Lazy Model Expansion: Interleaving Grounding with Search

Abstract

Finding satisfying assignments for the variables involved in a set of constraints can be cast as a (bounded) model generation problem: search for (bounded) models of a theory in some logic. The state-of-the-art approach for bounded model generation for rich knowl-edge representation languages like Answer Set Programming (ASP) and FO(.-) and a CSP modeling language such as Zinc, is ground-and-solve : reduce the theory to a ground or propositional one and apply a search algorithm to the resulting theory. An important bottleneck is the blow-up of the size of the theory caused by the grounding phase. Lazily grounding the theory during search is a way to overcome this bottleneck. We present a the..