Parent State ID: 9
State Depth: 6
Action Taken: stack(d, b)
Action Reasoning: To achieve the goal state, we need block d on top of block b. Since block b is clear, we can directly place block d onto block b.
State Description: Block `c` is held in the hand and not clear. Block `b` is on the table and supporting block `d`. Block `d` is on block `b` and supporting block `a`. Block `a` is clear on block `d`. The hand is holding block `c`.
Action Path: ['unstack(d, a)', 'put-down(d)', 'unstack(a, c)', 'stack(a, d)', 'unstack(c, b)', 'stack(d, b)']

INACTIVE REASON: deactivated because diagram generation failed or invalid action chosen: The hand is not holding block `d`, violating the precondition for the `stack` action.
