In the initial position White "threatens mate" (set play in one move). Black avoids this mate and after his first move White "threatens" the same mate again. Black is again obliged to avoid it and eventually a different mate occurs.
See also: Apparent mate; Garai theme; Bukovinszky-Garai theme.
Korponai, József
Problem, TT-33, 1961 (v)
1st Prize
1...Sde3#
1.fxe5
Bb6
2.e4
Sce3#
1.fxe5 Bb6 2.?? Sde3#