Metamath Proof Explorer


Theorem smflimsup

Description: The superior limit of a sequence of sigma-measurable functions is sigma-measurable. Proposition 121F (d) of Fremlin1 p. 39 . (Contributed by Glauco Siliprandi, 23-Oct-2021)

Ref Expression
Hypotheses smflimsup.n _ m F
smflimsup.x _ x F
smflimsup.m φ M
smflimsup.z Z = M
smflimsup.s φ S SAlg
smflimsup.f φ F : Z SMblFn S
smflimsup.d D = x n Z m n dom F m | lim sup m Z F m x
smflimsup.g G = x D lim sup m Z F m x
Assertion smflimsup φ G SMblFn S

Proof

Step Hyp Ref Expression
1 smflimsup.n _ m F
2 smflimsup.x _ x F
3 smflimsup.m φ M
4 smflimsup.z Z = M
5 smflimsup.s φ S SAlg
6 smflimsup.f φ F : Z SMblFn S
7 smflimsup.d D = x n Z m n dom F m | lim sup m Z F m x
8 smflimsup.g G = x D lim sup m Z F m x
9 fveq2 n = j n = j
10 9 iineq1d n = j m n dom F m = m j dom F m
11 nfcv _ q dom F m
12 nfcv _ m q
13 1 12 nffv _ m F q
14 13 nfdm _ m dom F q
15 fveq2 m = q F m = F q
16 15 dmeqd m = q dom F m = dom F q
17 11 14 16 cbviin m j dom F m = q j dom F q
18 17 a1i n = j m j dom F m = q j dom F q
19 10 18 eqtrd n = j m n dom F m = q j dom F q
20 19 cbviunv n Z m n dom F m = j Z q j dom F q
21 20 eleq2i x n Z m n dom F m x j Z q j dom F q
22 nfcv _ q F m x
23 nfcv _ m x
24 13 23 nffv _ m F q x
25 15 fveq1d m = q F m x = F q x
26 22 24 25 cbvmpt m Z F m x = q Z F q x
27 26 fveq2i lim sup m Z F m x = lim sup q Z F q x
28 27 eleq1i lim sup m Z F m x lim sup q Z F q x
29 21 28 anbi12i x n Z m n dom F m lim sup m Z F m x x j Z q j dom F q lim sup q Z F q x
30 29 rabbia2 x n Z m n dom F m | lim sup m Z F m x = x j Z q j dom F q | lim sup q Z F q x
31 nfcv _ x Z
32 nfcv _ x j
33 nfcv _ x q
34 2 33 nffv _ x F q
35 34 nfdm _ x dom F q
36 32 35 nfiin _ x q j dom F q
37 31 36 nfiun _ x j Z q j dom F q
38 nfcv _ w j Z q j dom F q
39 nfv w lim sup q Z F q x
40 nfcv _ x lim sup
41 nfcv _ x w
42 34 41 nffv _ x F q w
43 31 42 nfmpt _ x q Z F q w
44 40 43 nffv _ x lim sup q Z F q w
45 nfcv _ x
46 44 45 nfel x lim sup q Z F q w
47 fveq2 x = w F q x = F q w
48 47 mpteq2dv x = w q Z F q x = q Z F q w
49 48 fveq2d x = w lim sup q Z F q x = lim sup q Z F q w
50 49 eleq1d x = w lim sup q Z F q x lim sup q Z F q w
51 37 38 39 46 50 cbvrabw x j Z q j dom F q | lim sup q Z F q x = w j Z q j dom F q | lim sup q Z F q w
52 7 30 51 3eqtri D = w j Z q j dom F q | lim sup q Z F q w
53 27 mpteq2i x D lim sup m Z F m x = x D lim sup q Z F q x
54 nfrab1 _ x x n Z m n dom F m | lim sup m Z F m x
55 7 54 nfcxfr _ x D
56 nfcv _ w D
57 nfcv _ w lim sup q Z F q x
58 55 56 57 44 49 cbvmptf x D lim sup q Z F q x = w D lim sup q Z F q w
59 8 53 58 3eqtri G = w D lim sup q Z F q w
60 nfcv _ x i
61 60 35 nfiin _ x q i dom F q
62 nfcv _ w q i dom F q
63 nfv w sup ran q i F q x * <
64 60 42 nfmpt _ x q i F q w
65 64 nfrn _ x ran q i F q w
66 nfcv _ x *
67 nfcv _ x <
68 65 66 67 nfsup _ x sup ran q i F q w * <
69 68 45 nfel x sup ran q i F q w * <
70 47 mpteq2dv x = w q i F q x = q i F q w
71 70 rneqd x = w ran q i F q x = ran q i F q w
72 71 supeq1d x = w sup ran q i F q x * < = sup ran q i F q w * <
73 72 eleq1d x = w sup ran q i F q x * < sup ran q i F q w * <
74 61 62 63 69 73 cbvrabw x q i dom F q | sup ran q i F q x * < = w q i dom F q | sup ran q i F q w * <
75 74 a1i i = k x q i dom F q | sup ran q i F q x * < = w q i dom F q | sup ran q i F q w * <
76 fveq2 i = k i = k
