- Artificial Intelligence, Law and Society, Institutional Economics, Programming Languages, Expert Systems, Multiagent Systems, and 31 moreEpistemology, Agent-based modeling, Agent Based Simulation, Legal Theory, Narrative Theory, Institutional Theory, Legal narratives, Philosophy, Cognitive Science, Philosophy Of Language, Narratology, Theory of Mind, Legal Philosophy, Law and Politics, Folk Psychology, Speech acts, Knowledge Representation and Reasoning, Semiotics, Semantics, Argumentation, Complex Systems Science, Social-Ecological Systems, Cognitive Modeling, Philosophy Of Law, Distributed Cognition, Legal Reasoning, Analytic Philosophy, Normativity, Philosophy of Mind, Social Ontology, and Computer Science(Epistemology, Agent-based modeling, Agent Based Simulation, Legal Theory, Narrative Theory, Institutional Theory, Legal narratives, Philosophy, Cognitive Science, Philosophy Of Language, Narratology, Theory of Mind, Legal Philosophy, Law and Politics, Folk Psychology, Speech acts, Knowledge Representation and Reasoning, Semiotics, Semantics, Argumentation, Complex Systems Science, Social-Ecological Systems, Cognitive Modeling, Philosophy Of Law, Distributed Cognition, Legal Reasoning, Analytic Philosophy, Normativity, Philosophy of Mind, Social Ontology, and Computer Science)edit
Principles of cognitive economy would require that concepts about objects, properties and relations should be introduced only if they simplify the conceptualisation of a domain. Unexpectedly, classic logic conditionals, specifying... more
Principles of cognitive economy would require that concepts about objects, properties and relations should be introduced only if they simplify the conceptualisation of a domain. Unexpectedly, classic logic conditionals, specifying structures holding within elements of a formal conceptualisation, do not always satisfy this crucial principle. The paper argues that this requirement is captured by supervenience, hereby further identified as a property necessary for compression. The resulting theory suggests an alternative explanation of the empirical experiences observable in selection tasks, associating human performance with con-ditionals on the ability of dealing with compression, rather than with logic necessity.
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This paper provides an updated formalization of the operation of contrast, and shows that, by applying it on conceptual spaces, membership functions to categories as e.g. those captured by adjectives or directional relationships emerge as... more
This paper provides an updated formalization of the operation of contrast, and shows that, by applying it on conceptual spaces, membership functions to categories as e.g. those captured by adjectives or directional relationships emerge as a natural by-product. Because the outcome of contrast depends not only on the objects contrasted (a target and a reference, as for instance a prototype), but also on the frame in which those are contained, it is argued that contrast enables a continuous contextualization, offering a basis for " on the fly " predication. This investigation is then used for inferring general requirements for its application and generalization, and for comparison with current practices in the conceptual space literature.
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Several computational methods have been proposed to evaluate the relevance of an instantiated cause to an observed consequence. The paper reports on an experiment to investigate the adequacy of some of these methods as descriptors of... more
Several computational methods have been proposed to evaluate the relevance of an instantiated cause to an observed consequence. The paper reports on an experiment to investigate the adequacy of some of these methods as descriptors of human judgments about causal relevance.
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Responsibility, as referred to in everyday life, as explored in moral philosophy and debated in jurisprudence, is a multiform, ill-defined but inescapable notion for reasoning about actions. Its presence in all social constructs suggests... more
Responsibility, as referred to in everyday life, as explored in moral philosophy and debated in jurisprudence, is a multiform, ill-defined but inescapable notion for reasoning about actions. Its presence in all social constructs suggests the existence of an underlying cognitive base. Following this hypothesis, and building upon simplicity theory, the paper proposes a novel computational approach.
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Within the general objective of conceiving a cognitive architecture for image interpretation able to generate outputs relevant to several target user profiles, the paper elaborates on a set of operations that should be provided by a... more
Within the general objective of conceiving a cognitive architecture for image interpretation able to generate outputs relevant to several target user profiles, the paper elaborates on a set of operations that should be provided by a cognitive space to guarantee the generation of relevant descriptions. First, it attempts to define a working definition of contrast operation. Then, revisiting well-known results in cognitive studies, it sketches a definition of similarity based on contrast, distinguished from the metric defined on the conceptual space.
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Developing systems operating in alignment with norms is not a straightforward endeavour. Part of the problems derive from the suggestion that law concerns a system of norms, which, in abstract, in a fixed point in time, could be... more
Developing systems operating in alignment with norms is not a straightforward endeavour. Part of the problems derive from the suggestion that law concerns a system of norms, which, in abstract, in a fixed point in time, could be approached and expressed atemporally, but, when it is contextualized and applied, it naturally deals with a continuous flow of events that modifies the normative directives as well. The paper presents an alternative approach to some of these problems, exemplified by well-known deontic puzzles, by extending the Petri net notation, most common in process modeling, to Logic Programming Petri Nets. The resulting visual formalism represents in a integrated, yet distinct fashion, procedural and declarative aspects of the system under study.
