Antonino Rotolo

NMR Workshop 2025 Conference Paper

Deontic Argumentation

• Guido Governatori
• Antonino Rotolo

We address the issue of defining a semantics for deontic argumentation that supports weak permission. Some recent results show that grounded semantics do not support weak permission when there is a conflict between two obligations. We provide a definition of Deontic Argumentation Theory accounting for weak permission, and we recall the result about grounded semantics. Then, we propose a new semantics that supports weak permission.

AILAW Journal 2023 Journal Article

An approach to temporalised legal revision through addition of literals

• Martín O. Moguillansky
• Diego C. Martinez
• Luciano H. Tamargo
• Antonino Rotolo

Abstract As lawmakers produce norms, the underlying normative system is affected showing the intrinsic dynamism of law. Through undertaken actions of legal change, the normative system is continuously modified. In a usual legislative practice, the time for an enacted legal provision to be in force may differ from that of its inclusion to the legal system, or from that in which it produces legal effects. Even more, some provisions can produce effects retroactively in time. In this article we study a simulation of such process through the formalisation of a temporalised logical framework upon which a novel belief revision model tackles the dynamic nature of law. Represented through intervals, the temporalisation of sentences allows differentiating the temporal parameters of norms. In addition, a proposed revision operator allows assessing change to the legal system by including a new temporalised literal while preserving the time-based consistency. This can be achieved either by pushing out conflictive pieces of pre-existing norms or through the modification of intervals in which such norms can be either in force, or produce effects. Finally, the construction of the temporalised revision operator is axiomatically characterised and its rational behavior proved through a corresponding representation theorem.

JELIA Conference 2023 Conference Paper

Stable Normative Explanations: From Argumentation to Deontic Logic

• Cecilia Di Florio
• Antonino Rotolo
• Guido Governatori
• Giovanni Sartor

Abstract This paper reconstructs in the context of formal argumentation the notion of stable explanation developed elsewhere in Defeasible Logic. With this done, we discuss the deontic meaning of this notion and show how to build from argumentation neighborhood structures for deontic logic where a stable explanation can be characterised.

AILAW Journal 2022 Journal Article

Thirty years of Artificial Intelligence and Law: overviews

• Michał Araszkiewicz
• Trevor Bench-Capon
• Enrico Francesconi
• Marc Lauritsen
• Antonino Rotolo

Abstract The first issue of Artificial Intelligence and Law journal was published in 1992. This paper discusses several topics that relate more naturally to groups of papers than a single paper published in the journal: ontologies, reasoning about evidence, the various contributions of Douglas Walton, and the practical application of the techniques of AI and Law.

FLAP Journal 2021 Journal Article

Time, Defeasible Logic and Belief Revision: Pathways to Legal Dynamics.

• Luciano H. Tamargo
• Diego C. Martínez
• Antonino Rotolo
• Guido Governatori

In order to properly model norm change in the law, temporal aspects of legal dynamics must be considered. Since there exist several time-based features of law that should be studied, we discuss two interesting approaches: one based on defeasible logic and the other based on belief revision. Each of these makes use of one of the two classic forms of reasoning about time: point-based and interval-based. Both formalisms provide the necessary logical infrastructure to address the characterization of complex behaviour of legal dynamics.

FLAP Journal 2019 Journal Article

A Deontic Argumentation Framework Towards Doctrine Reification.

• Régis Riveret
• Antonino Rotolo
• Giovanni Sartor

A modular rule-based argumentation system is proposed to represent and reason upon conditional norms featuring obligations, prohibitions, and (strong or weak) permissions. The approach is based on common constructs in computational models of argument: rule-based arguments, argumentation graphs, argument labelling semantics and statement labelling semantics. Deontic reasoning patterns are captured with defeasible rule schemata to the greatest extent, towards the reification of doctrinal pieces. We show then that bivalent statement labellings can fall short to address normative completeness, and for this reason, we propose to use trivalent labelling semantics. Given an argumentation graph, deontic statuses can be computed efficiently. The system is illustrated with a scenario featuring a violation and a contrary-to-duty obligation.

AILAW Journal 2019 Journal Article

An axiomatic characterization of temporalised belief revision in the law

• Luciano H. Tamargo
• Diego C. Martinez
• Antonino Rotolo
• Guido Governatori

Abstract This paper presents a belief revision operator that considers time intervals for modelling norm change in the law. This approach relates techniques from belief revision formalisms and time intervals with temporalised rules for legal systems. Our goal is to formalise a temporalised belief base and corresponding timed derivation, together with a proper revision operator. This operator may remove rules when needed or adapt intervals of time when contradictory norms are added in the system. For the operator, both constructive definition and an axiomatic characterisation by representation theorems are given.

FLAP Journal 2019 Journal Article

Time and Compensation Mechanisms in Checking Legal Compliance.

• Guido Governatori
• Antonino Rotolo

In this paper we extend the logic of violation proposed by [23] with time, more precisely, we temporalise that logic. The resulting system allows us to capture many subtleties of the concept of legal compliance. In particular, the formal characterisation of compliance can handle different types of legal obligation and different temporal constraints over them. The logic is also able to represent, and reason about, chains of reparative obligations, since in many cases the fulfillment of these types of obligation still amounts to legally acceptable situations.

FLAP Journal 2017 Journal Article

Handling Norms in Multi-agent Systems by Means of Formal Argumentation.

