Accrual of arguments in defeasible argumentation
In this paper we address an often overlooked problem in defeasible argumentation:
how do we deal with arguments that are on their own defeated, but together
remain undefeated? Pollock (1991) finds this accrual of arguments a natural
supposition, but then surprisingly denies its existence. We think that
arguments do accrue. To handle the accrual of arguments, we introduce compound
defeat of arguments. We call the defeat of arguments compound, if groups
of arguments can be defeated by other groups of arguments. The formalism
presented in this paper is based on this notion of compound defeat. It
adequately handles the accrual of arguments.
Verheij, Bart (1995). Accrual of arguments in defeasible argumentation.
Dutch/German Workshop on Nonmonotonic Reasoning. Proceedings of the
Second Workshop, pp. 217-224. Delft University of Technology, Utrecht
University. Also published as report SKBS/B3.A/95-01.