Metamath Proof Explorer


Theorem meaiuninclem

Description: Measures are continuous from below (bounded case): if E is a sequence of increasing measurable sets (with uniformly bounded measure) then the measure of the union is the union of the measure. This is Proposition 112C (e) of Fremlin1 p. 16. (Contributed by Glauco Siliprandi, 8-Apr-2021)

Ref Expression
Hypotheses meaiuninclem.m φMMeas
meaiuninclem.n φN
meaiuninclem.z Z=N
meaiuninclem.e φE:ZdomM
meaiuninclem.i φnZEnEn+1
meaiuninclem.b φxnZMEnx
meaiuninclem.s S=nZMEn
meaiuninclem.f F=nZEniN..^nEi
Assertion meaiuninclem φSMnZEn

Proof

Step Hyp Ref Expression
1 meaiuninclem.m φMMeas
2 meaiuninclem.n φN
3 meaiuninclem.z Z=N
4 meaiuninclem.e φE:ZdomM
5 meaiuninclem.i φnZEnEn+1
6 meaiuninclem.b φxnZMEnx
7 meaiuninclem.s S=nZMEn
8 meaiuninclem.f F=nZEniN..^nEi
9 0xr 0*
10 9 a1i φnZ0*
11 pnfxr +∞*
12 11 a1i φnZ+∞*
13 1 adantr φnZMMeas
14 eqid domM=domM
15 4 ffvelcdmda φnZEndomM
16 13 14 15 meaxrcl φnZMEn*
17 13 15 meage0 φnZ0MEn
18 6 adantr φnZxnZMEnx
19 simp1 φnZxnZMEnxφnZ
20 simp2 φnZxnZMEnxx
21 simp3 φnZxnZMEnxnZMEnx
22 19 simprd φnZxnZMEnxnZ
23 rspa nZMEnxnZMEnx
24 21 22 23 syl2anc φnZxnZMEnxMEnx
25 16 3ad2ant1 φnZxMEnxMEn*
26 rexr xx*
27 26 3ad2ant2 φnZxMEnxx*
28 11 a1i φnZxMEnx+∞*
29 simp3 φnZxMEnxMEnx
30 ltpnf xx<+∞
31 30 3ad2ant2 φnZxMEnxx<+∞
32 25 27 28 29 31 xrlelttrd φnZxMEnxMEn<+∞
33 19 20 24 32 syl3anc φnZxnZMEnxMEn<+∞
34 33 3exp φnZxnZMEnxMEn<+∞
35 34 rexlimdv φnZxnZMEnxMEn<+∞
36 18 35 mpd φnZMEn<+∞
37 10 12 16 17 36 elicod φnZMEn0+∞
38 37 7 fmptd φS:Z0+∞
39 rge0ssre 0+∞
40 39 a1i φ0+∞
41 38 40 fssd φS:Z
42 3 peano2uzs nZn+1Z
43 42 adantl φnZn+1Z
44 4 ffvelcdmda φn+1ZEn+1domM
45 43 44 syldan φnZEn+1domM
46 13 14 15 45 5 meassle φnZMEnMEn+1
47 7 a1i φS=nZMEn
48 fvexd φnZMEnV
49 47 48 fvmpt2d φnZSn=MEn
50 2fveq3 n=mMEn=MEm
51 50 cbvmptv nZMEn=mZMEm
52 7 51 eqtri S=mZMEm
53 2fveq3 m=n+1MEm=MEn+1
54 fvexd φnZMEn+1V
55 52 53 43 54 fvmptd3 φnZSn+1=MEn+1
56 49 55 breq12d φnZSnSn+1MEnMEn+1
57 46 56 mpbird φnZSnSn+1
58 49 eqcomd φnZMEn=Sn
59 58 breq1d φnZMEnxSnx
60 59 ralbidva φnZMEnxnZSnx
61 60 biimpd φnZMEnxnZSnx
62 61 adantr φxnZMEnxnZSnx
