The various types of places andtransitions are shown in Table I. In our method, the proposedmodel for transitions has a two-level hierarchical structure. Thehigh level transitions are represented as dashed outline rectangles, while the low level ones are denoted by bars, outline rectangles, and filled rectangles. The transition of the dashed outlinerectangle has a synchronous characteristic in order to satisfy thebehavior of fuzzy logic inference, which is shown in the lastentry of Table I.