Attempt Number: 4
Error Message: The action 'left(robot1, tile_1-4, tile_1-3)' has already been explored.

Action Reasoning:
The robot is currently on tile_1-4 and needs to move towards tile_1-0 to start painting the first row. Since none of the tiles are painted yet, the best action is to move the robot left towards tile_1-0. This is the shortest path to reach the starting position for painting the first row. Moving left will bring the robot closer to tile_1-0, where it can then paint tile_0-0 black, which matches the goal state's requirement for the first tile.

New State Description:
Robot1 has moved from tile_1-4 to tile_1-3, holding a black paint gun. Tile_1-4 is now clear, and tile_1-3 is occupied by Robot1.

Action Chosen:
left(robot1, tile_1-4, tile_1-3)
