The Logic of Knowledge Bases


The idea of knowledge bases lies at the heart of symbolic, or "traditional," artificial intelligence. A knowledge-based system decides how to act by running formal reasoning procedures over a body of explicitly represented knowledge—a knowledge base. The system is not programmed for specific tasks; rather, it is told what it needs to know and expected to infer the rest.

This book is about the logic of such knowledge bases. It describes in detail the relationship between symbolic representations of knowledge and abstract states of knowledge, exploring along the way the foundations of knowledge, knowledge bases, knowledge-based systems, and knowledge representation and reasoning. Assuming some familiarity with first-order predicate logic, the book offers a new mathematical model of knowledge that is general and expressive yet more workable in practice than previous models. The book presents a style of semantic argument and formal analysis that would be cumbersome or completely impractical with other approaches. It also shows how to treat a knowledge base as an abstract data type, completely specified in an abstract way by the knowledge-level operations defined over it.

Table of Contents

  1. Preface
  2. Acknowledgments
  3. 1. Introduction
  4. 2. A First-Order Logical Language
  5. 3. An Epistemic Logical Language
  6. 4. Logical Properties of Knowledge
  7. 5. The TELL and ASK Operations
  8. 6. Knowledge Bases as Representations of Epistemic States
  9. 7. The Representation Theorem
  10. 8. Only-Knowing
  11. 9. Only-Knowing and Autoepistemic Logic
  12. 10. On the Proof Theory of OL
  13. 11. Only-Knowing-About
  14. 12. Avoiding Logical Omniscience
  15. 13. The Logic EOL
  16. 14. Knowledge and Action
  17. Epilogue
  18. References
  19. Index