Combining Closed World Assumptions with Stable Negation

We study the semantics of disjunctive logic programs that simultaneously contain multiple kinds of default negations. We introduce operators not G , not W , and not STB in the language of logic programs to represent the Generalized Closed World Assumption, the Weak Generalized Closed World Assumption, and the stable negation, respectively. The notion of stratiication involving diierent kinds of negations is deened and the meaning of stratiied programs with multiple negations is described. The class of stratiied programs is extended to the class of quasi-stratiied programs and the semantics of the latest class is studied.