Paolo Baldan Andrea Corradini Hartmut Ehrig Reiko Heckel Barbara König Bisimilarity and Behaviour-Preserving Reconfigurations of Open Petri Nets http://arxiv.org/abs/0809.4115 2008 CoRR abs/0809.4115 db/journals/corr/corr0809.html#abs-0809-4115 informal publication