Papers by Guido Governatori
Lecture Notes in Computer Science, Dec 1, 2006
One of Semantic Web strengths is the ability to address incomplete knowledge. However, at present... more One of Semantic Web strengths is the ability to address incomplete knowledge. However, at present, it cannot handle incomplete knowledge directly. Also, it cannot handle non-monotonic reasoning. In this paper, we extend ALC - Defeasible Description Logic with existential quantifier, i.e., ALE Defeasible Description Logic. Also, we modify some parts of the logic, resulting in an increasing efficiency in its reasoning. Description logics, which is a language based on first order logic, cannot handle incomplete and inconsistent knowledge well. In fact, it is often that complete and consistent information or knowledge are very hard to obtain. Consequently, there is an urgent need to extend description logics with a non-monotonic part which can handle incomplete and inconsistent knowledge better than themselves. Defeasible logic, developed by Nute , is a well-established nonmonotonic reasoning system. Its outstanding properties are low computational complexity and ease of implementation. Thus, this logic is the nonmonotonic part of our choice. Governatori [3] proposes a formalism to extend ALC -with defeasibility. He combines the description logic formalism with the defeasible logic formalism, creating a logic that can handle both monotonic and nonmonotonic information coherently. We extend this work to be able to handle existential quantification.
Springer eBooks, 2008
Historically, business process design has been driven by business objectives, specifically proces... more Historically, business process design has been driven by business objectives, specifically process improvement. However this cannot come at the price of control objectives which stem from various legislative, standard and business partnership sources. Ensuring the compliance to regulations and industrial standards is an increasingly important issue in the design of business processes. In this paper, we advocate that control objectives should be addressed at an early stage, i.e., design time, so as to minimize the problems of runtime compliance checking and consequent violations and penalties. To this aim, we propose supporting mechanisms for business process designers. This paper specifically presents a support method which allows the process designer to quantitatively measure the compliance degree of a given process model against a set of control objectives. This will allow process designers to comparatively assess the compliance degree of their design as well as be better informed on the cost of non-compliance.
Modal Rules: Extending Defeasible Logic with Modal Operators
Lecture Notes in Computer Science, 2018
In this paper we present a general methodology to extend Defeasible Logic with modal operators. W... more In this paper we present a general methodology to extend Defeasible Logic with modal operators. We motivate the reasons for this type of extension and we argue that the extension will allow for a robust knowledge framework in different application areas.
International Journal of Cooperative Information Systems, Jun 1, 2005
This paper presents an approach for the specification and implementation of translating contracts... more This 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.
Lecture Notes in Computer Science, 2009
We present the design and implementation of SPINdle -an open source Java based defeasible logic r... more We present the design and implementation of SPINdle -an open source Java based defeasible logic reasoner capable to perform efficient and scalable reasoning on defeasible logic theories (including theories with over 1 million rules). The implementation covers both the standard and modal extensions to defeasible logics. It can be used as a standalone theory prover and can be embedded into any applications as a defeasible logic rule engine. It allows users or agents to issues queries, on a given knowledge base or a theory generated on the fly by other applications, and automatically produces the conclusions of its consequences. The theory can also be represented using XML.
Springer eBooks, 2006
we showed how to combine propositional multimodal logics using Gabbay's fibring methodology. In t... more we showed how to combine propositional multimodal logics using Gabbay's fibring methodology. In this paper we extend the above mentioned works by providing a tableau-based proof technique for the combined/fibred logics. To achieve this end we first make a comparison between two types of tableau proof systems, (graph & path), with the help of a scenario (The Friend's Puzzle). Having done that we show how to uniformly construct a tableau calculus for the combined logic using Governatori's labelled tableau system KEM. We conclude with a discussion on KEM's features. This work was supported by the Australian Research Council under Discovery Project DP0558854 on "A Formal Approach to Resource Allocation in Service Oriented Marketplaces". 1 General modal systems with an arbitrary set of normal modal operators all characterised by the axiom K: 2(ϕ → ψ) → (2ϕ → 2ψ) and the necessitation rule. i.e., ϕ/ 2ϕ.
Unravel legal references in defeasible deontic logic
Legal documents often contain references to either other documents, or other parts (of the same d... more Legal documents often contain references to either other documents, or other parts (of the same document). The use of references is meant to reduce the complexity of the documents; however, they pose serious concerns for the formal (logical) representation of the norms stipulated in the document itself. We propose an approach to directly model the references in a logic language and to resolve them during the computation of the legal effects in force in a case. The approach is proved to be computationally feasible and to have an efficient algorithmic implementation.
Theorem Proving with Analytic Tableaux and Related Methods, 1996
Dealing with label dependent deontic modalities
ABSTRACT
Un Modello Formale Per Il Ragionamento Giuridico
... Vorrei ringraziare Paolo Di Giusto, Alessio Lomuscio e Alessandra Russo e soprattutto i miei ... more ... Vorrei ringraziare Paolo Di Giusto, Alessio Lomuscio e Alessandra Russo e soprattutto i miei colleghi del CIRFID Paola Benassi, Paola Cattabriga, AntoninoRotolo, e Silvia Vida per aver contribuito a determinare ambienti di ...
