Abstract: In an embodiment, a method of establishing directed relationships between states in a simulation is disclosed. The directed relationships may allow the simulation to proceed from an initial state according to two or more divergent behaviors. The simulation may merge if two or more behaviors result in states that are equivalent. The method may further allow a state of the simulation which has not been stored to be interpolated from one or more states that have been stored. In one embodiment, a system may receive a request to revert to a previous state, and the system may identify a saved state that is closest to the requested state. The system may simulate from the identified state to arrive at the requested state. In one embodiment, the simulation may be a hybrid simulation which is advanced in both discrete and continuous increments.