منابع مشابه
Maltsev Families of Varieties Closed under Join or Maltsev Product
Maltsev families of varieties which are closed under join or Maltsev product are investigated. New Maltsev conditions for congruence semi-distributivity are given.
متن کاملMaltsev + Datalog --> Symmetric Datalog
Let B be a finite, core relational structure and let A be the algebra associated to B, i.e. whose terms are the operations on the universe of B that preserve the relations of B. We show that if A generates a so-called arithmetical variety then CSP(B), the constraint satisfaction problem associated to B, is solvable in Logspace; in fact ¬CSP(B) is expressible in symmetric Datalog. In particular,...
متن کاملLocalizations of Maltsev Varieties
We give an abstract characterization of categories which are localizations of Maltsev varieties. These results can be applied to characterize localizations of naturally Maltsev varieties.
متن کاملMaltsev on Top
Let A be an idempotent algebra, α ∈ ConA such that A/α has few subpowers, and m be a fixed natural number. There is a polynomial time algorithm that can transform any constraint satisfaction problem over A with relations of arity at most m into an equivalent problem which is m consistent and in which each domain is inside an α block. Consequently if the induced algebras on the blocks of α gener...
متن کاملOn Maltsev Digraphs
We study digraphs preserved by a Maltsev operation: Maltsev digraphs. We show that these digraphs retract either onto a directed path or to the disjoint union of directed cycles, showing in this way that the constraint satisfaction problem for Maltsev digraphs is in logspace, L. We then generalize results from Kazda (2011) to show that a Maltsev digraph is preserved not only by a majority opera...
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ژورنال
عنوان ژورنال: Journal of Pure and Applied Algebra
سال: 1995
ISSN: 0022-4049
DOI: 10.1016/0022-4049(95)90021-7