Conditionals are omnipresent, in everyday life as well as in scientific
environments; they represent generic knowledge acquired inductively or
learned from books. They tie a flexible and highly interrelated network
of connections along which reasoning is possible and which can be
applied to different situations. Therefore, conditionals are important,
but also quite problematic objects in knowledge representation.
This book presents a new approach to conditionals which captures their
dynamic, non-proportional nature particularly well by considering
conditionals as agents shifting possible worlds in order to establish
relationships and beliefs. This understanding of conditionals yields a
rich theory which makes complex interactions between conditionals
transparent and operational. Moreover, it provides a unifying and
enhanced framework for knowledge representation, nonmonotonic reasoning,
belief revision, and even for knowledge discover