Algebraic Petri nets as defined by Reisig [
17] lack a feature for modelling distributed network algorithms, viz.
flexible arcs. In this paper we equip algebraic Petri nets with flexible arcs and we call the resulting extension
algebraic system nets. We demonstrate that algebraic system nets are better suited for modelling distributed algorithms.
Besides this practical motivation for introducing algebraic system nets there is a theoretical one. The concept of place invariants introduced along with algebraic Petri nets has a slight insufficiency: There may be place invariants of an unfolded algebraic
Petri net which cannot be expressed as a place invariant of the algebraic Petri net itself. By introducing algebraic system
nets along with a slightly more general concept of place invariants we also eliminate this insufficiency.
Moreover, we generalize the concept of place invariants which we call simulations. Many well-known concepts of Petri net theory such as siphons, traps, modulo-invariants, sur-invariants and sub-invariants are special cases of a simulation. Still, a simulation can be verified in the same style as classical place invariants of
algebraic Petri nets.
Keywords Algebraic Petri nets - place invariants - verification techniques
Supported by the DFG: Konsensalgorithmen