Vas speaks

[mhull]

Having been brought up in the east end of London in the sixties I may be more adept at both dishing out and absorbing abuse than Graham........

I can assure you that I have developed a very tough skin Keith.

Would that you could answer fair questions instead of avoiding them by playing the martyr.

[PauloSoare]

Graham, I think that Vas should say that a year ago, before Zach discovered the similarities between Rybka and Fruit. He would have been more clear and perhaps avoided this whole mess.
The fact is that of Rybka 1 to 4, Vas showed his talents as a programmer.

[Graham Banks]

Graham, I think that Vas should say that a year ago, before Zach discovered the similarities between Rybka and Fruit. He would have been more clear and perhaps avoided this whole mess.
The fact is that of Rybka 1 to 4, Vas showed his talents as a programmer.

Hi Paulo,

I agree with you.
Let's hope that this mess can be cleared up soon, one way or the other. It's been going on way too long.

Cheers,
Graham.

[Jouni]

I personally think there is nothing wrong to use Fruit code, when it's available. I would even say You are stupid, if You don't use best possible
code to start with! But of course You should say it clearly when selling software. I find Vasik sayings a little conflicting as:

"The Rybka source code is original. I used lots of ideas from Fruit..."

vs

"all of the Rybka versions are original, in the sense that I always wrote the source code myself (with the standard exceptions like various low-level snippets, magic numbers)..."

Jouni

[IQ]

http://www.open-chess.org/viewtopic.php?f=3&t=1138

“Hi David,

I’m not really sure what to say. The Rybka source code is original. I used lots of ideas from Fruit, as I have mentioned many times. Both Fruit and Rybka also use all sorts of common computer chess ideas.

Aside from that, this document is horribly bogus. All that “Rybka code” isn’t Rybka code, it’s just someone’s imagination.

Best regards,
Vas”

And when I (David Levy) asked for clarification as to whether this response meant that the Rybka 1 source code was original, Vasik replied:

“all of the Rybka versions are original, in the sense that I always wrote the source code myself (with the standard exceptions like various low-level snippets, magic numbers, etc).”

Wow, up to know it was only known that Vas admitted to taking ideas. But this statement of his is telling, he basically admits to violating the GPL! If I read this correctly He admitted to taking "low level snippets" back in 2008. This could have spared us a whole lot of discussion here. If those snippets are from Fruit (or any other proram) he violated the GPL and/or copyright. THis closes the case - Vas admits to taking more than ideas. Thanks Graham for clarifying this.

Where do you read that Vas admits violating GPL?, as I surely don't see it. With regards to "snippes ..." I think he was referring to public domain code, and I don't think that he was admitting to violating anything. Unlike many here, I think quoting Vas is important just as hearing Fabien's point of view is also important. They are the two parties that are most involved in this issue, yet they both seem uncannily quiet about the issue.

Please do not be naive. The question was clearly ask in the context of fruit and fruit only. Specifically the interviewer pressed Vas to clarify his previous statement on exactly what he took from fruit. Only then Vas brings into play the "code snippets". That Vas suddenly talks totally out of context about some "public domain" program where he copied snippets from is wishful thinking on your part. Much more likely is that Vas would consider something like an UCI parser as a "low level snippet" - as proven by analysis of the binary. Another tell-sign is the inclusion of "except for the standard exceptions" - a typical qualifier to cover his bases. It might be common practice in Vas's mind, but more to the point this is called "plagiarism".
Also i find it pretty amazing that he puts Zaks report into the realm of "imagination". At least its a verifyable document, that allows everybody to check for themselves. I for one did a couple of samples using ida-pro and found it to be accurate.

[K I Hyams]

I personally think there is nothing wrong to use Fruit code, when it's available. I would even say You are stupid, if You don't use best possible
code to start with!

The whole point is that he may have used Fruit code for a purpose for which it wasn’t available. As a consequence, he may have misrepresented what he had done. In addition, he may have deprived Fabien of funds to which he was entitled. Some of us are not as sanguine as you appear to be about such behaviour.

I think that many of us should be grateful to Graham Banks, who performed a useful service by drawing our attention to the significant quote below.

But as I have mentioned, at first the Rybka-Fruit case was mere rumour. More recently, however, these rumours have become firm allegations, made by expert chess programmers and supported by evidence which appears on the surface to be rather compelling, both in its nature and in its volume

Perhaps we can accept that evidence “which appears on the surface to be rather compelling, both in its nature and in its volume. ”, together with the fact that Fruit was protected code (which is not in dispute) as a starting point.

If we do, then as Rajlich released Rybka 1 midway through the period during which Fabien was selling Fruit commercially, money that would otherwise have been spent on Fruit will have been spent on Rybka instead. Money that should have gone into Fabien’s pocket, went into Rajlich’s pocket instead.

Some might take the view that, if Rajlich used Fabien’s protected code, he first stole his property and then used that stolen property to steal his income.

It appears that Fabien Letouzey is a man without a sense of humour; his recent actions indicate that he doesn’t find the irony that may reside in the case to be funny. Either way, from the comments that Bob has made, his initial interest in the case has not gone away. In other words, he appears to have found enough substance in the allegations to justify a thorough investigation.

