On Temporal Regulations and Commitment Protocols

The proposal of Elisa Marengo’s thesis is to extend commitment protocols in order to (i) allow for expressing commitments to temporal regulations, and (ii) to supply a tool for expressing laws, conventions and the like, in order to specify legal interactions. These two aspects will be deeply investigated in the proposal of a unified framework. This proposal is part of ongoing work that will be included in the thesis. 1 Commitment Protocols: Strengths and Shortcomings The issues of communication and cooperation are crucial in the area of Multiagent systems (MAS). The common solution is to rely on agent interaction protocols. Among different proposals, commitment protocols [Singh, 1999] have been widely adopted. All agents involved in an interaction ruled by a commitment protocol share the semantics of a set of actions which affect the social state. Semantics is based on the notion of social commitment. The idea is that if an agent takes a commitment towards another agent to bring about a condition, then, it will behave in such a way to fulfill the engagement sooner or later. In this respect, commitment protocols have a deontic nature, because a commitment introduces a social expectation on the responsibility of some agent towards some other agent to perform something or to achieve some result. Commitment protocols suit well open MAS because they are respectful of the agents’ autonomy, since no introspections to the agents’ mental states is required; they are dynamic because commitments can be created, released, deleted and suchlike, and they are flexible because agents are free to take advantage of opportunities or to follow shortcuts. Commitment protocols have fundamentally changed the process of protocol specification from a procedural approach (i.e., prescribing how an interaction is to be executed) to a declarative one (i.e., describing what interaction is to take place) [Winikoff et al., 2005]. However, in many practical situations it is necessary to express some hints on how the interaction should evolve. This does not mean going back to procedural approaches, but it means reconsidering the how. In particular, it could be necessary to express commitments to temporal regulations and to represent legal patterns of interaction. Temporal regulations are needed to express commitments to achieve something and in a specified order. For instance, an insurance company commits to paying an innetwork surgeon for a procedure only after a covered patient has undergone the procedure. Patterns of interaction, instead, can capture conventions, laws, preferences, habits, or rules that, in general, constrain a certain reality. For example, in the context of a democratic assembly, a participant cannot speak if she has not obtained the floor. The thesis focuses on these lacks, by proposing an extension of commitment protocols. The proposal (i) extends the regulative nature of commitments with the possibility of explicitly committing to temporal regulations, and (ii) supplies a way for expressing patterns of interaction, capturing laws, conventions and whatever constrain the interaction. Until now, these are two disjoint solutions for two different problems. The final step of the thesis will be to investigate the correlations among the two and to propose a unified framework. 2 Temporal Regulations and Commitment Protocols Commitments have a regulative nature in the sense that the debtor is bound to the creditor to make the condition in the commitment become true. However, it is often necessary to specify patterns of interaction and temporal regulations which require a degree of expressiveness that commitments alone do not have. The first step in this direction is described in [Marengo et al., 2011] and consists in a new formalization of commitments where temporal regulations are incorporated as content of the commitments. In this way regulations assume a normative force which is due to the regulative nature of commitments. For example, the commitment C(x, y, , a · b) expresses the engagement of x towards y to make a and b happens and in the given order. Participants to the interaction will be able to guide their actions locally, in order to not violate any commitment they have taken, and to judge the compliance of their counterparties. Indeed, since regulations are placed inside commitments, the debtor will be considered responsible and thus liable for any violation. For this reason it becomes fundamental for an agent to establish, before tak2824 Proceedings of the Twenty-Second International Joint Conference on Artificial Intelligence