Metamath Proof Explorer


Theorem heiborlem3

Description: Lemma for heibor . Using countable choice ax-cc , we have fixed in advance a collection of finite 2 ^ -u n nets ( Fn ) for X (note that an r -net is a set of points in X whose r -balls cover X ). The set G is the subset of these points whose corresponding balls have no finite subcover (i.e. in the set K ). If the theorem was false, then X would be in K , and so some ball at each level would also be in K . But we can say more than this; given a ball ( y B n ) on level n , since level n + 1 covers the space and thus also ( y B n ) , using heiborlem1 there is a ball on the next level whose intersection with ( y B n ) also has no finite subcover. Now since the set G is a countable union of finite sets, it is countable (which needs ax-cc via iunctb ), and so we can apply ax-cc to G directly to get a function from G to itself, which points from each ball in K to a ball on the next level in K , and such that the intersection between these balls is also in K . (Contributed by Jeff Madsen, 18-Jan-2014)

Ref Expression
Hypotheses heibor.1 J=MetOpenD
heibor.3 K=u|¬v𝒫UFinuv
heibor.4 G=yn|n0yFnyBnK
heibor.5 B=zX,m0zballD12m
heibor.6 φDCMetX
heibor.7 φF:0𝒫XFin
heibor.8 φn0X=yFnyBn
Assertion heiborlem3 φgxGgxG2ndx+1BxgxB2ndx+1K

