Parking Domain:
---------------

This domain involves parking cars on a street with N curb locations 
where cars can be double parked but not triple parked. The goal is 
to move from one configuration of parked cars to another configuration 
by driving cars from one curb location to another. The problems in the 
competition contain 2*(N-1) cars, which allows one free curb space and 
guarantees solvability. The problem difficulty is scaled by increasing 
the number of curb locations. 

This domain is isomorphic to a bounded-table blocks world domain where
there are N table locations and 2*(N-1) blocks and towers are only allowed 
to contain 2 blocks. 

