Zobrazeno 1 - 10
of 14
pro vyhledávání: '"STEFAN V. VATEV"'
Autor:
RUMEN DIMITROV, VALENTINA HARIZANOV, ANDREY MOROZOV, PAUL SHAFER, ALEXANDRA A. SOSKOVA, STEFAN V. VATEV
Cohesive powers of computable structures are effective analogs of ultrapowers, where cohesive sets play the role of ultrafilters. Let $\omega$, $\zeta$, and $\eta$ denote the respective order-types of the natural numbers, the integers, and the ration
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0a82405c627d611ed2e733171f478881
Autor:
Stefan V. Vatev, Nikolay Bazhenov
Publikováno v:
Lecture Notes in Computer Science ISBN: 9783030514655
CiE
CiE
We continue the study of computable embeddings for pairs of structures, i.e. for classes containing precisely two non-isomorphic structures. Surprisingly, even for some pairs of simple linear orders, computable embeddings induce a non-trivial degree
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::516d930157419f8db4b2dc3c56698ddc
https://doi.org/10.1007/978-3-030-51466-2_1
https://doi.org/10.1007/978-3-030-51466-2_1
Autor:
Valentina S. Harizanov, Alexandra A. Soskova, Stefan V. Vatev, Wesley Calvert, A. N. Frolov, Julia F. Knight, Charles F. D. McCoy
Publikováno v:
Journal of Logic and Computation. 28:1499-1522
We say that a structure $\mathcal{A}$ admits \emph{strong jump inversion} provided that for every oracle $X$, if $X'$ computes $D(\mathcal{C})'$ for some $\mathcal{C}\cong\mathcal{A}$, then $X$ computes $D(\mathcal{B})$ for some $\mathcal{B}\cong\mat
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0b83f8f504e289d1b390c34bf3884f2e
https://doi.org/10.1093/logcom/exy025
https://doi.org/10.1093/logcom/exy025
There is a Turing computable embedding $\Phi$ of directed graphs $A$ in undirected graphs. Moreover, there is a fixed tuple of formulas that give a uniform interpretation; i.e., for all directed graphs $A$, these formulas interpret $A$ in $\Phi(G)$.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::644e84c5507e99aded23b79de4ed5da0
Autor:
Valentina S. Harizanov, Andrei S. Morozov, Paul Shafer, Rumen D. Dimitrov, Alexandra A. Soskova, Stefan V. Vatev
Publikováno v:
Computing with Foresight and Industry ISBN: 9783030229955
CiE
CiE
Cohesive powers of computable structures can be viewed as effective ultraproducts over effectively indecomposable sets called cohesive sets. We investigate the isomorphism types of cohesive powers \(\varPi _{C} \mathcal {L}\) for familiar computable
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::17d13e13fd665cca6d40093da778e76b
https://doi.org/10.1007/978-3-030-22996-2_15
https://doi.org/10.1007/978-3-030-22996-2_15
Publikováno v:
Computing with Foresight and Industry ISBN: 9783030229955
CiE
CiE
We study computable embeddings for pairs of structures, i.e. for classes containing precisely two non-isomorphic structures. We show that computable embeddings induce a non-trivial degree structure for two-element classes consisting of computable str
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::824f6d536c4e6816427475ffa71192a7
https://doi.org/10.1007/978-3-030-22996-2_8
https://doi.org/10.1007/978-3-030-22996-2_8
Autor:
Stefan V. Vatev
Publikováno v:
Lecture Notes in Computer Science ISBN: 9783642390524
CiE
CiE
In this paper we investigate the question of existence of a jump inversion structure for a given structure \(\mathcal{A}\) in the context of their respective degree spectra and the sets definable in them by computable infinitary formulae. More specif
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::728ec4cb203966fae91b79339598e9e0
https://doi.org/10.1007/978-3-642-39053-1_49
https://doi.org/10.1007/978-3-642-39053-1_49
Autor:
Stefan V. Vatev
Publikováno v:
Models of Computation in Context ISBN: 9783642218743
CiE
CiE
In the present paper we investigate a relation, called conservative extension, between abstract structures A and B, possibly with different signatures and |A| ⊆ |B|. We give a characterisation of this relation in terms of computable Σn formulae an
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0fa0e542cb7eb8a45e4c3fafa512cf81
https://doi.org/10.1007/978-3-642-21875-0_32
https://doi.org/10.1007/978-3-642-21875-0_32
Autor:
DIMITROV, RUMEN, HARIZANOV, VALENTINA, MOROZOV, ANDREY, SHAFER, PAUL, SOSKOVA, ALEXANDRA A., VATEV, STEFAN V.
Publikováno v:
Journal of Symbolic Logic; Sep2023, Vol. 88 Issue 3, p947-1004, 58p
Publikováno v:
Journal of Symbolic Logic; Sep2023, Vol. 88 Issue 3, pf1-f3, 3p