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This work presents elements for an alternative oper-ationalization of monitoring and diagnosis of multi-agent systems (MAS). In contrast to traditional accounts of model-based diagnosis, and most proposals concerning non-compliance, our... more
This work presents elements for an alternative oper-ationalization of monitoring and diagnosis of multi-agent systems (MAS). In contrast to traditional accounts of model-based diagnosis, and most proposals concerning non-compliance, our method does not consider any commitment towards the individual unit of agency. Identity is considered to be mostly an attribute to assign responsibility , and not as the only referent that may be source of intentionality. The proposed method requires as input a set of prototypical agent-roles known to be relevant for the domain, and an observation, i.e. evidence collected by a monitor agent. We elaborate on a concrete example concerning tax frauds in real-estate transactions.
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The paper introduces an agent architecture centered around the notions of commitment, expectation, affordance, and susceptibility. These components are to a certain measure at the base of any agent system, however, inspired by research... more
The paper introduces an agent architecture centered around
the notions of commitment, expectation, affordance, and susceptibility. These components are to a certain measure at the base of any agent system, however, inspired by research in explanation-based decision making, this contribution attempts to make explicit and start organizing under the same operationalization neglected figures as negative commitment, negative expectation, etc.
the notions of commitment, expectation, affordance, and susceptibility. These components are to a certain measure at the base of any agent system, however, inspired by research in explanation-based decision making, this contribution attempts to make explicit and start organizing under the same operationalization neglected figures as negative commitment, negative expectation, etc.
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Inspired by research in precedential reasoning in law, the paper presents a set of algorithms for the conversion of rule bases between priority-based and constraint-based representations. Such algorithms can be used for the analysis of a... more
Inspired by research in precedential reasoning in law, the paper presents a set of algorithms for the conversion of rule bases between priority-based and constraint-based representations. Such algorithms can be used for the analysis of a rule base, and for the study of the impact of the introduction of new rules. In addition, the paper explores an optimization mechanism, built upon assumptions about the world in which the rule-based system operates, providing a model of environmental adaptation. The investigation is relevant to practical reasoning, agent modeling and agent programming.
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Rather than as abstract entities, jural relations are analyzed in terms of the bindings they create on the individual behaviour of concurrent social agents. Investigating a simple sale transaction modeled with Petri Nets, we argue that... more
Rather than as abstract entities, jural relations are analyzed in terms of the bindings they create on the individual behaviour of concurrent social agents. Investigating a simple sale transaction modeled with Petri Nets, we argue that the concepts on the two Hohfeldian squares rely on the implicit reference to a "transcendental" collective entity, to which the two parties believe or are believed to belong. From this perspective, we observe that both liabilities and duties are associated to obligations, respectively of an epistemic or practical nature. The fundamental legal concepts defined by Hohfeld are revisited accordingly, leading to the construction of two Hohfeldian prisms.
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Current research in legal argumentation theory tries to bridge the gap between representations of the arguments brought by parties, and representations of factors and dimensions, as used in case-based reasoning frameworks. The present... more
Current research in legal argumentation theory tries to bridge the gap between representations of the arguments brought by parties, and representations of factors and dimensions, as used in case-based reasoning frameworks. The present paper targets the same objective, but taking an alternative approach. Instead of reasoning in terms of attack or support relationships between claims, we consider the relation of the collected messages with alternative interpretations of the case, thus referring to explanation-based argumentation (EBA). This shift of perspective allows us to start an alternative investigation into some of the questions raised in the literature. A prototype application is presented along with the paper.
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The paper investigates a representational model for narratives, aiming to facilitate the acquisition of the systematic core of stories concerning legal cases, i.e. the set of causal and temporal relationships that govern the world in... more
The paper investigates a representational model for narratives, aiming to facilitate the acquisition of the systematic core of stories concerning legal cases, i.e. the set of causal and temporal relationships that govern the world in which the narrated scenario takes place. At the discourse level, we consider narratives as sequences of messages collected in an observation, including descriptions of agents, of agents’ behaviour and of mechanisms relative to physical, mental and institutional domains. At the content level, stories correspond to synchronizations of embodied agent-roles scripts. Following this approach, the Pierson v Post case is analyzed in detail and represented as a Petri net.
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The paper investigates the connection of the concept of affordance with the concept of institution, fundamental in social sciences and in legal theory, with the purpose of delineating a working definition of social affordance. This hybrid... more
The paper investigates the connection of the concept of affordance with the concept of institution, fundamental in social sciences and in legal theory, with the purpose of delineating a working definition of social affordance. This hybrid concept enriches the representation tools to be used with agent-roles, knowledge components we use as basis in explaining and interpreting socio-legal scenarios. The paper shows how social affordances are of critical importance to model the agent-role embodiment mechanism.
