Cognitive stigmergy

This paper outlines an approach to analysing minimal cognition that brings out its social and historical dimensions. It proposes a model, the coordinated systems approach (CSA), which understands cognition as a coordinated coalition of loosely autonomous processes responsible for goal-directedness in a system. On this view, even individual cognition has something of a social flavour to it. The central concept of the paper is stigmergy: a process where the material 1 trace of actions of system elements in their environment is a sign that coordinates a group of semi-autonomous processes in future actionsthis is the social dimension. The historical dimension refers to longer term processes which establish the coordinative power of the sign and endow it with normative force. According to this proposal, a full explanation of cognitive capabilities should reference both dimensions. In the second half of the paper the CSA is let loose on some puzzles in 4E cognition. Can the model deal with old problems such as that of cognitive bloat, or new problems such as the supposed external memory of the slime mould Physarum polycephalum? Potentially, the approach could be used to analyse minimal cognitive phenomena over a range of scales from bacteria to human beings.

In order to synthesize stigmergy a model needs to be created that allows a collective of agents to achieve global results through local interactions in some environment. This locality of interactions between the agents and between the agent and the environment allows for the distribution of the entire system without any centralization. Stigmergy is found among social insects in nature. These natural systems show remarkable flexibility, robustness and selforganisation. These characteristics are sort after in modern software systems. Utilizing stigmergy in an artificial system allows agents to interact with one another and with the general topology in a non-centralized manner, thus giving rise to a collective solution when solving of certain tasks. Even though the agents are localized their interaction with the stigmergy layer allows other agents to be affected by the interactions. The methology of mimicking stigmergy into a software system will be described and a description of the model used to synthesize stigmergy will be given. The potential utilization of stigmergy by software agents to interact with each other and to solve certain tasks collectively is also demonstrated.

Stigmergy, usually used on simple problems, can be applied to more complex ones by encoding them in the agents' environment. We show how stigmergic agents can plan over a hierarchical task network, a resource-oriented dialect of the TAEMS language. Our results reveal an important distinction among HTN's.

Wrong beliefs, known by some as 'alternative facts', have proliferated lately in important areas of human life, including social, political, and public health domains. This can be and has been damaging. This brief article proposes an epistemological category classification of these wrong beliefs, with the following mappings: a) 'No-Information' marked by willful blindness produces 'Empty Beliefs'; b) 'Mis-Information' yields 'Mis(taken) Beliefs'; and c) 'Dis-Information' predicated on blatant distortions produces 'Dis(torted) Beliefs'. This simple classification system, is perhaps epistemologically satisfying, and moreover could have positive policy implications.

A library-based extension of JAVA, the SIMPA framework, introduced a new abstraction based on agent-oriented concepts. Agents are autonomous entities that cooperate by exploiting artifacts, representing resources that are dynamically created and shared by agents. In this paper we present a core calculus integrating techniques coming from the area of concurrency and from OO programming. The syntax of the calculus with its static and dynamic semantics are introduced through an example. The calculus aims to foster the formalization (and proof) of type soundness of SIMPA programs and the development of techniques for analyzing the computational behaviour of agents and artifacts.

A library-based extension of JAVA, the SIMPA framework, introduced a new abstraction based on agent-oriented concepts. Agents are autonomous entities that cooperate by exploiting artifacts, representing resources that are dynamically created and shared by agents. In this paper we present a core calculus integrating techniques coming from the area of concurrency and from OO programming. The syntax of the calculus with its static and dynamic semantics are introduced through an example. The calculus aims to foster the formalization (and proof) of type soundness of SIMPA programs and the development of techniques for analyzing the computational behaviour of agents and artifacts.

The pervasive computing scenario provides a diffused presence of technological appliances distributed in the environment and interacting by means of wired or wireless networks. These computational units should be able to fruitfully exploit interactions with other components (eg information sources) in order to supply context aware services and support advanced forms of interaction among users. The aim of this paper is to show how models and frameworks for Multi-Agent Systems (MAS) can be exploited to design and ...

