More Structure Theory

There are some interesting connections between the structural liveness of a Petri net and the rank of its incidence matrix. They are presented in the first part of this chapter. In the second part, it is shown that these connections lead to a principle of duality with regard to the structure and the behaviour of free-choice nets. They also lead to a reduction algorithm characterising precisely the set of well-formed FC-nets, and to a structural characterisation of reversible FC-nets via traps.