Title
Dual encoding using constraint coverings
Abstract
Constraint satisfaction problems (CSPs) involve finding an assignment of values to variables that satisfy a set of constraints between variables. Non-binary constraints have recently begun to attract more attention, since many real-life problems are naturally expressed as non-binary formulations. In order to solve a non-binary CSP, one either uses an algorithm that has been generalised for non-binary constraint satisfaction or one can convert the problem into an equivalent binary CSP, The dual encoding has been shown to be impractical in some cases where the constraints have very large domains, but need to be represented in extension. It is often the case that such constraints (e.g. all-diff) have compact intensional representations, and this is often the reason why algorithms based on the primal graph which can store them intensionally have an edge. In this paper we present a dual encoding that is based on the construction of constraint coverings from the original CSP. This allows us to benefit from the intensional representation of some constraints that are impractical to represent extensionally. We show how this covering based dual encoding can be used to address the space complexity issue of the dual encodings, while still retaining the soundness and completeness of the solution procedures.
Year
DOI
Venue
2000
10.1007/3-540-44533-1_47
PRICAI
Keywords
Field
DocType
original csp,non-binary formulation,dual encodings,constraint covering,constraint satisfaction problem,non-binary constraint,dual encoding,compact intensional representation,non-binary constraint satisfaction,non-binary csp,satisfiability,constraint satisfaction,space complexity
Constraint satisfaction,Local consistency,Computer science,Constraint graph,Constraint programming,Constraint satisfaction problem,Complexity of constraint satisfaction,Constraint satisfaction dual problem,Artificial intelligence,Constraint logic programming,Machine learning
Conference
ISBN
Citations 
PageRank 
3-540-67925-1
0
0.34
References 
Authors
12
3
Name
Order
Citations
PageRank
S. Nagarajan100.34
S. D. Goodwin200.34
A. Sattar300.34