Empty Marking of Petri Net and Related Properties

A marking M is said to be an empty marking in a Petri net Σ=(S,T;F,M) if M(s)=0 for every s∈S[1].An empty marking may be an initial marking of a net system,or a reacheable marking for a net system of which the initial marking is not empty[1].Reproducibility of empty marking is discussed by [2].We indicate that an empty marking mary also be a repetitive marking in some net systems in this paper.Moreover,the physical background of empt markings in three case above are discussed,some properties of net structure related to the empty markings are proven.