Publications in Constraint Programming

Articles in Refereed Journals:

1. Christel Baier, Marjan Sirjani, Farhad Arbab, Jan J. M. M. Rutten. Modeling component connectors in Reo by constraint automata. Sci. Comput. Program., Vol. 61, Num. 2, pages 75-113, 2006.
   Abstract: In this paper we introduce constraint automata and propose them as an operational model for Reo, an exogenous coordination language for compositional construction of component connectors based on a calculus of channels. By providing composition operators for constraint automata and defining notions of equivalence and refinement relations for them, this paper covers the foundations for building tools to address concerns such as the automated construction of the automaton for a given component connector, equivalence checking or containment checking of the behavior of two given connectors, and verification of coordination mechanisms.

2. George A. Papadopoulos, Farhad Arbab. Coordination Models and Languages. Advances in Computers, Vol. 46, pages 330-401, 1998.
   Abstract: A new class of models, formalisms and mechanisms has recently evolved for describing concurrent and distributed computations based on the concept of "coordination". The purpose of a coordination model and associated language is to provide a means of integrating a number of possibly heterogeneous components together, by interfacing with each component in such a way that the collective set forms a single application that can execute on and take advantage of parallel and distributed systems. In this chapter we initially define and present in sufficient detail the fundamental concepts of what constitutes a coordination model or language. We then go on to classify these models and languages as either "data-driven" or "control-driven" (also called "process-" or "task-oriented"). Next, the main existing coordination models and languages are described in sufficient detail to let the reader appreciate their features and put them into perspective with respect to each other. The chapter ends with a discussion comparing the various models and some conclusions.

Articles in Refereed Conferences:

1. Marco Alberti, Federico Chesani, Marco Gavanelli, Evelina Lamma, Paola Mello, Marco Montali, Sergio Storari, Paolo Torroni. Computational Logic for Run-Time Verification of Web Services Choreographies: Exploiting the OCS-SI Tool. WS-FM, pages 58-72, 2006.
   Abstract: In this work, we investigate the feasibility of using a framework based on computational logic, and mainly defined in the context of Multi-Agent Systems for Global Computing (SOCS UE Project), for modeling choreographies of Web Services with respect to the conversational aspect. One of the fundamental motivations of using computational logic, beside its declarative and highly expressive nature, is given by its operational counterpart, that can provide a proof-theoretic framework able to verify the consistency of services designed in a cooperative and incremental manner. In particular, in this paper we show that suitable "Social Integrity Constraints", introduced in the SOCS social model, can be used for specifying global protocols at the choreography level. In this way, we can use a suitable tool, derived from the proof-procedure defined in the context of the SOCS project, to check at run-time whether a set of existing services behave in a conformant manner w.r.t. the defined choreography.

2. Laurent Fribourg, Marcos Veloso Peixoto. Concurrent Constraint Automata. International Logic Programming Symposium, 1993.
   Abstract: We address the problem of the specification and the proof of properties of concurrent systems which manipulate an unbounded number of data. We propose an approach based on an extended notion of automata, called "Concurrent Constraint Automata (CCA)". A CCA is an automaton with constraints and synchronous communication. By automata with constraints, we mean a state machine whose actions and states contain parameters that take their value in the set of natural numbers. (...)