Metamath Proof Explorer


Theorem bcthlem5

Description: Lemma for bcth . The proof makes essential use of the Axiom of Dependent Choice axdc4uz , which in the form used here accepts a "selection" function F from each element of K to a nonempty subset of K , and the result function g maps g ( n + 1 ) to an element of F ( n , g ( n ) ) . The trick here is thus in the choice of F and K : we let K be the set of all tagged nonempty open sets (tagged here meaning that we have a point and an open set, in an ordered pair), and F ( k , <. x , z >. ) gives the set of all balls of size less than 1 / k , tagged by their centers, whose closures fit within the given open set z and miss M ( k ) .

Since M ( k ) is closed, z \ M ( k ) is open and also nonempty, since z is nonempty and M ( k ) has empty interior. Then there is some ball contained in it, and hence our function F is valid (it never maps to the empty set). Now starting at a point in the interior of U. ran M , DC gives us the function g all whose elements are constrained by F acting on the previous value. (This is all proven in this lemma.) Now g is a sequence of tagged open balls, forming an inclusion chain (see bcthlem2 ) and whose sizes tend to zero, since they are bounded above by 1 / k . Thus, the centers of these balls form a Cauchy sequence, and converge to a point x (see bcthlem4 ). Since the inclusion chain also ensures the closure of each ball is in the previous ball, the point x must be in all these balls (see bcthlem3 ) and hence misses each M ( k ) , contradicting the fact that x is in the interior of U. ran M (which was the starting point). (Contributed by Mario Carneiro, 6-Jan-2014)

Ref Expression
Hypotheses bcth.2 J = MetOpen D
bcthlem.4 φ D CMet X
bcthlem.5 F = k , z X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k
bcthlem.6 φ M : Clsd J
bcthlem5.7 φ k int J M k =
Assertion bcthlem5 φ int J ran M =

