Journal article 898 views 199 downloads
Overt choice
Matthew de Brecht,
Arno Pauly 
,
Matthias Schröder
,
Matthias Schröder
Computability, Volume: 9, Issue: 3-4, Pages: 169 - 191
Swansea University Author:
Arno Pauly
-
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DOI (Published version): 10.3233/com-190253
Abstract
We introduce and study the notion of overt choice for countably-based spaces and for CoPolish spaces. Overt choice is the task of producing a point in a closed set specified by what open sets intersect it. We show that the question of whether overt choice is continuous for a given space is related t...
| Published in: | Computability |
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| ISSN: | 2211-3568 2211-3576 |
| Published: |
IOS Press
2020
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| Online Access: |
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| URI: | https://cronfa.swan.ac.uk/Record/cronfa53986 |
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| Abstract: |
We introduce and study the notion of overt choice for countably-based spaces and for CoPolish spaces. Overt choice is the task of producing a point in a closed set specified by what open sets intersect it. We show that the question of whether overt choice is continuous for a given space is related to topological completeness notions such as the Choquet-property; and to whether variants of Michael’s selection theorem hold for that space. For spaces where overt choice is discontinuous it is interesting to explore the resulting Weihrauch degrees, which in turn are related to whether or not the space is Fréchet–Urysohn. |
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| Keywords: |
Weihrauch reducibility, computable topology, quasi-Polish space |
| College: |
Faculty of Science and Engineering |
| Issue: |
3-4 |
| Start Page: |
169 |
| End Page: |
191 |