HYBRID KNOWLEDGE BASES

Deductive databases that interact with, and are accessed by, reasoning agents in the real world (such as logic controllers in automated manu facturing, weapons guidance systems, aircraft landing systems, land-ve hicle maneuvering systems, and air-traffic control systems) must have the ability to deal with multiple modes of reasoning. Specifically, th e types of reasoning we are concerned with include, among others, reas oning about time, reasoning about quantitative relationships that may be expressed in the form of differential equations or optimization pro blems, and reasoning about numeric modes of uncertainty about the doma in which the database seeks to describe. Such databases may need to ha ndle diverse forms of data structures, and frequently they may require use of the assumption-based nonmonotonic representation of knowledge. A hybrid knowledge base is a theoretical framework capturing all the above modes of reasoning. The theory tightly unifies the Constraint Lo gic Programming Scheme of Jaffar and Lassez [11], the Generalized Anno tated Logic Programming Theory of Kifer and Subrahmanian [16], and the Stable Model semantics of Gelfond and Lifschitz [6]. New techniques a re introduced which extend both the work on Annotated Logic Programmin g and the Stable Model semantics. (Proofs are omitted from the paper t o ensure readability. Complete details of all results may be found in [23].)