26 search results - page 2 / 6 » Closed and Logical Relations for Over- and Under-Approximati... |
CP
2010
Springer
13 years 3 months ago
2010
Springer
Abstract. We study the lattice structure of sets (monoids) of surjective hyper-operations on an n-element domain. Through a Galois connection, these monoids form the algebraic coun...
KRDB
2003
13 years 6 months ago
2003
This paper introduces schema tuple queries and argues for their suitability in representing knowledge over standard relational databases. Schema tuple queries are queries that ret...
ICDT
2010
ACM
13 years 9 months ago
2010
ACM
Relational data exchange deals with translating a relational database instance over some source schema into a relational database instance over some target schema, according to a ...
CSL
2008
Springer
13 years 7 months ago
2008
Springer
Abstract. A positive temporal template (or a positive temporal constraint language) is a relational structure whose relations can be defined over countable dense linear order witho...
JCSS
2000
13 years 5 months ago
2000
It is a well-known result of Fagin that the complexity class NP coincides with the class of problems expressible in existential second-order logic ( 1 1), which allows sentences c...