Parent State ID: 17
State Depth: 5
Action Taken: unstack(d, a)
Action Reasoning: To achieve the goal state, we need to move block d to the table so that block a can be stacked on it. The next logical step is to unstack block d from block a.
State Description: Block d is now held in the hand and is no longer on block a. Block a is clear and on the table. Block b remains on block c, and both are on the table. The hand is not empty as it holds block d.
Action Path: ['unstack(c, b)', 'put-down(c)', 'pick-up(b)', 'stack(b, c)', 'unstack(d, a)']
