ok, well let's see the two blocks of code from Fruit and Rybkabob wrote:And when shown that the blocks of code are identical between two programs, and when expert witnesses testify that this is not just an improbable event, but an event of such rarity that one would be as likely to accept that a monkey typed one of them, he might begin go to "hmmm..."chrisw wrote:Your honour will tell you he doesn't understand a word you're talking about. He will ask you how that piece of text demonstrates an equivalence between Fruit and Rybka.bob wrote:I would say "look here, your honor:"
http://www.talkchess.com/forum/viewtopi ... 67&t=23118
He'll say, yes, he knows he is not a programmer, but he can see that you have presented him with part of a computer program written with strange words. He'll say, where in the other program do these same strange words appear in the same order and in length. Then he'll ask the other side what they have to say.
There _might_ be a valid explanation. But in the absence of anything, the evidence defies explanation by just "random chance of two programmers coming up with the same code." We are not used to seeing duplication in 100 line programs, much less in programs of the complexity of computer chess. I suppose one could try a diff between pairs of open source programs and see how frequently you find one line, two consecutive lines, ..., N consecutive lines that are the same. For it to happen between these two specific examples, there must be _several_ other programs that would show some sort of significant match between pairs of them.
Of course that won't quite catch all copies since diff is unaware of equivalent names and equivalent expressions which are different syntactically (a=b+c opposed to a=c+b or a+=b; a+= c or any of a dozen other ways to do the same thing.
The only issue I have with any of this is that some want to say "this is just luck". I say "crapola to the luck idea". And I base that on grading assignments from 1970 to date, from programs that are only 30 lines or so long, to programs that are thousands of lines long. I remember worrying about this in a numerical analysis class I taught for the first time. We were looking at all sorts of traditional numerical analysis, and one example was the "Crout method" for solving systems of equations. As an UG, I wrote this in about 14 lines of code, total. Typical student was about 30 lines. I was afraid that given a specific algorithm, that the programs would be near copies. Wrong. No two were anywhere near "copies". And that has repeated in every course I have taken. If I were to ask a group of chess programmers to carefully and clearly explain SEE, no code, just an explanation anyone could use to write a piece of code, no two people would produce anywhere near the same text, although all would likely get most of the relevant explanation in. They would likely vary in which pieces to include (include pinned pieces or not, overloaded pieces or not, pieces behind pieces or not, etc). If, for something that simple, we can't get a high level of duplication, how will we do so in something as complex as a chess program?
Rybka 1.0 vs. Strelka
Moderator: Ras
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chrisw
Re: Wanted: some opposition to the provided evidence
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Rolf
- Posts: 6081
- Joined: Fri Mar 10, 2006 11:14 pm
- Location: Munster, Nuremberg, Princeton
Re: Wanted: some opposition to the provided evidence
chrisw wrote:ok, well let's see the two blocks of code from Fruit and Rybkabob wrote:And when shown that the blocks of code are identical between two programs, and when expert witnesses testify that this is not just an improbable event, but an event of such rarity that one would be as likely to accept that a monkey typed one of them, he might begin go to "hmmm..."chrisw wrote:Your honour will tell you he doesn't understand a word you're talking about. He will ask you how that piece of text demonstrates an equivalence between Fruit and Rybka.bob wrote:I would say "look here, your honor:"
http://www.talkchess.com/forum/viewtopi ... 67&t=23118
He'll say, yes, he knows he is not a programmer, but he can see that you have presented him with part of a computer program written with strange words. He'll say, where in the other program do these same strange words appear in the same order and in length. Then he'll ask the other side what they have to say.
There _might_ be a valid explanation. But in the absence of anything, the evidence defies explanation by just "random chance of two programmers coming up with the same code." We are not used to seeing duplication in 100 line programs, much less in programs of the complexity of computer chess. I suppose one could try a diff between pairs of open source programs and see how frequently you find one line, two consecutive lines, ..., N consecutive lines that are the same. For it to happen between these two specific examples, there must be _several_ other programs that would show some sort of significant match between pairs of them.
Of course that won't quite catch all copies since diff is unaware of equivalent names and equivalent expressions which are different syntactically (a=b+c opposed to a=c+b or a+=b; a+= c or any of a dozen other ways to do the same thing.
The only issue I have with any of this is that some want to say "this is just luck". I say "crapola to the luck idea". And I base that on grading assignments from 1970 to date, from programs that are only 30 lines or so long, to programs that are thousands of lines long. I remember worrying about this in a numerical analysis class I taught for the first time. We were looking at all sorts of traditional numerical analysis, and one example was the "Crout method" for solving systems of equations. As an UG, I wrote this in about 14 lines of code, total. Typical student was about 30 lines. I was afraid that given a specific algorithm, that the programs would be near copies. Wrong. No two were anywhere near "copies". And that has repeated in every course I have taken. If I were to ask a group of chess programmers to carefully and clearly explain SEE, no code, just an explanation anyone could use to write a piece of code, no two people would produce anywhere near the same text, although all would likely get most of the relevant explanation in. They would likely vary in which pieces to include (include pinned pieces or not, overloaded pieces or not, pieces behind pieces or not, etc). If, for something that simple, we can't get a high level of duplication, how will we do so in something as complex as a chess program?
Look, how Bob is now running hot in his campaign. Funny, but I thought it all the time. This isnt science what Bob is showing. It's like his absolution of the mean IBM fraud (from science position) against Kasparov.
