Parent State ID: 13
State Depth: 7
Action Taken: stack(d, b)
Action Reasoning: The goal state requires block `d` on top of block `b`. Since block `d` is currently on the table and clear, the next best action is to stack `d` onto `b` to get closer to the goal configuration.
State Description: Block `a` is on block `d` and is clear. Block `b` is on the table and supporting block `d`. Block `c` is on the table and is clear. Block `d` is on block `b` and supporting block `a`. The hand is empty.
Action Path: ['unstack(d, a)', 'put-down(d)', 'unstack(a, c)', 'stack(a, d)', 'unstack(c, b)', 'put-down(c)', '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.
