Theory of regions

From HandWiki

The Theory of regions is an approach for synthesizing a Petri net from a transition system. As such, it aims at recovering concurrent, independent behavior from transitions between global states. Theory of regions handles elementary net systems as well as P/T nets and other kinds of nets. An important point is that the approach is aimed at the synthesis of unlabeled Petri nets only.


Definition

A region of a transition system [math]\displaystyle{ (S, \Lambda, \rightarrow) }[/math] is a mapping assigning to each state [math]\displaystyle{ s \in S }[/math] a number [math]\displaystyle{ \sigma(s) }[/math] (natural number for P/T nets, binary for ENS) and to each transition label a number [math]\displaystyle{ \tau(\ell) }[/math] such that consistency conditions [math]\displaystyle{ \sigma(s') = \sigma(s) + \tau(\ell) }[/math] holds whenever [math]\displaystyle{ (s,\ell,s') \in \rightarrow }[/math].[1]

Intuitive explanation

Each region represents a potential place of a Petri net.

Mukund: event/state separation property, state separation property.[2]

References

  • Badouel, Eric; Darondeau, Philippe (1998), Reisig, Wolfgang; Rozenberg, Grzegorz, eds., "Theory of regions" (in en), Lectures on Petri Nets I: Basic Models: Advances in Petri Nets, Lecture Notes in Computer Science (Berlin, Heidelberg: Springer): pp. 529–586, doi:10.1007/3-540-65306-6_22, ISBN 978-3-540-49442-3