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Бинарный предикат, транзитивное замыкание, две-три переменные: сыграем в домино?
Логические исследования. 2023. Т. 29. № 1. С. 114–146.
Tiling problems are a convenient tool for studying algorithmic complexity of problems arising in various branches of mathematics, including logic. The paper describes modelling of domino problems using the first-order language, as well as some additional language constructs, some of which are not elementary. This enables us both to obtain simple proofs of known facts about undecidability of satisfiability problems for various fragments of the first-order language and to obtain some new results. It is known that the satisfiability problem for the first-order formulas containing at most two individual variables is decidable; it is also known that the transitivity of a binary relation and the composition of binary relations are first-order definable with formulas of three individual variables. We show that addition of the operator of transitivity test for a binary relation (or a stronger tool, the transitive closure operator), together with the operator of composition, results in an undecidable satisfiability problem for formulas with two individual variables, a single binary predicate letter, and equality.
Брычков М. Е., Незнанов А.А., Программирование 2026 № 4 С. 50–66
The matrix profile (MP) quickly became one of the most important time series preprocessing methods when it was introduced in 2016, facilitating the solution of a wide range of time series analysis problems, in particular anomaly and pattern detection problems. The high significance has led to the emergence of various tools for MP calculating, but ...
Added: October 9, 2026
ООО "Издательство Юрайт ", 2026.
The Collection of Olympiad Problems (COP) in Probability Theory and Mathematical Statistics (PTMS) is offered as a teaching aid primarily for university students and faculty as a developmental supplementary resource, expanding the range of problems to be solved in lectures, seminars, and out-of-class independent work with students in various formats, including (as the title suggests) ...
Added: October 9, 2026
Aleskerov F. T., Вайншток А. П., Делахова А. М. et al., Информационные процессы 2026 Т. 26 № 3 С. 895–913
The development and effective management of territorial entities are priority issues for all states, particularly in the context of the digital transformation of public administration. Over the past decade, the integration of information technologies into municipal and regional planning has significantly altered approaches to strategic development, service delivery, and public engagement. This paper describes the ...
Added: October 9, 2026
Kupavskii A., Noskov F., Forum of Mathematics, Sigma 2026 Vol. 14 Article 124
We call a family of $s$ sets $\{F_1, \ldots, F_s\}$ a sunflower with $s$ petals if, for any distinct $i, j \in [s]$, one has $F_i \cap F_j = \cap_{u = 1}^s F_u$. The set $C = \cap_{u = 1}^s F_u$ is called the {\it core} of the sunflower. It is a classical result of ...
Added: October 8, 2026
Flamarion M. V., Pelinovsky E., Chaos, Solitons and Fractals 2026 Vol. 213 No. 2 Article 119245
This article concerns the study of modulational instability in the rotated-modified Gardner–Whitham (rmGW) equation. This model incorporates both quadratic and cubic nonlinearities, similarly to the Gardner equation, while also retaining the fully dispersive character of the Whitham equation together with a large-scale dispersive term analogous to that in the Ostrovsky equation. Using a classical multiple-scale asymptotic expansion, we ...
Added: October 8, 2026
Люксембург А. А., УРСС, 2005.
Изучается возможность автоматизированного построения математических теорий. Рассматривается дедуктивная система, основанная на языке логики предикатов первого порядка, объектами системы являются математические выражения или формулы, которые описывают математические объекты или их свойства. В дедуктивной системе выводятся математические определения и теоремы. Для доказательства теорем используются методы автоматического доказательства. Разработан алгоритм, выводящий часть формул системы. Для решения задачи используется аппарат математической ...
Added: October 7, 2026
Aleskerov F. T., Chaika E., Дерендяев А. Б. et al., Procedia Computer Science 2026 No. 287 P. 590–595
Under conditions of dynamic socio-economic changes, effective planning and decision-making are key factors in ensuring a high quality of life for the population in territories. This paper presents a decision support system for territorial administrations for the development and implementation of sustainable development strategies, using one of the regions of the Russian Federation – the ...
