Parent State ID: 17
State Depth: 7
Action Taken: unstack(d, c)
Action Reasoning: To achieve the goal state, we need to move block 'a' on top of block 'b'. First, we need to clear block 'c' by unstacking block 'd' from it.
State Description: Block 'a' is on the table and clear. Block 'c' is on top of block 'b' and clear. Block 'b' is on the table. Block 'd' is held in the hand and no longer on block 'c'. The hand is not empty.
Action Path: ['unstack(d, a)', 'put-down(d)', 'unstack(a, c)', 'put-down(a)', 'pick-up(d)', 'stack(d, c)', 'unstack(d, c)']
