Parent State ID: 41
State Depth: 11
Action Taken: stack(a, b)
Action Reasoning: To achieve the goal state, we need to place block 'a' on top of block 'b'. Currently, block 'a' is clear and on the table, and block 'b' is also clear on the table. Therefore, the best action is to stack 'a' on 'b'.
State Description: Block 'a' is now on top of block 'b', which is on the table. Block 'a' is clear. Block 'b' is supporting block 'a'. Block 'c' is on top of block 'b' and supporting block 'd'. Block 'd' is on top of block 'c' and clear. The hand is empty.
Action Path: ['unstack(d, a)', 'put-down(d)', 'unstack(a, c)', 'put-down(a)', 'pick-up(d)', 'stack(d, c)', 'unstack(d, c)', 'stack(d, c)', 'unstack(d, c)', 'stack(d, c)', 'stack(a, b)']

INACTIVE REASON: deactivated because diagram generation failed or invalid action chosen: The action's preconditions are not satisfied: block 'b' is not clear, and the hand is not holding 'a'.
