This chapter presents formats (compositions) of simulation results. For example, the function ‘gpensim’ returns the simulation result, which is used by functions ‘prnss’ (print state space) and ‘plotp’ (plot tokens in places). Suppose the user wants to circumvent the GPenSIM functions for printing and plotting the results and create a new function. However, this new function still has to use the result output by ‘gpensim’. Hence, the user needs to understand the composition of the resulting output by ‘gpensim’.