Semantics for Pollock’s defeasible reasoning*

Abstract

Many researchers have proposed argumentation-based rear soning as a viable alternative to reasoning systems with a flat epistemological structure. Perhaps one of the longest standing approaches heis been in the Oscar project, led by John Pollock. Unfortunately, without a formjil semaintics, it is often difficult to evaluate the various incarnations of defeaisible reasoning. We provide a semantics for Pollocks defeeisible reasoning in terms of Bondarenko et al.’s unified framework for default reasoning. We also indicate some interned inconsistencies bet.