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Subject: Re: What constitutes a clone?

Author: Dann Corbit

Date: 17:35:48 02/15/05

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On February 15, 2005 at 20:28:47, Uri Blass wrote:

>On February 15, 2005 at 19:31:58, Dann Corbit wrote:
>
>>On February 15, 2005 at 18:38:43, John Merlino wrote:
>>
>>>I'm not trying to start a brutally long thread here, but I'm just curious about
>>>how people feel about a particularly touchy subject -- clones. What, in your
>>>mind, would lead you to the conclusion that an engine is a clone?
>>>
>>>Let's forget trying to find ways to PROVE that a clone is a clone; I'm just
>>>trying to define one. For the sake of argument, assume that the author of this
>>>engine in question tells you exactly what he did and did not do, and you must
>>>decide whether to call it a clone or not.
>>>
>>>Here are some hypothetical questions to start the debate:
>>>
>>>If the author took Crafty and completely rewrote the evaluation code and nothing
>>>else, would it be a clone?
>>
>>Yes.  If you violate the rules of the software agreement, it is clearly a clone.
>>
>>>How about if the author rewrote the evaluation code and search algorithm only,
>>>but left the hashing code, et. al.?
>>
>>Clone.
>>
>>>How about if the author rewrote everything EXCEPT for the evaluation?
>>
>>Clone.
>>
>>>How about if the author rewrote everything EXCEPT for Crafty's evaluation of
>>>passed pawns?
>>
>>Clone.
>>
>>>I think you can see where I'm driving. Obviously, many engine authors have
>>>studied Crafty and other engines whose authors have graciously provided their
>>>source code. But, for an engine to not be considered a clone, does it have to be
>>>absolutely 100% the work of the author? (Forget about Nalimov's EGTB probing
>>>code and any other code that can be used with permission).
>>>
>>>Many thanks in advance for your thoughts,
>>>
>>>jm (who's just preparing for any eventuality during his upcoming stint as
>>>moderator :-)
>>
>>If there is one single line of Crafty code used without permission or
>>acknowledgement then it is a clone.
>
>No
>There can be one single line even by accident.
>one line from Crafty's code is
>int      phase;
>
>You cannot blame every program that include this line to be a crafty clone.

That is true.  And the legal definition actually has some certain standard for
the number of lines that read exactly the same.  But I do not know what it is
exactly.

I meant that (in my opinion) if you borrow something, you must give credit, even
if you change it.  No matter how small the thing you borrowed was.

Now, if I should write a quicksort routine, and you should write a quicksort
routine, and everyone in here should write a quicksort routine, some of them
will be line by line identical because it is a simple algorithm.  Nobody cloned
anybody.

But if I write one and you look at it and type out the same thing, then that is
a clone.

I guess it boils down to right and wrong and credit where credit is due.

Just like academic stuff, what is plaguarism?  It is taking ideas without
permission -- or using almost all of a work and changing little teeny bits of it
and then calling it your own.

If I quote a sentence and give credit -- that's fair use.  I don't think the
author can prevent it even if he does not like me.  But if I use large passages
without permission or if I use even small passages and do not give credit then
clearly I have done something wrong.

It is just like that with software as well.

IMO-YMMV.

P.S.
I'm not a lawyer, so anything construed as legal advice here is worth exactly
what you paid for it.



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