Parent State ID: 3
State Depth: 3
Action Taken: unstack(a, c)
Action Reasoning: To achieve the goal state, we need to move block 'a' onto block 'b'. First, we must unstack block 'a' from block 'c' to make it available for stacking onto block 'b'.
State Description: Block a is held in the hand. Block c is clear and on top of block b. Block b is on the table. Block d is on the table and clear. The hand is holding block a.
Action Path: ['unstack(d, a)', 'put-down(d)', 'unstack(a, c)']
