A Skeptical Theory of Mixed Inheritance

  • John F. Horty
Chapter

Abstract

This paper is concerned with the problem of providing a semantic account for inheritance networks capable of representing both strict and defeasible information. The importance of representing defeasible information in a knowledge base—particularly, in a frame- or network-based inheritance reasoner — has been widely recognized ever since the publication of Minsky’s original paper on frames [11]. Although early systems designed to allow defeasible inheritance reasoning, such as FRL [12] and NETL [6], were subject to semantic difficulties in their treatment of cancellation, these problems by now are essentially solved. In fact, there exist today a number of well-defined and intuitively attractive theories of defeasible inheritance, including those of Touretzky [15], Sandewall [13], and Horty et al. [8]. The variety of these theories does not seem to indicate any kind of instability or chaos in our understanding, but instead, the presence of a range of options in the design space for defeasible inheritance reasoners; some of these options are surveyed in Touretzky et al. [16].

Keywords

Skeptical Theory Mixed Network Positive Path Negative Path Mixed Degree 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Kluwer Academic Publishers 1990

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  • John F. Horty

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