A Paraconsistent Multi-agent Framework for Dealing with Normative Conflicts (original) (raw)

Non-monotonic reasoning with normative conflicts in multi-agent deontic logic

Journal of Logic and Computation, 2013

MDL that avoids explosion when faced with agents and groups with conflicting directives. Although PMDL consistently deals with normative conflicts, it is too weak to account for many intuitive everyday normative inferences. That is why we non-monotonically strengthen PMDL in Section 5. This strengthening takes place within the adaptive logics framework for non-monotonic reasoning. The strengthening results in the adaptive logics PMDL r and PMDL m , two logics that are intermediate in inferential power between the systems PMDL and MDL. PMDL r and PMDL m approximate the classical setting in the sense that they take normative conflicts to be false whenever the premises allow for it. In doing so, PMDL m is slightly more powerful than PMDL r. This paper fits within the larger project of adaptive deontic logics devised for consistently accommodating normative conflicts (see e.g. [7, 29, 39, 41]). It improves on earlier work presented in [6]. We compare the logics PMDL r and PMDL m to both logics of action and adaptive deontic logics in Section 6. 2 ML, a simple multi-agent logic of action 2.1 Definition 2.1.1 Language and conventions We use a denumerable set P of propositional constants (atoms) p, q, r,. . ., and a finite non-empty set I = {i 1 ,. .. , i n } of agents. Since we will in the remainder often refer to groups of agents J in I, i.e. non-empty subsets of I, the following notation is useful for this:

An adaptive logic framework for conditional obligations and deontic dilemmas

(For correct references compare the uploaded file) Lou Goble proposed in his [6] logics which are able to deal with deontic conflicts by restricting the inheritance principle. In [3] he developed this systems further in order to treat conditional obligations. One of the central problems for dyadic deontic logics is to properly treat the restricted applicability of the principle “strengthening the antecedent”. In most cases of moral reasoning we want to derive from an obligation A under condition B, that A is also obliged under condition B and C. However, there are important counterexamples. Goble proposed a weakened rational monotonicity principle to tackle this problem. This solution is suboptimal as it is for some examples counter-intuitive or even leads to explosion. The paper identifies also other problems of Goble’s systems. An adaptive logic framework is proposed which is able to tackle these problems. For the adaptive logics there is no need for further explicit additions of permission statements to the premise set which was for Goble’s logics a consequence of restricting inheritance. The addition of such statements was ad hoc and in need to be done externally by the user. The proof dynamics of the adaptive logic takes care of this as a part of the reasoning process which is explicated by the proof. Furthermore, for non-conflicting premise sets the adaptive logics are equivalent to Goble’s dyadic version of standard deontic logic.

Normative Multi-Agent Systems and Kelsenian Jurisprudence

ArXiv, 2017

A multi-agent system (MAS) is a collection of autonomous entities, called agents, that interact to fulfil the system’s intended behavior. When regulated by a collection of rules, also called norms, such a system is referred as a Normative MAS (NorMAS). The standard technique to reason on NorMAS uses Deontic Logic as underlying logic where norms becomes formulae in the associated theory. However, it is known to fail on the modeling of contrary-to-duty scenarios, also called deontic paradoxes, since the resulting theories turn out to be inconsistent. In this paper, we propose a new approach to reason on NorMAS, based on Intuitionistic Hybrid Logic (IHL) and Kelsenian Jurisprudence. Essentially, norms are represented as nominals in the associated IHL theory. We discuss normative conflict identification according to Hill’s functional taxonomy, that generalizes from standard identification by impossibility-of-jointcompliance test. Norm conflicts are resolved by norm precedence, naturally...

Modeling Normative Multi-Agent Systems from a Kelsenian Perspective

arXiv: Logic in Computer Science, 2017

Standard Deontic Logic (SDL) has been used as the underlying logic to model and reason over Multi-Agent Systems governed by norms (NorMAS). It is known that SDL is not able to represent contrary-to-duty (CTD) scenarios in a consistent way. That is the case, for example, of the so-called Chisholm paradox, which models a situation in which a conditional obligation that specifies what must be done when a primary obligation is violated holds. In SDL, the set of sentences that represent the Chisholm paradox derives inconsistent sentences. Due to the autonomy of the software agents of a NorMAS, norms may be violated and the underlying logic used to model the NorMAS should be able to represent violation scenarios. The contribution of this paper is threefold: (i) we present how Kelsenian thinking, from his jurisprudence in the context of legal ontologies, and Intuitionist Hybrid Logic can be adopted in the modeling of NorMAS, (ii) discuss how this approach overcomes limitations of the SDL a...

