We must ensure, before closing a UR, it really not be solved. If there is any information (including a turn forbidden without any additional message) in the UR may be sufficient to resolve it, so do not close before checking.
We must ensure, before closing a UR, it really not be solved. If there is any information (including a turn forbidden without any additional message) in the UR may be sufficient to resolve it, so do not close before checking.