lastProp = pro_queue_c.pollFirst();
// revision of the variable
int aid = p2i.get(lastProp.getId());
assert schedule_c[aid] : "try to propagate an unscheduled propagator";
schedule_c[aid] = false;
PropagatorEventType evt = event_c[aid];
event_c[aid] = PropagatorEventType.VOID;
assert lastProp.isActive() : "propagator is not active:" + lastProp;
if (Configuration.PRINT_PROPAGATION) {
Trace.printPropagation(null, lastProp);
}
lastProp.coarseERcalls++;
lastProp.propagate(evt.getStrengthenedMask());
}