Metamath Proof Explorer


Theorem mbflimsup

Description: The limit supremum of a sequence of measurable real-valued functions is measurable. (Contributed by Mario Carneiro, 7-Sep-2014) (Revised by AV, 12-Sep-2020)

Ref Expression
Hypotheses mbflimsup.1 Z = M
mbflimsup.2 G = x A lim sup n Z B
mbflimsup.h H = m sup n Z B m +∞ * * <
mbflimsup.3 φ M
mbflimsup.4 φ x A lim sup n Z B
mbflimsup.5 φ n Z x A B MblFn
mbflimsup.6 φ n Z x A B
Assertion mbflimsup φ G MblFn

Proof

Step Hyp Ref Expression
1 mbflimsup.1 Z = M
2 mbflimsup.2 G = x A lim sup n Z B
3 mbflimsup.h H = m sup n Z B m +∞ * * <
4 mbflimsup.3 φ M
5 mbflimsup.4 φ x A lim sup n Z B
6 mbflimsup.5 φ n Z x A B MblFn
7 mbflimsup.6 φ n Z x A B
8 1 fvexi Z V
9 8 mptex n Z B V
10 9 a1i φ x A n Z B V
11 uzssz M
12 1 11 eqsstri Z
13 zssre
14 12 13 sstri Z
15 14 a1i φ x A Z
16 1 uzsup M sup Z * < = +∞
17 4 16 syl φ sup Z * < = +∞
18 17 adantr φ x A sup Z * < = +∞
19 3 10 15 18 limsupval2 φ x A lim sup n Z B = sup H Z * <
20 imassrn H Z ran H
21 4 adantr φ x A M
22 7 anass1rs φ x A n Z B
23 22 fmpttd φ x A n Z B : Z
24 5 ltpnfd φ x A lim sup n Z B < +∞
25 3 1 limsupgre M n Z B : Z lim sup n Z B < +∞ H :
26 21 23 24 25 syl3anc φ x A H :
27 26 frnd φ x A ran H
28 20 27 sstrid φ x A H Z
29 26 fdmd φ x A dom H =
30 29 ineq1d φ x A dom H Z = Z
31 sseqin2 Z Z = Z
32 14 31 mpbi Z = Z
33 30 32 eqtrdi φ x A dom H Z = Z
34 uzid M M M
35 4 34 syl φ M M
36 35 1 eleqtrrdi φ M Z
37 36 adantr φ x A M Z
38 37 ne0d φ x A Z
39 33 38 eqnetrd φ x A dom H Z
40 imadisj H Z = dom H Z =
41 40 necon3bii H Z dom H Z
42 39 41 sylibr φ x A H Z
43 5 leidd φ x A lim sup n Z B lim sup n Z B
44 22 rexrd φ x A n Z B *
45 44 fmpttd φ x A n Z B : Z *
46 5 rexrd φ x A lim sup n Z B *
47 3 limsuple Z n Z B : Z * lim sup n Z B * lim sup n Z B lim sup n Z B y lim sup n Z B H y
48 15 45 46 47 syl3anc φ x A lim sup n Z B lim sup n Z B y lim sup n Z B H y
49 43 48 mpbid φ x A y lim sup n Z B H y
50 ssralv Z y lim sup n Z B H y y Z lim sup n Z B H y
51 14 49 50 mpsyl φ x A y Z lim sup n Z B H y
52 3 limsupgf H : *
53 ffn H : * H Fn
54 52 53 ax-mp H Fn
55 breq2 z = H y lim sup n Z B z lim sup n Z B H y
56 55 ralima H Fn Z z H Z lim sup n Z B z y Z lim sup n Z B H y
57 54 15 56 sylancr φ x A z H Z lim sup n Z B z y Z lim sup n Z B H y
58 51 57 mpbird φ x A z H Z lim sup n Z B z
59 breq1 y = lim sup n Z B y z lim sup n Z B z
60 59 ralbidv y = lim sup n Z B z H Z y z z H Z lim sup n Z B z
61 60 rspcev lim sup n Z B z H Z lim sup n Z B z y z H Z y z
62 5 58 61 syl2anc φ x A y z H Z y z
63 infxrre H Z H Z y z H Z y z sup H Z * < = sup H Z <
64 28 42 62 63 syl3anc φ x A sup H Z * < = sup H Z <
65 df-ima H Z = ran H Z
66 26 feqmptd φ x A H = i H i
67 66 reseq1d φ x A H Z = i H i Z
68 resmpt Z i H i Z = i Z H i
69 14 68 ax-mp i H i Z = i Z H i
70 67 69 eqtrdi φ x A H Z = i Z H i
71 14 sseli i Z i
72 ffvelrn H : i H i
73 26 71 72 syl2an φ x A i Z H i
