(15.07.2013) A complicated chess problem with specific Circe Assassin and Proca Retractor effects by the romanian tandem Vlaicu Crisan and Paul Raican!

1.Sa6-c7! Ba8-b7+ 2.Kc2-b1  b7-b6+ 3.Kb2-c2 c7-c6+

4.Bc3xb4(b7, -bRb7) Ra7-b7+ 5.Bd4xc3(c7, -wPc7) c4-c3+

6.Kc2-b2 Bb7-a8+ 7.c6-c7 Bc8-b7+ 8.d5xBc6(Bc8, -wQc8)

& 1.Qg4+ Kxd5(d2)#

Mate with black King from distance, possible in Circe Assassin genre.

A complex and specific retro play. (Authors)

Circe Assassin: the captured unit reappear on its game-array square even if the rebirth square is occupied. And then the occupying unit disappears for good. (Hence a unit on its home square cannot be removed.)

Proca retractor: white retracts n moves to reach a position for a normal problem (usually a #1). White must retract a legal move, Black defends by retiring any move he wishes. If a capture is retracted, the capturer decides if and which piece was captured.