Probabilistic Arc Consistency

The two most popular backtrack algorithms for solving Constraint Satisfaction Problems (CSPs) are Forward Checking (FC) and Maintaining Arc Consistency (MAC). MAC maintains full arc consistency while FC maintains a limited form of arc consistency during search. Previous work has shown that there is no single champion algorithm: MAC is more efficient on sparse problems which are tightly constrained but FC has an increasing advantage as problems become dense and constraints loose. Ideally a good search algorithm should find the right balance—for any problem—between visiting fewer nodes in the search tree and reducing the work that is required for detecting and removing inconsistent values. We propose to maintain a probabilistic arc consistency during search to achieve this. The idea is to assume that a support exists and skip the process of seeking a support if the probability of having some support for a value is at least equal to some, carefully chosen, stipulated bound. Experime...

• Type: Conference
• Year: 2005
• Where: CP
• Authors: Deepak Mehta, Marc R. C. van Dongen
• Keywords: Arc Consistency, CP 2005, Probabilistic Arc Consistency, Problems, Programming Languages