Parent State ID: 43
State Depth: 8
Action Taken: stack(a, d)
Action Reasoning: To achieve the goal state, we need to place block 'a' on block 'd'. Since block 'a' is currently held, the next best action is to stack 'a' on 'd'.
State Description: Block 'a' is now on top of block 'd', block 'd' is supporting block 'a' and is on the table. Block 'c' is on top of block 'b', and block 'b' is supporting block 'c'. The hand is empty.
Action Path: ['unstack(d, a)', 'put-down(d)', 'pick-up(a)', 'stack(a, d)', 'unstack(c, b)', 'stack(c, b)', 'unstack(a, d)', 'stack(a, d)']

INACTIVE REASON: Pruned in beam search