Advances in Modal Logic 6
Advances in Modal Logic, 2006
Lecture Notes in Computer Science, 2003
We develop a labelled tableaux system for the modal logic KD45 i-j n extended with epistemic noti... more We develop a labelled tableaux system for the modal logic KD45 i-j n extended with epistemic notions. This logic characterises a particular type of interpreted systems used to represent and reason about states of correct and incorrect functioning behaviour of the agents in a system, and of the system as a whole. The resulting tableaux system provides a simple decision procedure for the logic. We discuss these issues and we illustrate them with the help of simple examples
Springer eBooks, 2006
One of Semantic Web strengths is the ability to address incomplete knowledge. However, at present... more One of Semantic Web strengths is the ability to address incomplete knowledge. However, at present, it cannot handle incomplete knowledge directly. Also, it cannot handle non-monotonic reasoning. In this paper, we extend ALC - Defeasible Description Logic with existential quantifier, i.e., ALE Defeasible Description Logic. Also, we modify some parts of the logic, resulting in an increasing efficiency in its reasoning. Description logics, which is a language based on first order logic, cannot handle incomplete and inconsistent knowledge well. In fact, it is often that complete and consistent information or knowledge are very hard to obtain. Consequently, there is an urgent need to extend description logics with a non-monotonic part which can handle incomplete and inconsistent knowledge better than themselves. Defeasible logic, developed by Nute , is a well-established nonmonotonic reasoning system. Its outstanding properties are low computational complexity and ease of implementation. Thus, this logic is the nonmonotonic part of our choice. Governatori [3] proposes a formalism to extend ALC -with defeasibility. He combines the description logic formalism with the defeasible logic formalism, creating a logic that can handle both monotonic and nonmonotonic information coherently. We extend this work to be able to handle existential quantification.
AI & society, Dec 29, 2017
Online Social Networks (OSNs) captured the attention of the masses by offering attractive means o... more Online Social Networks (OSNs) captured the attention of the masses by offering attractive means of sharing personal information and developing social relationships. People expose personal information about their lives on OSNs. This may result in undesirable consequences of users' personal information leakage to an unwanted audience and raises privacy concerns. The issue of privacy has received significant attention in both the research literature and the mainstream media. In this paper, we present results of an empirical study that measure users' attitude towards interpersonal privacy concerns in online social networks. The results demonstrated a serious mismatch between privacy concerns of users and their information sharing behavior. Also, it indicated that strangers are part of user social circles this makes privacy protection more complicated and introduce an insider threat, whereas all existing privacy tools allow users to manage the outsider threat. Information and friend segregation strategies are suggested on the basis of user information disclosure and interaction pattern. We conclude that sensitivity of information and frequency of interaction, both, play a vital role in information and friend segregation.
Lecture Notes in Computer Science, 1996
In this paper we suggest ways in which logic and law may usefully relate; and we present an analy... more In this paper we suggest ways in which logic and law may usefully relate; and we present an analytic proof system dealing with the Jones Pörn's deontic logic of Ideality and Subideality, which offers some suggestions about how to embed legal systems in label formalism.
Springer eBooks, Nov 22, 2007
Traffic rules compliance checking of automated vehicle maneuvers
Artificial Intelligence and Law
Matrib leaf classification using Deep Neural Network: An Integrated Image Processing Technique
2022 IEEE Region 10 Symposium (TENSYMP)
Proceedings of the Eighteenth International Conference on Artificial Intelligence and Law
A critical challenge in "Rules as Code" ("RaC") initiatives is enhancing legal accuracy. In this ... more A critical challenge in "Rules as Code" ("RaC") initiatives is enhancing legal accuracy. In this paper, we present the preliminary results of a two-week, first of its kind experiment that aims to shed light on how different legally trained people interpret and convert Australian Commonwealth legislation into machine-executable code. We find that coders collaboratively agreeing on key legal terms, or atoms, before commencing independent coding work can significantly increase the similarity of their encoded rules. Participants nonetheless made a range of divergent interpretive choices, which we argue are most likely due to: (1) the complexity of statutory interpretation, (2) encoded provisions having varying levels of granularity, and (3) the functionality of our coding language. Based on these findings, we draw an important distinction between processes for technical validation of encoded rules, which focus on ensuring rules adhere to select coding languages and conventions, and processes of legal alignment, which we conceptualise as enhancing congruence between the encoded provisions and the true meaning of the statutory text in line with the modern approach to statutory interpretation. We argue that these processes are distinct but both critically important in enhancing the accuracy of encoded rules. We conclude by emphasising the need in RaC initiatives for multi-disciplinary expertise across specific legal subject matters, statutory interpretation and technical programming.
Legal Compliance in a Linked Open Data Framework
An approach for legal compliance representation and checking within a Linked Open Data framework ... more An approach for legal compliance representation and checking within a Linked Open Data framework is presented. It is based on modeling deontic norms in terms of ontology and ontology property restrictions. It is also shown how the approach can handle norm defeasibility. Such methodology is implemented by decidable fragments of OWL 2, while legal reasoning is implemented by available decidable reasoners.
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Papers by Guido Governatori