Database
BASIC TOPOLOGY
Topology
Limits and continuity in topological spaces
cncls2i
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cnntri
Metamath Proof Explorer
Ascii
Unicode
Theorem
cncls2i
Description:
Property of the preimage of a closure.
(Contributed by
Mario Carneiro
, 25-Aug-2015)
Ref
Expression
Hypothesis
cncls2i.1
⊢
Y
=
⋃
K
Assertion
cncls2i
⊢
F
∈
J
Cn
K
∧
S
⊆
Y
→
cls
⁡
J
⁡
F
-1
S
⊆
F
-1
cls
⁡
K
⁡
S
Proof
Step
Hyp
Ref
Expression
1
cncls2i.1
⊢
Y
=
⋃
K
2
cntop2
⊢
F
∈
J
Cn
K
→
K
∈
Top
3
1
clscld
⊢
K
∈
Top
∧
S
⊆
Y
→
cls
⁡
K
⁡
S
∈
Clsd
⁡
K
4
2
3
sylan
⊢
F
∈
J
Cn
K
∧
S
⊆
Y
→
cls
⁡
K
⁡
S
∈
Clsd
⁡
K
5
cnclima
⊢
F
∈
J
Cn
K
∧
cls
⁡
K
⁡
S
∈
Clsd
⁡
K
→
F
-1
cls
⁡
K
⁡
S
∈
Clsd
⁡
J
6
4
5
syldan
⊢
F
∈
J
Cn
K
∧
S
⊆
Y
→
F
-1
cls
⁡
K
⁡
S
∈
Clsd
⁡
J
7
1
sscls
⊢
K
∈
Top
∧
S
⊆
Y
→
S
⊆
cls
⁡
K
⁡
S
8
2
7
sylan
⊢
F
∈
J
Cn
K
∧
S
⊆
Y
→
S
⊆
cls
⁡
K
⁡
S
9
imass2
⊢
S
⊆
cls
⁡
K
⁡
S
→
F
-1
S
⊆
F
-1
cls
⁡
K
⁡
S
10
8
9
syl
⊢
F
∈
J
Cn
K
∧
S
⊆
Y
→
F
-1
S
⊆
F
-1
cls
⁡
K
⁡
S
11
eqid
⊢
⋃
J
=
⋃
J
12
11
clsss2
⊢
F
-1
cls
⁡
K
⁡
S
∈
Clsd
⁡
J
∧
F
-1
S
⊆
F
-1
cls
⁡
K
⁡
S
→
cls
⁡
J
⁡
F
-1
S
⊆
F
-1
cls
⁡
K
⁡
S
13
6
10
12
syl2anc
⊢
F
∈
J
Cn
K
∧
S
⊆
Y
→
cls
⁡
J
⁡
F
-1
S
⊆
F
-1
cls
⁡
K
⁡
S