Attempt Number: 4
Error Message: The action and resulting child state have already been explored.

Action Reasoning:
The last action taken was a move, where robot1 moved from tile_1-2 to tile_1-3. According to the logical conclusions, after a move, the next step is to change the color of the paint gun exactly once. Robot1 is currently holding black paint, and the goal state requires tile_0-3 to be painted white. Therefore, the best action is to change the color from black to white.

New State Description:
Robot1 is on tile_1-3 and is now holding white paint.

Action Chosen:
change-color(robot1, black, white)
