endpoint_sums_critical_reduction
    {D Q L Z S V C H I R W : ℝ}
    (hC : 1 ≤ C) (hH : 1 ≤ H) (hI : 1 ≤ I)
    (hS : 0 ≤ S) (hV : 0 ≤ V) (hVH : V ≤ H)
    (hSV : S ≤ C * V) (hR : 0 ≤ R) (hW : 0 ≤ W)
    (hQ : Q ≤ C * (S * (R + (Real.log I)^2) + V^2))
    (hL : L ≤ C * (V * (W + Real.log I) + V^2))
    (hZ : Z ≤ C * (Real.sqrt S * (W + (Real.log I)^((3 : ℝ)/2)) + V))
    (hD : D ≤ C * (V + Q + L + Real.sqrt V * Z)) :
    D ≤ C^2 * (9*C + 3*H + 3) * (S*R + V*(I+W)) := by
  have hC0 : 0 ≤ C := le_trans zero_le_one hC
  have hH0 : 0 ≤ H := le_trans zero_le_one hH
  have hI0 : 0 ≤ I := le_trans zero_le_one hI
  have hlog0 : 0 ≤ Real.log I := Real.log_nonneg hI
  have hlog : Real.log I ≤ I := (Real.log_le_sub_one_of_pos (by linarith)).trans (by linarith)
  have hlog2 := log_sq_le_four_mul hI
  have hlog3 := log_three_halves_le_four_mul hI
  have hsqrt := sqrt_mul_sqrt_le_of_le_mul hS hV hC hSV
  have hsqrtV : Real.sqrt V ≤ H :=
    (Real.sqrt_le_sqrt hVH).trans (Real.sqrt_le_self_iff.2 (Or.inr hH))
  have hV2 : V^2 ≤ H*V := by nlinarith
  have hVI : V ≤ V*I := by nlinarith
  have hHV : H*V ≤ H*V*I := by nlinarith
  have hSlog : S * (Real.log I)^2 ≤ 4*C*V*I := by
    calc
      S * (Real.log I)^2 ≤ (C*V) * (4*I) := mul_le_mul hSV hlog2 (sq_nonneg _) (by positivity)
      _ = 4*C*V*I := by ring
  have hQ' : Q ≤ C*(S*R + (4*C+H)*V*I) := by
    have hstep : S*(R+(Real.log I)^2)+V^2 ≤ S*R+(4*C+H)*V*I := by
      nlinarith
    exact hQ.trans (mul_le_mul_of_nonneg_left hstep hC0)
  have hL' : L ≤ C*(V*W + (1+H)*V*I) := by
    have hstep : V*(W+Real.log I)+V^2 ≤ V*W+(1+H)*V*I := by
      have := mul_le_mul_of_nonneg_left hlog hV
      nlinarith
    exact hL.trans (mul_le_mul_of_nonneg_left hstep hC0)
  have hZ' : Real.sqrt V * Z ≤ C*(C*V*W+(4*C+H)*V*I) := by
    calc
      Real.sqrt V * Z ≤ Real.sqrt V * (C*(Real.sqrt S*(W+(Real.log I)^((3:ℝ)/2))+V)) :=
        mul_le_mul_of_nonneg_left hZ (Real.sqrt_nonneg _)
      _ = C*((Real.sqrt V*Real.sqrt S)*(W+(Real.log I)^((3:ℝ)/2)) + Real.sqrt V*V) := by ring
      _ ≤ C*((C*V)*(W+4*I)+H*V*I) := by
        apply mul_le_mul_of_nonneg_left _ hC0
        apply add_le_add
        · exact mul_le_mul hsqrt (add_le_add le_rfl hlog3)
            (add_nonneg hW (Real.rpow_nonneg hlog0 _)) (by positivity)
        · exact (mul_le_mul_of_nonneg_right hsqrtV hV).trans hHV
      _ = C*(C*V*W+(4*C+H)*V*I) := by ring
  have hstart : D ≤ C*(V+C*(S*R+(4*C+H)*V*I)+C*(V*W+(1+H)*V*I)+
      C*(C*V*W+(4*C+H)*V*I)) := by
    apply hD.trans
    gcongr
  have hscale : 0 ≤ S*R := mul_nonneg hS hR
  have hVI0 : 0 ≤ V*I := mul_nonneg hV hI0
  have hVW0 : 0 ≤ V*W := mul_nonneg hV hW
  have hC2 : C ≤ C^2 := by nlinarith
  have hCpos : 0 ≤ C^2 := sq_nonneg C
  have hCV : C*V ≤ C^2*(V*I) := mul_le_mul hC2 hVI hV hCpos
  have hcoef1 : 1 ≤ 9*C+3*H+3 := by linarith
  have hcoef2 : 8*C+3*H+2 ≤ 9*C+3*H+3 := by linarith
  have hcoef3 : C+1 ≤ 9*C+3*H+3 := by linarith
  calc
    D ≤ C*V + C^2*(S*R) + C^2*(8*C+3*H+1)*(V*I) +
        C^2*(C+1)*(V*W) := by convert hstart using 1; ring
    _ ≤ C^2*(V*I) + C^2*(S*R) + C^2*(8*C+3*H+1)*(V*I) +
        C^2*(C+1)*(V*W) := by gcongr
    _ = C^2*(S*R+(8*C+3*H+2)*(V*I)+(C+1)*(V*W)) := by ring
    _ ≤ C^2*((9*C+3*H+3)*(S*R)+(9*C+3*H+3)*(V*I)+
        (9*C+3*H+3)*(V*W)) := by
      apply mul_le_mul_of_nonneg_left _ hCpos
      apply add_le_add
      · apply add_le_add
        · simpa using mul_le_mul_of_nonneg_right hcoef1 hscale
        · exact mul_le_mul_of_nonneg_right hcoef2 hVI0
      · exact mul_le_mul_of_nonneg_right hcoef3 hVW0
    _ = C^2*(9*C+3*H+3)*(S*R+V*(I+W)) := by ring

