PL
 |
EN
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 16

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  universal algebra
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Two Infinite Sequences of Pre-Maximal Extensions of the Relevant Logic E
100%
Typańska-Czajka L.
Bulletin of the Section of Logic
|
2019
|
tom 48
|
nr 1
EN
The only maximal extension of the logic of relevant entailment E is the classical logic CL. A logic L ⊆ [E,CL] called pre-maximal if and only if L is a coatom in the interval [E,CL]. We present two denumerable infinite sequences of premaximal extensions of the logic E. Note that for the relevant logic R there exist exactly three pre-maximal logics, i.e. coatoms in the interval [R,CL].
2
Structural Features in Ernst Schröder’s Work. Part I
100%
Bondoni D.
|
|
tom 20
|
nr 4
327-359
EN
In this paper articulated in two parts we propose a structural interpretation of Schröder’s work, pointing out his insistence on the priority of a whole in comparison with its parts. The examples are taken from the diverse areas in which Schröder was active, with a particular interest in his project of an absolute algebra. I am regretting for the bad quality of my English, hoping that notwithstanding the reader can grasp at least the fundamental tracts of my reasoning.
3
Structural Features in Ernst Schröder’s Work. Part II
100%
Bondoni D.
|
2012
|
tom 21
|
nr 3
271-315
EN
In this paper (the second of two parts) we propose a structural interpretation of Schroder’s work, pointing out his insistence on the priority of a whole in comparison with its parts. The examples are taken from the diverse areas in which Schroder was active, with a particular interest in his project of an absolute algebra.
4
Content available remote Weak products of universal algebras
100%
Sain I.
|
|
tom 28
|
nr 1
311-318
EN
Weak direct products of arbitrary universal algebras are introduced. The usual notion for groups and rings is a special case. Some universal algebraic properties are proved and applications to cylindric and polyadic algebras are considered.
5
Content available remote Equational bases for k-normal identities
100%
Penner P. , Wismath S.
|
2008
|
tom Vol. 41, nr 4
733-742
EN
The depth of a term may be used as a measurement of complexity of identities. For any natural number [...] have depth at least k. For any variety V, the k-normalization of V is the variety Nk(V) defined by all k-normal identities of V. We describe a process to produce from a basis for V a basis for Nk(V), for any variety V which has an idempotent term; when the type of V is finite and V is finitely based, this results in a finite basis for Nk(V) as well. This process encompasses several known examples, for varieties of bands and lattices, and allows us to give a new basis for the normalization of the variety PL of pseudo-complemented lattices.
6
Content available Minimal formations of universal algebras
100%
Guo W. , Shum K.
Discussiones Mathematicae - General Algebra and Applications
|
2001
|
tom 21
|
nr 2
201-205
EN
A class ℱ of universal algebras is called a formation if the following conditions are satisfied: 1) Any homomorphic image of A ∈ ℱ is in ℱ; 2) If α₁, α₂ are congruences on A and $A/α_{i} ∈ ℱ$, i = 1,2, then A/(α₁∩α₂) ∈ ℱ. We prove that any formation generated by a simple algebra with permutable congruences is minimal, and hence any formation containing a simple algebra, with permutable congruences, contains a minimum subformation. This result gives a partial answer to an open problem of Shemetkov and Skiba on formations of finite universal algebras proposed in 1989.
7
Content available remote Bisimulation Cuts For Structuring Markov Transition Systems
88%
Doberkat E.-E.
Fundamenta Informaticae
|
2016
|
tom Vol. 149, nr 4
363--383
EN
In Universal Algebra the structure of congruences for algebraic systems is fairly well investigated, and the relationship to the structure of the underlying system proper is well known. We propose a first step into this direction for studying the structure of congruences for stochastic relations. A Galois connection to a certain class of Boolean σ-algebras is exploited, atoms and antiatoms are identified, and it is show that a σ-basis exists. These constructions are applied to the problem of finding bisimulation cuts of a congruence. It cuts the relation through a span of morphisms with a minimum of joint events.
8
Content available remote Commutative loops of exponent 3 with x.(x.y)2=y2
88%
Armanious M.
|
2002
|
tom Vol. 35, nr 3
469-475
EN
It is well known that the class of Hall triple systems [5], Steiner triple systems in which each triangle generates an affine plane over GF(3), corresponds to the class of commutative Moufang loops of exponent 3 [6]. In this paper, we extend the class of algebras to the class of all commutative loops of exponent 3 satisfying the identity x.(x.y)2=y2, corresponding to the class of all Steiner triple systems. Such a commutative loop of exponent 3 with x . (x o y)2 = y2 is polynomially equivalent to a squag.
