has characteristic is generalization of multi-state agent-based simulation method Gillespie direct algorithm exact solution NFSim agent-based simulation method 2011-04-07 http://identifiers.org/biosimulators/bionetgen http://identifiers.org/doi/10.1038/nmeth.1546 A generalization a rule-based version of 'Gillespie's direct method' (SSA) [http://identifiers.org/biomodels.kisao/KISAO_0000029]. The method is guaranteed to produce the same results as the exact SSA [http://identifiers.org/biomodels.kisao/KISAO_0000029] by cycling over three primary steps. First, NFsim calculates the probability or propensity for each rule to take effect given the current molecular states. Second, it samples the time to the next reaction event and selects the corresponding reaction rule. Finally, NFsim executes the selected reaction by applying the rule and updating the molecular agents accordingly. AZ implicit-state Doob-Gillespie algorithm