Current State ID: 17
Current State Description: The hand is empty. Block 'a' is on block 'c' and is clear. Block 'b' is on the table with block 'd' on top of it. Block 'c' is supporting block 'a' and is no longer clear. Block 'd' is on block 'b' and is clear.

Child State ID: 30
Action Taken: unstack(d, b)
State Description: The hand is holding block 'd'. Block 'b' is now clear and on the table. Block 'a' is on block 'c' and is clear. Block 'c' is supporting block 'a' and is no longer clear.

