Lecture Notes in Computer Science 3472

5 Preorder Relations 149
The utility of various preorders should thus be estimated by taking all of their
features into consideration.
In the same line of thought, namely practical applications, we have presented
a practical framework for conformance testing based on the theory of preorders.
Finally, it is worth pointing out that our presentation has been made in
terms of labeled transition systems, as opposed to most of the literature, in
which process algebraic languages such as CCS, LOTOS, and variants thereof
are generally used. Labeled transition systems define however the semantics of
all these languages, so the translation of the results surveyed here into various
other formalisms should not be a problem. The upside of our approach is the
uniform and concise characterization of the preorders, although we lose some
expressiveness in doing so (however the literature cited therein always offers a
second, most of the time process algebraic view of the domain).
As well, we did not pay attention to contexts. Contexts admit however a
relatively straightforward approach once the rest of the apparatus is in place.