Current State ID: 5
Current State Description: Block c is now on the table and clear. Block b remains clear and on the table. Block a and block d are unchanged, with block d still on block a. The hand is empty.

Child State ID: 9
Action Taken: unstack(d, a)
State Description: Block d is now held in the hand and is no longer on block a. Block a is clear and on the table. Blocks b and c remain clear and on the table. The hand is holding block d.

Child State ID: 11
Action Taken: pick-up(b)
State Description: Block b is being held in the hand. Block c is clear and on the table. Block a and block d remain unchanged, with block d still on block a. The hand is no longer empty.

