Current State ID: 0
Current State Description: Block c is on the table. Block b is on top of block c and is clear. Block a is on the table and is clear. Block d is on the table and is clear. The hand is empty.

Child State ID: 1
Action Taken: unstack(b, c)
State Description: Block c is clear and on the table. Block b is held in the hand and is no longer on Block c. Block a is on the table and is clear. Block d is on the table and is clear. The hand is holding Block b.