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This paper presents an implementation for an explanation-based theory of argumentation. Instead of referring to attack/support relationships between arguments, as in traditional argumentation theories, we focus on the relation of messages... more
This paper presents an implementation for an explanation-based theory of argumentation. Instead of referring to attack/support relationships between arguments, as in traditional argumentation theories, we focus on the relation of messages with the space of hypothetical explanations. The consequences of this choice are two-fold. First, attack and support relationships become derivative measures. Second, we unveil a natural integration with probabilistic reasoning. The proposed operationalization is based on stable models semantics for logic programming.
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The paper introduces elements of a methodology for the acquisition of descriptions of social scenarios (e.g. cases) and for their synthesis to agent-based models. It proceeds along three steps. First, the case is analyzed at signal layer,... more
The paper introduces elements of a methodology for the acquisition of descriptions of social scenarios (e.g. cases) and for their synthesis to agent-based models. It proceeds along three steps. First, the case is analyzed at signal layer, i.e. the messages exchanged between actors. Second, the signal layer is enriched with implicit actions, intentions, and conditions necessary for the story to occur. This elicitation is based on elements provided with the story, common-sense, expert knowledge and direct interaction with the narrator. Third, the resulting scenario representation is synthesized as agent programs. These scripts correspond to descriptions of agent-roles observed in that social setting.
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Focusing on descriptions of behaviours concerning the application of law, the paper presents elements of a methodology that supports story acquisition for a scenario-based modelling framework. It introduces practical reasoning patterns... more
Focusing on descriptions of behaviours concerning the application of law, the paper presents elements of a methodology that supports story acquisition for a scenario-based modelling framework. It introduces practical reasoning patterns concerning action and power, which serve firstly as visual templates for the modeller, and secondly as building blocks of a story-model that can be analyzed and executed on a computational framework.
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This article presents a conceptual framework intended to describe and to abstract cases or scenarios of compliance and non-compliance. These scenarios are collected in order to be animated in an agent-based platform for purposes of design... more
This article presents a conceptual framework intended to describe and to abstract cases or scenarios of compliance and non-compliance. These scenarios are collected in order to be animated in an agent-based platform for purposes of design and validation of both new regulations and new implementations, or to be used as reference base for a diagnosis tool. In our approach, legal narratives become a source of agent-roles descriptions, i.e. abstractions of individual characters/agents from singular stories, feeding the target application framework.
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This paper presents a multi-agent framework intended to animate scenarios of compliance and non-compliance in a normative system. With the purpose of describing social human behaviour, we choose to reduce social complexity by creating... more
This paper presents a multi-agent framework intended to animate scenarios of compliance and non-compliance in a normative system. With the purpose of describing social human behaviour, we choose to reduce social complexity by creating models of the involved agents starting from stories, and completing them with background theories derived from common-sense and expert knowledge. For this reason, we explore how an institutional perspective can be taken into account in a computational framework. Roles, institutions and rules become components of the agent architecture. The social intelligence of the agent is distributed to several cognitive modules, performing the institutional thinking, whose outcomes are coordinated in the main decision-making cycle. The institutional logic is analyzed from a general simulation perspective, and a concrete possible choice is presented, drawn from fundamental legal concepts. As a concrete result, a preliminary implementation of the framework has been developed with Jason.
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What eventually determines the semantics of algorithmic decisionmaking in not the program artefact, nor—if applicable—the data used to create it, but the preparatory (enabling) and consequent (enabled) practices holding in the environment... more
What eventually determines the semantics of algorithmic decisionmaking in not the program artefact, nor—if applicable—the data used to create it, but the preparatory (enabling) and consequent (enabled) practices holding in the environment (computational and human) in which such algorithmic procedure is embedded. The notion of responsibility captures a very similar construct: in all human societies actions are evaluated in terms of the consequences they could reasonably cause, and of the reasons that motivate them. But to what extent does this function exist in computational systems? The paper aims to sketch links between several of the approaches and concepts proposed for responsible computing, from AI to networking, identifying gaps and possible directions for operationalization.
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Fraudulent actions of a trader or a group of traders can cause substantial disturbance to the market, both directly influencing the price of an asset or indirectly by misinforming other market participants. Such behavior can be a source... more
Fraudulent actions of a trader or a group of traders can cause substantial disturbance to the market, both directly influencing the price of an asset or indirectly by misinforming other market participants. Such behavior can be a source of systemic risk and increasing distrust for the market participants, consequences that call for viable countermeasures. Building on the foundations provided by the extant literature, this study aims to design an agent-based market model capable of reproducing the behavior of the Bitcoin market during the time of an alleged Bitcoin price manipulation that occurred between 2017 and early 2018. The model includes the mechanisms of a limit order book market and several agents associated with different trading strategies, including a fraudulent agent, initialized from empirical data and who performs market manipulation. The model is validated with respect to the Bitcoin price as well as the amount of Bitcoins obtained by the fraudulent agent and the trad...
