Database
BASIC TOPOLOGY
Topology
Compactness
uncmp
Next ⟩
fiuncmp
Metamath Proof Explorer
Ascii
Unicode
Theorem
uncmp
Description:
The union of two compact sets is compact.
(Contributed by
Jeff Hankins
, 30-Jan-2010)
Ref
Expression
Hypothesis
uncmp.1
⊢
X
=
⋃
J
Assertion
uncmp
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
J
↾
𝑡
S
∈
Comp
∧
J
↾
𝑡
T
∈
Comp
→
J
∈
Comp
Proof
Step
Hyp
Ref
Expression
1
uncmp.1
⊢
X
=
⋃
J
2
simpll
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
J
↾
𝑡
S
∈
Comp
∧
J
↾
𝑡
T
∈
Comp
→
J
∈
Top
3
simpll
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
J
∈
Top
4
ssun1
⊢
S
⊆
S
∪
T
5
sseq2
⊢
X
=
S
∪
T
→
S
⊆
X
↔
S
⊆
S
∪
T
6
4
5
mpbiri
⊢
X
=
S
∪
T
→
S
⊆
X
7
6
ad2antlr
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
S
⊆
X
8
1
cmpsub
⊢
J
∈
Top
∧
S
⊆
X
→
J
↾
𝑡
S
∈
Comp
↔
∀
m
∈
𝒫
J
S
⊆
⋃
m
→
∃
n
∈
𝒫
m
∩
Fin
S
⊆
⋃
n
9
3
7
8
syl2anc
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
J
↾
𝑡
S
∈
Comp
↔
∀
m
∈
𝒫
J
S
⊆
⋃
m
→
∃
n
∈
𝒫
m
∩
Fin
S
⊆
⋃
n
10
simprr
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
X
=
⋃
c
11
7
10
sseqtrd
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
S
⊆
⋃
c
12
unieq
⊢
m
=
c
→
⋃
m
=
⋃
c
13
12
sseq2d
⊢
m
=
c
→
S
⊆
⋃
m
↔
S
⊆
⋃
c
14
pweq
⊢
m
=
c
→
𝒫
m
=
𝒫
c
15
14
ineq1d
⊢
m
=
c
→
𝒫
m
∩
Fin
=
𝒫
c
∩
Fin
16
15
rexeqdv
⊢
m
=
c
→
∃
n
∈
𝒫
m
∩
Fin
S
⊆
⋃
n
↔
∃
n
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
17
13
16
imbi12d
⊢
m
=
c
→
S
⊆
⋃
m
→
∃
n
∈
𝒫
m
∩
Fin
S
⊆
⋃
n
↔
S
⊆
⋃
c
→
∃
n
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
18
17
rspcv
⊢
c
∈
𝒫
J
→
∀
m
∈
𝒫
J
S
⊆
⋃
m
→
∃
n
∈
𝒫
m
∩
Fin
S
⊆
⋃
n
→
S
⊆
⋃
c
→
∃
n
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
19
18
ad2antrl
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
∀
m
∈
𝒫
J
S
⊆
⋃
m
→
∃
n
∈
𝒫
m
∩
Fin
S
⊆
⋃
n
→
S
⊆
⋃
c
→
∃
n
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
20
11
19
mpid
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
∀
m
∈
𝒫
J
S
⊆
⋃
m
→
∃
n
∈
𝒫
m
∩
Fin
S
⊆
⋃
n
→
∃
n
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
21
9
20
sylbid
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
J
↾
𝑡
S
∈
Comp
→
∃
n
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
22
ssun2
⊢
T
⊆
S
∪
T
23
sseq2
⊢
X
=
S
∪
T
→
T
⊆
X
↔
T
⊆
S
∪
T
24
22
23
mpbiri
⊢
X
=
S
∪
T
→
T
⊆
X
25
24
ad2antlr
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
T
⊆
X
26
1
cmpsub
⊢
J
∈
Top
∧
T
⊆
X
→
J
↾
𝑡
T
∈
Comp
↔
∀
r
∈
𝒫
J
T
⊆
⋃
r
→
∃
s
∈
𝒫
r
∩
Fin
T
⊆
⋃
s
27
3
25
26
syl2anc
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
J
↾
𝑡
T
∈
Comp
↔
∀
r
∈
𝒫
J
T
⊆
⋃
r
→
∃
s
∈
𝒫
r
∩
Fin
T
