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Separated spaces: T0, T1, T2 (Hausdorff) ...
ispnrm
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pnrmnrm
Metamath Proof Explorer
Ascii
Unicode
Theorem
ispnrm
Description:
The property of being perfectly normal.
(Contributed by
Mario Carneiro
, 26-Aug-2015)
Ref
Expression
Assertion
ispnrm
⊢
J
∈
PNrm
↔
J
∈
Nrm
∧
Clsd
⁡
J
⊆
ran
⁡
f
∈
J
ℕ
⟼
⋂
ran
⁡
f
Proof
Step
Hyp
Ref
Expression
1
fveq2
⊢
j
=
J
→
Clsd
⁡
j
=
Clsd
⁡
J
2
oveq1
⊢
j
=
J
→
j
ℕ
=
J
ℕ
3
2
mpteq1d
⊢
j
=
J
→
f
∈
j
ℕ
⟼
⋂
ran
⁡
f
=
f
∈
J
ℕ
⟼
⋂
ran
⁡
f
4
3
rneqd
⊢
j
=
J
→
ran
⁡
f
∈
j
ℕ
⟼
⋂
ran
⁡
f
=
ran
⁡
f
∈
J
ℕ
⟼
⋂
ran
⁡
f
5
1
4
sseq12d
⊢
j
=
J
→
Clsd
⁡
j
⊆
ran
⁡
f
∈
j
ℕ
⟼
⋂
ran
⁡
f
↔
Clsd
⁡
J
⊆
ran
⁡
f
∈
J
ℕ
⟼
⋂
ran
⁡
f
6
df-pnrm
⊢
PNrm
=
j
∈
Nrm
|
Clsd
⁡
j
⊆
ran
⁡
f
∈
j
ℕ
⟼
⋂
ran
⁡
f
7
5
6
elrab2
⊢
J
∈
PNrm
↔
J
∈
Nrm
∧
Clsd
⁡
J
⊆
ran
⁡
f
∈
J
ℕ
⟼
⋂
ran
⁡
f