Effectively solving NP-SPEC encodings by translation to ASP

NP-SPEC is a language for specifying problems in NP in a declarative way. Despite the fact that the semantics of the language was given by referring to Datalog with circumscription, which is very close to answer set programming (ASP), so far the only existing implementations are by means of Prolog and via Boolean satisfiability solvers. In this paper, we present translations from NP-SPEC to ASP, and provide an experimental evaluation of existing implementations and the proposed translations into ASP using various ASP solvers. The results show that translating into ASP clearly has an edge over the existing translation into SAT, which involves an intrinsic grounding process. We also argue that it might be useful to incorporate certain language constructs of NP-SPEC into mainstream ASP.