Inheritance Theory An Artificial Intelligence Approach

This book is based on the doctoral dissertation of R. Al-Asady, completed at Exeter University, in 1993. It is concerned with creating an inheritance theroy from the AI point of view. Within Artificial Intelligence, the need to create sophisticated intelligent behavior based on commonsense reasoning has long been recognized. Such commonsense reasoning is characterized by the withdrawing of previously drawn conclusions when new information comes along. Research has demonstrated theft formalisms for dealing with commonsense reasoning require nonmonotonic capabilities where, typically, inferences based on incomplete knowledge need to be revised in the light of later information that fills in some of the gaps. In this book, an inheritance theory based on multiple inheritance structures with exceptions (nonmonotonic inheritance structures) is proposed. Without an adequate nonmonotonic inheritance reasoning technique, such as exceptional inheritance reasoning (EIR) as proposed in this volume, inheritance networks will produce inconsistencies. A number of nonmonotonic properties that enable EIR to subsume existing formalisms such as default logic and inferential distance ordering have been included within the reasoning technique presented here. An inheritance algorithm is also presented and a demonstration is included to show how it can be used to specify and implement various nonmonotonic inheritance problems. In addition, an inheritance formalism has been developed that is capable of dealing with ambiguous situations and can handle other classes of nonmonotonic problems apart from those already presented in the literature. Finally, in the application section, this inheritance formalism has been applied to two important domains, namely causal reasoning and analogical reasoning, to demonstrate the conceptual power and expressiveness of the formalism.