In: Transactions of the Society of Instrument and Control Engineers, Vol. 24, No. 6, pages 635-40. June 1988. In Japanese.
Abstract: The paper concerns the problem of finding a class of Petri nets such that a necessary and sufficient condition for reachability is obtainable. For this purpose, some classes of Petri nets are defined by structural conditions related to directed circuits. A necessary and sufficient condition for reachability can be obtained for a trap circuit Petri net and for a deadlock circuit Petri net.