Possibilistic and Extended Logic Programs

Based on our earlier work on partial logics and extended logic programs Wag91, Wag94, HJW96], and on the possibilistic logic of DLP94], we deene a compositional possibilistic rst-order logic with two kinds of negation as the logical basis of semi-possibilistic and possibilis-tic logic programs. We show that in the same way as the minimal model semantics of relational databases can be reened to the stable model semantics for normal logic programs (see GL88]), the minimal model semantics of fuzzy databases can be reened to the stable semantics for semi-possibilistic logic programs. We also show that while normal logic programs under the stable model semantics can be embedded in semi-possibilistic logic programs under our stable semantics, extended logic programs under the answer set semantics of GL90] can be embedded in possibilistic logic programs under our stable semantics.