Current State ID: 6
Current State Description: Block a is held in the hand. Block c is clear and on top of block b. Block b is on the table. Block d is on the table and clear. The hand is holding block a.

Child State ID: 7
Action Taken: stack(a, b)
State Description: Block a is on top of block b. Block c is clear and on top of block b. Block b is on the table with block a on top of it. Block d is on the table and clear. The hand is empty.

Child State ID: 8
Action Taken: put-down(a)
State Description: Block 'a' is on the table and clear. Block 'c' is clear and on top of block 'b'. Block 'b' is on the table. Block 'd' is on the table and clear. The hand is empty.