Proof

Step Hyp Ref Expression
1 heibor.1 J=MetOpenD
2 heibor.3 K=u|¬v𝒫UFinuv
3 heibor.4 G=yn|n0yFnyBnK
4 heibor.5 B=zX,m0zballD12m
5 heibor.6 φDCMetX
6 heibor.7 φF:0𝒫XFin
7 heibor.8 φn0X=yFnyBn
8 nn0ex 0V
9 fvex FtV
10 vsnex tV
11 9 10 xpex Ft×tV
12 8 11 iunex t0Ft×tV
13 3 relopabiv RelG
14 1st2nd RelGxGx=1stx2ndx
15 13 14 mpan xGx=1stx2ndx
16 15 eleq1d xGxG1stx2ndxG
17 df-br 1stxG2ndx1stx2ndxG
18 16 17 bitr4di xGxG1stxG2ndx
19 fvex 1stxV
20 fvex 2ndxV
21 1 2 3 19 20 heiborlem2 1stxG2ndx2ndx01stxF2ndx1stxB2ndxK
22 18 21 bitrdi xGxG2ndx01stxF2ndx1stxB2ndxK
23 22 ibi xG2ndx01stxF2ndx1stxB2ndxK
24 20 snid 2ndx2ndx
25 opelxp 1stx2ndxF2ndx×2ndx1stxF2ndx2ndx2ndx
26 24 25 mpbiran2 1stx2ndxF2ndx×2ndx1stxF2ndx
27 fveq2 t=2ndxFt=F2ndx
28 sneq t=2ndxt=2ndx
29 27 28 xpeq12d t=2ndxFt×t=F2ndx×2ndx
30 29 eleq2d t=2ndx1stx2ndxFt×t1stx2ndxF2ndx×2ndx
31 30 rspcev 2ndx01stx2ndxF2ndx×2ndxt01stx2ndxFt×t
32 26 31 sylan2br 2ndx01stxF2ndxt01stx2ndxFt×t
33 eliun 1stx2ndxt0Ft×tt01stx2ndxFt×t
34 32 33 sylibr 2ndx01stxF2ndx1stx2ndxt0Ft×t
35 34 3adant3 2ndx01stxF2ndx1stxB2ndxK1stx2ndxt0Ft×t
36 23 35 syl xG1stx2ndxt0Ft×t
37 15 36 eqeltrd xGxt0Ft×t
38 37 ssriv Gt0Ft×t
39 ssdomg t0Ft×tVGt0Ft×tGt0Ft×t
40 12 38 39 mp2 Gt0Ft×t
41 nn0ennn 0
42 nnenom ω
43 41 42 entri 0ω
44 endom 0ω0ω
45 43 44 ax-mp 0ω
46 vex tV
47 9 46 xpsnen Ft×tFt
48 inss2 𝒫XFinFin
49 6 ffvelcdmda φt0Ft𝒫XFin
50 48 49 sselid φt0FtFin
51 isfinite FtFinFtω
52 sdomdom FtωFtω
53 51 52 sylbi FtFinFtω
54 50 53 syl φt0Ftω
55 endomtr Ft×tFtFtωFt×tω
56 47 54 55 sylancr φt0Ft×tω
57 56 ralrimiva φt0Ft×tω
58 iunctb 0ωt0Ft×tωt0Ft×tω
59 45 57 58 sylancr φt0Ft×tω
60 domtr Gt0Ft×tt0Ft×tωGω
61 40 59 60 sylancr φGω
62 23 simp1d xG2ndx0
63 peano2nn0 2ndx02ndx+10
64 62 63 syl xG2ndx+10
65 ffvelcdm F:0𝒫XFin2ndx+10F2ndx+1𝒫XFin
66 6 64 65 syl2an φxGF2ndx+1𝒫XFin
67 48 66 sselid φxGF2ndx+1Fin
68 iunin2 tF2ndx+1BxtB2ndx+1=BxtF2ndx+1tB2ndx+1
69 oveq1 y=tyBn=tBn
70 69 cbviunv yFnyBn=tFntBn
71 fveq2 n=2ndx+1Fn=F2ndx+1
72 71 iuneq1d n=2ndx+1tFntBn=tF2ndx+1tBn
73 70 72 eqtrid n=2ndx+1yFnyBn=tF2ndx+1tBn
74 oveq2 n=2ndx+1tBn=tB2ndx+1
75 74 iuneq2d n=2ndx+1tF2ndx+1tBn=tF2ndx+1tB2ndx+1
76 73 75 eqtrd n=2ndx+1yFnyBn=tF2ndx+1tB2ndx+1
77 76 eqeq2d n=2ndx+1X=yFnyBnX=tF2ndx+1tB2ndx+1
78 77 rspccva n0X=yFnyBn2ndx+10X=tF2ndx+1tB2ndx+1
79 7 64 78 syl2an φxGX=tF2ndx+1tB2ndx+1
80 79 ineq2d φxGBxX=BxtF2ndx+1tB2ndx+1
81 15 fveq2d xGBx=B1stx2ndx
82 df-ov 1stxB2ndx=B1stx2ndx
83 81 82 eqtr4di xGBx=1stxB2ndx
84 83 adantl φxGBx=1stxB2ndx
85 inss1 𝒫XFin𝒫X
86 ffvelcdm F:0𝒫XFin2ndx0F2ndx𝒫XFin
87 6 62 86 syl2an φxGF2ndx𝒫XFin
88 85 87 sselid φxGF2ndx𝒫X
89 88 elpwid φxGF2ndxX
90 23 simp2d xG1stxF2ndx
91 90 adantl φxG1stxF2ndx
92 89 91 sseldd φxG1stxX
93 62 adantl φxG2ndx0
94 oveq1 z=1stxzballD12m=1stxballD12m
95 oveq2 m=2ndx2m=22ndx
96 95 oveq2d m=2ndx12m=122ndx
