\in R$ or $(x, \eta) \in E$.

$\eta$ represents the prima facie arguments and is referred to as evidence or environment. The idea that the valid arguments (and attackers) need to trace back to it is captured with the notions of e–support and e–supported attack[^4].

\[def:esup\] An argument $a\in A$ has **evidential support** (e–support) from a set $S\subseteq A$ iff $a=\eta$ or there is a non-empty $S' \subseteq S$ s.t. $S' E a$ and $\forall x \in S'$, $x$ has e–support from $S \setminus \{a\}$.

\[def:eatt\] A set $S\subseteq A$ carries out an **evidence supported attack** (e–supported attack) on $a$ iff $(S',a) \in R$ where $S' \subseteq S$, and for all $s \in S'$, $s$ has e–support from $S$. An e–supported attack by $S$ on $a$ is **minimal** iff there is no $S' \subset S$ that carries out an e–supported attack on $a$.

The EASs semantics are built around the notion of acceptability in a manner similar to those of Dung’s. However, in AFs only the attack relation was considered. In EASs, also sufficient support is required:

An argument $a$ is **acceptable** w.r.t. a set $S\subseteq A$ iff $a$ is e–supported by $S$ and given a minimal e–supported attack by 