The material presented in this paper is focused on the characteristics of open computational systems and, in particular, the issue of coordinating behavior in such systems, ie systemic coordination. Firstly, we introduce a conceptual framework for characterizing systemic coordination at different levels abstraction. Secondly, challenges and opportunities of this framework is outlined as a matter of exploiting a Service-oriented layered architecture for communicating entities (SOLACE) in combination with a particular coordination model ...

Abstract. In human society, almost any cooperative working context accounts for different kinds of object, tool, artifact in general, that humans adopt, share and intelligently exploit so as to support their working activities, in particular social ones. According to theories in human sciences such as Activity Theory, such entities have a key role in determining the success or failure of the activities, playing an essential function in simplifying complex tasks and—more generally—in designing solutions that scale with activity complexity. ...

Stigmergy, usually used on simple problems, can be applied to more complex ones by encoding them in the agents' environment. We show how stigmergic agents can plan over a hierarchical task network, a resource-oriented dialect of the TAEMS language. Our results reveal an important distinction among HTN's.

Agents and Artifacts" (A&A) and CARTAGO are becoming increasingly popular as, respectively, a general-purpose pro- gramming model and a related infrastructure for developing shared computational environments in agent-based software systems. However, so far there has been no work on devel- oping multiagent systems (MAS) where agents implemented and deployed in dierent agent-programming platforms can interact as part of the same

In human society, almost any cooperative working context accounts for different kinds of object, tool, artifact in general, that humans adopt, share and intelligently exploit so as to support their working activities, in particular social ones. According to theories in human sciences, such entities have a key role in determining the success or failure of the activities, playing an essential function in simplifying complex tasks and-more generally-in designing solutions that scale with activity complexity. Analogously to the human case, we claim that also (cognitive) multi-agent systems (MAS) could greatly benefit from the definition and systematic exploitation of a suitable notion of working environment, composed by different sorts of artifacts, dynamically constructed, shared and used by agents to support their working activities. Along this line, in this paper we introduce and discuss a programming model called A&A (Agents and Artifacts), which aims at directly modelling and engineering such aspects in the context of cognitive MAS. Besides the conceptual framework, we present the current state of prototyping technologies implementing A&A principles-CARTAGO platform in particular-, and show how they can be integrated with existing cognitive MAS programming frameworks, adopting the Jason programming platform as the reference case.

Stigmergy has been adopted in MAS (multi-agent systems) and in other fields as a technique for realising forms of emergent coordination in societies composed by a large amount of ant-like, nonrational agents. In this paper we discuss a conceptual (and engineering) framework for exploring the use of stigmergy in the context of societies composed by cognitive / rational agents, as a means for supporting highlevel, knowledge-based social activities.multi-agent We refer to this kind of stigmergy as cognitive stigmergy. Cognitive stigmergy is based on the use of artifacts as tools populating and structuring the agent working environment, and which agents perceive, share and rationally use for their individual goals. Artifacts are environment abstractions that mediate agent interaction and enable emergent coordination: as such, they can be used to encapsulate and enact the stigmergic mechanisms and the shared knowledge upon which emergent coordination processes are based. In this paper, we start exploring this scenario introducing an agentbased framework for cognitive stigmergy based on artifacts. After discussing the main conceptual issues-the notion of cognitive stigmergy and the role of artifacts-, we sketch an abstract architecture for cognitive stigmergy, and outline its implementation upon the TuCSoN agent coordination infrastructure.

The pervasive computing scenario provides a diffused presence of technological appliances distributed in the environment and interacting by means of wired or wireless networks. These computational units should be able to fruitfully exploit interactions with other components (eg information sources) in order to supply context aware services and support advanced forms of interaction among users. The aim of this paper is to show how models and frameworks for Multi-Agent Systems (MAS) can be exploited to design and ...

