|Sommario:||The work presented in this report concerns the most recent developments of a calculus used to derive (mainly structural)
properties of Symmetric Nets (SNs). The calculus that is being extended in this report was introduced about 15 years ago,
with the aim of efficiently computing useful structural properties of SNs, representing them in a symbolic and compact
A SN model consists of places (modeling the state) and transitions (modeling activities and events) connected by arcs
decorated with arc expressions. The calculus proposed in this report allows to manipulate and combine the arc expressions
through operators like the transpose, the composition or the intersection, in order to derive new expressions representing various structural properties in symbolic form. The underlying language resembles the arc expressions language and extends it by including filters. This report in particular presents a complete treatment of the composition operator, when applied to language elements mapping on sets.
The calculus has been implemented in a library whose functions can be accessed through a command-line interface: the
tool is called SN-expression and can be downloaded from www.di.unito.it/~depierro/SNex.|