Review of the hardback: 'Antonelli applies some of the techniques developed in Kripke's approach to the paradoxes to generalize some of the most popular formalisms for nonmonotonic reasoning, particularly Default Logic. The result is a complex and sophisticated theory that is technically solid and attractive from an intuitive standpoint.' John Horty, Committee on Philosophy and the Sciences, University of Maryland Review of the hardback: '... accessible to an audience with no previous exposure to either defeasible inheritance or default reasoning.' Zentralblatt MATH