Abstract. In human society, almost any cooperative working context accounts for different kinds of object, tool, artifact in general, that humans adopt, share and intelligently exploit so as to support their working activities, in particular social ones. According to theories in human sciences such as Activity Theory, such entities have a key role in determining the success or failure of the activities, playing an essential function in simplifying complex tasks and—more generally—in designing solutions that scale with activity complexity. ...

Stigmergy has been adopted in MAS (multi-agent systems) and in other fields as a technique for realising forms of emergent coordination in societies composed by a large amount of ant-like, nonrational agents. In this paper we discuss a conceptual (and engineering) framework for exploring the use of stigmergy in the context of societies composed by cognitive / rational agents, as a means for supporting highlevel, knowledge-based social activities.multi-agent We refer to this kind of stigmergy as cognitive stigmergy. Cognitive stigmergy is based on the use of artifacts as tools populating and structuring the agent working environment, and which agents perceive, share and rationally use for their individual goals. Artifacts are environment abstractions that mediate agent interaction and enable emergent coordination: as such, they can be used to encapsulate and enact the stigmergic mechanisms and the shared knowledge upon which emergent coordination processes are based. In this paper, we start exploring this scenario introducing an agentbased framework for cognitive stigmergy based on artifacts. After discussing the main conceptual issues-the notion of cognitive stigmergy and the role of artifacts-, we sketch an abstract architecture for cognitive stigmergy, and outline its implementation upon the TuCSoN agent coordination infrastructure.

In the general context of Group Decision Support System (GDSS), the paper investigates the possibility to externalize and support from a metacognitive perspective the effective use of facilitation knowledge with self-development capabilities. The experimental results make evident that these capabilities may be easily engineered by adopting the basic principles of the design for emergence in constructing an e-meeting facilitation tool that act as a stigmergic collaborative environment for the participants. Basically, the GDSS needs to provide a minimal structure for modeling the group decision process (GDP) which enables a participant-driven approach to group facilitation and magnify the sense of social participation. In this way the GDSS may provide a collaborative environment where unpredictable and more effective models of GDP design will emerge through the exploration of the problem space.

This paper describes a Java-based framework for developing componentbased software systems supporting adaptation with logic laws and considering component interactions as a first-class aspect. On the one side, the framework makes it possible to specify the logic of interaction at the component-level, in terms of input and output interfaces, the events generated and observed by a component, and related information about the management of the control flow. On the other side, it is possible to specify the logic of interaction at the inter-component level, providing a modelling and linguistic support for designing and (dynamically) programming the glue among the components, enabling general forms of adaptation, observation and construction of the interaction space. As a result, the framework supports the adaptation of components at different levels: from interoperability among heterogeneous and unknown components, to the support for dynamic introduction, removal and update of components, to general coordination patterns, such as workflow. The framework uses first-order logic as the reference computational model for describing and defining the logic of interaction: the modalities adopted by components to interact, the adaptation laws gluing the components and the interaction events occurring in the system are expressed as facts and rules. They compose the (evolving) logic theories describing and defining the interaction at the system level, and can be observed and controlled at runtime to allow dynamic re-configurability.

In the general context of Group Decision Support System (GDSS), the paper investigates the possibility to externalize and support from a metacognitive perspective the effective use of facilitation knowledge with self-development capabilities. The experimental results make evident that these capabilities may be easily engineered by adopting the basic principles of the design for emergence in constructing an e-meeting facilitation tool that act as a stigmergic collaborative environment for the participants. Basically, the GDSS needs to provide a minimal structure for modeling the group decision process (GDP) which enables a participant-driven approach to group facilitation and magnify the sense of social participation. In this way the GDSS may provide a collaborative environment where unpredictable and more effective models of GDP design will emerge through the exploration of the problem space.

