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Degree spectra of unary relations on \(\langle \omega, \leq \rangle\). (English) Zbl 1419.03038

Glymour, Clark (ed.) et al., Logic, methodology and philosophy of science. Proceedings of the 13th international congress, Beijing, China, August 2007. London: College Publications. 36-55 (2009).
Summary: A computable presentation of the linearly ordered set \((\omega,\le)\), where \(\omega\) is the set of natural numbers and \(\le\) is the natural order on \(\omega\), is any linearly ordered set \(\mathbf{L}=(\omega,\le_L)\) isomorphic to \((\omega,\le)\) such that \(\le_L\) is a computable relation. Let \(X\) be subset of \(\omega\) and \(X_L\) be the image of \(X\) in the linear order \(\mathbf{L}\) under the isomorphism between \((\omega,\le)\) and \(\mathbf{L}\). The degree spectrum of \(X\) is the set of all Turing degrees of \(X_L\) as one runs over all computable presentations of \((\omega,\le)\). In this paper we study the degree spectra of subsets of \(\omega\).
For the entire collection see [Zbl 1309.03002].

MSC:

03D20 Recursive functions and relations, subrecursive hierarchies
03D25 Recursively (computably) enumerable sets and degrees
03D45 Theory of numerations, effectively presented structures