Value-based practical reasoning: Modal Logic + Argumentation

in Frontiers in Artificial Intelligence and Applications (2022), 353

Autonomous agents are supposed to be able to finish tasks or achieve goals that are assigned by their users through performing a sequence of actions. Since there might exist multiple plans that an agent ... [more ▼]

Autonomous agents are supposed to be able to finish tasks or achieve goals that are assigned by their users through performing a sequence of actions. Since there might exist multiple plans that an agent can follow and each plan might promote or demote different values along each action, the agent should be able to resolve the conflicts between them and evaluate which plan he should follow. In this paper, we develop a logic-based framework that combines modal logic and argumentation for value-based practical reasoning with plans. Modal logic is used as a technique to represent and verify whether a plan with its local properties of value promotion or demotion can be followed to achieve an agent's goal. We then propose an argumentation-based approach that allows an agent to reason about his plans in the form of supporting or objecting to a plan using the verification results. [less ▲]

BTPK-based learning: An Interpretable Method for Named Entity Recognition

E-print/Working paper (2022)

Named entity recognition (NER) is an essential task in natural language processing, but the internal mechanism of most NER models is a black box for users. In some high-stake decision-making areas ... [more ▼]

Named entity recognition (NER) is an essential task in natural language processing, but the internal mechanism of most NER models is a black box for users. In some high-stake decision-making areas, improving the interpretability of an NER method is crucial but challenging. In this paper, based on the existing Deterministic Talmudic Public announcement logic (TPK) model, we propose a novel binary tree model (called BTPK) and apply it to two widely used Bi-RNNs to obtain BTPK-based interpretable ones. Then, we design a counterfactual verification module to verify the BTPK-based learning method. Experimental results on three public datasets show that the BTPK-based learning outperform two classical Bi-RNNs with self-attention, especially on small, simple data and relatively large, complex data. Moreover, the counterfactual verification demonstrates that the explanations provided by the BTPK-based learning method are reasonable and accurate in NER tasks. Besides, the logical reasoning based on BTPK shows how Bi-RNNs handle NER tasks, with different distance of public announcements on long and complex sequences. [less ▲]

Base Argumentation as an Abstraction of Deductive Argumentation

in Baroni, Pietro; Benzmüller, Christoph; Wáng, Yì N. (Eds.) Logic and Argumentation - 4th International Conference, CLAR 2021, Hangzhou, China, October 20-22, 2021, Proceedings (2021)

Base argumentation is a logic-based instantiation of abstract argumentation. Each base argument is a subset of the given knowledge base. In this paper, we show that base argumentation satisfies some ... [more ▼]

Base argumentation is a logic-based instantiation of abstract argumentation. Each base argument is a subset of the given knowledge base. In this paper, we show that base argumentation satisfies some rationality postulates, and that base argumentation is equivalent to deductive argumentation under complete semantics. Due to its simplicity, base argumentation can be seen as an abstraction of deductive argumentation. [less ▲]

From Classical to Non-monotonic Deontic Logic Using ASPIC+

in Logic, Rationality, and Interaction - 7th International Workshop LORI 2019, Chongqing, China, October 18-21, 2019, Proceedings (2019)

In this paper we use formal argumentation to design non-monotonic deontic logics, based on two monotonic deontic logics. In particular, we use the structured argumentation theory ASPIC􀀀 to define non ... [more ▼]

In this paper we use formal argumentation to design non-monotonic deontic logics, based on two monotonic deontic logics. In particular, we use the structured argumentation theory ASPIC􀀀 to define non-monotonic variants of well-understood modal logics. We illustrate the approach using argumentation about free-choice permission. [less ▲]

Prioritized norms in formal argumentation

in Journal of Logic and Computation (2018)

To resolve conflicts amongst norms, various non-monotonic formalisms can be used to perform prioritized normative reasoning. Meanwhile, formal argumentation provides a way to represent non-monotonic ... [more ▼]

To resolve conflicts amongst norms, various non-monotonic formalisms can be used to perform prioritized normative reasoning. Meanwhile, formal argumentation provides a way to represent non-monotonic logics. In this paper we propose a representation of prioritized normative reasoning by argumentation. Using hierarchical abstract normative systems (HANS), we define three kinds of prioritized normative reasoning approaches called Greedy, Reduction and Optimization. Then, after formulating an argumentation theory for a HANS, we show that for a totally ordered HANS, Greedy and Reduction can be represented in argumentation by applying the weakest link and the last link principles, respectively, and Optimization can be represented by introducing additional defeats capturing the idea that for each argument that contains a norm not belonging to the maximal obeyable set then this argument should be rejected. [less ▲]

Prioritized Norms and Defaults in Formal Argumentation

in Deontic Logic and Normative Systems (2016) (2016)

Deontic logic sentences define what an agent ought to do when faced with a set of norms. These norms may come into conflict such that a priority ordering over them is necessary to resolve these conflicts ... [more ▼]

Deontic logic sentences define what an agent ought to do when faced with a set of norms. These norms may come into conflict such that a priority ordering over them is necessary to resolve these conflicts. Dung's seminal paper raised the - so far open - challenge of how to use formal argumentation to represent non monotonic logics, highlighting argumentation's value in exchanging, communicating and resolving possibly conflicting viewpoints in distributed scenarios. In this paper, we propose a formal framework to study various properties of prioritized non monotonic reasoning in formal argumentation, in line with this idea. More precisely, we show how a version of prioritized default logic and Brewka-Eiter's construction in answer set programming can be obtained in argumentation via the weakest and last link principles. We also show how to represent Hansen's recent construction for prioritized normative reasoning by adding arguments using weak contraposition via permissive norms, and their relationship to Caminada's "hang yourself" arguments. [less ▲]

Encompassing Uncertainty in Argumentation Schemes.

in Frontiers and Connections between Argumentation Theory and Natural Language Processing 2014. (2014)

In existing literature, little attention has been paid to the problems of how the un- certainty reflected by natural language text (e.g. verbal and linguistic uncertainty) can be explicitly formulated in ... [more ▼]

In existing literature, little attention has been paid to the problems of how the un- certainty reflected by natural language text (e.g. verbal and linguistic uncertainty) can be explicitly formulated in argumentation schemes, and how argumentation schemes enriched with various types of uncertainty can be exploited to support argumentation mining and evaluation. In this paper, we focus on the first problem, and introduce some preliminary ideas about how to clas- sify and encompass uncertainty in argu- mentation schemes [less ▲]