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Normative positions are sometimes illustrated in diagrams, in particular in didactic contexts. Traditional examples are the Aristotelian polygons of opposition for deontic modalities (squares, triangles, hexagons, etc.), and the... more
Normative positions are sometimes illustrated in diagrams, in particular in didactic contexts. Traditional examples are the Aristotelian polygons of opposition for deontic modalities (squares, triangles, hexagons, etc.), and the Hohfeldian squares for obligative and potestative concepts. Relying on previous work, we show that Hohfeld’s framework can be used as a basis for developing several Aristotelian polygons and more complex diagrams. Then, we illustrate how logical theories of increasing strength can be built based on these diagrams, and how those theories enable us to determine in a computably efficient way whether a set of normative positions can be derived from another set of normative positions.
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Several solutions for specifying normative artefacts (norms, contracts, policies) in a computational processable way have been presented in the literature. Amongst the most recent efforts we acknowledge e.g. LegalRuleML [11,9], PROLEG... more
Several solutions for specifying normative artefacts (norms, contracts, policies) in a computational processable way have been presented in the literature. Amongst the most recent efforts we acknowledge e.g. LegalRuleML [11,9], PROLEG [14], InstAL [10], ODRL [6,1], Symboleo [15], FLINT/eFLINT [21,20], and Logical English [7]. Legal core ontologies (e.g. LKIF-core [3], UFO-L [2]) have been proposed to systematize concepts and relationships relevant to normative reasoning. However, no solution amongst those has achieved general acceptance. Even more unexpectedly, there exists no common ground (nor representational, nor computational) enabling us to compare these solutions. Yet, all these efforts share the same motivation (representing normative directives), therefore it is plausible that there may be a representational model encompassing all of them. This presentation will introduce DPCL, a domain-specific language (DSL) for specifying higherlevel policies (including norms, contracts,...
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For being potentially destructive, in practice incomprehensible and for the most unintelligible, contemporary technology is setting high challenges on our society. New conception methods are urgently required. Reorganizing ideas and... more
For being potentially destructive, in practice incomprehensible and for the most unintelligible, contemporary technology is setting high challenges on our society. New conception methods are urgently required. Reorganizing ideas and discussions presented in AI and related fields, this position paper aims to highlight the importance of normware--that is, computational artifacts specifying norms--with respect to these issues, and argues for its irreducibility with respect to software by making explicit its neglected ecological dimension in the decision-making cycle.
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This article presents a conceptual framework intended to describe and to abstract cases or scenarios of compliance and non-compliance. These scenarios are collected in order to be animated in an agent-based platform for purposes of design... more
This article presents a conceptual framework intended to describe and to abstract cases or scenarios of compliance and non-compliance. These scenarios are collected in order to be animated in an agent-based platform for purposes of design and validation of both new regulations and new implementations, or to be used as reference base for a diagnosis tool. In our approach, legal narratives become a source of agent-roles descriptions, i.e. abstractions of individual characters/agents from singular stories, feeding the target applicative framework.
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Developing systems operating in alignment with norms is not a straightforward endeavour. Part of the problems derive from the suggestion that law concerns a system of norms, which, in abstract, in a fixed point in time, could be... more
Developing systems operating in alignment with norms is not a straightforward endeavour. Part of the problems derive from the suggestion that law concerns a system of norms, which, in abstract, in a fixed point in time, could be approached and expressed atemporally, but, when it is contextualized and applied, it deals with a continuous flow of events modifying the normative directives as well. The paper presents an alternative approach to some of these problems, exemplified by well-known deontic puzzles, by extending the Petri net notation, most common in process modeling, to Logic Programming Petri Nets. The resulting visual formalism represents in a integrated, yet distinct fashion, procedural and declarative aspects of the system under study, including normative ones.
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Responsibility, as referred to in everyday life, as explored in moral philosophy and debated in jurisprudence, is a multiform, ill-defined but inescapable notion for reasoning about actions. Its presence in all social constructs suggests... more
Responsibility, as referred to in everyday life, as explored in moral philosophy and debated in jurisprudence, is a multiform, ill-defined but inescapable notion for reasoning about actions. Its presence in all social constructs suggests the existence of an underlying cognitive base. Following this hypothesis, and building upon simplicity theory, the paper proposes a novel computational approach.
