Issues of Integration and Balancing in Hybrid

In the last several years the hybrid approach to Knowledge Representation has received much attention, because it was felt that one monolithic knowledge representation formalism cannot meet all representational demands. In this paper we will present one particular hybrid knowledge representation system, BACK, concentrating on matters of how to integrate diierent subformalisms and their interpretation. In particular, `balancing the expressiveness' of the respective subformalisms and combining the reasoning of the subsystems in a sound way is discussed. This will lead to a new view on the realization inference, rst described by Mark, as a process of constraint propagation.