Declarative semantics for inconsistent database programs

In this paper an ongoing research on inconsistent database programs is presented, which can be viewed as an extension of logic programming. By Literal Database Program (LDP) we mean a finite set of universally closed clauses of the form L0←L1,...,Lm where m≥0, Li's are literals. We define a set of intended models MOD(P) for a given program P with the help of interpretations defined on an extension of the Herbrand base. Instead of resolving inconsistency at all costs, our system is aimed to supply an inference control after the appearance of some primitive inconsistent units. It keeps the good conflict knowledge, namely those, that come from different, equally trusted sources and proposes mechanism telling one how to act when the primitive inconsistency arises. A characterization of the semantics for the proposed literal database programs is given by means of general properties of non-monotonic inference operations. Some points for future considerations are also announced.