Added: October 7, 2026
Bernardin C., Gonçalves P., Olla S., Mathematical Physics Analysis and Geometry 2024 Vol. 27 No. 7
We consider the macroscopic limit for the space-time density fluctuations in the open symmetric simple exclusion in the quasi-static scaling limit. We prove that the distribution of these fluctuations converge to a gaussian space-time field that is delta correlated in time but with long-range correlations in space. ...
Added: October 6, 2026
Bernardin C., Chhaibi R., Najnudel J. et al., Probability Theory and Related Fields 2026 Vol. 195 P. 1823–1875
We study the celebrated Shiryaev-Wonham filter (Wonham, W.M., in J. Soc. Ind. Appl. Math. 347–369, 1964) in its historical setup, where the hidden Markov jump process has two states. We are interested in the weak noise regime for the observation equation. Interestingly, this becomes a strong noise regime for the filtering equations. Earlier results of ...
Added: October 5, 2026
Ismailov A., Spiridonov V., Успехи математических наук 2026 Т. 81 № 5 С. 183–184
Получена новая формула для цепной дроби Аски–Вильсона в форме отношения двух q-гипер-геометрических рядов. ...
Added: October 5, 2026
Abdulkhaev K., Shirokov D., Advances in Applied Clifford Algebras 2026 Vol. 36 P. 1–21
In this paper, we present explicit formulas for the inverse and determinant in geometric (Clifford) algebras over vector spaces of dimension n = 7. The derivation of these formulas is made possible by generalizing the concept of conjugation to basis conjugation operations. We further develop a general method for constructing such formulas over odd-dimensional spaces ...
Added: October 4, 2026
Kuninets A., IEEE Transactions on Information Theory 2026 P. 1–1
In this work we study the applicability of Quasi-Cyclic Subfield Subcodes of Dual Elliptic (QC-SSDE) codes for integration into code-based cryptographic schemes. Detailed algorithms are provided for constructing parity-check matrices as well as block-circulant parity-check matrices for this family of codes, accompanied by empirical results that enable the construction of QC-SSDE codes with predetermined dimensions. ...
Added: October 3, 2026
Medvedev G., Alexandrov Artem, Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2026 Vol. 114 Article 044102
Graphons are measurable functions used to describe the asymptotic behavior of convergent graph families. Originally motivated by problems in combinatorics and graph theory, graphons have found numerous applications in the modeling and analysis of dynamical processes on networks. In this work, we use graphons to formulate the Ising model on convergent graph sequences, which include ...
Added: October 2, 2026
Pochinka O., Baranov D., Nozdrinova E., Теоретическая и математическая физика 2026 Т. 229 № 1 С. 3–14
The Birman–Williams problem on describing the planetary link of a fibered knot K in S^3 has been partially solved. Using Nielsen's theory for the classification of periodic surface homeomorphisms and its close relationship with the theory of gradient-like diffeomorphisms, it is proved that the planetary link of the trefoil (the unique periodic fibered knot of genus ...
Added: October 2, 2026
Lubashevsky I., Lubashevskiy V., Physica D: Nonlinear Phenomena 2026 Vol. 498 Article 135441
We develop a novel cloud-function formalism describing the dynamical relationship between sensory-information processing in large-scale brain networks (supraliminal processing) and the content of the mental representation of an observed object. The formalism combines elements of neural field theory for large-scale neural activity with the spatial characteristics of perceived objects and their embedding in the environment ...
Added: October 2, 2026
Zlotnik A., Математические заметки 2026 Т. 120 № 6 С. 1005–1009
Численным методам решения систем газодинамических уравнений посвящена обширная литература. Ранее было разработано и успешно апробировано специальное семейство симметричных по пространству консервативных разностных методов, основанных на предварительной кинетической, точнее, квазигазодинамической (КГД), регуляризации этих уравнений. Актуальной задачей является построение численных методов, которые обладают не только свойством консервативности по массе, импульсу и полной энергии, но и удовлетворяют условиям энтропийной ...