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This paper presents a multidisciplinary approach (media studies, computer science, and legal scholarship) for the analysis of systems that rely on AI components as central components of their design. Taking recommender systems more... more
This paper presents a multidisciplinary approach (media studies, computer science, and legal scholarship) for the analysis of systems that rely on AI components as central components of their design. Taking recommender systems more generally and the one built by YouTube more specifically, we develop a methodology for conceptualizing and studying the broad array of “ideas”, “norms”, or “values” such systems mobilize. Instead of limiting ourselves to a narrow understanding of these terms, we take into account, for example, translations from economic models, social theories, legal requirements, ethical principles, technical knowledge, experiential evaluations, or other constructs used to define and justify design goals and decisions that shape the production of technical objects and, consequently, the object themselves. In this paper we discuss three directions for analysis and present first results. Investigating technical knowledge includes the study of scholarly literature and exper...
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Rather than as abstract entities, jural relations are analyzed in terms of the bindings they create on the individual behaviour of concurrent social agents. Investigating a simple sale transaction modeled with Petri Nets, we argue that... more
Rather than as abstract entities, jural relations are analyzed in terms of the bindings they create on the individual behaviour of concurrent social agents. Investigating a simple sale transaction modeled with Petri Nets, we argue that the concepts on the two Hohfeldian squares rely on the implicit reference to a "transcendental" collective entity, to which the two parties believe or are believed to belong. From this perspective, we observe that both liabilities and duties are associated to obligations, respectively of an epistemic or practical nature. The fundamental legal concepts defined by Hohfeld are revisited accordingly, leading to the construction of two Hohfeldian prisms.
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The paper investigates a representational model for narratives, aiming to facilitate the acquisition of the systematic core of stories concerning legal cases, i.e. the set of causal and temporal relationships that govern the world in... more
The paper investigates a representational model for narratives, aiming to facilitate the acquisition of the systematic core of stories concerning legal cases, i.e. the set of causal and temporal relationships that govern the world in which the narrated scenario takes place. At the discourse level, we consider narratives as sequences of messages collected in an observation, including descriptions of agents, of agents' behaviour and of mechanisms relative to physical, mental and institutional domains. At the content level, stories correspond to synchronizations of embodied agent-roles scripts. Following this approach, the Pierson v Post case is analyzed in detail and represented as a Petri net.
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Copyright It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open... more
Copyright It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content licence (like
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Current agent architectures implementing the belief-desire-intention (BDI) model consider agents which respond reactively to internal and external events by selecting the first-available plan. Priority between plans is hard-coded in the... more
Current agent architectures implementing the belief-desire-intention (BDI) model consider agents which respond reactively to internal and external events by selecting the first-available plan. Priority between plans is hard-coded in the program, and so the reasons why a certain plan is preferred remain in the programmer’s mind. Recent works that attempt to include explicit preferences in BDI agents treat preferences essentially as a rationale for planning tasks to be performed at run-time, thus disrupting the reactive nature of agents. In this paper we propose a method to include declarative preferences (i.e. concerning states of affairs) in the agent program, and to use them in a manner that preserves reactivity. To achieve this, the plan prioritization step is performed offline, by (a) generating all possible outcomes of situated plan executions, (b) selecting a relevant subset of situation/outcomes couplings as representative summary for each plan, (c) sorting the plans by evalua...
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This paper presents an implementation for an explanation-based theory of argumentation. Instead of referring to attack/support relationships between arguments, as in traditional argumentation theories, we focus on the relation of messages... more
This paper presents an implementation for an explanation-based theory of argumentation. Instead of referring to attack/support relationships between arguments, as in traditional argumentation theories, we focus on the relation of messages with the space of hypothetical explanations. The consequences of this choice are two-fold. First, attack and support relationships become derivative measures. Second, we unveil a natural integration with probabilistic reasoning. The proposed operationalization is based on stable models semantics for logic programming.
Research Interests:
In law, and, consequently, in AI & Law, argumentation, scenario-modeling, and the combination of both, are the traditional ways of theorizing about judicial reasoning and legal truth, while probabilistic reasoning has traditionally been... more
In law, and, consequently, in AI & Law, argumentation, scenario-modeling, and the combination of both, are the traditional ways of theorizing about judicial reasoning and legal truth, while probabilistic reasoning has traditionally been treated with suspicion2. Nevertheless, because of the growing relevance of forensic scientific evidence, a proper integration of probabilistic reasoning into the argumentation process is increasingly a debated problem. Pollock presents in [1] a lucid philosophical critique on how probabilistic methods approach the problem of justification, in the form of some interesting legal puzzles. He gives the following case: Jones says that the gunman had a moustache. Paul says that Jones was looking the other way and did not see what happened. Jacob says that Jones was watching carefully and had a clear view of the gunman. This is an example of “collective defeat” (Paul vs Jacob), which results in a “zombie argument” (Jones’). From this story, Pollock targets ...
