Metamath Proof Explorer


Theorem climcnds

Description: The Cauchy condensation test. If a ( k ) is a decreasing sequence of nonnegative terms, then sum_ k e. NN a ( k ) converges iff sum_ n e. NN0 2 ^ n x. a ( 2 ^ n ) converges. (Contributed by Mario Carneiro, 18-Jul-2014) (Proof shortened by AV, 10-Jul-2022)

Ref Expression
Hypotheses climcnds.1 φkFk
climcnds.2 φk0Fk
climcnds.3 φkFk+1Fk
climcnds.4 φn0Gn=2nF2n
Assertion climcnds φseq1+Fdomseq0+Gdom

Proof

Step Hyp Ref Expression
1 climcnds.1 φkFk
2 climcnds.2 φk0Fk
3 climcnds.3 φkFk+1Fk
4 climcnds.4 φn0Gn=2nF2n
5 nnuz =1
6 1zzd φseq1+Fdom1
7 1zzd φ1
8 nnnn0 nn0
9 2nn 2
10 simpr φn0n0
11 nnexpcl 2n02n
12 9 10 11 sylancr φn02n
13 12 nnred φn02n
14 fveq2 k=2nFk=F2n
15 14 eleq1d k=2nFkF2n
16 1 ralrimiva φkFk
17 16 adantr φn0kFk
18 15 17 12 rspcdva φn0F2n
19 13 18 remulcld φn02nF2n
20 4 19 eqeltrd φn0Gn
21 8 20 sylan2 φnGn
22 5 7 21 serfre φseq1+G:
23 22 adantr φseq1+Fdomseq1+G:
24 simpr φjj
25 24 5 eleqtrdi φjj1
26 nnz jj
27 26 adantl φjj
28 uzid jjj
29 peano2uz jjj+1j
30 27 28 29 3syl φjj+1j
31 simpl φjφ
32 elfznn n1j+1n
33 31 32 21 syl2an φjn1j+1Gn
34 simpll φjnj+1j+1φ
35 elfz1eq nj+1j+1n=j+1
36 35 adantl φjnj+1j+1n=j+1
37 nnnn0 jj0
38 peano2nn0 j0j+10
39 37 38 syl jj+10
40 39 ad2antlr φjnj+1j+1j+10
41 36 40 eqeltrd φjnj+1j+1n0
42 12 nnnn0d φn02n0
43 42 nn0ge0d φn002n
44 14 breq2d k=2n0Fk0F2n
45 2 ralrimiva φk0Fk
46 45 adantr φn0k0Fk
47 44 46 12 rspcdva φn00F2n
48 13 18 43 47 mulge0d φn002nF2n
49 48 4 breqtrrd φn00Gn
50 34 41 49 syl2anc φjnj+1j+10Gn
51 25 30 33 50 sermono φjseq1+Gjseq1+Gj+1
52 51 adantlr φseq1+Fdomjseq1+Gjseq1+Gj+1
53 2re 2
54 eqidd φseq1+FdomkFk=Fk
55 1 adantlr φseq1+FdomkFk
56 simpr φseq1+Fdomseq1+Fdom
57 5 6 54 55 56 isumrecl φseq1+FdomkFk
58 remulcl 2kFk2kFk
59 53 57 58 sylancr φseq1+Fdom2kFk
60 23 ffvelcdmda φseq1+Fdomjseq1+Gj
61 5 7 1 serfre φseq1+F:
62 61 ad2antrr φseq1+Fdomjseq1+F:
63 37 adantl φseq1+Fdomjj0
64 nnexpcl 2j02j
65 9 63 64 sylancr φseq1+Fdomj2j
66 62 65 ffvelcdmd φseq1+Fdomjseq1+F2j
67 remulcl 2seq1+F2j2seq1+F2j
68 53 66 67 sylancr φseq1+Fdomj2seq1+F2j
