Some Properties of Plausible Reasoning
  This paper presents a plausible reasoning system to illustrate some broad
issues in knowledge representation: dualities between different reasoning
forms, the difficulty of unifying complementary reasoning styles, and the
approximate nature of plausible reasoning. These issues have a common
underlying theme: there should be an underlying belief calculus of which the
many different reasoning forms are special cases, sometimes approximate. The
system presented allows reasoning about defaults, likelihood, necessity and
possibility in a manner similar to the earlier work of Adams. The system is
based on the belief calculus of subjective Bayesian probability which itself is
based on a few simple assumptions about how belief should be manipulated.
Approximations, semantics, consistency and consequence results are presented
for the system. While this puts these often discussed plausible reasoning forms
on a probabilistic footing, useful application to practical problems remains an
issue.
