The application of duals in the analysis of Petri nets

The closeness algorithm, an algorithm which guides the selection of the best form of either a primal or a dual for further analysis, is presented. The primal refers to the original Petri net, and a dual is a transformation of the primal form of a net. The use of the closeness algorithm is limited to a subclass of Petri nets called free-choice nets, where the primal and dual are both live and safe. The closeness algorithm can be very useful in simplifying the analysis of a Petri net. In the examples given, the time involved in generating all the states of a net is reduced by choosing the form of the net that will produce the fewest states