A data model for annotated programs

The information to be stored in databases in not always precise. A related issue is the handling of imperfect, flexible or vague queries. M. Kifer and V. S. Subrahmanian introduced generalized annotated logic programs (GAP) which unify and generalize various results and treatments of quantitative Datalog based model theoretic semantic. In this paper we discuss the problem of appropriate proof theoretic data model for restricted annotated programs. We face several problems: the semantics is not continuous, constraint based computational model is not effective and there is a problem with the definition of the natural join. We introduce a variant of annotated programs with continuous semantics, we define a new effective computational procedure and show a solution for the join problem. We use a connection to fuzzy Datalog and make use of an earlier model of fuzzy databases.