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Overt choice

Matthew de Brecht, Arno Pauly Orcid Logo, Matthias Schröder

Computability, Volume: 9, Issue: 3-4, Pages: 169 - 191

Swansea University Author: Arno Pauly Orcid Logo

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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...

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Published in: Computability
ISSN: 2211-3568 2211-3576
Published: IOS Press 2020
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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.
Keywords: Weihrauch reducibility, computable topology, quasi-Polish space
College: Faculty of Science and Engineering
Issue: 3-4
Start Page: 169
End Page: 191