Automatic symmetry detection in well-formed nets

  • Authors:
  • Yann Thierry-Mieg;Claude Dutheillet;Isabelle Mounier

  • Affiliations:
  • Laboratoire d'Informatique de Paris 6, SRC, France;Laboratoire d'Informatique de Paris 6, SRC, France;Laboratoire d'Informatique de Paris 6, SRC, France

  • Venue:
  • ICATPN'03 Proceedings of the 24th international conference on Applications and theory of Petri nets
  • Year:
  • 2003

Quantified Score

Hi-index 0.00

Visualization

Abstract

Formal verification of complex systems using high-level Petri Nets faces the so-called state-space explosion problem. In the context of Petri nets generated from a higher level specification, this problem is particularly acute due to the inherent size of the considered models. A solution is to perform a symbolic analysis of the reachability graph, which exploits the symmetry of a model. Well-Formed Nets (WN) are a class of high-level Petri nets, developed specifically to allow automatic construction of a symbolic reachability graph (SRG), that represents equivalence classes of states. This relies on the definition by the modeler of the symmetries of the model, through the definition of "static sub-classes". Since a model is self-contained, these (a) symmetries are actually defined by the model itself. This paper presents an algorithm capable of automatically extracting the symmetries inherent to a model, thus allowing its symbolic study by translating it to WN. The computation starts from the assumption that the model is entirely symmetric, then examines each component of a net to deduce the symmetry break it induces. This translation is transparent to the end-user, and is implemented as a service for the AMI-Net package. It is particularly adapted to models containing large value domains, yielding combinatorial gain in the size of the reachability graph.