Approximate well-founded semantics, query answering and generalized normal logic programs over lattices

The management of imprecise information in logic programs becomes to be important whenever the real world information to be represented is of imperfect nature and the classical crisp true, false approximation is not adequate. In this work, we consider generalized normal logic programs over complete lattices, where computable truth combination functions may appear in the rule bodies to manipulate truth values. It is an unifying umbrella for existing approaches for many-valued normal logic programs. We will provide declarative and fixed-point semantics of the logic and provide a simple and effective top-down query answering procedure by a transformation to an equational system over lattices.