Can you place two White rooks and a White knight on the board so that
the Black king (who must be on one of the four squares in the middle of
the board) shall be in check with no possible move open to him? "In
other words," the reader will say, "the king is to be shown checkmated."
Well, you can use the term if you wish, though I intentionally do not
employ it myself. The mere fact that there is no White king on the board
would be a sufficient reason for my not doing so.