On the Equivalence between Logic Programming and SETAF
João Alcântara, Renan Cordeiro, Samy Sá
TL;DR
This paper establishes a semantic and structural bridge between Normal Logic Programs ($NLP$) and Sets of Attacking Arguments Frameworks ($SETAF$). It develops translations $NLP\rightarrow SETAF$ and $SETAF\rightarrow NLP$, proving that key semantics align across the two formalisms, including an unexpected equivalence between $L$-stable models and semi-stable labellings. By introducing Redundancy-Free Atomic Logic Programs (RFALP) and a confluence-guaranteed transformation sequence $\mapsto_{\textit{UTPM}}$, the authors show RFALPs are as expressive as NLPs and that the translations are inverse for RFALP-SETaF pairs. Collectively, the work argues that NLPs and SETAFs are essentially the same formalism, with RFALP providing a robust, structure-preserving bridge that enables cross-pollination of techniques between logic programming and argumentation. The results advance a unified view of nonmonotonic reasoning and open avenues for applying SETAF-based reasoning methods to NLPs and vice versa.
Abstract
A framework with sets of attacking arguments (SETAF) is an extension of the well-known Dung's Abstract Argumentation Frameworks (AAFs) that allows joint attacks on arguments. In this paper, we provide a translation from Normal Logic Programs (NLPs) to SETAFs and vice versa, from SETAFs to NLPs. We show that there is pairwise equivalence between their semantics, including the equivalence between L-stable and semi-stable semantics. Furthermore, for a class of NLPs called Redundancy-Free Atomic Logic Programs (RFALPs), there is also a structural equivalence as these back-and-forth translations are each other's inverse. Then, we show that RFALPs are as expressive as NLPs by transforming any NLP into an equivalent RFALP through a series of program transformations already known in the literature. We also show that these program transformations are confluent, meaning that every NLP will be transformed into a unique RFALP. The results presented in this paper enhance our understanding that NLPs and SETAFs are essentially the same formalism. Under consideration in Theory and Practice of Logic Programming (TPLP).
