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

Action Reasoning:
The current state shows that robot1 is on tile_1-4, holding a white paint gun, and the last action was moving right. According to the logical conclusions, after a move, the next step should be to change the color of the paint gun. The goal state requires tile_0-4 to be painted black, so the robot needs to change its color from white to black to achieve this. 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_1-4, now holding a black paint gun.

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