Antonino Rotolo

Normative autonomy and normative co-ordination: Declarative power, representation, and mandate

AbstractIn this paper we provide a formal analysis of the idea of normative co-ordination. We argue that this idea is based on the assumption that agents can achieve flexible co-ordination by conferring normative positions to other agents. These positions include duties, permissions, and powers. In particular, we explain the idea of declarative power, which consists in the capacity of the power-holder of creating normative positions, involving other agents, simply by „proclaiming“ such positions. In addition, we account also for the concepts of representation, namely the representative’s capacity of acting in the name of his principal, and of mandate, which is the mandatee’s duty to act as the mandator has requested. Finally, we show how the framework can be applied to represent the contract-net protocol. Some brief remarks on future research and applications conclude this contribution.n

Labelled tableaux for nonmonotonic reasoning: Cumulative consequence relations

In this paper we present a labelled proof method for computing nonmonotonic consequence relations in a conditional logic setting. The method exploits the strong connection between these deductive relations and conditional logics, and it is based on the usual possible world semantics devised for the latter. The label formalism KEM, introduced to account for the semantics of normal modal logics, is easily adapted to the semantics of conditional logic by simply indexing labels with formulas. The basic inference rules are provided by the propositional system KE+ - a tableau-like analytic proof system devised to be used both as a refutation method and a direct method of proof - that is the classical core of KEM which is thus enlarged with suitable elimination rules for the conditional connective. The resulting algorithmic framework is able to compute cumulative consequence relations in so far as they can be expressed as conditional implications.

A Java Implementation of Temporal Defeasible Logic

In this paper we report on a Java implementation of a variant of Temporal Defeasible Logic, an extension of Defeasible Logic developed to capture the concept of temporal persistence. The system consists of three elements: a graphical user interface for selecting defeasible theories, and for visualizing conclusions; a parser, which translates sets of rules in TXT or RuleML formats; and the inference engine to compute conclusions.

Labelled Proofs for Quantified Modal Logic

In this paper we describe a modal proof system arising from the combination of a tableau-like classical system, which incorporates a restricted (“analytic”) version of the cut rule, with a label formalism which allows for a specialised, logic-dependent unification algorithm. The system provides a uniform proof-theoretical treatment of first-order (normal) modal logics with and without the Barcan Formula and/or its converse.

A Labelled Tableau Calculus for Nonmonotonic (Cumulative) Consequence Relations

In this paper we present a labelled proof method for computing nonmonotonic consequence relations in a conditional logic setting. The method is based on the usual possible world semantics for conditional logic. The label formalism KEM, introduced to account for the semantics of normal modal logics, is easily adapted to the semantics of conditional logic by simply indexing labels with formulas. The inference rules are provided by the propositional system KE + —a tableau-like analytic proof system devised to be used both as a refutation and a direct method of proof— enlarged with suitable elimination rules for the conditional connective. The resulting algorithmic framework is able to compute cumulative consequence relations in so far as they can be expressed as conditional implications.

Meaning Negotiation with Defeasible Logic

Agents negotiate the meaning of terms in numerous real-life situations. When they behave so, they can be used as the basis for providing an emulation paradigm for software agents, habilitating therefore socio-technical systems to perform meaning negotiation. In this paper we focus upon two methods for meaning negotiation in defeasible logic and provide room for an analysis of how the proposed approaches perform the aforementioned process. Finally we also provide a computational analysis of the process automation problem.

Deductive and Deontic Reasoning

This chapter offers a concise and elementary introduction to fundamental concepts in deductive and deontic reasoning.

A labelling framework for probabilistic argumentation

The combination of argumentation and probability paves the way to new accounts of qualitative and quantitative uncertainty, thereby offering new theoretical and applicative opportunities. Due to a variety of interests, probabilistic argumentation is approached in the literature with different frameworks, pertaining to structured and abstract argumentation, and with respect to diverse types of uncertainty, in particular the uncertainty on the credibility of the premises, the uncertainty about which arguments to consider, and the uncertainty on the acceptance status of arguments or statements. Towards a general framework for probabilistic argumentation, we investigate a labelling-oriented framework encompassing a basic setting for rule-based argumentation and its (semi-) abstract account, along with diverse types of uncertainty. Our framework provides a systematic treatment of various kinds of uncertainty and of their relationships and allows us to back or question assertions from the literature.