1. Introduction
1.1 What are DLs and where do they come from? 1.2 What are they good for and how are they used? 1.3 A brief history of description logic 1.4 How to use this book
2. A Basic Description Logic
2.1 The concept language of the DL ALC 2.2 ALC knowledge bases 2.2.1 ALC TBoxes 2.2.2 ALC ABoxes 2.2.3 Restricted TBoxes and concept definitions 2.3 Basic reasoning problems and services 2.4 Using reasoning services 2.5 Extensions of the basic DL ALC 2.5.1 Inverse roles 2.5.2 Number restrictions 2.5.3 Nominals 2.5.4 Role hierarchies 2.5.5 Transitive roles 2.6 DLs and other logics 2.6.1 DLs as decidable fragments of first-order logic 2.6.2 DLs as cousings of modal logic 2.7 Historical context and literature review