Parent State ID: 31
State Depth: 7
Action Taken: unstack(c, b)
Action Reasoning: To achieve the goal state, block 'b' needs to be on top of block 'c'. Since block 'c' is clear and block 'b' is currently supporting block 'c', we should unstack 'c' from 'b' to make 'b' clear.
State Description: Block 'c' is now held in the hand. Block 'b' is clear and on the table. Block 'a' remains on top of block 'd', and block 'd' is supporting block 'a'. The hand is no longer empty.
Action Path: ['unstack(d, a)', 'put-down(d)', 'pick-up(a)', 'stack(a, d)', 'unstack(c, b)', 'stack(c, b)', 'unstack(c, b)']

INACTIVE REASON: Pruned in beam search
