Reduction rules of Petri nets for verification of the communication protocol

Since functional reduction is based on relation instance maps from a set of output places of transition to the corresponding set of input places in an adjacent transition, the concept of composition is formalized as a new transition, and is compounded from two joinable transitions with the merging of the places of two transitions after eliminating common places. This method has one handicap as a subnet can not be reduced if there is no relationship between the two transitions. We present an advanced functional reduction for Petri nets utilizing a macrotransition and a macroplace in the hierarchical reduction method. We apply our scheme of advanced reduction rules to a TFTP (trivial file transport protocol).