[Retros] "half" proof games

[Noam Elkies]

<Nicolas.Dupont at math.univ-lille1.fr> writes:


> Noam's first example :



> 1 f3 ... 2 Kf2 ... 3 Ke3 ...#



> is clearly right. But his second one :



> 1 f3 ... 2 g4 ... 3 fxe4 ...#



> is dualistic (on the white side).


Again, there was no requirement that the White move-order be unique.


> I would be very surprised if  "f3 Kf2 Ke3" is not the unique solution

> in 3.


Even with the extra hypothesis

1 d4 ... 2 Kd2 ... 3 Kd3 ...#

seems to work.

NDE