Current State ID: 45
Current State Description: Block `a` is on the table and clear. Block `b` is on the table and clear. Block `c` is on the table and clear. Block `d` is being held by the hand and is no longer clear. The hand is holding block `d`.

Child State ID: 50
Action Taken: stack(d, b)
State Description: Block `a` is on the table and clear. Block `b` is on the table and not clear, as block `d` is on top of it. Block `c` is on the table and clear. Block `d` is on block `b` and clear. The hand is empty.