• Célia da Costa Pereira
• Beishui Liao
• Alessandra Malerba
• Antonino Rotolo
• Andrea G. B. Tettamanzi
• Leendert W. N. van der Torre
• Serena Villata

ECAI Conference 2014 Conference Paper

Strategic Argumentation is NP-Complete

• Guido Governatori
• Francesco Olivieri
• Simone Scannapieco
• Antonino Rotolo
• Matteo Cristani

We study the complexity of the Strategic Argumentation Problem for 2-player dialogue games where a player should decide what move (set of rules) to play at each turn in order to prove (disprove) a given thesis. We show that this is an NP-complete problem.

EUMAS Conference 2014 Conference Paper

Strategic Argumentation Under Grounded Semantics is NP-Complete

• Guido Governatori
• Michael J. Maher
• Francesco Olivieri
• Antonino Rotolo
• Simone Scannapieco

Abstract We study the complexity of the Strategic Argumentation Problem for 2-player dialogue games where a player should decide what move to play at each turn in order to prove (disprove) a given claim. We shall prove that this is an NP-complete problem. The result covers one the most popular argumentation semantics proposed by Dung [ 4 ]: the grounded semantics.

AAMAS Conference 2013 Conference Paper

Law Enforcement in Norm-Governed Learning Agents

• Régis Riveret
• Giuseppe Contissa
• Antonino Rotolo
• Jeremy V. Pitt

We study law enforcement mechanisms within a population of norm-governed learning agents. We show that a traditional analysis based on expected utility can be misleading, because learning agents tend to comply even though their surveillance is stopped. This has significant implications for the design of self-organising institutions with endogenous resources, where the cost of monitoring and norm enforcement has to be taken into consideration.

AILAW Journal 2012 Journal Article

Probabilistic rule-based argumentation for norm-governed learning agents

• Régis Riveret
• Antonino Rotolo
• Giovanni Sartor

Abstract This paper proposes an approach to investigate norm-governed learning agents which combines a logic-based formalism with an equation-based counterpart. This dual formalism enables us to describe the reasoning of such agents and their interactions using argumentation, and, at the same time, to capture systemic features using equations. The approach is applied to norm emergence and internalisation in systems of learning agents. The logical formalism is rooted into a probabilistic defeasible logic instantiating Dung’s argumentation framework. Rules of this logic are attached with probabilities to describe the agents’ minds and behaviours as well as uncertain environments. Then, the equation-based model for reinforcement learning, defined over this probability distribution, allows agents to adapt to their environment and self-organise.

IJCAI Conference 2011 Conference Paper

Norm Compliance of Rule-Based Cognitive Agents

• Antonino Rotolo

This paper shows how belief revision techniques can be used in Defeasible Logic to change rulebased theories characterizing the deliberation process of cognitive agents. We discuss intention reconsideration as a strategy to make agents compliant with the norms regulating their behavior.

KR Conference 2010 Conference Paper

Lex minus dixit quam voluit, lex magis dixit quam voluit: A formal study on legal interpretation

• Antonino Rotolo
• Guido Governatori
• Guido Boella
• Leendert van der Torre

AILAW Journal 2008 Journal Article

A computational framework for institutional agency

• Guido Governatori
• Antonino Rotolo

Abstract This paper provides a computational framework, based on defeasible logic, to capture some aspects of institutional agency. Our background is Kanger-Lindahl-Pörn account of organised interaction, which describes this interaction within a multi-modal logical setting. This work focuses in particular on the notions of counts-as link and on those of attempt and of personal and direct action to realise states of affairs. We show how standard defeasible logic (DL) can be extended to represent these concepts: the resulting system preserves some basic properties commonly attributed to them. In addition, the framework enjoys nice computational properties, as it turns out that the extension of any theory can be computed in time linear to the size of the theory itself.

JAAMAS Journal 2008 Journal Article

BIO logical agents: Norms, beliefs, intentions in defeasible logic

• Guido Governatori
• Antonino Rotolo

Abstract In this paper we follow the BOID (Belief, Obligation, Intention, Desire) architecture to describe agents and agent types in Defeasible Logic. We argue, in particular, that the introduction of obligations can provide a new reading of the concepts of intention and intentionality. Then we examine the notion of social agent (i. e. , an agent where obligations prevail over intentions) and discuss some computational and philosophical issues related to it. We show that the notion of social agent either requires more complex computations or has some philosophical drawbacks.

AAMAS Conference 2006 Conference Paper

The Cost of Social Agents

• Guido Governatori
• Antonino Rotolo
• Vineet Nair

LPAR Conference 2005 Conference Paper

Programming Cognitive Agents in Defeasible Logic

• Mehdi Dastani
• Guido Governatori
• Antonino Rotolo
• Leendert W. N. van der Torre

Abstract Defeasible Logic is extended to programming languages for cognitive agents with preferences and actions for planning. We define rule-based agent theories that contain preferences and actions, together with inference procedures. We discuss patterns of agent types in this setting. Finally, we illustrate the language by an example of an agent reasoning about web-services.

AILAW Journal 2004 Journal Article

Normative autonomy and normative co-ordination: Declarative power, representation, and mandate

• Jonathan Gelati
• Antonino Rotolo
• Giovanni Sartor
• Guido Governatori

Abstract In this paper we provide a formal analysis of the idea of normative co-ordination. We argue that this idea is based on the assumption that agents can achieve flexible co-ordination by conferring normative positions to other agents. These positions include duties, permissions, and powers. In particular, we explain the idea of declarative power, which consists in the capacity of the power-holder of creating normative positions, involving other agents, simply by „proclaiming“ such positions. In addition, we account also for the concepts of representation, namely the representative’s capacity of acting in the name of his principal, and of mandate, which is the mandatee’s duty to act as the mandator has requested. Finally, we show how the framework can be applied to represent the contract-net protocol. Some brief remarks on future research and applications conclude this contribution.