Formal ReSpecT in the A&A Perspective

Andrea Omicini
2007 Electronical Notes in Theoretical Computer Science  
Coordination models and languages have found a new course in the context of MAS (multiagent systems). By re-interpreting results in terms of agent-oriented abstractions, new conceptual spaces are found, which extend the reach of coordination techniques far beyond their original scope. This is for instance the case of coordination media, when recasted in terms of coordination artifacts in the MAS context. In this paper, we take the well-established ReSpecT language for programming tuple centre
more » ... haviour, and adopt the A&A (agents and artifacts) meta-model as a perspective to reinterpret, revise, extend and complete it. A formal model of the so-called A&A ReSpecT language is presented, along with an example illustrating its use for MAS coordination. Open access under CC BY-NC-ND license. investigations in areas like Sociology, Economics and Organisational Theory [16] . There, coordination is generally conceived as a means to integrate a multiplicity of diverse activities or processes in such a way that the resulting ensemble exhibits some desired / required features. The design of coordination mechanisms is particularly challenging in the field of MAS, as they are usually embedded in highly dynamic environments, and neither the number nor the behaviour of agents are possibly known at design time. However, conceptual foundations of the MAS area are still under impetuous development, pushed by deep and heterogeneous inputs from distributed computing, programming languages, software engineering, simulation, artificial intelligence, and other related areas that are today converging toward agent-orientedness [32] . Among the most promising approaches, the A&A meta-model [19] re-interprets MAS in terms of two fundamental abstractions: agents and artifacts. Agents are the active entities encapsulating control, which are in charge of the goals/tasks that altogether build up the whole MAS behaviour. Artifacts are instead the passive, reactive entities in charge of the services and functions that make individual agents work together in a MAS, and that shape agent environment according to the MAS needs. Altogether, the A&A meta-model has a deep impact on the way in which MAS are engineered [10], programmed [28], and simulated [11] . Along this line, coordination artifacts can be conceived as a generalisation of coordination media, as specialised artifacts encapsulating coordination services for MAS [19] . Bringing back the A&A meta-model to the coordination field suggests a number of interesting considerations. For instance, features of artifacts (like inspectability, forgeability, linkability, etc.) could be used to build up a framework for classifying coordination media, to understand and compare them along the coordination literature [18] . More generally, well-established coordination models and languages could be suitably reinterpreted within the A&A conceptual framework, and revised and extended accordingly-thus providing MAS engineers with well-known and tested technologies for the development of MAS based on the A&A meta-model. In this paper, we follow the latter line of thought. In particular, we take the ReSpecT language for programming the behaviour of tuple centres [15, 25] and its formal model [14] , and discuss its re-formulation in the A&A framework. Section 2 shortly discusses the A&A meta-model, and the main features of artifacts. Section 3 briefly recalls the essentials of the TuCSoN model and of the ReSpecT language. Section 4 introduces the new, revised ReSpecT syntax, along with an example of A&A ReSpecT coordination of agents. Section 5 presents the semantics of A&A ReSpecT, obtained by largely revising and extending the original one [14] along the A&A main lines. After Section 6 discusses relations with previous work and related literature, Section 7 provides for final remarks and future lines of work.
doi:10.1016/j.entcs.2007.03.006 fatcat:hlwq7nqp4fblnirt5qaxp7dtoa