Current research on database is strongly interested in: extending available models to support complex knowledge; combine logic programming and databases; deal with uncertain and/or fuzzy information. While many attempts have been made to bring together any two of the above, no serious attempt has been made to combine all of them. This work is based on the idea to join and hence utilize the power of all complex objects, logic programming and uncertain information.
In the implementation of complex objects, it can be concluded that logic programming is well suited, especially for the representation of nested relations. Furthermore, complex types like `range' and `set' could easily be modelled in prolog without any need for an extension of the language.