Timed soft concurrent constraint programs: an interleaved and a parallel approach

Stefano Bistarelli, Univ. of Perugia
Maurizio Gabbrielli, Univ. of Bologna
Maria Chiara Meo, Univ. “G. D’Annunzio” Pescara
Francesco Santini, CWI Amsterdam


We propose a timed and soft extension of Concurrent Constraint Programming. The time extension is based on the hypothesis of bounded asynchrony: the computation takes a bounded period of time and is measured by a discrete global clock. Action prefixing is then considered as the syntactic marker which distinguishes a time instant from the next one. Supported by soft constraints instead of crisp ones, tell and ask agents are now equipped with a preference (or consistency) threshold which is used to determine their success or suspension. In the paper we provide a language to describe the agents behavior, together with its operational and denotational semantics, for which we also prove the compositionality and correctness properties. After presenting a semantics using maximal parallelism of actions, we also describe a version for their interleaving on a single processor (with maximal parallelism for time elapsing). Coordinating agents that need to take decisions both on preference values and time events may benefit from this language.

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Bibtex (Use it for references)

journal = {Theory and Practice of Logic Programming},
publisher = {Cambridge University Press},
author = {Stefano Bistarelli and Maurizio Gabbrielli and Maria Chiara Meo and Francesco Santini },
title = {Timed soft concurrent constraint programs: an interleaved and a parallel approach},
volume = {15},
number = {6},
year = {2015},
pages = {743-782}