⊆
⋃
s
28
25
10
sseqtrd
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
T
⊆
⋃
c
29
unieq
⊢
r
=
c
→
⋃
r
=
⋃
c
30
29
sseq2d
⊢
r
=
c
→
T
⊆
⋃
r
↔
T
⊆
⋃
c
31
pweq
⊢
r
=
c
→
𝒫
r
=
𝒫
c
32
31
ineq1d
⊢
r
=
c
→
𝒫
r
∩
Fin
=
𝒫
c
∩
Fin
33
32
rexeqdv
⊢
r
=
c
→
∃
s
∈
𝒫
r
∩
Fin
T
⊆
⋃
s
↔
∃
s
∈
𝒫
c
∩
Fin
T
⊆
⋃
s
34
30
33
imbi12d
⊢
r
=
c
→
T
⊆
⋃
r
→
∃
s
∈
𝒫
r
∩
Fin
T
⊆
⋃
s
↔
T
⊆
⋃
c
→
∃
s
∈
𝒫
c
∩
Fin
T
⊆
⋃
s
35
34
rspcv
⊢
c
∈
𝒫
J
→
∀
r
∈
𝒫
J
T
⊆
⋃
r
→
∃
s
∈
𝒫
r
∩
Fin
T
⊆
⋃
s
→
T
⊆
⋃
c
→
∃
s
∈
𝒫
c
∩
Fin
T
⊆
⋃
s
36
35
ad2antrl
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
∀
r
∈
𝒫
J
T
⊆
⋃
r
→
∃
s
∈
𝒫
r
∩
Fin
T
⊆
⋃
s
→
T
⊆
⋃
c
→
∃
s
∈
𝒫
c
∩
Fin
T
⊆
⋃
s
37
28
36
mpid
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
∀
r
∈
𝒫
J
T
⊆
⋃
r
→
∃
s
∈
𝒫
r
∩
Fin
T
⊆
⋃
s
→
∃
s
∈
𝒫
c
∩
Fin
T
⊆
⋃
s
38
27
37
sylbid
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
J
↾
𝑡
T
∈
Comp
→
∃
s
∈
𝒫
c
∩
Fin
T
⊆
⋃
s
39
reeanv
⊢
∃
n
∈
𝒫
c
∩
Fin
∃
s
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
∧
T
⊆
⋃
s
↔
∃
n
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
∧
∃
s
∈
𝒫
c
∩
Fin
T
⊆
⋃
s
40
elinel1
⊢
n
∈
𝒫
c
∩
Fin
→
n
∈
𝒫
c
41
40
elpwid
⊢
n
∈
𝒫
c
∩
Fin
→
n
⊆
c
42
elinel1
⊢
s
∈
𝒫
c
∩
Fin
→
s
∈
𝒫
c
43
42
elpwid
⊢
s
∈
𝒫
c
∩
Fin
→
s
⊆
c
44
41
43
anim12i
⊢
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
→
n
⊆
c
∧
s
⊆
c
45
44
ad2antrl
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
n
⊆
c
∧
s
⊆
c
46
unss
⊢
n
⊆
c
∧
s
⊆
c
↔
n
∪
s
⊆
c
47
45
46
sylib
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
n
∪
s
⊆
c
48
elinel2
⊢
n
∈
𝒫
c
∩
Fin
→
n
∈
Fin
49
elinel2
⊢
s
∈
𝒫
c
∩
Fin
→
s
∈
Fin
50
unfi
⊢
n
∈
Fin
∧
s
∈
Fin
→
n
∪
s
∈
Fin
51
48
49
50
syl2an
⊢
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
→
n
∪
s
∈
Fin
52
51
ad2antrl
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
n
∪
s
∈
Fin
53
47
52
jca
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
n
∪
s
⊆
c
∧
n
∪
s
∈
Fin
54
elin
⊢
n
∪
s
∈
𝒫
c
∩
Fin
↔
n
∪
s
∈
𝒫
c
∧
n
∪
s
∈
Fin
55
vex
⊢
c
∈
V
56
55
elpw2
⊢
n
∪
s
∈
𝒫
c
↔
n
∪
s
⊆
c
57
56
anbi1i
⊢
n
∪
s
∈
𝒫
c
∧
n
∪
s
∈
Fin
↔
n
∪
s
⊆
c
∧
n
∪
s
∈
Fin
58
54
57
bitr2i
⊢
n
∪
s
⊆
c
∧
n
∪
s
∈
Fin
↔
n
∪
s
∈
𝒫
c
∩
Fin
59
53
58
sylib
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
n
∪
s
∈
𝒫
c
∩
Fin
60
simpllr
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
X
=
S
∪
T
61
ssun3
⊢
S
⊆
⋃
n
→
S
⊆
⋃
n
∪
⋃
s
62
ssun4
⊢
T
⊆
⋃
s
→
T
⊆
⋃
n
∪
⋃
s
63
61
62
anim12i
⊢
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
S
⊆
⋃
n
∪
⋃
s
∧
T
⊆
⋃
n
∪
⋃
s
64
63
ad2antll
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
S
⊆
⋃
n
∪
⋃
s
∧
