It is known that bottom-up query evaluation can be extended to work with disjunctive facts, but there seems to be the common assumption that it is much too ineecient for practical applications. In this paper, we improve the extended bottom-up evaluation by making the resolvable literal in a disjunctive fact unique. In many cases, this reduces an exponential behaviour to a polynomial one. We app...

One of the major hurdles to implementing a practical disjunctive database is the CoNP-completeness of executing queries. We demonstrate, however, that this problem is similar to the problem of computing the transitive closure of a node in a disjunctive graph. While this problem is also CoNP-complete in general, we show in this paper that there is a polynomial-time solution that solves it for ce...

It is now common practice to use structured sets of features to describe syntactic structures, and to compare such structured sets by some form of unification. It is extremely tempting to try to encode disjunctive information within this framework; unfortunately, general unification of disjunctive structures is NPcomplete, which is not a desirable property for the basic operation involved in co...

A lot of different proposals were made claiming to extend the wellfounded semantics to logic programs with disjunction. None of these however has been established as ’the’ disjunctive well-founded semantics which is mainly caused by the different intuitive ideas on which these semantics are based. In fact, some of them are even incomparable with respect to their derivable knowledge, and systema...

In both human and artificial societies some activities are only allowed to coalitions that satisfy certain criteria, e.g., to sufficiently large coalitions or coalitions which involve players of sufficient seniority. Simmons (1988) formalised this idea in the context of secret sharing schemes by defining the concept of a (disjunctive) hierarchical access structure. The mathematical concept whic...

in this paper, we firstly show that the $n$-dual operation of the right residual implication, which is induced by a left-conjunctive right arbitrary $vee$-distributive left semi-uninorm, is the right residual coimplication induced by its $n$-dual operation. as a dual result, the $n$-dual operation of the right residual coimplication, which is induced by a left-disjunctive right arbitrary $wedge...

We show that every propositional disjunctive logic program under the answer set semantics can be equivalently transformed into a normal one via unfolding and shifting. More precisely, after iteratively applying the unfolding operator for some rules in a disjunctive program, its shifted program, which is a normal program, must have the same answer sets as the original disjunctive program.