Temat: closure - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Finite atomistic lattices that can be represented as lattices of quasivarieties
Autorzy:: Adaricheva, K.
Dziobiak, Wiesław
Gorbunov, V.
Powiązania:: https://bibliotekanauki.pl/articles/1208668.pdf
Data publikacji:: 1993
Wydawca:: Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:: atomistic lattice
quasivariety
Mal'cev problem
equa-closure operator
semilattice
Opis:: We prove that a finite atomistic lattice can be represented as a lattice of quasivarieties if and only if it is isomorphic to the lattice of all subsemilattices of a finite semilattice. This settles a conjecture that appeared in the context of [11].
Źródło:: Fundamenta Mathematicae; 1993, 142, 1; 19-43
0016-2736
Pojawia się w:: Fundamenta Mathematicae
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: An abstract version of Sierpińskis theorem and the algebra generated by A and CA functions
Autorzy:: Cichoń, J.
Morayne, Michał
Powiązania:: https://bibliotekanauki.pl/articles/1208631.pdf
Data publikacji:: 1993
Wydawca:: Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:: analytic sets
universal functions
Baire function
uniform closure
cardinal number
Opis:: We give an abstract version of Sierpiński's theorem which says that the closure in the uniform convergence topology of the algebra spanned by the sums of lower and upper semicontinuous functions is the class of all Baire 1 functions. Later we show that a natural generalization of Sierpiński's result for the uniform closure of the space of all sums of A and CA functions is not true. Namely we show that the uniform closure of the space of all sums of A and CA functions is a proper subclass of the space of all functions measurable with respect to the least class containing intersections of analytic and coanalytic sets and which is closed under countable unions (A and CA functions are analogues of lower and upper semicontinuous functions, respectively, when measurability with respect to open sets is replaced by that with respect to analytic sets).
Źródło:: Fundamenta Mathematicae; 1993, 142, 3; 263-268
0016-2736
Pojawia się w:: Fundamenta Mathematicae
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Universal normal bases for the abelian closure of the field of rational numbers
Autorzy:: Hachenberger, Dirk
Powiązania:: https://bibliotekanauki.pl/articles/1207081.pdf
Data publikacji:: 2000
Wydawca:: Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:: cyclotomic field
abelian closure
normal basis/element
universally normal basis/element
completely normal basis/element
trace-compatible sequence
Źródło:: Acta Arithmetica; 2000, 93, 4; 329-341
0065-1036
Pojawia się w:: Acta Arithmetica
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: On the Leibniz congruences
Autorzy:: Font, Josep
Powiązania:: https://bibliotekanauki.pl/articles/1361077.pdf
Data publikacji:: 1993
Wydawca:: Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:: deductive system
protoalgebraic logic
Gentzen calculus
closure operator
abstract logic
algebraizable logic
Leibniz congruence
selfextensional logic
logical matrices
algebraic logic
Opis:: The aim of this paper is to discuss the motivation for a new general algebraic semantics for deductive systems, to introduce it, and to present an outline of its main features. Some tools from the theory of abstract logics are also introduced, and two classifications of deductive systems are analysed: one is based on the behaviour of the Leibniz congruence (the maximum congruence of a logical matrix) and the other on the behaviour of the Frege operator (which associates to every theory the interderivability relation modulo the theory). For protoalgebraic deductive systems the class of algebras associated in general turns out to be the class of algebra reducts of reduced matrices, which is the algebraic counterpart usually considered for this large class of deductive systems; but in the general case the new class of algebras shows a better behaviour.
Źródło:: Banach Center Publications; 1993, 28, 1; 17-36
0137-6934
Pojawia się w:: Banach Center Publications
Dostawca treści:: Biblioteka Nauki

Artykuł

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