“…Additionally, practical considerations dictate that the framework used for knowledge representation with uncertainty admit efficient implementation and efficient computations. Logic database programming, with its advantage of modularity and its powerful top-down and bottom-up query processing techniques, has attracted the attention of researchers and numerous frameworks for deductive databases with uncertainty have been proposed [2, 4, 5, 9, 10, 14-16, 18-22, 25-27, 35-39], where the underlying uncertainty formalism include probability theory [10,19,22,[25][26][27]39], fuzzy set theory [2,35,37,38], multi-valued logic [9,15,16,20,21] and possibilistic logic [5]. Roughly, based on the way in which uncertainty is associated with the facts and rules of a program, these frameworks can be classified into annotation based (AB) and implication based (IB).…”