Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Computability in partial combinatory algebras   We prove a number of elementary facts about computability in partial
combinatory algebras (pca's). We disprove a suggestion made by Kreisel about
using Friedberg numberings to construct extensional pca's. We then discuss
separability and elements without total extensions. We relate this to Ershov's
notion of precompleteness, and we show that precomplete numberings are not 1-1
in general.

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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: stat
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The categories of this paper are: supr-con
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The categories of this paper are: eess
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: quant-ph