+-+-+-+-+-+-+-+-+
| | | | | | | | |
+-+-+-+-+-+-+-+-+
| | |R|k|R|N| | |
+-+-+-+-+-+-+-+-+
| | | | | | | | |
+-+-+-+-+-+-+-+-+
If you place the pieces as follows (where only a portion of the board is
given, to save space), the Black king is in check, with no possible move
open to him. The reader will now see why I avoided the term "checkmate,"
apart from the fact that there is no White king. The position is
impossible in the game of chess, because Black could not be given check
by both rooks at the same time, nor could he have moved into check on
his last move.