The tractability of CSP classes defined by forbidden patterns

Details The tractability of CSP classes defined by forbidden patterns The tractability of CSP classes defined by forbidden patterns

2011-03-08

arxiv.org/abs/1103.1542v1

Computer Science

Artificial Intelligence

Scientific paper

The constraint satisfaction problem (CSP) is a general problem central to computer science and artificial intelligence. Although the CSP is NP-hard in general, considerable effort has been spent on identifying tractable subclasses. The main two approaches consider structural properties (restrictions on the hypergraph of constraint scopes) and relational properties (restrictions on the language of constraint relations). Recently, some authors have considered hybrid properties that restrict the constraint hypergraph and the relations simultaneously. Our key contribution is the novel concept of a CSP pattern and classes of problems defined by forbidden patterns (which can be viewed as forbidding generic subproblems). We describe the theoretical framework which can be used to reason about classes of problems defined by forbidden patterns. We show that this framework generalises relational properties and allows us to capture known hybrid tractable classes. Although we are not close to obtaining a dichotomy concerning the tractability of general forbidden patterns, we are able to make some progress in a special case: classes of problems that arise when we can only forbid binary negative patterns (generic subproblems in which only inconsistent tuples are specified). In this case we are able to characterise very large classes of tractable and NP-hard forbidden patterns. This leaves the complexity of just one case unresolved and we conjecture that this last case is tractable.

Affiliated with

Also associated with

No associations

Rating

The tractability of CSP classes defined by forbidden patterns does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The tractability of CSP classes defined by forbidden patterns, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The tractability of CSP classes defined by forbidden patterns will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-82748