/* DPOR persistent set procedure:
* for each new transition considered, check if it depends on any other previous transition executed before it
* on another process. If there exists one, find the more recent, and add its process to the interleave set.
* If the process is not enabled at this point, then add every enabled process to the interleave */
if (reduction_mode_ == ReductionMode::dpor) {
/* DPOR persistent set procedure:
* for each new transition considered, check if it depends on any other previous transition executed before it
* on another process. If there exists one, find the more recent, and add its process to the interleave set.
* If the process is not enabled at this point, then add every enabled process to the interleave */
if (reduction_mode_ == ReductionMode::dpor) {