63 62 reximdva φxnZMEnxxnZSnx
64 6 63 mpd φxnZSnx
65 3 2 41 57 64 climsup φSsupranS<
66 nfv nφ
67 nfv xφ
68 id nZnZ
69 fvex EnV
70 69 difexi EniN..^nEiV
71 70 a1i nZEniN..^nEiV
72 8 fvmpt2 nZEniN..^nEiVFn=EniN..^nEi
73 68 71 72 syl2anc nZFn=EniN..^nEi
74 73 adantl φnZFn=EniN..^nEi
75 1 14 dmmeasal φdomMSAlg
76 75 adantr φnZdomMSAlg
77 fzoct N..^nω
78 77 a1i φnZN..^nω
79 4 adantr φiN..^nE:ZdomM
80 fzossuz N..^nN
81 3 eqcomi N=Z
82 80 81 sseqtri N..^nZ
83 82 sseli iN..^niZ
84 83 adantl φiN..^niZ
85 79 84 ffvelcdmd φiN..^nEidomM
86 85 adantlr φnZiN..^nEidomM
87 76 78 86 saliuncl φnZiN..^nEidomM
88 saldifcl2 domMSAlgEndomMiN..^nEidomMEniN..^nEidomM
89 76 15 87 88 syl3anc φnZEniN..^nEidomM
90 74 89 eqeltrd φnZFndomM
91 13 14 90 meaxrcl φnZMFn*
92 13 90 meage0 φnZ0MFn
93 difssd φnZEniN..^nEiEn
94 74 93 eqsstrd φnZFnEn
95 13 14 90 15 94 meassle φnZMFnMEn
96 91 16 12 95 36 xrlelttrd φnZMFn<+∞
97 10 12 91 92 96 elicod φnZMFn0+∞
98 2fveq3 n=iMEn=MEi
99 98 breq1d n=iMEnxMEix
100 99 cbvralvw nZMEnxiZMEix
101 100 biimpi nZMEnxiZMEix
102 101 adantl φnZMEnxiZMEix
103 eleq1w n=inZiZ
104 103 anbi2d n=iφnZφiZ
105 oveq2 n=iNn=Ni
106 105 sumeq1d n=im=NnMFm=m=NiMFm
107 98 106 eqeq12d n=iMEn=m=NnMFmMEi=m=NiMFm
108 104 107 imbi12d n=iφnZMEn=m=NnMFmφiZMEi=m=NiMFm
109 eleq1w m=nmZnZ
110 109 anbi2d m=nφmZφnZ
111 oveq2 m=nNm=Nn
112 111 iuneq1d m=ni=NmFi=i=NnFi
113 111 iuneq1d m=ni=NmEi=i=NnEi
114 112 113 eqeq12d m=ni=NmFi=i=NmEii=NnFi=i=NnEi
115 110 114 imbi12d m=nφmZi=NmFi=i=NmEiφnZi=NnFi=i=NnEi
116 fveq2 i=nFi=Fn
117 116 cbviunv i=NmFi=n=NmFn
118 117 a1i φmZi=NmFi=n=NmFn
119 66 3 4 8 iundjiun φmZn=NmFn=n=NmEnnZFn=nZEnDisjnZFn
120 119 simplld φmZn=NmFn=n=NmEn
121 120 adantr φmZmZn=NmFn=n=NmEn
122 simpr φmZmZ
123 rspa mZn=NmFn=n=NmEnmZn=NmFn=n=NmEn
124 121 122 123 syl2anc φmZn=NmFn=n=NmEn
125 fveq2 n=iEn=Ei
126 125 cbviunv n=NmEn=i=NmEi
127 126 a1i φmZn=NmEn=i=NmEi
128 118 124 127 3eqtrd φmZi=NmFi=i=NmEi
129 115 128 chvarvv φnZi=NnFi=i=NnEi
130 68 3 eleqtrdi nZnN
131 130 adantl φnZnN
132 fvoveq1 n=iEn+1=Ei+1
133 125 132 sseq12d n=iEnEn+1EiEi+1
134 104 133 imbi12d n=iφnZEnEn+1φiZEiEi+1
