Logics and Multi-agents: towards a new symbolic model of cognition

Abstract

The last edition of CLIMA, held in 2001 in Paphos (Cyprus) ended with a panel session on the role of Computational Logic (CL) in Multi-Agent Systems (MAS).Two dimensions in MAS development were singled out and discussed: on the one hand reactivity vs. rationality, and on the other hand individuals vs. societies. Most of the points discussed aimed at justifying and motivating the application of CL techniques to MAS development: should be logics used to implement the individuals, or the society, or both? should be logics used to model the reactive part, or the pro-active part, or both? what do we want to achieve in terms of properties, openness to integration, etc.?A most intuitive reply to these questions could be that logic should be used for what logic is good at. For instance, logic programming-based techniques such as abductive and inductive logic programming seem suitable for modelling agent hypothetical reasoning and adaptability. Modal logic operators such as those adopted by a BDI agent model [3] could be a powerful and synthetic way to describe the agent behaviour and to put it into relationship with the other agents in a society. Model checking-based techniques can be applied to the verification of agent systems. A combination of multiple approaches, like modal and temporal logics, or abduction and induction in a logic programming framework, could be the key to achieve a more comprehensive agent and agent system architecture. But in this case, to determine which properties of the chosen combinations hold is not an easy task.At the time of this new edition of CLIMA, while the debate about the role of CL in MAS is still open, from within the CL community we are witnessing a growth of interest for Multi-Agent Systems considered per se as an interesting cognitive model. This is due to many reasons, among which, we would say, the need to put “abstract” reasoning in the context of a “concrete” environment, and to use logic not only to solve problems in a virtual world, but in a real arena. The multi-agent metaphor of intelligent individuals that are situated into dynamic and unpredictable environments and that can interact with each other by updating their beliefs, can be regarded then as the basis for a new symbolic model of cognition.