use Drone as knowledge.
order = linear.

module UpdateStatus(Health, Conditions, X1, Y1, RegionId) {
	if bel(not(status(Health, Conditions, X1, Y1, RegionId)), status(OldHealth, OldConditions, OldX1, OldY1, OldRegionId)) then
		delete(status(OldHealth, OldConditions, OldX1, OldY1, OldRegionId)) +
		insert(status(Health, Conditions, X1, Y1, RegionId)).
		
	if bel(not(status(_, _, _, _, _))) then
		insert(status(Health, Conditions, X1, Y1, RegionId)).
}