97 96 oveq2d m=2ndx1stxballD12m=1stxballD122ndx
98 ovex 1stxballD122ndxV
99 94 97 4 98 ovmpo 1stxX2ndx01stxB2ndx=1stxballD122ndx
100 92 93 99 syl2anc φxG1stxB2ndx=1stxballD122ndx
101 84 100 eqtrd φxGBx=1stxballD122ndx
102 cmetmet DCMetXDMetX
103 5 102 syl φDMetX
104 metxmet DMetXD∞MetX
105 103 104 syl φD∞MetX
106 105 adantr φxGD∞MetX
107 2nn 2
108 nnexpcl 22ndx022ndx
109 107 93 108 sylancr φxG22ndx
110 109 nnrpd φxG22ndx+
111 110 rpreccld φxG122ndx+
112 111 rpxrd φxG122ndx*
113 blssm D∞MetX1stxX122ndx*1stxballD122ndxX
114 106 92 112 113 syl3anc φxG1stxballD122ndxX
115 101 114 eqsstrd φxGBxX
116 df-ss BxXBxX=Bx
117 115 116 sylib φxGBxX=Bx
118 80 117 eqtr3d φxGBxtF2ndx+1tB2ndx+1=Bx
119 68 118 eqtrid φxGtF2ndx+1BxtB2ndx+1=Bx
120 eqimss2 tF2ndx+1BxtB2ndx+1=BxBxtF2ndx+1BxtB2ndx+1
121 119 120 syl φxGBxtF2ndx+1BxtB2ndx+1
122 23 simp3d xG1stxB2ndxK
123 83 122 eqeltrd xGBxK
124 123 adantl φxGBxK
125 fvex BxV
126 125 inex1 BxtB2ndx+1V
127 1 2 126 heiborlem1 F2ndx+1FinBxtF2ndx+1BxtB2ndx+1BxKtF2ndx+1BxtB2ndx+1K
128 67 121 124 127 syl3anc φxGtF2ndx+1BxtB2ndx+1K
129 85 66 sselid φxGF2ndx+1𝒫X
130 129 elpwid φxGF2ndx+1X
131 1 mopnuni D∞MetXX=J
132 105 131 syl φX=J
133 132 adantr φxGX=J
134 130 133 sseqtrd φxGF2ndx+1J
135 134 sselda φxGtF2ndx+1tJ
136 135 adantrr φxGtF2ndx+1BxtB2ndx+1KtJ
137 64 adantl φxG2ndx+10
138 id tF2ndx+1tF2ndx+1
139 snfi tB2ndx+1Fin
140 inss2 BxtB2ndx+1tB2ndx+1
141 ovex tB2ndx+1V
142 141 unisn tB2ndx+1=tB2ndx+1
143 uniiun tB2ndx+1=gtB2ndx+1g
144 142 143 eqtr3i tB2ndx+1=gtB2ndx+1g
145 140 144 sseqtri BxtB2ndx+1gtB2ndx+1g
146 vex gV
147 1 2 146 heiborlem1 tB2ndx+1FinBxtB2ndx+1gtB2ndx+1gBxtB2ndx+1KgtB2ndx+1gK
148 139 145 147 mp3an12 BxtB2ndx+1KgtB2ndx+1gK
149 eleq1 g=tB2ndx+1gKtB2ndx+1K
150 141 149 rexsn gtB2ndx+1gKtB2ndx+1K
151 148 150 sylib BxtB2ndx+1KtB2ndx+1K
152 ovex 2ndx+1V
153 1 2 3 46 152 heiborlem2 tG2ndx+12ndx+10tF2ndx+1tB2ndx+1K
154 153 biimpri 2ndx+10tF2ndx+1tB2ndx+1KtG2ndx+1
155 137 138 151 154 syl3an φxGtF2ndx+1BxtB2ndx+1KtG2ndx+1
156 155 3expb φxGtF2ndx+1BxtB2ndx+1KtG2ndx+1
157 simprr φxGtF2ndx+1BxtB2ndx+1KBxtB2ndx+1K
158 136 156 157 jca32 φxGtF2ndx+1BxtB2ndx+1KtJtG2ndx+1BxtB2ndx+1K
159 158 ex φxGtF2ndx+1BxtB2ndx+1KtJtG2ndx+1BxtB2ndx+1K
160 159 reximdv2 φxGtF2ndx+1BxtB2ndx+1KtJtG2ndx+1BxtB2ndx+1K
161 128 160 mpd φxGtJtG2ndx+1BxtB2ndx+1K
162 161 ralrimiva φxGtJtG2ndx+1BxtB2ndx+1K
163 1 fvexi JV
164 163 uniex JV
165 breq1 t=gxtG2ndx+1gxG2ndx+1
166 oveq1 t=gxtB2ndx+1=gxB2ndx+1
167 166 ineq2d t=gxBxtB2ndx+1=BxgxB2ndx+1
168 167 eleq1d t=gxBxtB2ndx+1KBxgxB2ndx+1K
169 165 168 anbi12d t=gxtG2ndx+1BxtB2ndx+1KgxG2ndx+1BxgxB2ndx+1K
170 164 169 axcc4dom GωxGtJtG2ndx+1BxtB2ndx+1Kgg:GJxGgxG2ndx+1BxgxB2ndx+1K
171 61 162 170 syl2anc φgg:GJxGgxG2ndx+1BxgxB2ndx+1K
172 exsimpr gg:GJxGgxG2ndx+1BxgxB2ndx+1KgxGgxG2ndx+1BxgxB2ndx+1K
173 171 172 syl φgxGgxG2ndx+1BxgxB2ndx+1K