[Retros] shortest proofgames of castling switchback

[Mario Richter]

Joost wrote:


> C+ for the first 17 moves. But white just has too many free moves, I 

> don't think it can be fully computertested.


It can be done (takes btw less than 3 seconds computer time - but
in the approach used, some minutes have to be added for 
preparing the computer input ), but not with the current 
versions of "Natch" and Co.

And yes - the verdict of my program was "Found one solution".

Regards,

  mario