• Curb_0 has car_3 parked on it. Car_3 is clear, meaning there are no cars double-parked behind it.  
• Curb_1 has car_2 parked on it. Car_2 is clear, meaning there are no cars double-parked behind it.  
• Curb_2 has car_0 parked on it. Car_0 is clear, meaning there are no cars double-parked behind it.  
• Curb_3 has car_1 parked on it. Car_1 is clear, meaning there are no cars double-parked behind it.