In this paper we introduce a novel semantics, called defense semantics, for
Dung's abstract argumentation frameworks in terms of a notion of (partial)
defence, which is a triple encoding that one argument is (partially) defended
by another argument via attacking the attacker of the first argument. In terms
of defense semantics, we show that defenses related to self-attacked arguments
and arguments in 3-cycles are unsatifiable under any situation and therefore
can be removed without affecting the defense semantics of an AF. Then, we
introduce a new notion of defense equivalence of AFs, and compare defense
equivalence with standard equivalence and strong equivalence, respectively.
Finally, by exploiting defense semantics, we define two kinds of reasons for
accepting arguments, i.e., direct reasons and root reasons, and a notion of
root equivalence of AFs that can be used in argumentation summarization.

通过引入新的语义 —— 防御语义，本文研究了 Dung 的抽象论证框架，并提出了两种类型的防御、防御等价性以及接受论证的两种理由，进而定义了摘要的根等价性。

论辩的防御语义：重访

Defense semantics of argumentation: revisit

In this paper we show how the defense relation among abstract arguments can
be used to encode the reasons for accepting arguments. After introducing a
novel notion of defenses and defense graphs, we propose a defense semantics
together with a new notion of defense equivalence of argument graphs, and
compare defense equivalence with standard equivalence and strong equivalence,
respectively. Then, based on defense semantics, we define two kinds of reasons
for accepting arguments, i.e., direct reasons and root reasons, and a notion of
root equivalence of argument graphs. Finally, we show how the notion of root
equivalence can be used in argumentation summarization.

本文提出了一种新的辩护关系和辩护图的概念，基于辩护语义，定义了两种接受论点的原因，即直接原因和根本原因，介绍了辩证汇总中根等价的概念。