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This paper provides an updated formalization of the operation of contrast, and shows that, by applying it on conceptual spaces, membership functions to categories as e.g. those captured by adjectives or directional relationships emerge as... more
This paper provides an updated formalization of the operation of contrast, and shows that, by applying it on conceptual spaces, membership functions to categories as e.g. those captured by adjectives or directional relationships emerge as a natural by-product. Because the outcome of contrast depends not only on the objects contrasted (a target and a reference, as for instance a prototype), but also on the frame in which those are contained, it is argued that contrast enables a continuous contextualization, offering a basis for “on the fly” predication. This investigation is used for inferring general requirements for the application of contrast and its generalization, and for comparison with current practices in the conceptual space literature.
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Conditional ceteris paribus preference networks (CP-nets) are commonly used to capture qualitative conditional preferences. In many use cases, when the preferential structure of an agent is incomplete, information from other preferential... more
Conditional ceteris paribus preference networks (CP-nets) are commonly used to capture qualitative conditional preferences. In many use cases, when the preferential structure of an agent is incomplete, information from other preferential structures (e.g. that of other users) preferences can be used to fill in the gaps. Earlier works proposed methods to symmetrically merge multiple incomplete CP-nets by means of voting semantics. However, the merged CP-net can contain preference relations that do not fit to a given user’s original preference profile. This paper proposes an asymmetric merging (or enriching) method to obtain and fill-in preference relations of a user’s CP-net from another CP-net in a way that preserves the original preference relations.
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Current research in legal argumentation theory tries to bridge the gap be-tween representations of the arguments brought by parties, and representations of factors and dimensions, as used in case-based reasoning frameworks. The present... more
Current research in legal argumentation theory tries to bridge the gap be-tween representations of the arguments brought by parties, and representations of factors and dimensions, as used in case-based reasoning frameworks. The present paper targets the same objective, but taking an alternative approach. Instead of reasoning in terms of attack or support relationships between claims, we consider the relation of the collected messages with alternative interpretations of the case, thus referring to explanation-based argumentation (EBA). This shift of perspective allows us to start an alternative investigation into some of the questions raised in the literature. A prototype application is presented along with the paper.
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Modelling, specifying and reasoning about complex systems requires to process in an integrated fashion declarative and procedural aspects of the target domain. The paper reports on an experiment conducted with a propositional version of... more
Modelling, specifying and reasoning about complex systems requires to process in an integrated fashion declarative and procedural aspects of the target domain. The paper reports on an experiment conducted with a propositional version of Logic Programming Petri Nets (LPPNs), a notation extending Petri Nets with logic programming constructs. Two semantics are presented: a denotational semantics that fully maps the notation to ASP via Event Calculus; and a hybrid operational semantics that process separately the causal mechanisms via Petri nets, and the constraints associated to objects and to events via Answer Set Programming (ASP). These two alternative specifications enable an empirical evaluation in terms of computational efficiency. Experimental results show that the hybrid semantics is more efficient w.r.t. sequences, whereas the two semantics follows the same behaviour w.r.t. branchings (although the denotational one performs better in absolute terms).
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For being potentially destructive, in practice incomprehensible and for the most unintelligible, contemporary technology is setting high challenges on our society. New conception methods are urgently required. Reorganizing ideas and... more
For being potentially destructive, in practice incomprehensible and for the most unintelligible, contemporary technology is setting high challenges on our society. New conception methods are urgently required. Reorganizing ideas and discussions presented in AI and related fields, this position paper aims to highlight the importance of normware--that is, computational artifacts specifying norms--with respect to these issues, and argues for its irreducibility with respect to software by making explicit its neglected ecological dimension in the decision-making cycle.
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This paper aims to set up a conceptual framework for studying the second-order guidance problem—that is, designing coordination mechanisms for autonomous actors by means of adequate monitoring and enforcement measures— in a way which is... more
This paper aims to set up a conceptual framework for studying the second-order guidance problem—that is, designing coordination mechanisms for autonomous actors by means of adequate monitoring and enforcement measures— in a way which is sensible for designers and users of data-sharing infrastructures such as digital market-places. The paper outlines a minimal, but reusable and extensible computational model to test the sustainability of diverse norm implementations, evaluating it against relevant higher-level models presented in the literature.
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In order to effectively implement guidance structures in a computational social system, directives which are specified in general terms of duties and rights need to be transformed in terms of powers and liabilities attributed to social... more
In order to effectively implement guidance structures in a computational social system, directives which are specified in general terms of duties and rights need to be transformed in terms of powers and liabilities attributed to social parties. The present paper is a work in progress report on an axiomatization of power structures in a logic programming setting, covering the intentional level in specifying actions, the connection between productive characterization of actions and causation, the default nature of action specifications, failures and omissions, the relations of causation and power, and the concept of interfering actions.
