A logic of defeasible argumentation: Constructing arguments in justification logic
| Autor: | Pandzic, S., LS Logische methoden in de AI, OFR - Theoretical Philosophy |
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| Přispěvatelé: | Faculty of Philosophy, Bernoulli Institute, LS Logische methoden in de AI, OFR - Theoretical Philosophy |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Linguistics and Language
Computer science 010102 general mathematics 0102 computer and information sciences structured argumentation 01 natural sciences Computer Science Applications Epistemology Computational Mathematics 010201 computation theory & mathematics Artificial Intelligence Defeasible argumentation Dung's framework Structured argumentation Justification logic Dung’s framework justification logic 0101 mathematics Default reasoning Abstract argumentation default reasoning |
| Zdroj: | Argument and Computation, 13(1), 3-47. IOS Press Argument and Computation, 13(1), 3. Taylor and Francis Ltd. |
| ISSN: | 1946-2166 |
| Popis: | In the 1980s, Pollock’s work on default reasons started the quest in the AI community for a formal system of defeasible argumentation. The main goal of this paper is to provide a logic of structured defeasible arguments using the language of justification logic. In this logic, we introduce defeasible justification assertions of the type t : F that read as “t is a defeasible reason that justifies F”. Such formulas are then interpreted as arguments and their acceptance semantics is given in analogy to Dung’s abstract argumentation framework semantics. We show that a large subclass of Dung’s frameworks that we call “warranted” frameworks is a special case of our logic in the sense that (1) Dung’s frameworks can be obtained from justification logic-based theories by focusing on a single aspect of attacks among justification logic arguments and (2) Dung’s warranted frameworks always have multiple justification logic instantiations called “realizations”. We first define a new justification logic that relies on operational semantics for default logic. One of the key features that is absent in standard justification logics is the possibility to weigh different epistemic reasons or pieces of evidence that might conflict with one another. To amend this, we develop a semantics for “defeaters”: conflicting reasons forming a basis to doubt the original conclusion or to believe an opposite statement. This enables us to formalize non-monotonic justifications that prompt extension revision already for normal default theories. Then we present our logic as a system for abstract argumentation with structured arguments. The format of conflicting reasons overlaps with the idea of attacks between arguments to the extent that it is possible to define all the standard notions of argumentation framework extensions. Using the definitions of extensions, we establish formal correspondence between Dung’s original argumentation semantics and our operational semantics for default theories. One of the results shows that the notorious attack cycles from abstract argumentation cannot always be realized as justification logic default theories. |
| Databáze: | OpenAIRE |
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