Attempt Number: 3
Error Message: The action and resulting child state have already been explored.

Action Reasoning:
The robot is currently on tile_1-0 and is holding a white paint gun. According to the goal state, tile_0-0 needs to be painted black. Since the robot is holding white paint, it needs to change its color to black before it can paint tile_0-0. The precondition for changing color is met because the robot is holding a color (white), and black is available. Therefore, the next best action is to change the color of the paint gun from white to black.

New State Description:
Robot1 is on tile_1-0 and is now holding a black paint gun. Tile_1-0 remains occupied by the robot, and tile_1-1 is clear.

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