Using methods from computer science, anthropology and cultural studies, we present the principles of Izbushka, an intelligent agent being constructed with the goal of understanding interactions in heterogeneous multiagent systems, and observing emergent phenomena in such agent

Mostly stemming from closed parallel systems, coordination models and technologies gained in scope and expressive power so as to deal with complex distributed systems. In particular, in the last decade nature-inspired coordination (NIC) models emerged as the most effective approaches to tackle the complexity of pervasive, intelligent, and self-* systems. In this review paper we discuss their evolution, by analysing the main motivations behind the research effort on NIC, the foremost features of the most successful models, and the key issues and challenges they bring along.

Research on agent-oriented software engineering (AOSE) methodologies and multi-agent system (MAS) infrastructures has developed in the last years along two opposite paths: while AOSE methodologies have essentially undergone a top-down evolution pushed by contributions from heterogeneous fields like human sciences, MAS infrastructures have mostly followed a bottom-up path growing from existing and widespread (typically object-oriented) technologies. This dichotomy has produced a conceptual gap between the proposed AOSE methodologies and the agent infrastructures actually available, as well as a technical gap in the MAS engineering practice, where methodologies are often built ad hoc out of MAS infrastructures, languages and tools. This paper proposes a new method for filling the gap between methodologies and infrastructures based on the definition and study of the metamodels of both AOSE methodologies and MAS infrastructures. By allowing structural representation of abstractions to b...

Complex computational systems.. .. .. intelligent, knowledge-intensive, pervasive, self-organising systems could be seen as the dynamic ensemble of a large number of distributed components, heterogeneous in nature, structure and behaviour put together somehow so as to build up a coherent overall system behaviour What is "somehow"? This is the key issue in the research for abstractions, models, technologies and methodologies for the engineering of complex systems This is the issue of coordination models and languages [

Stigmergy has been variously adopted in MASs (multi-agent systems) and in other fields as well—as a technique for realising forms of emergent coordination in societies composed by a large amount of typically simple, ant-like, non-rational agents. In this article we introduce a conceptual and engineering framework for exploring the use of stigmergy in the context of societies composed by cognitive / rational agents, as a means for supporting high-level, knowledge-based social activities. We refer to this kind of stigmergy as cognitive stigmergy. Cognitive stigmergy is based on the use of suitable engineered artifacts as tools populating the agent working environment, and which agents share and rationally use for their individual goals. Artifacts are first-class entities representing the environment that mediates agent interaction and enables emergent coordination: as such, they encapsulate and enact the stigmergic mechanisms and the shared knowledge upon which emergent coordination p...

Coordination models and languages are meant to provide abstractions and mechanisms to harness the space of interaction as one of the foremost sources of complexity in computational systems. Nature-inspired computing aims at understanding the mechanisms and patterns of complex natural systems in order to bring their most desirable features to computational systems. Thus, the promise of nature-inspired coordination models is to prove themselves fundamental in the design of complex computational systems-such as intelligent, knowledge-intensive, pervasive, adaptive, and self-organising ones. In this paper, we survey the most relevant natureinspired coordination models in the literature, focussing in particular on tuple-based models, and foresee the most interesting research trends in the field.

Recent approaches in Multi-Agent Systems are focusing on providing models and methodologies for the design of environments and special purpose tools supposed to ease programming in the large and scale up growing complexities. Among others, the Agents and Artifacts (A&A) approach introduced the notion af artifact as first class abstraction providing agents with external facilities, services and coordination medium explicitely conceived for promoting their activities. In this paper we analyse A&A systems by focusing on the functional roles played by artifacts. In particular, we here investigate the function of artifacts once they are employed in the context of societies of cognitve agents, i.e. agents capable to reason about their epistemic and motivational states. In this context, a twofold kind of interaction is envisaged. On the one side, artifact rapresentational function allows agent to improve epistemic states, i.e., by representing and sharing strategic knowledge in the overall system (doxastic use). On the other side, artifacts operational function allows agents to improve the repertoire of actions, i.e., by providing additional means which can be purposively triggered by agents to achieve goals (operational use). Some of the outcomes of this approach are discussed along with test cases showing agents engaged in goal-oriented activities relying on the transmission of relevant knowledge and the operations provided by artifacts.