74 73 rexrd φ x A i Z H i *
75 simplll φ x A i Z n i φ
76 1 uztrn2 i Z n i n Z
77 76 adantll φ x A i Z n i n Z
78 simpllr φ x A i Z n i x A
79 75 77 78 7 syl12anc φ x A i Z n i B
80 79 fmpttd φ x A i Z n i B : i
81 80 frnd φ x A i Z ran n i B
82 eqid n i B = n i B
83 82 79 dmmptd φ x A i Z dom n i B = i
84 simpr φ i Z i Z
85 84 1 eleqtrdi φ i Z i M
86 eluzelz i M i
87 85 86 syl φ i Z i
88 87 adantlr φ x A i Z i
89 uzid i i i
90 ne0i i i i
91 88 89 90 3syl φ x A i Z i
92 83 91 eqnetrd φ x A i Z dom n i B
93 dm0rn0 dom n i B = ran n i B =
94 93 necon3bii dom n i B ran n i B
95 92 94 sylib φ x A i Z ran n i B
96 85 adantlr φ x A i Z i M
97 uzss i M i M
98 96 97 syl φ x A i Z i M
99 98 1 sseqtrrdi φ x A i Z i Z
100 73 leidd φ x A i Z H i H i
101 14 a1i φ x A i Z Z
102 45 adantr φ x A i Z n Z B : Z *
103 simpr φ x A i Z i Z
104 14 103 sselid φ x A i Z i
105 3 limsupgle Z n Z B : Z * i H i * H i H i k Z i k n Z B k H i
106 101 102 104 74 105 syl211anc φ x A i Z H i H i k Z i k n Z B k H i
107 100 106 mpbid φ x A i Z k Z i k n Z B k H i
108 ssralv i Z k Z i k n Z B k H i k i i k n Z B k H i
109 99 107 108 sylc φ x A i Z k i i k n Z B k H i
110 99 adantr φ x A i Z k i i Z
111 110 resmptd φ x A i Z k i n Z B i = n i B
112 111 fveq1d φ x A i Z k i n Z B i k = n i B k
113 fvres k i n Z B i k = n Z B k
114 113 adantl φ x A i Z k i n Z B i k = n Z B k
115 112 114 eqtr3d φ x A i Z k i n i B k = n Z B k
116 115 breq1d φ x A i Z k i n i B k H i n Z B k H i
117 eluzle k i i k
118 117 adantl φ x A i Z k i i k
119 biimt i k n Z B k H i i k n Z B k H i
120 118 119 syl φ x A i Z k i n Z B k H i i k n Z B k H i
121 116 120 bitrd φ x A i Z k i n i B k H i i k n Z B k H i
122 121 ralbidva φ x A i Z k i n i B k H i k i i k n Z B k H i
123 109 122 mpbird φ x A i Z k i n i B k H i
124 ffn n i B : i n i B Fn i
125 breq1 z = n i B k z H i n i B k H i
126 125 ralrn n i B Fn i z ran n i B z H i k i n i B k H i
127 80 124 126 3syl φ x A i Z z ran n i B z H i k i n i B k H i
128 123 127 mpbird φ x A i Z z ran n i B z H i
129 brralrspcev H i z ran n i B z H i y z ran n i B z y
130 73 128 129 syl2anc φ x A i Z y z ran n i B z y
131 81 95 130 suprcld φ x A i Z sup ran n i B <
132 131 rexrd φ x A i Z sup ran n i B < *
133 81 adantr φ x A i Z k Z i k ran n i B
134 95 adantr φ x A i Z k Z i k ran n i B
135 130 adantr φ x A i Z k Z i k y z ran n i B z y
136 12 sseli k Z k
137 eluz i k k i i k
138 88 136 137 syl2an φ x A i Z k Z k i i k
139 138 biimprd φ x A i Z k Z i k k i
140 139 impr φ x A i Z k Z i k k i
141 140 115 syldan φ x A i Z k Z i k n i B k = n Z B k
142 80 adantr φ x A i Z k Z i k n i B : i
143 142 124 syl φ x A i Z k Z i k n i B Fn i
144 fnfvelrn n i B Fn i k i n i B k ran n i B
145 143 140 144 syl2anc φ x A i Z k Z i k n i B k ran n i B
146 141 145 eqeltrrd φ x A i Z k Z i k n Z B k ran n i B
147 133 134 135 146 suprubd φ x A i Z k Z i k n Z B k sup ran n i B <
