With the advantages of the diversity of choice, comes its complexity. These are the questions that the young field of Logic Engineering is supposed to investigate and, if possible, answer. What we know about Logic Engineering is still not a lot, and as yet there are no general answers to these questions. But much can be learned from analyzing in detail a particularly interesting case. This will be the main thrust of the work carried out in the thesis.
Description logics are a family of formal languages used for structured knowledge representation.
In addition, they provide a formal notion of inference in terms of this structured knowledge. They offer an assortment of specialized inference mechanisms to handle tasks like knowledge classification, structuring, etc. Connections between description languages and modal logics have been investigated, but a unifying logical background theory explaining their expressive power and logical characteristics was largely missing. This is the role to be played by hybrid logics. Hybrid languages are modal languages extended with the ability to explicitly refer to elements in the domain of a model.