1,721,327 research outputs found
A Logical Framework for Weak Permissions in Criminal Procedure
No full textWe study weak permissions in criminal trials, which require judicial determination due to the absence of explicit prohibitions. We thus sketch a dialogue game to address this issue, analyzing argumentative dynamics with common and private knowledge. By applying various argumentation semantics, we clarify the procedural implications for weak permissions
A Computational Model for Pragmatic Oddity
Full text linkWe introduce a computational model based on Deontic Defeasible Logic to handle the issue of Pragmatic Oddity. The key idea is that a conjunctive obligation is allowed only when each individual obligation is independent of the violation of the other obligations. The solution makes essential use of the constructive proof theory of the logic
Representing Business Contracts in RuleML
Full text linkThis paper presents an approach for the specification and implementation of translating contracts from a human-oriented form into an executable representation for monitoring. This will be done in the setting of RuleML. The task of monitoring contract execution and performance requires a logical account of deontic and defeasible aspects of legal language; currently such aspects are not covered by RuleML; accordingly we show how to extend it to cover such notions. From its logical form, the contract will be thus transformed into a machine readable rule notation and eventually implemented as executable semantics via any mark-up languages depending on the client's preference, for contract monitoring purposes
Legislative Dialogues with Incomplete Information
Full text linkThis paper extends previous work by presenting a framework for modelling legislative deliberation in the form of dialogues with incomplete information. Roughly, in such legislative dialogues coalitions are initially equipped with different theories which constitute their private knowledge. Under this assumption they can dynamically change and propose new legislation associated with different utility functions
Avoiding Pragmatic Oddity: a bottom-up Defeasible Deontic Logic
Full text linkThis paper presents an extension of Defeasible Deontic Logic to deal with the Pragmatic Oddity problem. The logic applies three general principles: (i) the Pragmatic Oddity problem must be solved within a general logical treatment of contrary- to-duty (CTD) reasoning; (ii) non-monotonic methods must be adopted to handle CTD reasoning; (iii) logical models of CTD reasoning must be computationally feasible and, if possible, efficient. The proposed extension of Defeasible Deontic Logic elaborates a preliminary version of the model proposed by Governatori and Rotolo [15]. The previous solution was based on particular characteristics of the (constructive, top-down) proof theory of the logic. However, that method introduces some degree of non-determinism. To avoid the problem, we provide a bottom-up characterization of the logic. The new characterization offers insights for the efficient implementation of the logic and allows us to establish the computational complexity of the problem
Deontic Ambiguities in Legal Reasoning
Full text linkWhat happens if the way in which we handle a genuine deontic conflict --i.e., a deontic ambiguity-- matters regarding the application of other norms that are not directly affected by that conflict? We argue that the law requires sometimes propagating the ambiguity to other norms and sometimes confining it to some norms only. We explore this issue and model different reasoning patterns. The problem is addressed in a new variant of Defeasible Deontic Logic. The contribution of this paper is threefold: (a) we extend the treatment of ambiguity blocking and propagation to Defeasible Deontic Logic; (b) we discuss reasoning patterns in the law, especially in criminal law, where we need to deal with both ambiguity blocking and ambiguity propagation in the same legal system and logic; (c) we devise an annotated variant of Defeasible Deontic Logic where we distinguish literals that must be obtained through an ambiguity-blocking mechanism from those that are derived using an ambiguity-propagating mechanism
Interpretation across legal systems
Full text linkIn this paper we extend a formal framework presented in [6] to model reasoning across legal systems. In particular, we propose a logical system that encompasses the various interpretative interactions occurring between legal systems in the context of private international law. This is done by introducing meta-rules to reason with interpretive canons
Revision of defeasible preferences
No full textThere are several contexts of non-monotonic reasoning where a priority between rules is established with the purpose of solving conflicts. We investigate how to modify such a priority (preference) relation in a non-monotonic logic in order to change the conclusions of the theory itself. We shall argue that the approach we adopt has a natural counterpart in legal reasoning and argumentation, where users cannot typically change the facts or the rules, but can propose their preferences about the relative strength of the rules.The main result of the present work is the proof that the problem of revising a non monotonic theory by changing only the superiority order between conflicting rules is, in general, computationally hard.After such an analysis, we identify three contraction/revision/update operations and study them against the AGM postulates for belief revision, to discover that only a (small) part of these postulates are satisfied in the specific non-monotonic setting. (C) 2018 Elsevier Inc. All rights reserved
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