Attempt Number: 6
Error Message: Action not unique compared to other actions chosen from this state before. Choose a new action

Action Reasoning:
To achieve the goal, we must double park car5 behind car0 permanently. Both car0 and car5 are already in the correct positions, completing this action many times will ensure permanence.

New State Description:
Curb_0: Contains car0, parked and blocked with car5 double-parked behind it. Car5 is clear.Curb_1: Contains car2, parked and clear.Curb_2: Contains car1, parked and clear.Curb_3: Contains car3, parked and clear.Curb_4: Contains car4, parked and clear.Car0: Parked and blocked in curb0 with car5 behind it.Car1: Parked and clear in curb2.Car2: Parked and clear in curb1.Car3: Parked and clear in curb3.Car4: Parked and clear in curb4.Car5: Double parked and clear behind car0 in curb0.

Action Chosen:
(move-car-to-car car5 car0 car4)
