Refining definitions with unknown opens using XSB for IDP3

ABSTRACT. FO(·)IDP3 is a declarative modeling language that extends first-order logic with inductive definitions, partial functions, types and aggregates. Its model generator IDP3 evaluates all definitions that depend on fully known information before grounding and solving the problem specification. In this paper, we introduce a technique which allows us to refine the interpretation of defined symbols when they depend on information that is only partially given instead of completely given. We extend our existing transformation of FO(·)IDP3 definitions to Tabled Prolog rules with support for definitions that depend on information that is possibly partially unknown. In this paper we present an algorithm that uses XSB Prolog to evaluate these rules in such a way that we achieve the most precise possible refinement of the defined symbols. Experimental results show that our technique derives extra information for the defined symbols.