Proof

Step Hyp Ref Expression
1 bcth.2 J = MetOpen D
2 bcthlem.4 φ D CMet X
3 bcthlem.5 F = k , z X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k
4 bcthlem.6 φ M : Clsd J
5 bcthlem5.7 φ k int J M k =
6 cmetmet D CMet X D Met X
7 metxmet D Met X D ∞Met X
8 2 6 7 3syl φ D ∞Met X
9 1 mopntop D ∞Met X J Top
10 8 9 syl φ J Top
11 4 frnd φ ran M Clsd J
12 eqid J = J
13 12 cldss2 Clsd J 𝒫 J
14 11 13 sstrdi φ ran M 𝒫 J
15 sspwuni ran M 𝒫 J ran M J
16 14 15 sylib φ ran M J
17 12 ntropn J Top ran M J int J ran M J
18 10 16 17 syl2anc φ int J ran M J
19 8 18 jca φ D ∞Met X int J ran M J
20 1 mopni2 D ∞Met X int J ran M J n int J ran M m + n ball D m int J ran M
21 20 3expa D ∞Met X int J ran M J n int J ran M m + n ball D m int J ran M
22 19 21 sylan φ n int J ran M m + n ball D m int J ran M
23 1 mopnuni D ∞Met X X = J
24 8 23 syl φ X = J
25 12 topopn J Top J J
26 10 25 syl φ J J
27 24 26 eqeltrd φ X J
28 reex V
29 rpssre +
30 28 29 ssexi + V
31 xpexg X J + V X × + V
32 27 30 31 sylancl φ X × + V
33 32 3ad2ant1 φ n int J ran M m + X × + V
34 12 ntrss3 J Top ran M J int J ran M J
35 10 16 34 syl2anc φ int J ran M J
36 35 24 sseqtrrd φ int J ran M X
37 36 3ad2ant1 φ n int J ran M m + int J ran M X
38 simp2 φ n int J ran M m + n int J ran M
39 37 38 sseldd φ n int J ran M m + n X
40 simp3 φ n int J ran M m + m +
41 39 40 opelxpd φ n int J ran M m + n m X × +
42 opabssxp x r | x X r + r < 1 k cls J x ball D r ball D z M k X × +
43 elpw2g X × + V x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k X × +
44 32 43 syl φ x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k X × +
45 44 adantr φ k z X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k X × +
46 42 45 mpbiri φ k z X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × +
47 simpl k z X × + k
48 rspa k int J M k = k int J M k =
49 5 47 48 syl2an φ k z X × + int J M k =
50 ssdif0 ball D z M k ball D z M k =
51 1st2nd2 z X × + z = 1 st z 2 nd z
52 51 ad2antll φ k z X × + z = 1 st z 2 nd z
53 52 fveq2d φ k z X × + ball D z = ball D 1 st z 2 nd z
54 df-ov 1 st z ball D 2 nd z = ball D 1 st z 2 nd z
55 53 54 eqtr4di φ k z X × + ball D z = 1 st z ball D 2 nd z
56 8 adantr φ k z X × + D ∞Met X
57 xp1st z X × + 1 st z X
58 57 ad2antll φ k z X × + 1 st z X
59 xp2nd z X × + 2 nd z +
60 59 ad2antll φ k z X × + 2 nd z +
61 bln0 D ∞Met X 1 st z X 2 nd z + 1 st z ball D 2 nd z
62 56 58 60 61 syl3anc φ k z X × + 1 st z ball D 2 nd z
63 55 62 eqnetrd φ k z X × + ball D z
64 10 adantr φ k z X × + J Top
65 ffvelrn M : Clsd J k M k Clsd J
66 4 47 65 syl2an φ k z X × + M k Clsd J
67 12 cldss M k Clsd J M k J
68 66 67 syl φ k z X × + M k J
69 60 rpxrd φ k z X × + 2 nd z *
70 1 blopn D ∞Met X 1 st z X 2 nd z * 1 st z ball D 2 nd z J
71 56 58 69 70 syl3anc φ k z X × + 1 st z ball D 2 nd z J
72 55 71 eqeltrd φ k z X × + ball D z J
73 12 ssntr J Top M k J ball D z J ball D z M k ball D z int J M k
74 73 expr J Top M k J ball D z J ball D z M k ball D z int J M k
75 64 68 72 74 syl21anc φ k z X × + ball D z M k ball D z int J M k
76 ssn0 ball D z int J M k ball D z int J M k
77 76 expcom ball D z ball D z int J M k int J M k
78 63 75 77 sylsyld φ k z X × + ball D z M k int J M k
79 50 78 syl5bir φ k z X × + ball D z M k = int J M k
80 79 necon2d φ k z X × + int J M k = ball D z M k
81 49 80 mpd φ k z X × + ball D z M k
82 n0 ball D z M k x x ball D z M k
83 8 3ad2ant1 φ k z X × + x ball D z M k D ∞Met X
84 12 difopn ball D z J M k Clsd J ball D z M k J
85 72 66 84 syl2anc φ k z X × + ball D z M k J
86 85 3adant3 φ k z X × + x ball D z M k ball D z M k J
87 simp3 φ k z X × + x ball D z M k x ball D z M k
88 simp2l φ k z X × + x ball D z M k k
89 nnrp k k +
90 89 rpreccld k 1 k +
91 88 90 syl φ k z X × + x ball D z M k 1 k +
92 1 mopni3 D ∞Met X ball D z M k J x ball D z M k 1 k + n + n < 1 k x ball D n ball D z M k
93 83 86 87 91 92 syl31anc φ k z X × + x ball D z M k n + n < 1 k x ball D n ball D z M k
94 simp1 φ k z X × + x ball D z M k φ
95 elssuni ball D z J ball D z J
96 72 95 syl φ k z X × + ball D z J
97 24 adantr φ k z X × + X = J
98 96 97 sseqtrrd φ k z X × + ball D z X
99 98 ssdifssd φ k z X × + ball D z M k X
100 99 sseld φ k z X × + x ball D z M k x X
101 100 3impia φ k z X × + x ball D z M k x X
102 simp2 φ k z X × + x ball D z M k k z X × +
103 rphalfcl n + n 2 +
104 rphalflt n + n 2 < n
105 breq1 r = n 2 r < n n 2 < n
106 105 rspcev n 2 + n 2 < n r + r < n
107 103 104 106 syl2anc n + r + r < n
108 107 ad2antlr φ x X k z X × + n + n < 1 k x ball D n ball D z M k r + r < n
109 df-rex r + r < n r r + r < n
110 simpr3 φ x X k z X × + n + r < n r + r +
111 110 rpred φ x X k z X × + n + r < n r + r
112 simpr1 φ x X k z X × + n + r < n r + n +
113 112 rpred φ x X k z X × + n + r < n r + n
114 simplrl φ x X k z X × + n + r < n r + k
115 114 nnrecred φ x X k z X × + n + r < n r + 1 k
116 simpr2 φ x X k z X × + n + r < n r + r < n
117 lttr r n 1 k r < n n < 1 k r < 1 k
118 117 expdimp r n 1 k r < n n < 1 k r < 1 k
119 111 113 115 116 118 syl31anc φ x X k z X × + n + r < n r + n < 1 k r < 1 k
