...fuzzy variables is a topic which leads to additional research issues. References 1. RY Al-Jaar and A. Desrochers, "Petri Nets in Automation and Manufacturing,"...Advances in Automation and Robotics, GN Saridis ed., vol. 2, JAI Press, pp. 153-218, 1991 2. A. Camurri and P. Franchi, "An Approach to the Design and Implementation...