Improving the Global Constraint SoftPrec

A soft global constraint SOFTPREC has been proposed recently for solving optimisation problems involving precedence relations. In this paper we present new pruning rules for this global constraint. We introduce a pruning rule that improves propagation from the objective variable to the decision variables, which is believed to be harder to achieve. We further introduce a pruning rule based on linear programming, and thereby make SOFTPREC a hybrid of constraint programming and linear programming. We present results demonstrating the efficiency of the pruning rules.

• Type: Journal
• Year: 2010
• Where: ECAI
• Authors: David Lesaint, Deepak Mehta, Barry O'Sullivan, Luis Quesada, Nic Wilson
• Keywords: Artificial Intelligence, ECAI 2010, Global Constraint, Pruning Rules, Soft Global Constraint