135 134 5 chvarvv φiZEiEi+1
136 84 135 syldan φiN..^nEiEi+1
137 136 adantlr φnZiN..^nEiEi+1
138 131 137 iunincfi φnZi=NnEi=En
139 129 138 eqtr2d φnZEn=i=NnFi
140 139 fveq2d φnZMEn=Mi=NnFi
141 nfv iφnZ
142 elfzuz iNniN
143 142 81 eleqtrdi iNniZ
144 143 adantl φiNniZ
145 fveq2 n=iFn=Fi
146 145 eleq1d n=iFndomMFidomM
147 104 146 imbi12d n=iφnZFndomMφiZFidomM
148 147 90 chvarvv φiZFidomM
149 144 148 syldan φiNnFidomM
150 149 adantlr φnZiNnFidomM
151 fzct Nnω
152 151 a1i φnZNnω
153 144 ssd φNnZ
154 119 simprd φDisjnZFn
155 145 cbvdisjv DisjnZFnDisjiZFi
156 154 155 sylib φDisjiZFi
157 disjss1 NnZDisjiZFiDisji=NnFi
158 153 156 157 sylc φDisji=NnFi
159 158 adantr φnZDisji=NnFi
160 141 13 14 150 152 159 meadjiun φnZMi=NnFi=sum^iNnMFi
161 fzfid φnZNnFin
162 2fveq3 n=iMFn=MFi
163 162 eleq1d n=iMFn0+∞MFi0+∞
164 104 163 imbi12d n=iφnZMFn0+∞φiZMFi0+∞
165 164 97 chvarvv φiZMFi0+∞
166 144 165 syldan φiNnMFi0+∞
167 166 adantlr φnZiNnMFi0+∞
168 161 167 sge0fsummpt φnZsum^iNnMFi=i=NnMFi
169 2fveq3 i=mMFi=MFm
170 169 cbvsumv i=NnMFi=m=NnMFm
171 170 a1i φnZi=NnMFi=m=NnMFm
172 168 171 eqtrd φnZsum^iNnMFi=m=NnMFm
173 140 160 172 3eqtrd φnZMEn=m=NnMFm
174 108 173 chvarvv φiZMEi=m=NiMFm
175 2fveq3 m=nMFm=MFn
176 175 cbvsumv m=NiMFm=n=NiMFn
177 176 a1i φiZm=NiMFm=n=NiMFn
178 174 177 eqtrd φiZMEi=n=NiMFn
179 178 breq1d φiZMEixn=NiMFnx
180 179 ralbidva φiZMEixiZn=NiMFnx
181 180 biimpd φiZMEixiZn=NiMFnx
182 181 imp φiZMEixiZn=NiMFnx
183 102 182 syldan φnZMEnxiZn=NiMFnx
184 183 ex φnZMEnxiZn=NiMFnx
185 184 reximdv φxnZMEnxxiZn=NiMFnx
186 6 185 mpd φxiZn=NiMFnx
187 66 67 2 3 97 186 sge0reuzb φsum^nZMFn=supraniZn=NiMFn<
188 98 cbvmptv nZMEn=iZMEi
189 7 188 eqtri S=iZMEi
190 189 a1i φS=iZMEi
191 178 mpteq2dva φiZMEi=iZn=NiMFn
192 190 191 eqtrd φS=iZn=NiMFn
193 192 rneqd φranS=raniZn=NiMFn
194 193 supeq1d φsupranS<=supraniZn=NiMFn<
195 187 194 eqtr4d φsum^nZMFn=supranS<
196 195 eqcomd φsupranS<=sum^nZMFn
197 3 uzct Zω
198 197 a1i φZω
199 66 1 14 90 198 154 meadjiun φMnZFn=sum^nZMFn
200 199 eqcomd φsum^nZMFn=MnZFn
201 119 simplrd φnZFn=nZEn
202 201 fveq2d φMnZFn=MnZEn
203 196 200 202 3eqtrd φsupranS<=MnZEn
204 65 203 breqtrd φSMnZEn