69 59 adantr φseq1+Fdomj2kFk
70 1 2 3 4 climcndslem2 φjseq1+Gj2seq1+F2j
71 70 adantlr φseq1+Fdomjseq1+Gj2seq1+F2j
72 eqidd φseq1+Fdomjk12jFk=Fk
73 65 5 eleqtrdi φseq1+Fdomj2j1
74 simpll φseq1+Fdomjφ
75 elfznn k12jk
76 1 recnd φkFk
77 74 75 76 syl2an φseq1+Fdomjk12jFk
78 72 73 77 fsumser φseq1+Fdomjk=12jFk=seq1+F2j
79 1zzd φseq1+Fdomj1
80 fzfid φseq1+Fdomj12jFin
81 75 ssriv 12j
82 81 a1i φseq1+Fdomj12j
83 eqidd φseq1+FdomjkFk=Fk
84 1 ad4ant14 φseq1+FdomjkFk
85 2 ad4ant14 φseq1+Fdomjk0Fk
86 simplr φseq1+Fdomjseq1+Fdom
87 5 79 80 82 83 84 85 86 isumless φseq1+Fdomjk=12jFkkFk
88 78 87 eqbrtrrd φseq1+Fdomjseq1+F2jkFk
89 57 adantr φseq1+FdomjkFk
90 2rp 2+
91 90 a1i φseq1+Fdomj2+
92 66 89 91 lemul2d φseq1+Fdomjseq1+F2jkFk2seq1+F2j2kFk
93 88 92 mpbid φseq1+Fdomj2seq1+F2j2kFk
94 60 68 69 71 93 letrd φseq1+Fdomjseq1+Gj2kFk
95 94 ralrimiva φseq1+Fdomjseq1+Gj2kFk
96 brralrspcev 2kFkjseq1+Gj2kFkxjseq1+Gjx
97 59 95 96 syl2anc φseq1+Fdomxjseq1+Gjx
98 5 6 23 52 97 climsup φseq1+Fdomseq1+Gsupranseq1+G<
99 climrel Rel
100 99 releldmi seq1+Gsupranseq1+G<seq1+Gdom
101 98 100 syl φseq1+Fdomseq1+Gdom
102 nn0uz 0=0
103 1nn0 10
104 103 a1i φ10
105 20 recnd φn0Gn
106 102 104 105 iserex φseq0+Gdomseq1+Gdom
107 106 biimpar φseq1+Gdomseq0+Gdom
108 101 107 syldan φseq1+Fdomseq0+Gdom
109 1zzd φseq0+Gdom1
110 61 adantr φseq0+Gdomseq1+F:
111 elfznn k1j+1k
112 31 111 1 syl2an φjk1j+1Fk
113 simpll φjkj+1j+1φ
114 peano2nn jj+1
115 114 adantl φjj+1
116 elfz1eq kj+1j+1k=j+1
117 eleq1 k=j+1kj+1
118 117 biimparc j+1k=j+1k
119 115 116 118 syl2an φjkj+1j+1k
120 113 119 2 syl2anc φjkj+1j+10Fk
121 25 30 112 120 sermono φjseq1+Fjseq1+Fj+1
122 121 adantlr φseq0+Gdomjseq1+Fjseq1+Fj+1
123 0zd φseq0+Gdom0
124 eqidd φseq0+Gdomn0Gn=Gn
125 20 adantlr φseq0+Gdomn0Gn
126 simpr φseq0+Gdomseq0+Gdom
127 102 123 124 125 126 isumrecl φseq0+Gdomn0Gn
128 110 ffvelcdmda φseq0+Gdomjseq1+Fj
129 0zd φ0
130 102 129 20 serfre φseq0+G:0
131 130 adantr φseq0+Gdomseq0+G:0
132 ffvelcdm seq0+G:0j0seq0+Gj
133 131 37 132 syl2an φseq0+Gdomjseq0+Gj
134 127 adantr φseq0+Gdomjn0Gn
135 110 adantr φseq0+Gdomjseq1+F:
136 simpr φseq0+Gdomjj
