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Перегляд Algebra and Discrete Mathematics, 2003, Vol. 2 за датою випуску

Репозиторій DSpace/Manakin

Перегляд Algebra and Discrete Mathematics, 2003, Vol. 2 за датою випуску

Сортувати за: Порядок: Результатів:

  • A note on maximal ideals in ordered semigroups 
    Kehayopulu, N.; Ponizovskii, J.; Tsingelis, M. (Algebra and Discrete Mathematics, 2003)
    In commutative rings having an identity element, every maximal ideal is a prime ideal, but the converse statement does not hold, in general. According to the present note, similar results for ordered semigroups and ...
  • Green’s relations on the seminearring of full hypersubstitutions of type (n) 
    Changphas, Th.; Denecke, K. (Algebra and Discrete Mathematics, 2003)
    Hypersubstitutions are mappings which are used to define hyperidentities and solid varieties. In this paper we will show that the set of all hypersubstitutions of a given type forms a seminearring. We will give a full ...
  • On intersections of normal subgroups in free groups 
    Kulikova, O.V. (Algebra and Discrete Mathematics, 2003)
    Let N₁ (respectively N₂) be a normal closure of a set R₁ = {ui} (respectively R₂ = {vj}) of cyclically reduced words of the free group F(A). In the paper we consider geometric conditions on R₁ and R₂ for N₁ ∩ N₂ = [N₁, ...
  • Hyperbolic spaces from self-similar group actions 
    Nekrashevych, V. (Algebra and Discrete Mathematics, 2003)
    We show that the limit space of a contracting selfsimilar group action is the boundary of a naturally defined Gromov hyperbolic space.
  • Multi-algebras from the viewpoint of algebraic logic 
    Cırulis, J. (Algebra and Discrete Mathematics, 2003)
    Where U is a structure for a first-order language L ≈ with equality ≈, a standard construction associates with every formula f of L ≈ the set kfk of those assignments which fulfill f in U. These sets make up a (cylindric ...
  • Ramseyan variations on symmetric subsequences 
    Verbitsky, O. (Algebra and Discrete Mathematics, 2003)
    A theorem of Dekking in the combinatorics of words implies that there exists an injective order-preserving transformation f : {0, 1, . . . , n} → {0, 1, . . . , 2n} with the restriction f(i + 1) ≤ f(i) + 2 such that for ...
  • An additive divisor problem in Z[i] 
    Savasrtu, O.V.; Varbanets, P.D. (Algebra and Discrete Mathematics, 2003)
  • On subgroups of saturated or totally bounded paratopological groups 
    Banakh, T.; Ravsky, S. (Algebra and Discrete Mathematics, 2003)
    A paratopological group G is saturated if the inverse U ⁻¹ of each non-empty set U ⊂ G has non-empty interior. It is shown that a [first-countable] paratopological group H is a closed subgroup of a saturated (totally ...
  • Binary coronas of balleans 
    Protasov, I.V. (Algebra and Discrete Mathematics, 2003)
    A ballean B is a set X endowed with some family of subsets of X which are called the balls. We postulate the properties of the family of balls in such a way that a ballean can be considered as an asymptotic counterpart ...
  • H- and R-cross-sections of the full finite semigroup Tn 
    Pyekhtyeryev, V. (Algebra and Discrete Mathematics, 2003)
    All H− and R− cross-sections of the full finite semigroup Tn of all transformations of the set N = {1, 2, . . . , n} are described.
  • N – real fields 
    Feigelstock, S. (Algebra and Discrete Mathematics, 2003)
    A field F is n-real if −1 is not the sum of n squares in F. It is shown that a field F is m-real if and only if rank (AAt ) = rank (A) for every n × m matrix A with entries from F. An n-real field F is n-real closed ...
  • On check character systems over quasigroups and loops 
    Belyavskaya, G.B. (Algebra and Discrete Mathematics, 2003)
    In this article we study check character systems that is error detecting codes, which arise by appending a check digit an to every word a₁a₂...an₋₁ : a₁a₂...an₋₁ → a₁a₂...an₋₁an with the check formula (...((a₁ · δa₂) · δ ...
  • An algebraic version of the Strong Black Box 
    Göbel, R.; Wallutis, S.L. (Algebra and Discrete Mathematics, 2003)
    Various versions of the prediction principle called the “Black Box” are known. One of the strongest versions can be found in [EM]. There it is formulated and proven in a model theoretic way. In order to apply it to ...
  • Structural properties of extremal asymmetric colorings 
    Verbitsky, O. (Algebra and Discrete Mathematics, 2003)
    Let Ω be a space with probability measure µ for which the notion of symmetry is defined. Given A ⊆ Ω, let ms(A) denote the supremum of µ(B) over symmetric B ⊆ A. An r-coloring of Ω is a measurable map χ : Ω → {1, . . . , ...
  • On equivalence of some subcategories of modules in Morita contexts 
    Kashu, A.I. (Algebra and Discrete Mathematics, 2003)
  • Flows in graphs and the homology of free categories 
    Husainov, A.A.; Calısıcı, H. (Algebra and Discrete Mathematics, 2003)
    We study the R−module of generalized flows in a graph with coefficients in the R−representation of the graph over a ring R with 1 and show that this R−module is isomorphic to the first derived functor of the colimit. ...
  • On 2-state Mealy automata of polynomial growth 
    Reznykov, I.I. (Algebra and Discrete Mathematics, 2003)
    We consider the sequence of 2-state Mealy automata over the finite alphabets, that have polynomial growth orders and define the infinitely presented automatic transformation semigroups.
  • On the separability of the restriction functor 
    Theohari-Apostolidi, Th.; Vavatsoulas, H. (Algebra and Discrete Mathematics, 2003)
    Let G be a group, Λ = L σ∈G Λσ a strongly graded ring by G, H a subgroup of G and ΛH = L σ∈H Λσ. We give a necessary and sufficient condition for the ring Λ/ΛH to be separable, generalizing the corresponding result ...
  • On a group theoretical construction of expanding graphs 
    Ustimenko, V.A. (Algebra and Discrete Mathematics, 2003)
  • On power structures 
    Bosnjak, I.; Madarasz, R. (Algebra and Discrete Mathematics, 2003)
    In general, power structure of a structure A (with universe A) is an appropriate structure defined on the power set P(A). There are lot of papers concerning this topic in which power structures appear explicitly or ...

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