Smodels: A System for Answer Set Programming
  The Smodels system implements the stable model semantics for normal logic
programs. It handles a subclass of programs which contain no function symbols
and are domain-restricted but supports extensions including built-in functions
as well as cardinality and weight constraints. On top of this core engine more
involved systems can be built. As an example, we have implemented total and
partial stable model computation for disjunctive logic programs. An interesting
application method is based on answer set programming, i.e., encoding an
application problem as a set of rules so that its solutions are captured by the
stable models of the rules. Smodels has been applied to a number of areas
including planning, model checking, reachability analysis, product
configuration, dynamic constraint satisfaction, and feature interaction.
