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Browsing Публикации сотрудников КФУ Scopus by Author "Yamaleev M."

Browsing Публикации сотрудников КФУ Scopus by Author "Yamaleev M."

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  • Classifying equivalence relations in the Ershov hierarchy 
    Bazhenov N.; Mustafa M.; San Mauro L.; Sorbi A.; Yamaleev M. (2020)
    © 2020, The Author(s). Computably enumerable equivalence relations (ceers) received a lot of attention in the literature. The standard tool to classify ceers is provided by the computable reducibility ⩽ c. This gives rise ...
  • Computable isomorphisms of distributive lattices 
    Bazhenov N.; Mustafa M.; Yamaleev M. (2019)
    © Springer Nature Switzerland AG 2019. A standard tool for the classifying computability-theoretic complexity of equivalence relations is provided by computable reducibility. This gives rise to a rich degree-structure which ...
  • Degrees of categoricity of rigid structures 
    Bazhenov N.; Yamaleev M. (2017)
    © Springer International Publishing AG 2017. We prove that there exists a properly 2-c.e. Turing degree d which cannot be a degree of categoricity of a rigid structure.
  • Downward density of exact degrees 
    Liu J.; Wu G.; Yamaleev M. (2015)
    © 2015, Pleiades Publishing, Ltd. In this paper we study exact d.c.e. degrees, the class of d.c.e. degrees which is strictly between the class of degrees of tops of bubbles and the class of isolated d.c.e. degrees.We show ...
  • Elementary theories and structural properties of d-c.e. and n-c.e. degrees 
    Arslanov M.; Kalimullin I.; Yamaleev M. (2016)
    © 2016, Pleiades Publishing, Ltd.This paper is a survey on the upper semilattices of Turing and enumeration degrees of n-c.e. sets. Questions on the structural properties of these semilattices, and some model-theoretic ...
  • Nondensity of double bubbles in the D.C.E. degrees 
    Andrews U.; Kuyper R.; Lempp S.; Soskova M.; Yamaleev M. (2017)
    © Springer International Publishing AG 2017.In this paper, we show that the so-called “double bubbles” are not downward dense in the d.c.e. degrees. Here, a pair of d.c.e. degrees d1 > d2 > 0 forms a double bubble if all ...
  • Nonexistence of minimal pairs in L[d] 
    Fang C.; Liu J.; Wu G.; Yamaleev M. (2015)
    © Springer International Publishing Switzerland 2015. For a d.c.e. set D with a d.c.e. approximation (Formula presented.), the Lachlan set of D is defined as (Formula presented.). For a d.c.e. degree d, L[d] is defined as ...
  • On a problem of Ishmukhametov 
    Fang C.; Wu G.; Yamaleev M. (2013)
    Given a d.c.e. degree d, consider the d.c.e. sets in d and the corresponding degrees of their Lachlan sets. Ishmukhametov provided a systematic investigation of such degrees, and proved that for a given d.c.e. degree d > ...
  • On the Problem of Definability of the Computably Enumerable Degrees in the Difference Hierarchy 
    Arslanov M.; Yamaleev M. (2018)
    © 2018, Pleiades Publishing, Ltd. Questions of definability of computably enumerable degrees in the difference hierarchy (degrees of sets from finite levels of the Ershov difference hierarchy) are studied. Several approaches ...
  • Strong noncuppability in low computably enumerable degrees 
    Yamaleev M. (2010)
    We prove the existence of noncomputable low computably enumerable degrees b < a such that b is strongly noncuppable to a in the class R. © 2010 Allerton Press, Inc.
  • The d.r.e wtt-Degrees are Dense 
    Wang S.; Wu G.; Yamaleev M. (2019)
    © 2019, Springer Nature Switzerland AG. We prove in this paper that the d.r.e. wtt-degrees are dense, improving a result of Wu and Yamaleev. Our result is a direct generalization of Ladner and Sasso’s splitting theorem for ...
  • Turing Degrees in Refinements of the Arithmetical Hierarchy 
    Selivanov V.; Yamaleev M. (2018)
    © 2018, Springer Science+Business Media, LLC, part of Springer Nature. We investigate the problem of characterizing proper levels of the fine hierarchy (up to Turing equivalence). It is known that the fine hierarchy exhausts ...

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