This paper develops a new approach to computational argumentation that is informed by philosophical and linguistic views. Namely, it takes into account two ideas that have received little attention in the literature on computational argumentation: First, an agent may rationally reject an argument based on mere doubt, thus not all arguments they could defend must be accepted; and, second, that it is sometimes more natural to think in terms of which individual sentences or claims an agent accepts in a debate, rather than which arguments. In order to incorporate these two ideas into a computational approach, we first define the notion of structured bipolar argumentation frameworks (SBAFs), where arguments consist of sentences and we have both an attack and a support relation between them. Then, we provide semantics for SBAFs with two features: (1) Unlike with completeness-based semantics, our semantics do not force agents to accept all defended arguments. (2) In addition to argument extensions, which give acceptable sets of arguments, we also provide semantics for language extensions that specify acceptable sets of sentences. These semantics represent reasonable positions an agent might have in a debate. Our semantics lie between the admissible and complete semantics of abstract argumentation. Further, our approach can be used to provide a new perspective on existing approaches. For instance, we can specify the conditions under which an agent can ignore support between arguments (i.e. under which the use of abstract argumentation is warranted) and we show that deductive support semantics is a special case of our approach.

翻译：本文提出了一种受哲学和语言学观点启发的计算论证新方法。该方法考虑了计算论证文献中较少关注的两个观点：第一，智能体可以仅基于怀疑而理性地拒绝一个论点，因此并非所有其能够辩护的论点都必须被接受；第二，有时更自然的思考方式是在辩论中关注智能体接受哪些具体句子或主张，而非接受哪些论点。为了将这两个观点融入计算方法，我们首先定义了结构化双极论证框架（SBAFs）的概念，其中论点由句子构成，且句子间同时存在攻击和支持关系。随后，我们为SBAFs提供了具有两个特征的语义：(1) 与基于完备性的语义不同，我们的语义不强制智能体接受所有被辩护的论点。(2) 除了给出可接受论点集合的论点外延，我们还提供了语言外延的语义，用于指定可接受的句子集合。这些语义代表了智能体在辩论中可能持有的合理立场。我们的语义介于抽象论证的可容许语义与完备语义之间。此外，我们的方法可为现有研究提供新视角。例如，我们可以明确智能体在何种条件下可以忽略论点间的支持关系（即抽象论证的适用条件），并证明演绎支持语义是我们方法的一个特例。