84-Problem Solution.

Solution: 1. Kg4-h4! waiting
1. ... Bc6 ad lib [a] 2. Ba2(x)d5 [A] #
1. ... Sb5 ad lib 2. Rd1(x)d4#

Black king's surrounding squares are unoccupied, and the monarch is far from the board's edges, so we have here a position called mirror mate.