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...
In [2], Downey and Greenberg use the ordinals below ε0 to bound the number of mind-changes of comput...
Abstract. We prove that the degree structures of the d.c.e. and the 3-c.e. Turing degrees are not el...
In this article, we investigate model-theoretic properties of various Turing degree structures in th...
In this paper we investigate questions about the definability of classes of n-computably enumerable ...
© 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 ...
This thesis is concerned with three special properties of Turing degree structure and the Ershov hie...
© 2018 - IOS Press and the authors. All rights reserved. In 1971 B. Cooper proved that there exists ...
© 2018, Pleiades Publishing, Ltd. Questions of definability of computably enumerable degrees in the ...
Abstract. An n-r.e. set can be defined as the symmetric difference of n recursively enumerable sets....
© Springer International Publishing AG 2017.This paper is a survey on the upper semilattices of Turi...
Abstract. This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. O...
© 2019 Elsevier B.V. In the late 1980s, Selivanov used typed Boolean combinations of arithmetical se...
In [2], Downey and Greenberg use the ordinals below ε0 to bound the number of mind-changes of comput...
Abstract. We prove that the degree structures of the d.c.e. and the 3-c.e. Turing degrees are not el...
In this article, we investigate model-theoretic properties of various Turing degree structures in th...
In this paper we investigate questions about the definability of classes of n-computably enumerable ...
© 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 ...
This thesis is concerned with three special properties of Turing degree structure and the Ershov hie...
© 2018 - IOS Press and the authors. All rights reserved. In 1971 B. Cooper proved that there exists ...
© 2018, Pleiades Publishing, Ltd. Questions of definability of computably enumerable degrees in the ...
Abstract. An n-r.e. set can be defined as the symmetric difference of n recursively enumerable sets....
© Springer International Publishing AG 2017.This paper is a survey on the upper semilattices of Turi...
Abstract. This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. O...
© 2019 Elsevier B.V. In the late 1980s, Selivanov used typed Boolean combinations of arithmetical se...
In [2], Downey and Greenberg use the ordinals below ε0 to bound the number of mind-changes of comput...
Abstract. We prove that the degree structures of the d.c.e. and the 3-c.e. Turing degrees are not el...