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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">kaz29</journal-id><journal-title-group><journal-title xml:lang="ru">Вестник Казахстанско-Британского технического университета</journal-title><trans-title-group xml:lang="en"><trans-title>Herald of the Kazakh-British Technical University</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">1998-6688</issn><issn pub-type="epub">2959-8109</issn><publisher><publisher-name>Казахстанско-Британский Технический Университет</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.55452/1998-6688-2023-20-2-67-72</article-id><article-id custom-type="elpub" pub-id-type="custom">kaz29-708</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>МАТЕМАТИЧЕСКИЕ НАУКИ</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>MATHEMATICAL SCIENCES</subject></subj-group></article-categories><title-group><article-title>АППРОКСИМАЦИИ ТЕОРИЙ СТРУКТУР С ОДНИМ ОТНОШЕНИЕМ ЭКВИВАЛЕНТНОСТИ</article-title><trans-title-group xml:lang="en"><trans-title>APPROXIMATIONS OF THE THEORIES OF STRUCTURES WITH ONE EQUIVALENCE RELATION</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-5088-0208</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Мархабатов</surname><given-names>Н. Д.</given-names></name><name name-style="western" xml:lang="en"><surname>Markhabatov</surname><given-names>N. D.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Мархабатов Нурлан Дарханулы, кафедра алгебры и геометрии</p><p>ул. Кажымукана, 13, Алматинский район, 010000, г. Астана</p></bio><bio xml:lang="en"><p>Markhabatov Nurlan Darkhanuly, Department of Algebra and Geometry</p><p>st. Kazhymukan 13, Almaty district, 010000, Astana</p></bio><email xlink:type="simple">nur_24.08.93@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru">Евразийский Национальный университет им. Л.Н.Гумилева<country>Казахстан</country></aff><aff xml:lang="en">Eurasian National University. L.N. Gumilyov<country>Kazakhstan</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2023</year></pub-date><pub-date pub-type="epub"><day>02</day><month>07</month><year>2023</year></pub-date><volume>20</volume><issue>2</issue><fpage>67</fpage><lpage>72</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Мархабатов Н.Д., 2023</copyright-statement><copyright-year>2023</copyright-year><copyright-holder xml:lang="ru">Мархабатов Н.Д.</copyright-holder><copyright-holder xml:lang="en">Markhabatov N.D.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://vestnik.kbtu.edu.kz/jour/article/view/708">https://vestnik.kbtu.edu.kz/jour/article/view/708</self-uri><abstract><p>В последнее время бурно развиваются различные методы, схожие к «принципу переноса», когда одно свойство структуры или частей этой структуры выполняется во всех бесконечных структурах или в другой алгебраической структуре. К таким методам относятся гладко аппроксимируемые структуры, голографические структуры, почти надежные теории и псевдоконечных структуры, аппроксимируемые конечными структурами. Псевдоконечные структуры — это математические структуры, которые напоминают конечные структуры, но на самом деле не являются конечными. Они важны в различных областях математики, включая теорию моделей и алгебраическую геометрию. Псевдоконечные структуры — это увлекательная область математической логики, которая устраняет разрыв между конечными и бесконечными структурами. Они позволяют изучать бесконечные структуры способами, напоминающими конечные структуры, и обеспечивают связь с различными другими концепциями теории моделей. Дальнейшее изучение псевдоконечных структур будет продолжать открывать новые идеи и приложения в математике и за ее пределами. Псевдоконечные теории — это раздел математической логики, изучающий структуры, которые в чем-то похожи на конечные структуры, но могут быть бесконечно большими в других отношениях. Это область исследований, которая находится на пересечении теории моделей и теории чисел и имеет дело с бесконечными структурами, которые имеют некоторые общие свойства с конечными структурами, например, имеют только конечное число элементов с точностью до изоморфизма. А. Лахлан ввел понятие гладко аппроксимируемых структур, чтобы изменить направление анализа с конечного на бесконечное, т. е. классифицировать большие конечные структуры, которые кажутся гладкими приближениями к бесконечному пределу. Теория псевдоконечных структур особенно актуальна для изучения отношений эквивалентности. В данной работе исследуется теоретико-модельное свойство теории отношений эквивалентности, в частности, свойство псевдоконечности. Пусть L = {E}, где E – отношение эквивалентности на L-структуре. Доказано, что любая ω-категоричная L-структура M гладко аппроксимируема. Также доказано, что любая бесконечная L-структура M является псевдоконечной.</p></abstract><trans-abstract xml:lang="en"><p>Recently, various methods similar to the “transfer principle” have been rapidly developing, where one property of a structure or pieces of this structure is satisfied in all infinite structures or in another algebraic structure. Such methods include smoothly approximable structures, holographic structures, almost sure theories, and pseudofinite structures approximable by finite structures. Pseudofinite structures are mathematical structures that resemble finite structures but are not actually finite. They are important in various areas of mathematics, including model theory and algebraic geometry. Pseudofinite structures are a fascinating area of mathematical logic that bridge the gap between finite and infinite structures. They allow studying infinite structures in ways that resemble finite structures, and they provide a connection to various other concepts in model theory. Further studying pseudofinite structures will continue to reveal new insights and applications in mathematics and beyond. Pseudofinite theory is a branch of mathematical logic that studies structures that are similar in some ways to finite structures, but can be infinitely large in other ways. It is an area of research that lies at the intersection of model theory and number theory and deals with infinite structures that share some properties with finite structures, such as having only finitely many elements up to isomorphism. A. Lachlan introduced the concept of smoothly approximable structures in order to change the direction of analysis from finite to infinite, that is, to classify large finite structures that seem to be smooth approximations to an infinite limit. The theory of pseudofinite structures is particularly relevant for studying equivalence relations. In this paper, we study the model-theoretic property of the theory of equivalence relations, in particular, the property of smooth approximability. Let L = {E}, where Е is an equivalence relation. We prove that an any ω-categorical L-structure M is smoothly approximable. We also prove that any infinite L-structure M is pseudofinite.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>псевдоконечная структура</kwd><kwd>псевдоконечная теория</kwd><kwd>отношение эквивалентности</kwd><kwd>аппроксимация</kwd><kwd>аппроксимация теории</kwd><kwd>гладко аппроксимируемая структура</kwd></kwd-group><kwd-group xml:lang="en"><kwd>pseudofinite structure</kwd><kwd>pseudofinite theory</kwd><kwd>equivalence relation</kwd><kwd>approximation</kwd><kwd>approximation of theory</kwd><kwd>smoothly approximable structure</kwd></kwd-group><funding-group xml:lang="en"><funding-statement>The study was partially supported by the Scientific Committee for Education and Science of the Republic of Kazakhstan (AP19674850, AP19677451).</funding-statement></funding-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Markhabatov N.D. 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