Abstract
In this paper a knowledge-based experimental tool for Petri nets modelling and analysis is presented. The tool consists of a graphical editor, allowing the capture and editing of Petri net graphs, integrated with an expert system allowing an automated analysis of an edited Petri net graph. According to goals set by the user, the expert system performs the necessary reasoning about reachability and invariance properties of the analysed Petri net graph and displays inferred results to the user. The core of this expert system is based on rules capturing the general knowledge (i.e. expertise) about reachability and invariance of Petri nets. The definition of these rules forms an interesting and original part of the work. Prolog was used as the implementation language of the expert system.