FIPA Communicative Acts in Defeasible Logic

In agent communication languages, the inferences that can be made on the basis of a communicative action are inherently conditional, and non-monotonic. For example, a proposal only leads to a commitment, on the condition that it is accepted. And in a persuasion dialogue, assertions may later be retracted. In this paper we therefore present a defeasible logic that can be used to express a semantics for agent communication languages, and to efficiently make inferences on the basis of communicative actions. The logic is non-monotonic, allows nested rules and mental attitudes as the content of communicative actions, and has an explicit way of expressing persistence over time. Moreover, it expresses that mental attitudes are publicly attributed to agents playing roles in the dialogue. To illustrate the usefulness of the logic, we reformalize the meta-theory underlying the FIPA semantics for agent communication, focusing on inform and propose. We show how composed speech acts can be formalized, and extend the semantics with an account of persuasion

Time and defeasibility in FIPA ACL semantics

AbstractInferences about speech acts are often conditional, non-monotonic, and involve the issue of time. Most agent communication languages, however, ignore these issues, due to the difficulty to combine them in a single formalism. This paper addresses such issues in defeasible logic, and shows how to express a semantics for ACLs in order to make non-monotonic inferences on the basis of speech acts

From Message Exchanges to Communicative Acts to Commitments

Our research aims at providing an alternative model of agent communication to the one proposed by the Foundation for Intelligent Physical Agents (FIPA). We adopt the mainstream perspective that views agent communication as the performance of communicative acts, but we shift the focus from agents' mental states to their social state. Starting from the FIPA Communicative Act Library, we provide a commitment-based semantics for a significant set of acts. This analysis leads to a classification of such acts that is to shed some light on topics that have not been dealt with in an effective way yet