Future data and knowledge base systems will require new and improved functions such as richer data modeling capabilities, more powerful query languages, and new conceptions of query answers. Future query languages will need to include hypothetical, abductive, meta-, and modal reasoning, involving both knowledge and belief. And intentional answers will ultimately lead to cooperative query answering which takes into consideration a user's expectations. This book explores the formalization of new queries and answers, and emphasizes the important role of non-classical logic. It shows how logic...

The rapid development of wireless digital communication technology has cre ated capabilities that software systems are only beginning to exploit. The falling cost of both communication and of mobile computing devices (laptop computers, hand-held computers, etc. ) is making wireless computing affordable not only to business users but also to consumers. Mobile computing is not a "scaled-down" version of the established and we- studied field of distributed computing. The nature of wireless communication media and the mobility of computers combine to create fundamentally new problems in...

The rapid development of wireless digital communication technology has cre- ated capabilities that software systems are only beginning to exploit. The falling cost of both communication and of mobile computing devices (laptop computers, hand-held computers, etc. ) is making wireless computing affordable not only to business users but also to consumers. Mobile computing is not a "scaled-down" version of the established and we- studied field of distributed computing. The nature of wireless communication media and the mobility of computers combine to create fundamentally new problems in...