12 research outputs found
Failure Trace Semantics for a Process Algebra with Time-outs
This paper extends a standard process algebra with a time-out operator,
thereby increasing its absolute expressiveness, while remaining within the
realm of untimed process algebra, in the sense that the progress of time is not
quantified. Trace and failures equivalence fail to be congruences for this
operator; their congruence closure is characterised as failure trace
equivalence
Weak equivalence of higher-dimensional automata
This paper introduces a notion of equivalence for higher-dimensional
automata, called weak equivalence. Weak equivalence focuses mainly on a
traditional trace language and a new homology language, which captures the
overall independence structure of an HDA. It is shown that weak equivalence is
compatible with both the tensor product and the coproduct of HDAs and that,
under certain conditions, HDAs may be reduced to weakly equivalent smaller ones
by merging and collapsing cubes.This research was partially supported by FCT (Fundacao para a Ciencia e a Tecnologia, Portugal) through project UID/MAT/00013/2013
Weak equivalence of higher-dimensional automata
This paper introduces a notion of equivalence for higher-dimensional
automata, called weak equivalence. Weak equivalence focuses mainly on a
traditional trace language and a new homology language, which captures the
overall independence structure of an HDA. It is shown that weak equivalence is
compatible with both the tensor product and the coproduct of HDAs and that,
under certain conditions, HDAs may be reduced to weakly equivalent smaller ones
by merging and collapsing cubes
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