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Перегляд Algebra and Discrete Mathematics, 2003, Vol. 2 за назвою

Репозиторій DSpace/Manakin

Перегляд Algebra and Discrete Mathematics, 2003, Vol. 2 за назвою

Сортувати за: Порядок: Результатів:

  • 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.
  • 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 ...
  • 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 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 a group theoretical construction of expanding graphs 
    Ustimenko, V.A. (Algebra and Discrete Mathematics, 2003)
  • 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 ...
  • On equivalence of some subcategories of modules in Morita contexts 
    Kashu, A.I. (Algebra and Discrete Mathematics, 2003)
  • On equivalence of some subcategories of modules in Morita contexts 
    Kashu, A.I. (Algebra and Discrete Mathematics, 2003)
  • On faithful actions of groups and semigroups by orientation-preserving plane isometries 
    Vorobets, Y. (Algebra and Discrete Mathematics, 2003)
    Feitful representations of two generated free groups and free semigroups by orientation-preserving plane isometries constructed.
  • 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, ...
  • On large indecomposable modules, endo-wild representation type and right pure semisimple rings 
    Simson, D. (Algebra and Discrete Mathematics, 2003)
    The existence of large indecomposable right Rmodules over a right artinian ring R is discussed in connection with the pure semisimplicity problem and the endo-wildness of the category Mod(R) of right R-modules. Some ...
  • 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 ...
  • 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 ...
  • On the representation of a number as a sum of the k-th powers in an arithmetic progression 
    Prosyanyuk, N.S. (Algebra and Discrete Mathematics, 2003)
    In this paper we obtain the asymptotic formula for a natural n ≤ x which representate as a sum of two non-negative k-th powers in an arithmetic progression.
  • 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 ...
  • Post-critically finite self-similar groups 
    Bondarenko, E.; Nekrashevych, V. (Algebra and Discrete Mathematics, 2003)
    We describe in terms of automata theory the automatic actions with post-critically finite limit space. We prove that these actions are precisely the actions by bounded automata and that any self-similar action by bounded ...
  • Principal quasi-ideals of cohomological dimension 1 
    Novikov, B.V. (Algebra and Discrete Mathematics, 2003)
    We prove that a principal quasi-ideal of a noncommutative free semigroup has cohomological dimension 1 if and only if it is free.
  • 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 ...
  • 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, . . . , ...

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