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Focusing on descriptions of behaviours concerning the application of law, the paper presents elements of a methodology that supports story acquisition for a scenario-based modelling framework. It introduces practical reasoning patterns... more
Focusing on descriptions of behaviours concerning the application of law, the paper presents elements of a methodology that supports story acquisition for a scenario-based modelling framework. It introduces practical reasoning patterns concerning action and power, which serve firstly as visual templates for the modeller, and secondly as building blocks of a story-model that can be analyzed and executed on a computational framework.
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Artificial Intelligence (AI) started out with an ambition to reproduce the human mind, but, as the sheer scale of that ambition became apparent, quickly retreated into either studying specialized intelligent behaviours, or proposing... more
Artificial Intelligence (AI) started out with an ambition to reproduce the human mind, but, as the sheer scale of that ambition became apparent, quickly retreated into either studying specialized intelligent behaviours, or proposing overarching architectural concepts for interfacing specialized intelligent behaviour components, conceived of as agents in a kind of organization. This agent-based modeling paradigm, in turn, proves to have interesting applications in understanding, simulating, and predicting the behaviour of social and legal structures on an aggregate level. This chapter examines a number of relevant cross-cutting concerns, conceptualizations, modeling problems and design challenges in large-scale distributed Artificial Intelligence, as well as in institutional systems, and identifies potential grounds for novel advances.
In law, and, consequently, in AI & Law, argumentation, scenario-modeling, and the combination of both, are the traditional ways of theorizing about judicial reasoning and legal truth, while probabilistic reasoning has traditionally been... more
In law, and, consequently, in AI & Law, argumentation, scenario-modeling, and the combination of both, are the traditional ways of theorizing about judicial reasoning and legal truth, while probabilistic reasoning has traditionally been treated with suspicion2. Nevertheless, because of the growing relevance of forensic scientific evidence, a proper integration of probabilistic reasoning into the argumentation process is increasingly a debated problem. Pollock presents in [1] a lucid philosophical critique on how probabilistic methods approach the problem of justification, in the form of some interesting legal puzzles. He gives the following case: Jones says that the gunman had a moustache. Paul says that Jones was looking the other way and did not see what happened. Jacob says that Jones was watching carefully and had a clear view of the gunman. This is an example of “collective defeat” (Paul vs Jacob), which results in a “zombie argument” (Jones’). From this story, Pollock targets ...
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Everyone experiences, at a certain point in life, that what the law states, how public services implement the law and how people actually behave are three different matters which are only loosely aligned. Evidently, they do have some... more
Everyone experiences, at a certain point in life, that what the law states, how public services implement the law and how people actually behave are three different matters which are only loosely aligned. Evidently, they do have some ground in common. How can we operationally define this ground? In a context of increasing expectations concerning the quality and agility of public services, this thesis approaches this question focusing specifically on public administrations. These organizations provide a good test bench for the investigation: the semi-formalization of regulations is an advantage for modeling purposes. Their mandates are defined by the sources of law, but they have partial control over the regulatory system as well. Their implementations count as implementations of law, as they translate what is defined at policy level into operational terms. As participants in the social system, they accumulate informal knowledge of failures, such as cases of non-compliance, and of mi...
Rights expressions languages (RELs) express and govern legally binding behavior within technological environments. The Open Digital Rights Language (ODRL), used to represent statements about the usage of digital assets, is amongst the... more
Rights expressions languages (RELs) express and govern legally binding behavior within technological environments. The Open Digital Rights Language (ODRL), used to represent statements about the usage of digital assets, is amongst the most popular RELs today and has become a W3C recommendation to enhance the web’s functionality and interoperability. This paper reflects on the representational power of ODRL from a practical perspective; utilizing use cases and examples, we discuss the challenges, issues, and limitations we came across while investigating the language as a potential solution for the regulation of data-sharing infrastructures.
Several computational methods have been proposed to evaluate the relevance of an instantiated cause to an observed consequence. The paper reports on an experiment to investigate the adequacy of some of these methods as descriptors of... more
Several computational methods have been proposed to evaluate the relevance of an instantiated cause to an observed consequence. The paper reports on an experiment to investigate the adequacy of some of these methods as descriptors of human judgments about causal relevance.
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With the purpose of modeling, specifying and reasoning in an integrated fashion with procedural and declarative aspects (both commonly present in cases or scenarios), the paper introduces Logic Programming Petri Nets (LPPN), an extension... more
With the purpose of modeling, specifying and reasoning in an integrated fashion with procedural and declarative aspects (both commonly present in cases or scenarios), the paper introduces Logic Programming Petri Nets (LPPN), an extension to the Petri Net notation providing an interface to logic programming constructs. Two semantics are presented. First, a hybrid operational semantics that separates the process component, treated with Petri nets, from the constraint/terminological component, treated with Answer Set Programming (ASP). Second, a denotational semantics maps the notation to ASP fully, via Event Calculus. These two alternative specifications enable a preliminary evaluation in terms of reasoning efficiency.
