Parent State ID: 15
State Depth: 7
Action Taken: stack(d, b)
Action Reasoning: The goal sequence is to have block `d` on block `b` and block `a` on block `d`. First, we'll stack `d` onto `b` as both are clear, setting the base of this stack.
State Description: Block `a` is on the table and clear. Block `b` is on the table, not clear, supporting block `d`. Block `c` is on the table and clear. Block `d` is now on top of block `b` and clear. The hand is empty.
Action Path: ['unstack(d, a)', 'put-down(d)', 'unstack(a, c)', 'put-down(a)', '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 `stack(d, b)`.
