No. 173, October 1998
10156 - Peter Schäfer Die Schwalbe Heft 173, 10/1998
13+11. Retract one White move, then mate in five
10+15. Is Black lost? (b) wPa6 -> a5
11+12. Release the position
11+14. Release the position
15+12. Release the position
13+14. Release the position
16+13. Proof game in 19.5 moves
15+6. Proof game in 23.0 moves
4+5. (Martian Circe) Retract 5 moves and mate in 1 It is not important whether you assume Proca-retractor or Høeg-retractor since there is no uncapture in the solution.