Propagating degrees of truth on an argumentation framework: an abstract account of fuzzy argumentation

This paper proposes a computational framework to reason with conflicting and gradual evidence. The framework is a synthesis of Dung's seminal work in argumentation semantics with multi-valued logic. Abstract grounded semantics is used to identify the conditions under which a conclusion can be accepted, while multi-valued logic operators are used to quantify the degree of truth of such conditions. We propose a truth-compositional recursive computation based on the notion of irrelevant arguments, and we discuss examples using the major multi-valued logics: Godel's, Zadeh's and Łukasiewicz's logic.