Language behavior description of structure-complex Petri net based on decomposition

In order to analyze the behaviors of a structure-complex Petri net, a new decomposition method for Petri net based on defining an index for the place set is introduced, with which a structure-complex Petri net can be decomposed into a set of structure-simple subnet systems in which the number of input place set or the output place set of any transition is less than or equal to one. The characters of the subnet systems are analyzed in detail and the methods to obtain their language expressions are presented. With analyzing the language relationships between the subnet systems and the original system, an algorithm to express the behaviors of any structure-complex Petri net is given, which is useful to analyze the physical systems with Petri net languages.