Add to ORKG© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimWe introduce a hierarchy of sets which can be derived from the integers using countable collections. Such families can be coded into countable algebraic structures preserving their algorithmic properties. We prove that for different finite levels of the hierarchy the corresponding algebraic structures have different classes of possible degree spectra
We survey known results on spectra of structures and on spectra of relations on computable structure...
In this paper we investigate questions about the definability of classes of n-computably enumerable ...
Abstract. This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. O...
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimWe introduce a hierarchy of sets which can be deriv...
© J.UCS.In this paper we introduce a hierarchy of families which can be derived from the integers us...
In this paper we introduce a hierarchy of families which can be derived from the integers using coun...
This paper is a survey of results on countable families with natural degree spectra. These results w...
We study the enumerability of families relative to the enumeration degrees. It is shown that if a fa...
© 2016, Association for Symbolic Logic.We study Turing degrees a for which there is a countable stru...
Generalizations to various levels of Ershov's hierarchy of the relationship between n-computable enu...
If ν and μ are some Δcomputable numberings of families of sets of the naturals then P(x,y) ⇔ ν(x)′ ≠...
Abstract. Given a countable structure A, we dene the degree spectrum DS(A) of A to be the set of all...
We survey known results on spectra of structures and on spectra of relations on computable structure...
In this paper we investigate questions about the definability of classes of n-computably enumerable ...
Abstract. This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. O...
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimWe introduce a hierarchy of sets which can be deriv...
© J.UCS.In this paper we introduce a hierarchy of families which can be derived from the integers us...
In this paper we introduce a hierarchy of families which can be derived from the integers using coun...
This paper is a survey of results on countable families with natural degree spectra. These results w...
We study the enumerability of families relative to the enumeration degrees. It is shown that if a fa...
© 2016, Association for Symbolic Logic.We study Turing degrees a for which there is a countable stru...
Generalizations to various levels of Ershov's hierarchy of the relationship between n-computable enu...
If ν and μ are some Δcomputable numberings of families of sets of the naturals then P(x,y) ⇔ ν(x)′ ≠...
Abstract. Given a countable structure A, we dene the degree spectrum DS(A) of A to be the set of all...
We survey known results on spectra of structures and on spectra of relations on computable structure...
In this paper we investigate questions about the definability of classes of n-computably enumerable ...
Abstract. This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. O...