Read Operators and their Expressiveness in Process Algebras

Flavio Corradini
(University of Camerino)
Maria Rita Di Berardini
(University of Camerino)
Walter Vogler
(University of Augsburg)

We study two different ways to enhance PAFAS, a process algebra for modelling asynchronous timed concurrent systems, with non-blocking reading actions. We first add reading in the form of a read-action prefix operator. This operator is very flexible, but its somewhat complex semantics requires two types of transition relations. We also present a read-set prefix operator with a simpler semantics, but with syntactic restrictions. We discuss the expressiveness of read prefixes; in particular, we compare them to read-arcs in Petri nets and justify the simple semantics of the second variant by showing that its processes can be translated into processes of the first with timed-bisimilar behaviour. It is still an open problem whether the first algebra is more expressive than the second; we give a number of laws that are interesting in their own right, and can help to find a backward translation.

In Bas Luttik and Frank Valencia: Proceedings 18th International Workshop on Expressiveness in Concurrency (EXPRESS 2011), Aachen, Germany, 5th September 2011, Electronic Proceedings in Theoretical Computer Science 64, pp. 31–43.
Published: 20th August 2011.

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