Integration of functions in logic database systems

We extend Datalog, a logic programming language for rule-based systems, by respectively integrating types, negation and functions. This extention of Datalog is called MilAnt. Furthermore, MilAnt consistency is defined as a stronger form of consistency for functions. It is known that consistency for functions is undecidable. We prove that MilAnt consistency is decidable and an algorithm is given to detect the MilAnt consistency of a MilAnt program. To this end, we use a mixture of dependencies that are local to a rule and dependencies that are global for the whole program