An Implementation for Recognizing Rule Replacements in Non-ground Answer-Set Programs

Answer-set programming (ASP) has emerged as an important paradigm for declarative problem solving, and provides a host for many different application domains on the basis of nonmonotonic logic programs. The increasing popularity in ASP has raised also the interest in semantic comparisons of programs in ASP [3, 4], which are nowadays recognized as a theoretical basis for program optimization, where equivalencepreserving modifications are of primary interest; in particular, rewriting rules which allow to perform a local change in a program are important. Many such rules have been considered in the propositional setting (cf., e.g., [1, 6]) but just recently have been extended to the practicably important case of non-ground programs [2].