Add to ORKGIn this article, we investigate model-theoretic properties of various Turing degree structures in the hierarchy of Δ 0 2-sets which is well known in the literature as Ershov Hierarchy. In particular, questions of definability of m-c.e. degrees in the structure of n-c.e. degrees, where m<n, elementary equivalences, extendability of partial order extensions are considered. © 2010 The Author. Published by Oxford University Press. All rights reserved
© 2019 Elsevier B.V. In the late 1980s, Selivanov used typed Boolean combinations of arithmetical se...
Abstract. This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. O...
In [2], Downey and Greenberg use the ordinals below ε0 to bound the number of mind-changes of comput...
In this article, we investigate model-theoretic properties of various Turing degree structures in th...
© 2016, Pleiades Publishing, Ltd.This paper is a survey on the upper semilattices of Turing and enum...
In the paper we present a survey on n-c.e. Turing and e-degrees. Also we discuss some open problems ...
In this paper we investigate questions about the definability of classes of n-computably enumerable ...
© 2018 - IOS Press and the authors. All rights reserved. In 1971 B. Cooper proved that there exists ...
This thesis is concerned with three special properties of Turing degree structure and the Ershov hie...
© 2018, Pleiades Publishing, Ltd. Questions of definability of computably enumerable degrees in the ...
© Springer International Publishing AG 2017.This paper is a survey on the upper semilattices of Turi...
Abstract. An n-r.e. set can be defined as the symmetric difference of n recursively enumerable sets....
It is proved that if 1 < m < 2p ≤ n for some integer p then the elementary theories of posets of m-c...
Abstract. We prove that the degree structures of the d.c.e. and the 3-c.e. Turing degrees are not el...
© 2019 Elsevier B.V. In the late 1980s, Selivanov used typed Boolean combinations of arithmetical se...
Abstract. This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. O...
In [2], Downey and Greenberg use the ordinals below ε0 to bound the number of mind-changes of comput...
In this article, we investigate model-theoretic properties of various Turing degree structures in th...
© 2016, Pleiades Publishing, Ltd.This paper is a survey on the upper semilattices of Turing and enum...
In the paper we present a survey on n-c.e. Turing and e-degrees. Also we discuss some open problems ...
In this paper we investigate questions about the definability of classes of n-computably enumerable ...
© 2018 - IOS Press and the authors. All rights reserved. In 1971 B. Cooper proved that there exists ...
This thesis is concerned with three special properties of Turing degree structure and the Ershov hie...
© 2018, Pleiades Publishing, Ltd. Questions of definability of computably enumerable degrees in the ...
© Springer International Publishing AG 2017.This paper is a survey on the upper semilattices of Turi...
Abstract. An n-r.e. set can be defined as the symmetric difference of n recursively enumerable sets....
It is proved that if 1 < m < 2p ≤ n for some integer p then the elementary theories of posets of m-c...
Abstract. We prove that the degree structures of the d.c.e. and the 3-c.e. Turing degrees are not el...
© 2019 Elsevier B.V. In the late 1980s, Selivanov used typed Boolean combinations of arithmetical se...
Abstract. This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. O...
In [2], Downey and Greenberg use the ordinals below ε0 to bound the number of mind-changes of comput...