On improving efficiency of model checking through systematically ...

Chapter 2
Specifying input systems
As previously described in Section 1.3, the input system has to be specified
in Nbac input language. In this chapter, we introduce three different ways
to obtain an Nbac input model. Since people may need to try the new
combination approach on systems that are initially modeled in PMC/Uppaal,
we define a framework to transform an PMC/Uppaal model to an Nbac input
model. Such a framework is neccessary because Nbac input model is specified
in a low-level format which mainly involves variables and dataflow equations
on variables while PMC/Uppaal model is specified in a higher level format
that involves locations and transitions of an automaton.
We first present components of an Nbac input model in Section 2.1.
Then we give a short introduction of XTG structure in Section 2.2. Next,
we list three methods to obtain an input model and describe in details the
construction of an Nbac model from a PMC/Uppaal model in Section 2.3. The
procedure is illustrated by the construction of the Fischer’s protocol model.
2.1 Nbac input model
Nbac input model is specified in a simple low-level format including dataflow
equations on Boolean and Integer variables since Nbac was originally made
to analyse programs written in Lustre [2] dataflow synchronous language.
Let M be an Nbac input model. Let Var decl be the variable declaration
part of M. LetTrans the set of dataflow equations of M. LetAssert, Init,
Final be Boolean expressions indicating the assertion, initial condition and
final condition of M, respectively. Using these definitions, M is described
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