77 76 iineq1d i = k q i dom F q = q k dom F q
78 77 eleq2d i = k w q i dom F q w q k dom F q
79 76 mpteq1d i = k q i F q w = q k F q w
80 79 rneqd i = k ran q i F q w = ran q k F q w
81 80 supeq1d i = k sup ran q i F q w * < = sup ran q k F q w * <
82 81 eleq1d i = k sup ran q i F q w * < sup ran q k F q w * <
83 78 82 anbi12d i = k w q i dom F q sup ran q i F q w * < w q k dom F q sup ran q k F q w * <
84 83 rabbidva2 i = k w q i dom F q | sup ran q i F q w * < = w q k dom F q | sup ran q k F q w * <
85 75 84 eqtrd i = k x q i dom F q | sup ran q i F q x * < = w q k dom F q | sup ran q k F q w * <
86 85 cbvmptv i Z x q i dom F q | sup ran q i F q x * < = k Z w q k dom F q | sup ran q k F q w * <
87 fveq2 y = w F p y = F p w
88 87 mpteq2dv y = w p l F p y = p l F p w
89 88 rneqd y = w ran p l F p y = ran p l F p w
90 89 supeq1d y = w sup ran p l F p y * < = sup ran p l F p w * <
91 90 cbvmptv y i Z x p i dom F p | sup ran p i F p x * < l sup ran p l F p y * < = w i Z x p i dom F p | sup ran p i F p x * < l sup ran p l F p w * <
92 fveq2 p = q F p = F q
93 92 dmeqd p = q dom F p = dom F q
94 93 cbviinv p i dom F p = q i dom F q
95 94 eleq2i x p i dom F p x q i dom F q
96 nfcv _ q F p x
97 nfcv _ p F q
98 nfcv _ p x
99 97 98 nffv _ p F q x
100 92 fveq1d p = q F p x = F q x
101 96 99 100 cbvmpt p i F p x = q i F q x
102 101 rneqi ran p i F p x = ran q i F q x
103 102 supeq1i sup ran p i F p x * < = sup ran q i F q x * <
104 103 eleq1i sup ran p i F p x * < sup ran q i F q x * <
105 95 104 anbi12i x p i dom F p sup ran p i F p x * < x q i dom F q sup ran q i F q x * <
106 105 rabbia2 x p i dom F p | sup ran p i F p x * < = x q i dom F q | sup ran q i F q x * <
107 106 mpteq2i i Z x p i dom F p | sup ran p i F p x * < = i Z x q i dom F q | sup ran q i F q x * <
108 107 fveq1i i Z x p i dom F p | sup ran p i F p x * < l = i Z x q i dom F q | sup ran q i F q x * < l
109 92 fveq1d p = q F p w = F q w
110 109 cbvmptv p l F p w = q l F q w
111 110 rneqi ran p l F p w = ran q l F q w
112 111 supeq1i sup ran p l F p w * < = sup ran q l F q w * <
113 108 112 mpteq12i w i Z x p i dom F p | sup ran p i F p x * < l sup ran p l F p w * < = w i Z x q i dom F q | sup ran q i F q x * < l sup ran q l F q w * <
114 91 113 eqtri y i Z x p i dom F p | sup ran p i F p x * < l sup ran p l F p y * < = w i Z x q i dom F q | sup ran q i F q x * < l sup ran q l F q w * <
115 114 a1i l = k y i Z x p i dom F p | sup ran p i F p x * < l sup ran p l F p y * < = w i Z x q i dom F q | sup ran q i F q x * < l sup ran q l F q w * <
116 fveq2 l = k i Z x q i dom F q | sup ran q i F q x * < l = i Z x q i dom F q | sup ran q i F q x * < k
117 fveq2 l = k l = k
118 117 mpteq1d l = k q l F q w = q k F q w
119 118 rneqd l = k ran q l F q w = ran q k F q w
120 119 supeq1d l = k sup ran q l F q w * < = sup ran q k F q w * <
121 116 120 mpteq12dv l = k w i Z x q i dom F q | sup ran q i F q x * < l sup ran q l F q w * < = w i Z x q i dom F q | sup ran q i F q x * < k sup ran q k F q w * <
122 115 121 eqtrd l = k y i Z x p i dom F p | sup ran p i F p x * < l sup ran p l F p y * < = w i Z x q i dom F q | sup ran q i F q x * < k sup ran q k F q w * <
123 122 cbvmptv l Z y i Z x p i dom F p | sup ran p i F p x * < l sup ran p l F p y * < = k Z w i Z x q i dom F q | sup ran q i F q x * < k sup ran q k F q w * <
124 3 4 5 6 52 59 86 123 smflimsuplem8 φ G SMblFn S