Agent-Oriented Programming (AOP) provides an effective level of abstraction for tackling the programming of mainstream software applications, in particular those that involve complexities related to concurrency, asynchronous events management and context-sensitive behaviour. In this paper we support this claim in practice by discussing the application of AOP technologies-Jason and CArtAgO in particular-for the development of smart nomadic applications based on the Google Android platform.

Service-Oriented Architecture (SOA) is more and more recognised by the industry as the reference blueprint for building inter-operable, distributed enterprise applications based on open standards such as Web Services (WS). In the current state-of-the-art, the programming models for engineering SOA systems proposed by the leading industries are essentially component-based-typically, rooted in object-oriented abstractions and technologies. On the side, such a choice benefits from the well-know advantages of component-based software engineering and from the maturity of the available technologies; on the other, however, the abstraction level provided is inadequate to model some fundamental SOA aspects-such as autonomy, control-uncoupling, data-driven interaction, activities-as firstclass concepts. Such features can be modelled quite naturally by adopting an agent-oriented perspective. In this paper we describe simpA-WS, a Java-based framework for developing SOA/WS applications which adopts an agentoriented programming model based on the general-purpose Agents and Artifacts meta-model (A&A). simpA-WS makes it possible to conceive, design and program services (and applications using services) as workspaces where ensemble of pro-active, activity-oriented entities (agents) work together by exploiting different kinds of passive function-oriented entities (artifacts) used as resources, along with tools to support their business activities. Accordingly, we first present the simpA-WS framework and the related simpA language-an extension of Java aimed at capturing the A&A metaphors as first-class entities; we then show how agents and artifacts can be programmed in simpA and how SOA/WS applications can be programmed in simpA-WS; a simple running example is discussed for concreteness. • the service requestor, which encapsulates the business logic on how to use services: from an interaction point of view, this results in sending and receiving messages in compliance with the service interface specification;

"Agents and Artifacts" (A&A) and CARTAGO are becoming increasingly popular as, respectively, a general-purpose programming model and a related infrastructure for developing shared computational environments in agent-based software systems. However, so far there has been no work on developing multiagent systems (MAS) where agents implemented and deployed in different agent-programming platforms can interact as part of the same MAS with a shared environment. Due to the generality of CARTAGO environments and its Java-based implementation, we have successfully implemented an open multi-agent system where heterogeneous agents developed with different platforms-namely Jason, 2APL as BDI-based approaches and simpA as an activityoriented approach rather than BDI-based-work together in shared workspaces where they interact and cooperate by dynamically creating and using shared artifacts, analogously to human working environments. This paper shows how this was achieved by first presenting a general model for incorporating a theory of use and observation of artifacts in cognitive agents, then describing a general approach for developing such heterogeneous MAS using CARTAGO integrated with existing agent-oriented programming platforms.

Harsh consequences of social inequality and unsustainable practices are responsible for altered local landscapes, and an unbalanced global system challenging designers to resolve inter-linked problems of mammoth complexity, that are more than just wicked. These problems are extremely volatile and uniquea nexus of interconnected vicious loop of complex local actions exerting changes in global patterns of vast magnitude in scale as well as impact, that insist upon urgent action to ensure 'collective survival'. To sustain and save the social and environmental fabric, we need adaptable and self-sustainable systems with equitable prospects of contestation for harnessing collective actions. We recommend stigmergy-a naturally evolved phenomenon for collective survival, as a possible approach for harnessing collective intelligence and action to achieve a common global goal, and argue for the characteristics that make it appropriate for resolving complex concerns of high magnitude.

