Towards answer set programming with sorts

Existing ASP languages lack support for conveniently specifying objects, their sorts and the sorts of the parameters of relations in an application domain. However, such support may allow a programmer to better structure the program, to automatically determine some syntax and semantic errors and to avoid thinking about safety of ASP rules - non-declarative conditions on rules required by existing ASP systems. In this paper, we define the syntax and semantics of a knowledge representation language SPARC which offers explicit constructs to specify objects, relations, and their sorts. The language expands CR-Prolog - an extension of ASP by consistency restoring rules. We introduce an implementation of SPARC based on its translation to DLV with weak constraints. A syntax checking algorithm helps to avoid errors related to misspellings as well as simple type errors. Another type checking algorithm flags program rules which, due to type conflicts, have no ground instantiations.