Since in the step-independent scheme more than one step may be taken at a time, there may be a situation in which the specified system is able to perform an infinite number of reactions without incrementing time. This is called an infinite loop.
If the system is in state S1 and event E is generated or if in state S2 and event F is generated, the simulation toggles infinitely between S1 and S2.
To avoid infinite loops, a phase limit is defined which restricts the number of steps that can be taken without advancing time. Phase limit restricts the length of all supersteps, even those that would not result in an infinite loop. The phase limit is set using the Steps per Go parameter.