منابع مشابه
Subdirectly irreducible separable dynamic algebras
A characterization of the subdirectly irreducible separable dynamic algebras is presented. The notions developed for this study were also suitable to describe the previously found class of the simple separable dynamic algebras.
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In this paper we give suitable notions of congruences and subdirectly irreducible algebras for the class of quasi-modal algebras introduced in [1]. We also prove some characterizations of subdirectly irreducible algebras following the similar results given by G. Sambin [5] for modal algebras.
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This paper is centred around a nice conjecture, known to Wolfgang Rautenberg and myself since 1978: a modal algebra A is subdirectly irreducible if and only if its dual frame A∗ is initial, or generated (see definitions in the text). I here show that in full generality the conjecture is false, but that it becomes true under some mild additional assumptions. Unfortunately, some counterexamples s...
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We give a characterization of the simple, and of the subdirectly irreducible boolean algebras with operators (including modal algebras), in terms of the dual descriptive frame. These characterizations involve a special binary quasi-reachability relation on the dual structure; we call a point u a quasi-root of the dual structure if every ultrafilter is quasireachable from u. We prove that a bool...
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We prove that a finite unary algebra with at least two operation symbols is a homomorphic image of a (finite) subdirectly irreducible algebra if and only if the intersection of all its subalgebras which have at least two elements is nonempty. We are concerned with the following question: Which algebras are homomorphic images of subdirectly irreducible algebras? A necessary condition, discovered...
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ژورنال
عنوان ژورنال: Czechoslovak Mathematical Journal
سال: 2003
ISSN: 0011-4642,1572-9141
DOI: 10.1023/b:cmaj.0000024509.21971.44