A new semantics for ACL based on commitments and penalties

International audienceIn complex multi agent systems, the agents may be heterogeneous and possibly designed by different programmers. Thus, the importance of defining a standard framework for agent communication languages (ACL) with a clear semantics has been widely recognized. The semantics should be verifiable, clear and practical. Most classical proposals (for instance, mentalistic semantics) fail to meet these objectives. This paper proposes a logic-based semantics which is social in nature. The basic idea is to associate with each speech act a clear meaning in terms of a commitment induced by that speech act, and a penalty to be paid in case that commitment is violated. A violation criterion based on the existence of arguments is then defined per speech act. We show that the proposed semantics satisfies some key properties that ensure that the approach is well-founded. The logical setting makes the semantics verifiable. Moreover, it is shown that the new semantics is practical since it captures the dynamic of dialogues, and shows clearly how isolated speech acts can be connected for building dialogues