Solving fairy proof games: “Jacobi” by François Labelle

Solving fairy proof games: “Jacobi” by François Labelle

Dear retro friends,

I would like to introduce “Jacobi”, a new program that can solve fairy proof games. The home page is at . The program is a web app that runs in your browser and requires no installation.

read more…

I hope that you find it useful! – François Labelle

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Juraj Lörinc
October 31, 2017 18:48

Great addition to the toolbox of fairy chess composers.

My Patrol chess PG in 14 from 1994 seems to be correct! 🙂

shankar ram
shankar ram
November 1, 2017 17:26

“Julia” is already taken…
There is a programming language with that name… 😉

François Labelle
François Labelle
November 1, 2017 20:14

I would like to draw attention to a feature that I added specially with Julia’s Fairies in mind. It is the output language “py2web format”. Julia probably prefers to receive solutions in this format since JF is using Py2Web to display diagrams and solutions.

If you see something like “{display-departure-file}” in the output, do not remove it! It is a Py2Web annotation that will disambiguate the algebraic notation.

One example of this is . Solving the Popeye code from Geoff’s comment in Jacobi gives

1.c7-c8=S 2.a7-a8=Q 3.Qa8-h1 4.Sc8-b6 5.Sb6-d7 6.Sd7-f8 7.g7-g8=R 8.Rg8-g6 9.Kh8-g8 10.h7-h8=B 11.Bh8-g7 12.Qh1-h8 13.Sf8-h7 14.Bg7-f8 15.Qa1-g7 {display-departure-file} 16.Rf5-f6 {display-departure-rank} 17.f4-f5 18.Bc1-h6 19.g4-g5 {==}

which is exactly what you would send to Julia. For problems that don’t work in Py2Web, Julia might prefer to receive “English-S” output. In case of doubt, send both.

Ladislav Packa
Ladislav Packa
November 19, 2017 09:33

Would it be possible to interrupt the solution and continue with it later?

François Labelle
François Labelle
November 19, 2017 17:14

Does the Pause/Resume button do what you want? You have to keep the window open though. One day I might add the ability to resume even after a reboot.

Paul Rãican
Paul Rãican
November 22, 2017 11:18

Meanwhile, the 0.2.2 version was launched. It has now Chess960 condition. For example, Tacu’s enigma 17222 (Die Schwalbe 287/2017) is tested in 3 seconds.

Victor Casas
Victor Casas
December 14, 2017 02:23

Es Jacobi un clon de Popeye?

Paul Rãican
Paul Rãican
January 13, 2018 15:30

The first 13 moves of P1109636 (Graefrath) tested by Jacobi in about 18 hours:
Done. Compute time = 64072.550 s
exact solutions (1)

1.h4 c6 2.h5 Qb6 3.h6 Qxf2 4.hxg7 Qxe1 5.gxh8=K Qxd1 6.Kxg8 Qxc1 7.Kxh7 Qxb1 8.Rxb1 Bh6 9.Kxh6 f5 10.Kh5 Kf7 11.Kh4 Ke6 12.Kg3 Kd5 13.Kf2 f4

Maybe somebody should completely verify. The last white move is 14.Ke1.

Paul Rãican
Paul Rãican
February 25, 2018 08:55

Nr.325 (PG11.5, Multicaptures, Rãican) is the first PG with this condition checked by Jacobi, version 0.3.1., in about 2 days.

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