Principles of cognitive economy would require that concepts about objects, properties and relations should be introduced only if they simplify the conceptualisation of a domain. Unexpectedly, classic logic conditionals, specifying... more
Principles of cognitive economy would require that concepts about objects, properties and relations should be introduced only if they simplify the conceptualisation of a domain. Unexpectedly, classic logic conditionals, specifying structures holding within elements of a formal conceptualisation, do not always satisfy this crucial principle. The paper argues that this requirement is captured by supervenience, hereby further identified as a property necessary for compression. The resulting theory suggests an alternative explanation of the empirical experiences observable in Wason's selection tasks, associating human performance with conditionals on the ability of dealing with compression, rather than with logic necessity.
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To align representations of law, of implementations of law and of concrete behaviours, we designed a common ground representational model for the three domains, based on the notion of position, building upon Petri nets. This paper reports... more
To align representations of law, of implementations of law and of concrete behaviours, we designed a common ground representational model for the three domains, based on the notion of position, building upon Petri nets. This paper reports on work to define subsumption between positional models.
The combination of smart contracts with blockchain technology enables the authentication of the contract and limits the risks of non-compliance. In principle, smart contracts can be processed more efficiently compared to traditional... more
The combination of smart contracts with blockchain technology enables the authentication of the contract and limits the risks of non-compliance. In principle, smart contracts can be processed more efficiently compared to traditional paper-based contracts. However, current smart contracts have very limited capabilities with respect to normative representations, making them too distant from actual contracts. In order to reduce this gap, the paper presents an architectural analysis to see the role of computational artifacts in terms of various ex-ante and ex-post enforcement mechanisms. The proposed framework is assessed using scenarios concerning data-sharing operations bound by legal requirements from the General Data Protection Regulation (GDPR) and data-sharing agreements.
Computational systems are traditionally approached from control-oriented perspectives; however, as soon as we move from centralized to decentralized computational infrastructures, direct control needs to be replaced by distributed... more
Computational systems are traditionally approached from control-oriented perspectives; however, as soon as we move from centralized to decentralized computational infrastructures, direct control needs to be replaced by distributed coordination mechanisms that are on par with institutional constructs observable in human societies (contracts, agreements, enforcement mechanisms, etc.). This paper presents a formalization of Hohfeld’s framework building upon a logic whose language includes primitive operators of ability and parametric deontic operators. The proposal is meant to highlight the fundamental interaction between deontic and potestative concepts and contains proofs of soundness and completeness with respect to a class of relational models.
The paper introduces an Agent-Oriented Programming (AOP) framework based on the Belief-Desire-Intention (BDI) model of agency. The novelty of this framework is in relying on the Actor model, instantiating each intentional agent as an... more
The paper introduces an Agent-Oriented Programming (AOP) framework based on the Belief-Desire-Intention (BDI) model of agency. The novelty of this framework is in relying on the Actor model, instantiating each intentional agent as an autonomous micro-system run by actors. The working hypothesis behind this choice is that defining the agents via actors results in a more fine-grained modular architecture and that the execution of agent-oriented programs is enhanced (in scalability as well as in performance) by relying on robust implementations of Actor models such as Akka. The framework is benchmarked and analyzed quantitatively and qualitatively against three other AOP frameworks: Jason, ASTRA and Sarl.
The paper sketches and elaborates on a framework integrating agent-based modelling with advanced quantitative probabilistic methods based on copula theory. The motivation for such a framework is illustrated on a artificial market... more
The paper sketches and elaborates on a framework integrating agent-based modelling with advanced quantitative probabilistic methods based on copula theory. The motivation for such a framework is illustrated on a artificial market functioning with canonical asset pricing models, showing that dependencies specified by copulas can enrich agent-based models to capture both micro-macro effects (e.g. herding behaviour) and macro-level dependencies (e.g. asset price dependencies). In doing that, the paper highlights the theoretical challenges and extensions that would complete and improve the proposal as a tool for risk analysis.
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Research Interests:
Computational agents based upon the belief-desire-intention (BDI) architecture generally use reactive rules to trigger the execution of plans. For various reasons, certain plans might be preferred over others at design time. Most BDI... more
Computational agents based upon the belief-desire-intention (BDI) architecture generally use reactive rules to trigger the execution of plans. For various reasons, certain plans might be preferred over others at design time. Most BDI agents platforms use hard-coding these preferences in some form of the static ordering of the reactive rules, but keeping the preferential structure implicit limits script reuse and generalization. This paper proposes an approach to add qualitative preferences over adoption/avoidance of procedural goals into an agent script, building upon the well-known notation of conditional ceteris paribus preference networks (CP-nets). For effective execution, the procedural knowledge and the preferential structure of the agent are mapped in an off-line fashion into a new reactive agent script. This solution contrasts with recent proposals integrating preferences as a rationale in the decision making cycle, and so overriding the reactive nature of BDI agents.