Inclusion dependencies in vague relational databases

In order to model the real world with imprecise and uncertain information, various extended relational data models were proposed. Vague set, as a generalized fuzzy set, has more powerful ability to process fuzzy information than fuzzy set. In this paper, a kind of vague relational model and a partial order base on set containment of vague sets are given. Based on the definition of partial order, the paper focuses on the issues of vague inclusion dependencies (VINDs), and show that Casanova et al.´s axiom system is sound and complete for VINDs being satisfied in vague databases.