Preprocessing Algorithms for non-binary Disjunctive Constraint Satisfaction

Abstract

Some constraint languages are more powerful than others because they allow us to express a larger collection of problems. More generally, the finite constraint satisfaction problem (CSP) with arbitrary constraints (non-binary), is known to be NP-complete 9, whereas many families of restricted constraints have been identified like tracta ble subproblems [1][7]. We propose two preprocessing algorithms in order to study the consistency check (the consistency algorithm) when a new non-binary constraint is inserted into the system and to reduce the variable domains (the reduction algorithm) that participate in these non-binary disjunctive temporal constraints. Following, we can apply some of the techniques to solve this CSP. Thus, we can manage more complex and expressive constraints that many real problems must deal with.