Interfacing the agents with their environment is a classical problem when designing multiagent systems. However, the models pertaining to this interface generally choose to either embed it in the agents, or in the environment. In this position paper, we propose to highlight the role of agent bodies as primary components of the multiagent system design. We propose a tentative definition of an agent body, and discuss its responsibilities in terms of MAS components. The agent body takes from both agent and environment: low-level agent mechanisms such as perception and influences are treated locally in the agent bodies. These mechanism participate in the cognitive process, but are not driven by symbol manipulation. Furthermore, it allows to define several bodies for one mind, either to simulate different capabilities, or to interact in the different environments-physical, social-the agent is immersed in. We also draw the main challenges to apply this concept effectively.

Stigmergy is usually used to model semantically simple problems such as routing. It can be applied to more complex problems by encoding them in the stigmergic environment. We demonstrate this approach by showing how stigmergic agents can plan over a hierarchical task network, specifically a resource-oriented dialect of the TAEMS language.

Mainstream research in Web Services is currently looking at two main aspects, namely formally describing interactions among services, and finding and combining services. Much work made in the intelligent agents area is being applied to these issues. In this paper, we investigate the application of agent research to Web Services from a different perspective, that is, procedural learning. The final objective is to enable an adaptive system (an agent in our terminology) to discover or being fed with knowledge concerning how to solve a specific set of problems in a specific software or physical environment. Our work is a preliminary step into the issue, with the main objective of assessing how current Web Services technology can support a component, described in terms of beliefs, desires and intentions, dynamically adapting its behaviour to new environments.

Mainstream research in Web Services is currently looking at two main aspects, namely formally describing interactions among services, and finding and combining services. Much work made in the intelligent agents area is being applied to these issues. In this paper, we investigate the application of agent research to Web Services from a different perspective, that is, procedural learning. The final objective is to enable an adaptive system (an agent in our terminology) to discover or being fed with knowledge concerning how to solve a specific set of problems in a specific software or physical environment. Our work is a preliminary step into the issue, with the main objective of assessing how current Web Services technology can support a component, described in terms of beliefs, desires and intentions, dynamically adapting its behaviour to new environments.

Stigmergy is a biological term used when discussing insect or swarm behavior, and describes a model supporting environmental communication separately from artifacts or agents. This phenomenon is demonstrated in the behavior of ants and their food gathering process when following pheromone trails, or termites and their termite mound building processes.

In this work, a metamodel is introduced for CArtAgO infrastructure which can be used in the modeling of software agents on this infrastructure. The metamodel allows the programming of artifact-based environments for multi-agent systems. It can be used for different agent platforms as it is independent of the specifications of these platforms. Also, a graphical concrete syntax is developed for the proposed metamodel and a modeling tool is provided. The use of syntax and the modeling tool is demonstrated with the JaCaMo Gold Miners case study which consists the development of software agents for finding gold within a certain area.

Artifacts for Multi-Agent Systems have been defined as runtime entities providing some kind of function or service that agents can fruitfully exploit to achieve their individual or social goals. In order to enable agents to autonomously discover the available services, select the proper artifact(s), and use the services they need, it is necessary to describe the services offered by artifacts in terms of (i) what each service does, (ii) how to access it, and (iii) how it works. In this paper we explore how OWL-S (Ontology Web Language for Services), a language specifically aimed for the description of Web Services, can be exploited also for describing the services offered by artifacts. In particular, we investigate how to represent the artifact features by means of OWL-S, provide an example, and discuss some preliminary results in terms of advantages and limitations of this approach.

L’organisation traditionnelle de l’entreprise – la bureaucratie hiérarchique – est décriée, au moins depuis Peter Drucker, par la plupart des penseurs du management. En utilisant la démarche ethnographique,
nous avons étudié diverses entreprises qui, depuis des
dizaines d’années, sont parvenues à instaurer une forme organisationnelle radicalement différente dans laquelle les salariés sont entièrement libres d’agir pour le bien de l’entreprise. Et puis nous sommes allés encore plus loin dans notre recherche ; nous avons étudié la démarche de leadership nécessaire pour bâtir de telles organisations. Enfin, nous avons apporté une attention toute particulière à leur performance en temps de crise.

