[Retros] A new program to solve fairy proof games

François Labelle flab at wismuth.com
Sun Nov 5 01:36:48 EDT 2017

Hi Michel,

Thank you for the bug report.

Actually the bug has to do with castling and not en passant. A minimal 
example is

forsyth rsbqk2r/ppP1bppp/8/8/8/8/PPP1PPPP/RSBQKBSR
stip a=>b 1.0 forsyth rSbq1rk1/pp2bppp/8/8/8/8/PPP1PPPP/RSBQKBSR
cond Hypervolage

Jacobi v0.1 fails to see the solution 1.cxb8=S O-O.

This bug affects proof games with a condition where a piece can change 
color, so Andernach, AntiAndernach, Volage, Hypervolage, Masand, and 
Circe Turncoats. Such problems that were verified using Jacobi v0.1 
shouldn't be considered C+ because cooks with castling can be missed. 
The bug doesn't affect Tacu enigmas (proof games with only undefined 
pieces and ColorThePieces). The bug will be fixed in v0.2 which I think 
will be ready sometime this week. Sorry about the bug!


CAILLAUD Michel wrote:
> Hello,
> Going on testing version 0.1...
> Jacobi 0.1 doesn't solve PDB P1240567
> Guy Sobrecases dia5.5 r1bq1rk1/pp1sbppp/8/8/8/8/PPP1PPPP/RSBQKBSR 
> Hypervolage
> The reason obviously is that Jacobi 0.1 ignores en passant capture in 
> Hypervolage (Popeye and Winchloe play it).
> So, with this version, Jacobi cannot be used to test Hypervolage 
> problems (cooks with en passant can be missed).

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