Verification query rollbacks are the most critical part of the predictive management system. They are handled in a slightly different fashion from causality failure rollbacks. A state verification failure causes the LP state to be corrected at the time of the state verification which failed. The state, , has been obtained from the actual device from the verification query at time . The LP rolls back to exactly with state, . States greater than are removed from the state queue . Anti-messages are sent from the output message queue for all messages greater than . The LP continues forward execution from this point. Note that this implies that the message and state queues cannot be purged of elements which are older than the GVT. Only elements which are older than real time can be purged.