Attempt Number: 3
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 provided, after a move, the next step should be to change the color of the paint gun. Currently, robot1 is holding black paint, and the next tile to be painted (tile_0-3) should be white according to the goal state. Therefore, the best action is to change the color of the paint gun from black to white.

New State Description:
Robot1 is on tile_1-3, holding white paint. Tile_1-3 is occupied by robot1, and tile_1-2 is clear.

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