On Variable Precision Limited Tolerance Based Dependency in IIS

The paper first analyses the expanded rough set models in [1,2], proposes a new variable precision limited tolerance model to deal with incomplete information systems based on variable precision limited tolerance relation, that is a more restrictive condition imposed on the similarity between objects by attribute values. It then introduces new definitions of object dependency, knowledge dependency and dependency degree. Using them as basic concepts, it does reductions. Through an example, it shows that this new reduction approach is rational and efficient. .