T
⊆
⋃
n
∪
⋃
s
65
unss
⊢
S
⊆
⋃
n
∪
⋃
s
∧
T
⊆
⋃
n
∪
⋃
s
↔
S
∪
T
⊆
⋃
n
∪
⋃
s
66
64
65
sylib
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
S
∪
T
⊆
⋃
n
∪
⋃
s
67
60
66
eqsstrd
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
X
⊆
⋃
n
∪
⋃
s
68
uniun
⊢
⋃
n
∪
s
=
⋃
n
∪
⋃
s
69
67
68
sseqtrrdi
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
X
⊆
⋃
n
∪
s
70
elpwi
⊢
c
∈
𝒫
J
→
c
⊆
J
71
70
adantr
⊢
c
∈
𝒫
J
∧
X
=
⋃
c
→
c
⊆
J
72
71
ad2antlr
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
c
⊆
J
73
47
72
sstrd
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
n
∪
s
⊆
J
74
uniss
⊢
n
∪
s
⊆
J
→
⋃
n
∪
s
⊆
⋃
J
75
74
1
sseqtrrdi
⊢
n
∪
s
⊆
J
→
⋃
n
∪
s
⊆
X
76
73
75
syl
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
⋃
n
∪
s
⊆
X
77
69
76
eqssd
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
X
=
⋃
n
∪
s
78
unieq
⊢
d
=
n
∪
s
→
⋃
d
=
⋃
n
∪
s
79
78
rspceeqv
⊢
n
∪
s
∈
𝒫
c
∩
Fin
∧
X
=
⋃
n
∪
s
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
80
59
77
79
syl2anc
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
∧
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
∧
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
81
80
exp32
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
n
∈
𝒫
c
∩
Fin
∧
s
∈
𝒫
c
∩
Fin
→
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
82
81
rexlimdvv
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
∃
n
∈
𝒫
c
∩
Fin
∃
s
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
∧
T
⊆
⋃
s
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
83
39
82
biimtrrid
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
∃
n
∈
𝒫
c
∩
Fin
S
⊆
⋃
n
∧
∃
s
∈
𝒫
c
∩
Fin
T
⊆
⋃
s
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
84
21
38
83
syl2and
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
c
∈
𝒫
J
∧
X
=
⋃
c
→
J
↾
𝑡
S
∈
Comp
∧
J
↾
𝑡
T
∈
Comp
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
85
84
impancom
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
J
↾
𝑡
S
∈
Comp
∧
J
↾
𝑡
T
∈
Comp
→
c
∈
𝒫
J
∧
X
=
⋃
c
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
86
85
expd
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
J
↾
𝑡
S
∈
Comp
∧
J
↾
𝑡
T
∈
Comp
→
c
∈
𝒫
J
→
X
=
⋃
c
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
87
86
ralrimiv
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
J
↾
𝑡
S
∈
Comp
∧
J
↾
𝑡
T
∈
Comp
→
∀
c
∈
𝒫
J
X
=
⋃
c
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
88
1
iscmp
⊢
J
∈
Comp
↔
J
∈
Top
∧
∀
c
∈
𝒫
J
X
=
⋃
c
→
∃
d
∈
𝒫
c
∩
Fin
X
=
⋃
d
89
2
87
88
sylanbrc
⊢
J
∈
Top
∧
X
=
S
∪
T
∧
J
↾
𝑡
S
∈
Comp
∧
J
↾
𝑡
T
∈
Comp
→
J
∈
Comp