Intuitionistic Description Logic and Legal Reasoning

Abstract The main aim of this paper is to study the notion of conditional right by means of constructive type theory (CTT) which provides the means to develop a system of contentual inferences rather than of syntactic derivations. Moreover, in line with Armgardt, we will first study the general notion of dependence as triggered by hypotheticals and then the logical structure of dependence specific to conditional right.We will develop this idea in a dialogical framework where the distinction between local reason and strategic reason leads to the further distinction between two basic kinds of pieces of evidence and where meanings is constituted by the interaction of obligations and entitlements. The present paper is based on Rahman (2015). However, though the underlying CTT-analysis is the same, the dialogical reconstruction makes use of a new way of linking dialogical logic and CTT.

Artificial Intelligence and Law, 1996

This paper describes a model of legal reasoning and a logic for reasoning with rules, principles and goals that is especially suited to this model of legal reasoning. The paper consists of three parts. The first part describes a model of legal reasoning based on a two-layered view of the law. The first layer consists of principles and goals that express fundamental ideas of a legal system. The second layer contains legal rules which in a sense summarise the outcome of the interaction of the principles and goals for a number of case types. Both principles, goals and rules can be used in legal arguments, but their logical roles are different. One characteristic of the model of legal reasoning described in the first part of the paper is that it takes these logical differences into account. Another characteristic is that it pays serious attention to the phenomena of reasoning about the validity and acceptance of rules, respectively principles and goals, and about the application of legal rules, and the implications of these arguments for the use of rules, principles and goals in deriving legal conclusions for concrete cases. The second part of the paper first describes a logic (Reason-Based Logic) that is especially suited to deal with legal arguments as described in terms of the previously discussed model. The facilities of the logic are illustrated by means of examples that correspond to the several aspects of the model. The third part of the paper deals with a number of logico-philosophical reflections on Reason-Based Logic. The occasion is also used to compare these presuppositions with theories of defeasible reasoning based on the comparison of arguments.

Proce ed ings of LO AIT 07, 2007

The overarching goal of the paper is to question the distinction between rules and principles. I analyze Robert Alexy's conception of rules and principles and argue that it may be handled formally with the use of defeasible logic rather than classical logic. I further claim that defeasible logic does not provide a sharp logical criterion for distinguishing between rules and principles, and argue that there exist no such non-logical criteria. In conclusion I posit that the distinction in question has only a didactic value.

Lecture Notes in Computer Science, 2012

Although the formalization of legal documents is quite useful, they contain various kinds of if-then relations. In this paper, we aim at formalizing the prerequisite-effect structure in temporal/causal settings. We regard the progress of time as hereditary accessibility in temporal states, and thus we introduce Kripke semantics. Our ultimate objective is to construct a legal reasoning system, however, since those various kinds of logical relations may complicate the reasoning system we avoid to introduce multiple modal operators. We stay in simple intuitionistic logic, and we will extend it to include the prerequisite-effect structure. Then, the structure is defined in the augmentation of known facts, that is, the effect is immediately follows after the prerequisite is satisfied.

2019

This paper concerns arbitrary relations in law and extends beyond concrete types of legal relations. There is no established ontology of relations in the legal domain, although ontologies of legal concepts are discussed in literature. Different legal terms, such as duty, contract, debt, husband, etc. can be viewed as relations. However, on the meta-level, there is no model of relation types in law. This paper tackles the following types of relations: (a) direct relation; (b) an indirect relation through tertium comparationis; (c) subsumption, i.e. a relation between fact, which is in Is, and the normative condition, which is in Ought; and (d) amplitude relation. We follow Arthur Kaufmann's assertion that relations in law can be managed similarly to substances.

Studia Humana

The aim of this article is to argue that the nature of law influences the logic of legal reasoning and to give an impression of how this ‘works’. The argument consists of three steps. In the first step it is shown how classical logic is based on an underlying view of the world. This view has no place for rules and as a result, classical logic wrestles with rules and their role in (legal) reasoning. In the second step, an alternative view of the world is presented. In this view, a central place is taken by social reality and by the role of rules in it. In the third step, it is shown how traditional forms of legal reasoning are better suited than classical logic to deal with legal rules and that these traditional forms better fit the ‘social’ image of law that was presented in the second step.

Artificial Intelligence and Law, 2007

... when it concerns the prohibition against performing certain inferences (against reasoning in cer ... conditionals represent a fundamental, through often misunder-stood, construct of legal knowledge. ... B must at least provide for defeasible normative detachment: the ante-cedent ...

Legal knowledge and information systems: JURIX …, 2001

77 What to Expect from Legal Logic? Jaap Hage Department of Metajuridica Faculty of Law Universiteit Maastricht The Netherlands jaap. hage@ metajur. unimaas. nl Abstract. This paper argues for a proper position for legal logic in between a general theory of legal reasoning and a ...

There are two competing views on what makes propositions of law true. The one, legal realism, takes it that propositions of law are true because they reflect an independently existing reality of legal facts. These facts would be generated by legal rules which would operate autonomously, without need for human intervention. The institutional theory of law illustrates this view. On this view it is the function of legal arguments to reconstruct the results of the autonomous rule application. The other view is legal constructivism, according to which propositions of law are true because they are the conclusion of the best (possible) legal argument. On this view the function of legal argumentation is constitutive: argumentation determines the contents of the law. This paper argues that legal realism is not very plausible because it is based on metaphysical assumptions which cannot be verified or falsified. Legal constructivism would be more plausible, in particular in the variant where the law is determined by the best actual legal argument. This position is defended by means of a brief exposition of the so-called ‘Erlanger-approach’ to legal justification.

2019

Artificial Intelligence and Law, 2009

I shall compare two views of legal concepts: as nodes in inferential nets and as categories in an ontology (a conceptual architecture). Firstly, I shall introduce the inferential approach, consider its implications, and distinguish the mere possession of an inferentially defined concept from the belief in the concept’s applicability, which also involves the acceptance of the concept’s constitutive inferences. For