120 8 anim1i φ x X D ∞Met X x X
121 120 adantr φ x X k z X × + D ∞Met X x X
122 rpxr r + r *
123 rpxr n + n *
124 id r < n r < n
125 122 123 124 3anim123i r + n + r < n r * n * r < n
126 125 3coml n + r < n r + r * n * r < n
127 1 blsscls D ∞Met X x X r * n * r < n cls J x ball D r x ball D n
128 121 126 127 syl2an φ x X k z X × + n + r < n r + cls J x ball D r x ball D n
129 sstr2 cls J x ball D r x ball D n x ball D n ball D z M k cls J x ball D r ball D z M k
130 128 129 syl φ x X k z X × + n + r < n r + x ball D n ball D z M k cls J x ball D r ball D z M k
131 119 130 anim12d φ x X k z X × + n + r < n r + n < 1 k x ball D n ball D z M k r < 1 k cls J x ball D r ball D z M k
132 simpllr φ x X k z X × + n + r < n r + x X
133 132 110 jca φ x X k z X × + n + r < n r + x X r +
134 131 133 jctild φ x X k z X × + n + r < n r + n < 1 k x ball D n ball D z M k x X r + r < 1 k cls J x ball D r ball D z M k
135 134 3exp2 φ x X k z X × + n + r < n r + n < 1 k x ball D n ball D z M k x X r + r < 1 k cls J x ball D r ball D z M k
136 135 com35 φ x X k z X × + n + n < 1 k x ball D n ball D z M k r + r < n x X r + r < 1 k cls J x ball D r ball D z M k
137 136 imp5d φ x X k z X × + n + n < 1 k x ball D n ball D z M k r + r < n x X r + r < 1 k cls J x ball D r ball D z M k
138 137 eximdv φ x X k z X × + n + n < 1 k x ball D n ball D z M k r r + r < n r x X r + r < 1 k cls J x ball D r ball D z M k
139 109 138 syl5bi φ x X k z X × + n + n < 1 k x ball D n ball D z M k r + r < n r x X r + r < 1 k cls J x ball D r ball D z M k
140 108 139 mpd φ x X k z X × + n + n < 1 k x ball D n ball D z M k r x X r + r < 1 k cls J x ball D r ball D z M k
141 140 rexlimdva2 φ x X k z X × + n + n < 1 k x ball D n ball D z M k r x X r + r < 1 k cls J x ball D r ball D z M k
142 94 101 102 141 syl21anc φ k z X × + x ball D z M k n + n < 1 k x ball D n ball D z M k r x X r + r < 1 k cls J x ball D r ball D z M k
143 93 142 mpd φ k z X × + x ball D z M k r x X r + r < 1 k cls J x ball D r ball D z M k
144 143 3expia φ k z X × + x ball D z M k r x X r + r < 1 k cls J x ball D r ball D z M k
145 144 eximdv φ k z X × + x x ball D z M k x r x X r + r < 1 k cls J x ball D r ball D z M k
146 82 145 syl5bi φ k z X × + ball D z M k x r x X r + r < 1 k cls J x ball D r ball D z M k
147 81 146 mpd φ k z X × + x r x X r + r < 1 k cls J x ball D r ball D z M k
148 opabn0 x r | x X r + r < 1 k cls J x ball D r ball D z M k x r x X r + r < 1 k cls J x ball D r ball D z M k
149 147 148 sylibr φ k z X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k
150 eldifsn x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k
151 46 149 150 sylanbrc φ k z X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × +
152 151 ralrimivva φ k z X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × +
153 3 fmpo k z X × + x r | x X r + r < 1 k cls J x ball D r ball D z M k 𝒫 X × + F : × X × + 𝒫 X × +
154 152 153 sylib φ F : × X × + 𝒫 X × +
155 154 3ad2ant1 φ n int J ran M m + F : × X × + 𝒫 X × +
156 1z 1
157 nnuz = 1
158 156 157 axdc4uz X × + V n m X × + F : × X × + 𝒫 X × + g g : X × + g 1 = n m n g n + 1 n F g n
159 33 41 155 158 syl3anc φ n int J ran M m + g g : X × + g 1 = n m n g n + 1 n F g n
160 simpl1 φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n φ
161 160 2 syl φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n D CMet X
162 160 4 syl φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n M : Clsd J
163 simpl3 φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n m +
164 39 adantr φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n n X
165 simpr1 φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n g : X × +
166 simpr2 φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n g 1 = n m
167 simpr3 φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n n g n + 1 n F g n
168 fvoveq1 n = k g n + 1 = g k + 1
169 id n = k n = k
170 fveq2 n = k g n = g k
171 169 170 oveq12d n = k n F g n = k F g k
172 168 171 eleq12d n = k g n + 1 n F g n g k + 1 k F g k
173 172 cbvralvw n g n + 1 n F g n k g k + 1 k F g k
174 167 173 sylib φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n k g k + 1 k F g k
175 1 161 3 162 163 164 165 166 174 bcthlem4 φ n int J ran M m + g : X × + g 1 = n m n g n + 1 n F g n n ball D m ran M
176 159 175 exlimddv φ n int J ran M m + n ball D m ran M
177 12 ntrss2 J Top ran M J int J ran M ran M
178 10 16 177 syl2anc φ int J ran M ran M
179 sstr2 n ball D m int J ran M int J ran M ran M n ball D m ran M
180 178 179 syl5com φ n ball D m int J ran M n ball D m ran M
181 ssdif0 n ball D m ran M n ball D m ran M =
182 180 181 syl6ib φ n ball D m int J ran M n ball D m ran M =
183 182 necon3ad φ n ball D m ran M ¬ n ball D m int J ran M
184 183 3ad2ant1 φ n int J ran M m + n ball D m ran M ¬ n ball D m int J ran M
185 176 184 mpd φ n int J ran M m + ¬ n ball D m int J ran M
186 185 3expa φ n int J ran M m + ¬ n ball D m int J ran M
187 186 nrexdv φ n int J ran M ¬ m + n ball D m int J ran M
188 22 187 pm2.65da φ ¬ n int J ran M
189 188 eq0rdv φ int J ran M =