Analysing inference rules for cardinality constraints

In this paper, we analyse cardinality constraints for n-ary relationship types. In general, cardinality constraints consist of minimum and maximum parts. We extend the approach presented in an earlier paper, Dolezal (1999) which analysed the maximum part of the cardinality constraints to the minimum part and define a powerful semantics of the minimum part of cardinality constraints. In scope of an n-ary relationship type, there are dependencies between cardinality constraints. We give inference rules for cardinality constraints consisting both of minimum and maximum parts and prove the correctness of the rules. We show that the minimum and maximum parts of cardinality constraints are mutually dependent, although we work with 0 and 1 values for the minimum part and 1 and N values for the maximum part. The given framework is a basis for the future research of dependencies between different kinds of cardinality constraints.