The widespread diffusion and availability of multicore architectures is going to make more and more aspects of concurrency and distribution to be part of mainstream programming and software engineering. The SIMPA framework is a recently proposed library-based extension of JAVA that introduces on top of the OO layer a new abstraction layer based on agent-oriented concepts. A SIMPA program is organized in terms of dynamic set of autonomous pro-active task-oriented entities -the agents -that cooperate by exploiting some artifacts, that represents resources and tools that are dynamically constructed, shared and co-used by agents. In this paper we promote the applicability of the agent and artifact metamodel in OO programming a step further. Namely, we propose a core calculus that integrates techniques coming from concurrency theory and from OO programming languages to provide a first basic formal framework for designing agent-oriented languages and studying properties of agent-oriented programs.

In human society, almost any cooperative working context accounts for different kinds of object, tool, artifact in general, that humans adopt, share and intelligently exploit so as to support their working activities, in particular social ones. According to theories in human sciences such as Activity Theory, such entities have a key role in determining the success or failure of the activities, playing an essential function in simplifying complex tasks and-more generally-in designing solutions that scale with activity complexity. Analogously to the human case, we claim that also (cognitive) multi-agent systems (MAS) could greatly benefit from the definition and systematic exploitation of a suitable notion of working environment, composed by different sorts of artifacts, dynamically constructed, shared and used by agents to support their working activities. Along this line, in this paper we describe a programming model called A&A (Agents and Artifacts), which aims at directly modelling and engineering such aspects in the context of cognitive MAS. Besides the conceptual framework, we present the current state of prototyping technologies implementing A&A principles-CARTAGO platform in particular-, and show how they can be integrated with existing cognitive MAS programming frameworks, adopting the Jason programming platform as the reference case.

Stigmergy has been adopted in MAS (multi-agent systems) and in other fields as a technique for realising forms of emergent coordination in societies composed by a large amount of ant-like, nonrational agents. In this paper we discuss a conceptual (and engineering) framework for exploring the use of stigmergy in the context of societies composed by cognitive / rational agents, as a means for supporting highlevel, knowledge-based social activities.multi-agent We refer to this kind of stigmergy as cognitive stigmergy. Cognitive stigmergy is based on the use of artifacts as tools populating and structuring the agent working environment, and which agents perceive, share and rationally use for their individual goals. Artifacts are environment abstractions that mediate agent interaction and enable emergent coordination: as such, they can be used to encapsulate and enact the stigmergic mechanisms and the shared knowledge upon which emergent coordination processes are based.

More and more aspects of concurrency and concurrent programming are becoming part of mainstream programming and software engineering, as a result of several factors, such as the widespread availability of multi-core / parallel architectures and Internet-based systems. Java has been one of the first mainstream languages providing a firstclass native support for multi-threading, with basic low level fine-grained concurrency mechanisms. Besides this fine-grained support to concurrency, the identification of higher-level-more coarse-grained -support is important as soon as programming and engineering complex concurrent applications is considered, helping to bridge the gap between system design, implementation and testing. Accordingly, in this paper we present simpA, a library-based extension of Java which introduces a high-level coarse-grained support to prototyping complex, multi-threaded / concurrent applications: Java programmers are provided with an agent-oriented abstraction layer on top of the basic OO layer to organize and structure applications.

More and more aspects of concurrency and concurrent programming are becoming part of mainstream programming and software engineering, due to several factors such as the widespread availability of multicore / parallel architectures and Internet-based systems. Besides the typical fine-grained support currently provided, however, we seek in this paper for an higher-level approach. We present simpA, a library-based extension of Java which provides programmers with agent and artifact abstractions on top of the basic OO layer, as a means to organise and structure concurrent applications. To pave the way towards identifying a true language extension for simpA, we define a core calculus of agents and artifacts, by suitabling mixing techniques coming from object-orientation and concurrency theory.