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A locally compact non-k_2-space #1172

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17 changes: 17 additions & 0 deletions spaces/S000210/README.md
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---
uid: S000210
name: Isbell's locally compact non-k-space topology on $\omega_1+1$
refs:
- doi: 10.1090/S0002-9939-1987-0891170-3
name: A distinguishing example in k-spaces (Isbell)
- mathse: 3904987
name: Answer to "Is there a locally compact space which is not a k-space"
---

The set $\omega_1+1$ generated by the basis
$\{[0,\omega_1)\setminus F:F\text{ finite}\}\cup\{[\alpha,\omega_1]\setminus F:\alpha<\omega_1,F\text{ finite}\}$.

Constructed by Isbell in
{{doi:10.1090/S0002-9939-1987-0891170-3}}
as an example of a {P130} space which is not {P141}.
See also {{mathse:3904987}}.
7 changes: 7 additions & 0 deletions spaces/S000210/properties/P000002.md
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---
space: S000210
property: P000002
value: true
---

By construction.
7 changes: 7 additions & 0 deletions spaces/S000210/properties/P000039.md
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---
space: S000210
property: P000039
value: true
---

By construction.
7 changes: 7 additions & 0 deletions spaces/S000210/properties/P000099.md
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---
space: S000210
property: P000099
value: false
---

The sequence $x_n=n$ converges to both $0$ and $1$.
7 changes: 7 additions & 0 deletions spaces/S000210/properties/P000114.md
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---
space: S000210
property: P000114
value: true
---

By construction.
7 changes: 7 additions & 0 deletions spaces/S000210/properties/P000141.md
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---
space: S000210
property: P000141
value: false
---

TODO
7 changes: 7 additions & 0 deletions spaces/S000210/properties/P000191.md
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---
space: S000210
property: P000191
value: false
---

Any countable intersection of open sets is infinite.
11 changes: 11 additions & 0 deletions spaces/S000210/properties/P000208.md
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---
space: S000210
property: P000208
value: true
refs:
- doi: 10.1090/S0002-9939-1987-0891170-3
name: A distinguishing example in k-spaces (Isbell)
---

Given a cover of a non-empty subspace $S$, the least element of the subspace belongs to
a member of the cover that contains $S\setminus F$ for some finite set $F$.
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