9
Content available remote Submonoids of generalized hypersubstitutions
75%
Leeratanavalee S.
|
2007
|
tom Vol. 40, nr 1
13-22
EN
In this paper we define the operation G on the set of all generalized hypersubstitutions and investigate some algebraic-structural properties of the set of all generalized hypersubstitutions and of some submonoids M of the set of all generalized hypersubstitutions, respectively.
10
Content available remote M-hyperquasivarieties
75%
Graczyńska E. , Schweigert D.
|
2006
|
tom Vol. 39, nr 1
33-42
EN
We consider the notion of M-hyper-quasi-identities and M-hyperquasi-varieties, as a common generalization of the concept of quasi-identity (hyper-quasi-identity) and quasivariety (hyper-quasivariety) invented by A. I. Mal'cev, cf. [13], cf. [6] and hypervariety invented by the authors in [15], [8] and hy p erqu as i variety [9]. The results of this paper were presented on the 69th Workshop on General Algebra, held at Potsdam University (Germany) on March 18-20, 2005.
11
Content available remote A note an algebraic characterization of higher level hypergraphs and higher level partitions
75%
Korczyński W.
|
2006
|
tom Vol. 39, nr 2
255-265
EN
In the paper the duality of the the notions of (higher) hypergraph and (higher) partition is shown. Both higher level hypergraphs and higher partitions are characterized algebr aically as left and right regular bands.
12
Content available remote Sameness between based universal algebras
75%
Ricci G.
|
2009
|
tom Vol. 42, nr 1
3-22
EN
This is the continuation of the paper "Transformations between Menger systems". To define when two universal algebras with bases "are the same", here we propose a universal notion of transformation that comes from a triple characterization concerning three representation facets: the determinations of the Menger system, analytic monoid and endomorphism representation corresponding to a basis. Hence, this notion consists of three equivalent definitions. It characterizes another technical variant and also the universal version of the very semi-linear transformations that were coordinate-free. Universal transformations allow us to check the actual invariance of general algebraic constructions, contrary to the seeming invariance of representation-free thinking. They propose a new interpretation of free algebras as superpositions of "analytic spaces" and deny that our algebras differ from vector spaces at fundamental stages. Contrary to present beliefs, even the foundation of abstract Linear Algebra turns out to be incomplete.
13
Content available remote Yet another note on congruence uniformity
75%
Goldstern M.
|
|
tom Vol. 38, nr 3
517--521
EN
We describe a countable unary algebra with few operations which is congruence uniform but not congruence regular, and we show that no uncountable algebra with these properties exists.
14
Content available remote Subdirect product representations of some unary extensions of semilattices
63%
Płonka J.
|
2008
|
tom Vol. 41, nr 2
263-272
EN
An algebra [...] represents the sequence so = (0, 3, l, l, . . .) if there are no constants in [...], there are exactly 3 distinct essentially unary polynomials in [...] and exactly l essentially n-ary polynomial in [...] for every n > l . It was proved in [4] that an algebra [..] represents the sequence so if and only if it is clone equivalent to a generic of one of three varieties V1, V2, V3, see Section l of [4]. Moreover, some representations of algebras from these varieties by means of semilattice ordered systems of algebras were given in [4] . In this paper we give another, by subdirect products, representation of algebras from V1, V2, V3. Moreover, we describe all subdirectly irreducible algebras from these varieties and we show that if an algebra [...] represents the sequence so, then it must be of cardinality at least 4.
15
Content available Decomposition of Congruence Modular Algebras into Atomic, Atomless Locally Uniform and Anti-Uniform Parts
63%
Staruch B. , Staruch B.
Bulletin of the Section of Logic
|
2016
|
tom 45
|
nr 3/4
EN
We describe here a special subdirect decomposition of algebras with modular congruence lattice. Such a decomposition (called a star-decomposition) is based on the properties of the congruence lattices of algebras. We consider four properties of lattices: atomic, atomless, locally uniform and anti-uniform. In effect, we describe a star-decomposition of a given algebra with modular congruence lattice into two or three parts associated to these properties.
16
Content available Irredundant Decomposition of Algebras into One-Dimensional Factors
63%
Staruch B.
Bulletin of the Section of Logic
|
2016
|
tom 45
|
nr 3/4
EN
We introduce a notion of dimension of an algebraic lattice and, treating such a lattice as the congruence lattice of an algebra, we introduce the dimension of an algebra, too. We define a star-product as a special kind of subdirect product. We obtain the star-decomposition of algebras into one-dimensional factors, which generalizes the known decomposition theorems e.g. for Abelian groups, linear spaces, Boolean algebras.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.