This paper investigates ultrafilters in the context of connectivity systems, defined as pairs
$(X, f) $ where $ X $ is a finite set and $ f $ is a symmetric submodular function. Ultrafilters …

In the database context, the hypertree decomposition method is used for query optimization,
whereby conjunctive queries having a low degree of cyclicity can be recognized and …

Publisher Summary Constraint programming is a powerful paradigm for solving
combinatorial search problems that draws on a wide range of techniques from artificial …

Constraint programming is a powerful paradigm for solving combinatorial search problems
that draws on a wide range of techniques from artificial intelligence, computer science …

Handbook of Knowledge Representation describes the essential foundations of Knowledge
Representation, which lies at the core of Artificial Intelligence (AI). The book provides an up …

Many natural combinatorial problems can be expressed as constraint satisfaction problems.
This class of problems is known to be NP-complete in general, but certain restrictions on the …

Several important decision problems on conjunctive queries (CQs) are NP-complete in
general but become tractable, and actually highly parallelizable, if restricted to acyclic or …

For more and more applications, it is important to be able to compute the treewidth of a given
graph and to find tree decompositions of small width reasonably fast. This paper gives an …

Many important combinatorial problems can be modeled as constraint satisfaction problems.
Hence, identifying polynomial-time solvable classes of constraint satisfaction problems has …

The Constraint Satisfaction Problem (CSP) provides a common framework for many
combinatorial problems. The general CSP is known to be NP-complete; however, certain …