[Tom Barrister]

Perhaps you have posted to the wrong person. I agree with your comments and I have already made a similar point in a post to Ansari.

I didn't know that I posted to anybody in particular. Mine was the next post after yours. I haven't found a way to reply, other than clicking the reply button in somebody's post, and yours was the closest one.

[K I Hyams]

Perhaps you have posted to the wrong person. I agree with your comments and I have already made a similar point in a post to Ansari.

I didn't know that I posted to anybody in particular. Mine was the next post after yours. I haven't found a way to reply, other than clicking the reply button in somebody's post, and yours was the closest one.

You were making the point that the significance of the contents of Graham’s post were unclear. Had I wanted to make that point, I would have wanted to address it to Graham specifically.

I always operate in “thread view” and using that, your post appears directly below mine with one indentation, implying that you were replying to me. I have never posted from “flat view” and so I don’t know how the system works there. However, in thread view and had I wanted to post to Graham, I would have opened Graham’s post and inside that post, clicked on either “reply” or “quote”. I would then expect my reply to appear, in thread view, below Graham’s post, with one indentation from it.

[Uri Blass]

David quotes this email fro Vas:

'Hi David,
I'm not really sure what to say. The Rybka source code is original. I used lots
of ideas from Fruit, as I have mentioned many times. Both Fruit and Rybka also
use all sorts of common computer chess ideas.
Aside from that, this document is horribly bogus. All that "Rybka code" isn't
Rybka code, it's just someone's imagination.
Best regards,
Vas”

The thing is Zach is not really making an argument that source code was directly copied. He is arguing that evaluation function ideas and values were taken. Vas does not seem to address this. I know if someone attacked me claiming my work was copied, I would do a lot more than simply deny it. I would give specific examples, just like Zach did.

There is nothing wrong with taking evaluation function ideas if it is not code.

Engine developers may know that fruit is using mobility function based on the number of squares that a piece can move into them and they also know that fruit use bigger numbers for bishop and knights and smaller numbers for rooks and queens.

Does it mean that they are not allowed to do the same only because these ideas are in fruit?

If we talk about the claim that values are taken then there is a positive probability that some values are going to be identical or almost the same if you use the same idea even if you do not remember the exact values.

[M ANSARI]

I personally think there is nothing wrong to use Fruit code, when it's available. I would even say You are stupid, if You don't use best possible
code to start with!

The whole point is that he may have used Fruit code for a purpose for which it wasn’t available. As a consequence, he may have misrepresented what he had done. In addition, he may have deprived Fabien of funds to which he was entitled. Some of us are not as sanguine as you appear to be about such behaviour.

I think that many of us should be grateful to Graham Banks, who performed a useful service by drawing our attention to the significant quote below.

But as I have mentioned, at first the Rybka-Fruit case was mere rumour. More recently, however, these rumours have become firm allegations, made by expert chess programmers and supported by evidence which appears on the surface to be rather compelling, both in its nature and in its volume

Perhaps we can accept that evidence “which appears on the surface to be rather compelling, both in its nature and in its volume. ”, together with the fact that Fruit was protected code (which is not in dispute) as a starting point.

If we do, then as Rajlich released Rybka 1 midway through the period during which Fabien was selling Fruit commercially, money that would otherwise have been spent on Fruit will have been spent on Rybka instead. Money that should have gone into Fabien’s pocket, went into Rajlich’s pocket instead.

Some might take the view that, if Rajlich used Fabien’s protected code, he first stole his property and then used that stolen property to steal his income.

It appears that Fabien Letouzey is a man without a sense of humour; his recent actions indicate that he doesn’t find the irony that may reside in the case to be funny. Either way, from the comments that Bob has made, his initial interest in the case has not gone away. In other words, he appears to have found enough substance in the allegations to justify a thorough investigation.

I think you are wrong in thinking that Fabien lost income even if Rybka turns out to have a GPL violation. Fabien was never in it for the money and the only requirement would be that if his code was used, that the source code of the new engine should be open ... nothing financial there. You could argue that Fabien was looking for financial compensation with Fruit 2.1 ... but that was done after the free source code of the earlier Fruit was published and there is no evidence that Vas used sources from disassembled closed source Fruit.

In the end it all comes down to whether the way that Vas used ideas from open source Fruit was legal or illegal. I think Vas made it pretty clear from his release notes in Rybka 1.0 beta that he went through open Fruit source code throughly, as well as through Crafty and other open source programs. You reach a point where some legal authority has to decide what constitutes a GPL violation ... does it have to be a verbatim copy to be a violation? Or is a re-write after getting ideas from the open source program, enough to circumvent the GPL requirements. To be honest I really don't know where the line is drawn, and I would guess that most people posting here also don't know. Of course everyone has his own opinion, and that seems to be different even among programmers. But in the end it would be good if an official legal entity would look into this case and decide either way. Hopefully if that happens, everyone would accept it as final and carry on ... but somehow I doubt that will happen.