148 147 expr φ x A i Z k Z i k n Z B k sup ran n i B <
149 148 ralrimiva φ x A i Z k Z i k n Z B k sup ran n i B <
150 3 limsupgle Z n Z B : Z * i sup ran n i B < * H i sup ran n i B < k Z i k n Z B k sup ran n i B <
151 101 102 104 132 150 syl211anc φ x A i Z H i sup ran n i B < k Z i k n Z B k sup ran n i B <
152 149 151 mpbird φ x A i Z H i sup ran n i B <
153 suprleub ran n i B ran n i B y z ran n i B z y H i sup ran n i B < H i z ran n i B z H i
154 81 95 130 73 153 syl31anc φ x A i Z sup ran n i B < H i z ran n i B z H i
155 128 154 mpbird φ x A i Z sup ran n i B < H i
156 74 132 152 155 xrletrid φ x A i Z H i = sup ran n i B <
157 156 mpteq2dva φ x A i Z H i = i Z sup ran n i B <
158 70 157 eqtrd φ x A H Z = i Z sup ran n i B <
159 158 rneqd φ x A ran H Z = ran i Z sup ran n i B <
160 65 159 eqtrid φ x A H Z = ran i Z sup ran n i B <
161 160 infeq1d φ x A sup H Z < = sup ran i Z sup ran n i B < <
162 19 64 161 3eqtrd φ x A lim sup n Z B = sup ran i Z sup ran n i B < <
163 162 mpteq2dva φ x A lim sup n Z B = x A sup ran i Z sup ran n i B < <
164 2 163 eqtrid φ G = x A sup ran i Z sup ran n i B < <
165 eqid x A sup ran i Z sup ran n i B < < = x A sup ran i Z sup ran n i B < <
166 eqid i = i
167 eqid x A sup ran n i B < = x A sup ran n i B <
168 simpll φ i Z n i φ
169 76 adantll φ i Z n i n Z
170 168 169 6 syl2anc φ i Z n i x A B MblFn
171 simpll φ i Z n i x A φ
172 76 ad2ant2lr φ i Z n i x A n Z
173 simprr φ i Z n i x A x A
174 171 172 173 7 syl12anc φ i Z n i x A B
175 79 ralrimiva φ x A i Z n i B
176 breq1 z = B z y B y
177 82 176 ralrnmptw n i B z ran n i B z y n i B y
178 175 177 syl φ x A i Z z ran n i B z y n i B y
179 178 rexbidv φ x A i Z y z ran n i B z y y n i B y
180 130 179 mpbid φ x A i Z y n i B y
181 180 an32s φ i Z x A y n i B y
182 166 167 87 170 174 181 mbfsup φ i Z x A sup ran n i B < MblFn
183 131 an32s φ i Z x A sup ran n i B <
184 183 anasss φ i Z x A sup ran n i B <
185 3 limsuple Z n Z B : Z * lim sup n Z B * lim sup n Z B lim sup n Z B i lim sup n Z B H i
186 15 45 46 185 syl3anc φ x A lim sup n Z B lim sup n Z B i lim sup n Z B H i
187 43 186 mpbid φ x A i lim sup n Z B H i
188 ssralv Z i lim sup n Z B H i i Z lim sup n Z B H i
189 14 187 188 mpsyl φ x A i Z lim sup n Z B H i
190 156 breq2d φ x A i Z lim sup n Z B H i lim sup n Z B sup ran n i B <
191 190 ralbidva φ x A i Z lim sup n Z B H i i Z lim sup n Z B sup ran n i B <
192 189 191 mpbid φ x A i Z lim sup n Z B sup ran n i B <
193 breq1 y = lim sup n Z B y sup ran n i B < lim sup n Z B sup ran n i B <
194 193 ralbidv y = lim sup n Z B i Z y sup ran n i B < i Z lim sup n Z B sup ran n i B <
195 194 rspcev lim sup n Z B i Z lim sup n Z B sup ran n i B < y i Z y sup ran n i B <
196 5 192 195 syl2anc φ x A y i Z y sup ran n i B <
197 1 165 4 182 184 196 mbfinf φ x A sup ran i Z sup ran n i B < < MblFn
198 164 197 eqeltrd φ G MblFn