137 26 adantl φseq0+Gdomjj
138 39 adantl φseq0+Gdomjj+10
139 138 nn0red φseq0+Gdomjj+1
140 nnexpcl 2j+102j+1
141 9 138 140 sylancr φseq0+Gdomj2j+1
142 141 nnred φseq0+Gdomj2j+1
143 2z 2
144 uzid 222
145 143 144 ax-mp 22
146 bernneq3 22j+10j+1<2j+1
147 145 138 146 sylancr φseq0+Gdomjj+1<2j+1
148 139 142 147 ltled φseq0+Gdomjj+12j+1
149 137 peano2zd φseq0+Gdomjj+1
150 141 nnzd φseq0+Gdomj2j+1
151 eluz j+12j+12j+1j+1j+12j+1
152 149 150 151 syl2anc φseq0+Gdomj2j+1j+1j+12j+1
153 148 152 mpbird φseq0+Gdomj2j+1j+1
154 eluzp1m1 j2j+1j+12j+11j
155 137 153 154 syl2anc φseq0+Gdomj2j+11j
156 eluznn j2j+11j2j+11
157 136 155 156 syl2anc φseq0+Gdomj2j+11
158 135 157 ffvelcdmd φseq0+Gdomjseq1+F2j+11
159 25 adantlr φseq0+Gdomjj1
160 simpll φseq0+Gdomjφ
161 elfznn k12j+11k
162 160 161 1 syl2an φseq0+Gdomjk12j+11Fk
163 114 adantl φseq0+Gdomjj+1
164 elfzuz kj+12j+11kj+1
165 eluznn j+1kj+1k
166 163 164 165 syl2an φseq0+Gdomjkj+12j+11k
167 160 166 2 syl2an2r φseq0+Gdomjkj+12j+110Fk
168 159 155 162 167 sermono φseq0+Gdomjseq1+Fjseq1+F2j+11
169 37 adantl φseq0+Gdomjj0
170 1 2 3 4 climcndslem1 φj0seq1+F2j+11seq0+Gj
171 160 169 170 syl2anc φseq0+Gdomjseq1+F2j+11seq0+Gj
172 128 158 133 168 171 letrd φseq0+Gdomjseq1+Fjseq0+Gj
173 eqidd φseq0+Gdomjn0jGn=Gn
174 169 102 eleqtrdi φseq0+Gdomjj0
175 elfznn0 n0jn0
176 160 175 105 syl2an φseq0+Gdomjn0jGn
177 173 174 176 fsumser φseq0+Gdomjn=0jGn=seq0+Gj
178 0zd φseq0+Gdomj0
179 fzfid φseq0+Gdomj0jFin
180 175 ssriv 0j0
181 180 a1i φseq0+Gdomj0j0
182 eqidd φseq0+Gdomjn0Gn=Gn
183 20 ad4ant14 φseq0+Gdomjn0Gn
184 49 ad4ant14 φseq0+Gdomjn00Gn
185 simplr φseq0+Gdomjseq0+Gdom
186 102 178 179 181 182 183 184 185 isumless φseq0+Gdomjn=0jGnn0Gn
187 177 186 eqbrtrrd φseq0+Gdomjseq0+Gjn0Gn
188 128 133 134 172 187 letrd φseq0+Gdomjseq1+Fjn0Gn
189 188 ralrimiva φseq0+Gdomjseq1+Fjn0Gn
190 brralrspcev n0Gnjseq1+Fjn0Gnxjseq1+Fjx
191 127 189 190 syl2anc φseq0+Gdomxjseq1+Fjx
192 5 109 110 122 191 climsup φseq0+Gdomseq1+Fsupranseq1+F<
193 99 releldmi seq1+Fsupranseq1+F<seq1+Fdom
194 192 193 syl φseq0+Gdomseq1+Fdom
195 108 194 impbida φseq1+Fdomseq0+Gdom