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This work is motivated by the difficulty of representing Environmental domains in a functional way. We present a formalization approach covering both environmental and computational needs. It allows us to produce an operational software for intelligent decision support on a Horizontal Subsurface Constructed Wetlands (HSCW) while capturing the most significant elements of the domain.

Extension-based argumentation semantics have shown to be a suitable approach for performing practical reasoning. Since extension-based argumentation semantics were formalized in terms of relationships between atomic arguments, it has been shown that extension-based argumentation semantics based on admissible sets such as stable semantics can be characterized in terms of answer sets. In this paper, we present an approach for characterizing SCC-recursive semantics in terms of answer set models. In particular, we will show a characterization of CF2 in terms of answer set models. This result suggests that not only extension-based argumentation semantics based on admissible sets can be characterized in terms of answer sets; but also extension-based argumentation semantics based on Strongly Connected Components can be characterized in terms of answer sets.

In this paper, by considering the idea that argumentation semantics can be viewed as a special form of logic programming semantics with negation as failure, we show that any logic programming semantics as the stable model semantics, the minimal models, etc., can define candidate argumentation semantics. These new argumentation semantics will overcome some of the problems of the Dung's argumentation semantics that have been discussed in the literature. The new argumentation semantics are based on a new recursive framework for logic programming semantics. This framework generalizes any logic programming semantics in order to build logic programming semantics which are always defined, satisfy the property of relevance and agree with the stable semantics for the class of stratified programs.

Extension-based argumentation semantics have been shown to be a suitable approach for performing practical reasoning. Since extension-based argumentation semantics were formalized in terms of relationships between atomic arguments, it has been shown that extension-based argumentation semantics (such as the grounded semantics and stable semantics) can be characterized by logic programming semantics with negation as failure. Recently, it has been shown that argumentation semantics such as the preferred semantics and the CF2 semantics can be characterized in terms of logic programming semantics. In this paper, we make a short overview w.r.t. recent results in the close relationship between extension-based semantics and logic programming semantics with negation as failure. We also show that there is enough evidence to believe that the use of declarative approaches based on logic programming semantics with negation as failure is a practical approach for performing practical reasoning following an argumentation reasoning approach.

One of the most representative semantics of Dung's approach is the grounded semantics. This semantics captures a skeptical approach, this means that given an argumentation framework the grounded semantics always identifies a single set of arguments, called grounded extension. It worth mentioning that the grounded semantics approach is one of the most useful argumentation approaches in real argumentation-based systems As argumentation can be abstractly defined as the interaction of arguments for and against some conclusion, a reasoning based on an abstract argumentation semantics for describing the interaction arguments is as important as to find an extension of an argumentation framework. In this paper, we introduce a novel formal argumentation method based on normal programs and rewriting systems which is able to - describe the interaction of arguments during the process of inferring an extension, and -define extensions of the grounded semantics based on specific rewriting rules which perform particular kind of reasoning as in reasoning by cases. Moreover, we point out that our codification of an argumentation framework as a normal program is a suitable codification for studying other abstract argumentation semantics as are the stable semantics and the preferred semantics.

Given an argumentation framework AF, we present a normal program Psi_{AF}, such that the preferred extensions of AF correspond exactly with the pstable models of Psi_{AF}. Moreover, we motivate the notion of suitable codifications for developing metainterpreters of argumentation theory based on logic programming.