Deontic Logic, Contrary to Duty Reasoning and Fault Tolerance

Electronic Notes in Theoretical Computer Science, 2009

Deontic Logic was introduced in the first half of the last century to formalize aspects of legal reasoning. Since then a lot of effort has gone into improving the formalism(s) and widening their applicability, including in Computer Science and Software Engineering. One strand of work has focused on the use of an action based approach to deontic operators, rather than the traditional property focused operators. We propose a new version of this kind of deontic logic that has very nice meta-logical properties, avoids many of the traditional problems of deontic logics and has an appealing treatment of contrary to duty reasoning. This kind of reasoning provides a kind of conditional reasoning about having violated normative constraints and describing the resulting consequences. We show how to apply this formalism to characterize fault tolerance mechanisms and to then reason about the properties of the mechanisms.

Tolerating Inconsistencies: A Study of Logic of Moral Conflicts

Bulletin of the Section of Logic

Moral conflicts are the situations which emerge as a response to deal with conflicting obligations or duties. An interesting case arises when an agent thinks that two obligations A and B are equally important, but yet fails to choose one obligation over the other. Despite the fact that the systematic study and the resolution of moral conflicts finds prominence in our linguistic discourse, standard deontic logic when used to represent moral conflicts, implies the impossibility of moral conflicts. This presents a conundrum for appropriate logic to address these moral conflicts. We frequently believe that there is a close connection between tolerating inconsistencies and conflicting moral obligations. In paraconsistent logics, we tolerate inconsistencies by treating them to be both true and false. In this paper, we analyze Graham Priest’s paraconsistent logic LP, and extend our examination to the deontic extension of LP known as DLP. We illustrate our work, with a classic example from ...

Introduction to Normative Multiagent Systems

2005

This special issue contains four selected and revised papers from the second international workshop on normative multiagent systems, for short NorMAS07 (Boella et al. (eds) Normative multiagent systems. Dagstuhl seminar proceedings 07122, 2007), held at Schloss Dagstuhl, Germany, in March 2007. At the workshop a shift was identified in the research community from a legal to an interactionist view on normative multiagent systems.

An Approach for Detecting and Resolving Indirect Normative Conflicts in Multi-agent Systems

Lecture Notes in Computer Science, 2018

In Multi-agent systems (MAS), norms can be adopt as a strategy to regulate and guide the behavior of software agents and avoid that unexpected actions occur in the system. In order to guarantee that the MAS runs properly, the set of norms must be free of conflict. Two norms are in conflict when the agent automatically violates a norm when adopts the other one. In this paper, we present an approach for detecting and resolving indirect conflicts among norms that regulate a multi-agent system. Indirect conflicts are those who arise among norms whose elements being regulated are not the same but are related. Our approach uses a lexical database and a domain ontology to detect indirect conflicts and the conflicts detected are resolved by manipulating the activation/deactivation conditions of the conflicting norms taking into account the relationships identified among the elements of the conflicting norms.

Normative Conflicts in a Dynamic Logic of Norms and Codes

Deontic Logic and Normative Systems (DEON 2018), 2018

In this paper we introduce two conflict tolerant and dynamic deontic systems DNC and DNC+ in which normative conflicts are analysed as conflicts between normative codes containing norms that prescribe the realisation of incompatible states of affairs. The systems present two crucial traits: first, norms and codes are explicitly represented in it; second, the connections between norms and codes and the way in which codes are updated by introducing new norms are properly defined. We will show how the systems can be used to fruitfully analyse paradigmatic cases of civil conflicts. Specifically , DNC and DNC+ will allow us to model the genesis of a conflict by keeping track of which agent triggered it and, relatedly, to capture the basic distinction between civil disobedience and conscientious objection.