Nonmonotonic logics were created as an abstraction of some types of
common sense reasoning, analogous to the way classical logic serves to
formalize ideal reasoning about mathematical objects. These logics are
nonmonotonic in the sense that enlarging the set of axioms does not
necessarily imply an enlargement of the set of formulas deducible from
these axioms. Such situations arise naturally, for example, in the use
of information of different degrees of reliability.
This book emphasizes basic concepts by outlining connections between
different formalisms of nonmonotonic logic, and gives a coherent
presentation of recent research results and reasoning techniques. It
provides a self-contained state-of-the-art survey of the area addressing
researchers in AI lo