theorem small_time_scale_reduction {S B V I J t : ℝ}
    (hB : 0 ≤ B) (hV : 0 ≤ V) (hI : 1 ≤ I) (hJ : 0 < J) (ht : 0 < t)
    (hS : S ≤ B*V*(t^((1:ℝ)/4)+I/J)) :
    S/t + V*(I+t^(-(3:ℝ)/4)) ≤
      (B+1)*V*I*(1+t^(-(3:ℝ)/4)+1/(t*J)) := by
  have hI0 : 0 ≤ I := le_trans zero_le_one hI
  have hW : 0 ≤ t^(-(3:ℝ)/4) := Real.rpow_nonneg ht.le _
  have htJ : 0 < t*J := mul_pos ht hJ
  have hpow : t^((1:ℝ)/4)/t = t^(-(3:ℝ)/4) := by
    rw [show -(3:ℝ)/4 = (1:ℝ)/4-1 by norm_num, Real.rpow_sub ht, Real.rpow_one]
  have hnoise : S/t ≤ B*V*(t^(-(3:ℝ)/4)+I/(t*J)) := by
    calc
      S/t ≤ (B*V*(t^((1:ℝ)/4)+I/J))/t := div_le_div_of_nonneg_right hS ht.le
      _ = B*V*(t^((1:ℝ)/4)/t+I/(t*J)) := by field_simp
      _ = B*V*(t^(-(3:ℝ)/4)+I/(t*J)) := by rw [hpow]
  have hfirst : (B+1)*V*t^(-(3:ℝ)/4) ≤ (B+1)*V*I*t^(-(3:ℝ)/4) := by
    have := mul_le_mul_of_nonneg_right
      (mul_le_mul_of_nonneg_left hI (show 0 ≤ (B+1)*V by positivity)) hW
    simpa using this
  have hsecond : B*V*I/(t*J) ≤ (B+1)*V*I/(t*J) := by gcongr; linarith
  have hthird : V*I ≤ (B+1)*V*I := by nlinarith [mul_nonneg hB (mul_nonneg hV hI0)]
  calc
    S/t + V*(I+t^(-(3:ℝ)/4)) ≤ B*V*(t^(-(3:ℝ)/4)+I/(t*J)) + V*(I+t^(-(3:ℝ)/4)) :=
      add_le_add hnoise le_rfl
    _ = (B+1)*V*t^(-(3:ℝ)/4) + B*V*I/(t*J) + V*I := by ring
    _ ≤ (B+1)*V*I*t^(-(3:ℝ)/4) + (B+1)*V*I/(t*J) + (B+1)*V*I :=
      add_le_add (add_le_add hfirst hsecond) hthird
    _ = (B+1)*V*I*(1+t^(-(3:ℝ)/4)+1/(t*J)) := by ring

theorem critical_differential_bound_of_endpoint_sums
    {D Q L Z S V C H I B J t : ℝ}
    (hC : 1 ≤ C) (hH : 1 ≤ H) (hI : 1 ≤ I) (hB : 0 ≤ B)
    (hS : 0 ≤ S) (hV : 0 ≤ V) (hVH : V ≤ H) (hSV : S ≤ C*V)
    (hJ : 0 < J) (ht : 0 < t)
    (hsmall : S ≤ B*V*(t^((1:ℝ)/4)+I/J))
    (hQ : Q ≤ C*(S*(1/t+(Real.log I)^2)+V^2))
    (hL : L ≤ C*(V*(t^(-(3:ℝ)/4)+Real.log I)+V^2))
    (hZ : Z ≤ C*(Real.sqrt S*(t^(-(3:ℝ)/4)+(Real.log I)^((3:ℝ)/2))+V))
    (hD : D ≤ C*(V+Q+L+Real.sqrt V*Z)) :
    D ≤ (C^2*(9*C+3*H+3)*(B+1))*V*I*
      (1+t^(-(3:ℝ)/4)+1/(t*J)) := by
  have hscale := endpoint_sums_critical_reduction hC hH hI hS hV hVH hSV
    (show 0 ≤ 1/t by positivity) (Real.rpow_nonneg ht.le _) hQ hL hZ hD
  have hreduce := small_time_scale_reduction hB hV hI hJ ht hsmall
  have hconst : 0 ≤ C^2*(9*C+3*H+3) := by positivity
  calc
    D ≤ C^2*(9*C+3*H+3)*(S/t+V*(I+t^(-(3:ℝ)/4))) := by
      simpa only [mul_one_div] using hscale
    _ ≤ C^2*(9*C+3*H+3)*((B+1)*V*I*(1+t^(-(3:ℝ)/4)+1/(t*J))) :=
      mul_le_mul_of_nonneg_left hreduce hconst
    _ = (C^2*(9*C+3*H+3)*(B+1))*V*I*(1+t^(-(3:ℝ)/4)+1/(t*J)) := by ring

end Problem367

end

end OAI