Broadening Label-based Argumentation Semantics with May-Must Scales (May-Must Argumentation)

The semantics as to which set of arguments in a given argumentation graph may be acceptable (acceptability semantics) can be characterised in a few different ways. Among them, labelling-based approach allows for concise and flexible determination of acceptability statuses of arguments through assignment of a label indicating acceptance, rejection, or undecided to each argument. In this work, we contemplate a way of broadening it by accommodating may- and must- conditions for an argument to be accepted or rejected, as determined by the number(s) of rejected and accepted attacking arguments. We show that the broadened label-based semantics can be used to express more mild indeterminacy than inconsistency for acceptability judgement when, for example, it may be the case that an argument is accepted and when it may also be the case that it is rejected. We identify that finding which conditions a labelling satisfies for every argument can be an undecidable problem, which has an unfavourable implication to existence of a semantics. We propose to address this problem by enforcing a labelling to maximally respect the conditions, while keeping the rest that would necessarily cause non-termination labelled undecided. Several semantics will be presented and the relation among them will be noted. Towards the end, we will touch upon possible research directions that can be pursued further.Comment: Changes made to the previous version. 1. Definitions of satisfaction of may/must conditions have been simplified. 2. Corrected the definition of a maximally designating labelling which is now called a maximally proper labelling instea

Logic and Argumentation [electronic resource] : Third International Conference, CLAR 2020, Hangzhou, China, April 6–9, 2020, Proceedings /

This book constitutes the refereed proceedings of the Third International Conference on Logic and Argumentation, CLAR 2020, held in Hangzhou, China, in April 2020. The 14 full and 7 short papers presented were carefully reviewed and selected from 31 submissions. The papers cover the focus of the CLAR series, including formal models of argumentation, logics for decision making and uncertainreasoning, formal models of evidence, con rmation, and justi cation, logics forgroup cognition and social network, reasoning about norms, formal representationsof natural language and legal texts, as well as applications of argumentationon climate engineering.Group Belief -- Broadening Label-based Argumentation Semantics with May-Must Scales -- Semirings of Evidence -- Logic Programming, Argumentation and Human Reasoning -- Reasoning about Degrees of Con rmation -- Ideal related algebras and their logics { Extended abstract -- Computer-supported Analysis of Arguments in Climate Engineering.-A Logic of Knowledge and Belief Based on Abstract Arguments -- A Meta-level Annotation Language for Legal Texts -- Towards an Executable Methodology for the Formalization of Legal Texts -- Goal-driven Structured Argumentation for Patient Management in a Multimorbidity Setting -- Intuitionistic-Bayesian Semantics of First-Order Logic for Generics -- Ambiguity Preference and Context Learning in Uncertain Signaling -- A Decidable Multi-Agent Logic for Reasoning about Actions, Instruments, and Norms -- Preservation of Admissibility with Rationality and Feasibility Constraints -- Uncertainty in Argumentation Schemes: Negative Consequences and Basic Slippery Slope -- Reasoning as Speech Acts -- Dynamics of Fuzzy Argumentation Frameworks -- Probabilistic three-value argumentation frameworks -- Further Steps Towards a Logic of Polarization in Social Networks -- A Formalization of the Slippery Slope Argument.This book constitutes the refereed proceedings of the Third International Conference on Logic and Argumentation, CLAR 2020, held in Hangzhou, China, in April 2020. The 14 full and 7 short papers presented were carefully reviewed and selected from 31 submissions. The papers cover the focus of the CLAR series, including formal models of argumentation, logics for decision making and uncertainreasoning, formal models of evidence, con rmation, and justi cation, logics forgroup cognition and social network, reasoning about norms, formal representationsof natural language and legal texts, as well as applications of argumentationon climate engineering