Between well-founded semantics and stable model semantics

Using fixpoint operations, we define a new semantics for Datalog programs with negation. The semantics is deterministic. Given a program /spl Delta/, the model of /spl Delta/ in the new semantics includes the well-founded model, and is included in all stable models, if such models exist. In particular, there exist programs that have no stable models, or their well-founded model is empty, but their model in the new semantics is meaningful.