Added: October 1, 2026
Vyugin I. V., Sashadhar D., Algebra and Number Theory 2026 P. 1–10
We study the K-Fibonacci sequence Fp modulo prime p. Cardinalities of sets |Fp+Fp| and |Fp⋅Fp| are estimated. We present the method of estimating doubling constant of some m-dimensional recurrent sets in Fp. ...
Added: October 1, 2026
Rezunik L., Alexandrov D., Mikhail Prozorskiy, , in: Intelligent Decision Technologies. Proceedings of the 17th KES-IDT 2025 ConferenceVol. 450.: Cham: Springer, 2026. P. 81–91.
Multi-Agent Systems (MAS) can benefit from Large Language Models (LLMs), but hallucinations pose risks to decision-making. This paper introduces an approach for creating MAS based on LLMs and proposes a generalized architecture for such systems. We ensure that reasoning is conducted through predicate logic to minimize errors, and LLMs are exclusively utilized to translate natural ...
Added: September 14, 2026
Dudakov S., Математика и теоретические компьютерные науки 2024 Т. 2 № 4 С. 51–65
We study the additive theory of arbitrary figures in linear spaces, that is, the theory of addition extended to sets of vectors. Our main result is the following: if a linear space is infinite, then the additive theory of figures allows to interpret second-order arithmetic and, therefore, has this or higher degree of undecidability. For ...
Added: March 18, 2026
Dudakov S., Вестник Тверского государственного университета. Серия: Прикладная математика 2025 № 1 С. 5–13
For infinite linear spaces, in our previous works, we have shown that theories of figures and subspaces are of high undecidability degree. They allow interpreting elementary arithmetic or second-order arithmetic (for infinite figures). For finite linear spaces, such a claim doesn't hold. It is because we can algorithmically enumerate all finite linear spaces and find ...
Added: March 18, 2026
Dudakov S., Известия РАН. Серия математическая 2025 Т. 89 № 2 С. 3–24
We consider algebras of finite subsets under the assumption that the original algebra is an infinite groupoid. For linear spaces over fields of finite characteristic, we prove that the finite subsets algebra is algorithmically equivalent to the first-order arithmetic. We also generalize this result to arbitrary infinite Abelian groups. As a corollary, for many classes ...
Added: March 18, 2026
Rybakov M., Вестник Тверского государственного университета. Серия: Прикладная математика 2023 № 1 С. 5–23
Доказывается неразрешимость и сильная неразрешимость (неарифметичность) теорий классов деревьев (при различных уточнениях понятия дерева и при различных требованиях к свойствам деревьев, включая конечность числа вершин) в языке с бинарной предикатной буквой, соответствующей дугам, равенством, оператором транзитивного замыкания и конгруэнтностью между парами вершин, которая определяется как равенство расстояния между вершинами первой пары расстоянию между вершинами второй ...
Added: July 7, 2023
The symmetric Post Correspondence Problem, and errata for the freeness problem for matrix semigroups
Birget J., Talambutsa A., International Journal of Algebra and Computation 2022 Vol. 32 No. 6 P. 1261–1274
In this paper, we define the symmetric Post Correspondence Problem (PCP) and prove that it is undecidable. As an application, we show that the original proof of undecidability of the freeness problem for 3×3 integer matrix semigroups works for the symmetric PCP, but not for the PCP in general. ...
Added: December 9, 2022
Poddiakov A., В кн.: Когнитивная психология.: М., Саратов: ПЕР СЭ, Ай Пи Эр Медиа, 2024. С. 202–204.
Рассматривается значение алгоритмической неразрешимости для когнитивной психологии. ...
Added: October 29, 2021