> [Checker] 2 actors remain, but none of them need to be interleaved (depth 3).
> [Checker] Backtracking from 2
> [Checker] DFS exploration ended. 6 unique states visited; 1 backtracks (0 transition replays, 7 states visited overall)
> [Checker] 2 actors remain, but none of them need to be interleaved (depth 3).
> [Checker] Backtracking from 2
> [Checker] DFS exploration ended. 6 unique states visited; 1 backtracks (0 transition replays, 7 states visited overall)