8 research outputs found
Models for CSP with availability information
We consider models of CSP based on recording what events are available as
possible alternatives to the events that are actually performed. We present
many different varieties of such models. For each, we give a compositional
semantics, congruent to the operational semantics, and prove full abstraction
and no-junk results. We compare the expressiveness of the different models.Comment: In Proceedings EXPRESS'10, arXiv:1011.601
All Linear-Time Congruences for Familiar Operators
The detailed behaviour of a system is often represented as a labelled
transition system (LTS) and the abstract behaviour as a stuttering-insensitive
semantic congruence. Numerous congruences have been presented in the
literature. On the other hand, there have not been many results proving the
absence of more congruences. This publication fully analyses the linear-time
(in a well-defined sense) region with respect to action prefix, hiding,
relational renaming, and parallel composition. It contains 40 congruences. They
are built from the alphabet, two kinds of traces, two kinds of divergence
traces, five kinds of failures, and four kinds of infinite traces. In the case
of finite LTSs, infinite traces lose their role and the number of congruences
drops to 20. The publication concentrates on the hardest and most novel part of
the result, that is, proving the absence of more congruences
FICS 2010
International audienceInformal proceedings of the 7th workshop on Fixed Points in Computer Science (FICS 2010), held in Brno, 21-22 August 201
Seeing beyond divergence
A long-standing complaint about the theory of CSP has been that all theories which encompass divergence are divergence-strict, meaning that nothing beyond the first divergence can be seen. In this paper we show that a congruence previously identified as the weakest one to predict divergence over LTS’s can be given a new fixed point theory, which we term reflected fixed points and thereby turned into a full CSP model which is congruent to the operational semantics.