-Popper and Lakatos are good but I'm stuck on Leibowitz
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mclane
- Posts: 18893
- Joined: Thu Mar 09, 2006 6:40 pm
- Location: US of Europe, germany
- Full name: Thorsten Czub
Re: Wanted: some opposition to the provided evidence
yes rolf. its an international conspiracy. and you are the one who can look through. you - without any programming skill, you tell us the top secret,Rolf wrote: Look, how Bob is now running hot in his campaign. Funny, but I thought it all the time. This isnt science what Bob is showing. It's like his absolution of the mean IBM fraud (from science position) against Kasparov.
evaluate our positions and help us through the nights.
messias.
what do you want us to do ?
shall we wear white clothes ?
shall we pray with you, the pope, for your grace to help us in the dilemma.
shall we all take hand by hand and feel free ?
hosianna. hosianna.
what a mean campaign this is.
and how holy your holyness.
let us fall on the floor and pray 10 ave marias.
amazing grace, how sweet our lord.
exactly.This isnt science what Bob is showing
its the way you say it.
YOU know the truth my lord.
you give us light and future, you make the flowers grow and the sun go up and down.
you are the master of our joy.
here is a meeting of the conspiracy-club that tried to fool you:
there they sat and planned to fool our gracious Lord Rolf.
and he was so strong to look through.
no. its a believe. a believe in evil.This isnt science what Bob is showing
only you pope rolf know the truth. and can you help us my lord ?
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Terry McCracken
- Posts: 16465
- Joined: Wed Aug 01, 2007 4:16 am
- Location: Canada
Re: Rybka 1.0 vs. Strelka
Don't you know?chrisw wrote:Terry,Terry McCracken wrote:Maybe not Bob...it gets lost fairly quickly.Zach Wegner wrote:The topic came up in another thread about the issue of comparing Strelka to Fruit vs. comparing Rybka 1.0 to Fruit. I am doing some disassembling of Rybka 1.0, so I will post the assembly that is equivalent to the last piece of code I had in Fruit. Just to let you know, this is by no means complete. I have filled in most of the function names and some of the variable names, but there is a lot left to do. This is just the result of a few day's work, more will come later.
The interesting thing that I found is that for this piece of code, Rybka 1.0 is more similar to Fruit than Strelka. Here are the differences:Code: Select all
.text:0040BCA0 start_search proc near ; CODE XREF: start_go+35F p .text:0040BCA0 .text:0040BCA0 var_44C = dword ptr -44Ch .text:0040BCA0 var_440 = dword ptr -440h .text:0040BCA0 undo = dword ptr -40h .text:0040BCA0 var_8 = dword ptr -8 .text:0040BCA0 num_moves = dword ptr -4 .text:0040BCA0 .text:0040BCA0 push ebp .text:0040BCA1 mov ebp, esp .text:0040BCA3 sub esp, 440h .text:0040BCA9 push ebx .text:0040BCAA push esi .text:0040BCAB push edi .text:0040BCAC push offset dword_669C60 .text:0040BCB1 mov dword_667A0C, -500 .text:0040BCBB mov dword_667A10, 500 .text:0040BCC5 call evaluate .text:0040BCCA add esp, 4 .text:0040BCCD test al, al .text:0040BCCF jz short loc_40BD25 .text:0040BCD1 mov ecx, dword_669C6C .text:0040BCD7 mov eax, dword_669C68 .text:0040BCDC not ecx .text:0040BCDE push ecx .text:0040BCDF not eax .text:0040BCE1 push eax .text:0040BCE2 push offset list_root .text:0040BCE7 call gen_evasions .text:0040BCEC mov ecx, list_root .text:0040BCF2 add esp, 12 .text:0040BCF5 xor eax, eax .text:0040BCF7 test ecx, ecx .text:0040BCF9 jz short loc_40BD15 .text:0040BCFB jmp short loc_40BD00 .text:0040BCFB ; --------------------------------------------------------------------------- .text:0040BCFD align 10h .text:0040BD00 .text:0040BD00 loc_40BD00: ; CODE XREF: start_search+5B j .text:0040BD00 ; start_search+73 j .text:0040BD00 mov list_root[eax*4], ecx .text:0040BD07 mov ecx, dword_66BC78[eax*8] .text:0040BD0E add eax, 1 .text:0040BD11 test ecx, ecx .text:0040BD13 jnz short loc_40BD00 .text:0040BD15 .text:0040BD15 loc_40BD15: ; CODE XREF: start_search+59 j .text:0040BD15 mov list_root[eax*4], 0 .text:0040BD20 jmp loc_40BDC2 .text:0040BD25 ; --------------------------------------------------------------------------- .text:0040BD25 .text:0040BD25 loc_40BD25: ; CODE XREF: start_search+2F j .text:0040BD25 mov edx, dword_667B9C .text:0040BD2B mov eax, dword_667B98 .text:0040BD30 mov ecx, dword_667B94 .text:0040BD36 push edx .text:0040BD37 mov edx, dword_667B90 .text:0040BD3D push eax .text:0040BD3E push ecx .text:0040BD3F push edx .text:0040BD40 push offset dword_66C070 .text:0040BD45 mov eax, offset list_root .text:0040BD4A call gen_captures .text:0040BD4F xor esi, esi .text:0040BD51 add esp, 20 .text:0040BD54 cmp list_root, esi .text:0040BD5A jz short loc_40BD6D .text:0040BD5C lea esp, [esp+0] .text:0040BD60 .text:0040BD60 loc_40BD60: ; CODE XREF: start_search+CB j .text:0040BD60 add esi, 1 .text:0040BD63 cmp list_root[esi*4], 0 .text:0040BD6B jnz short loc_40BD60 .text:0040BD6D .text:0040BD6D loc_40BD6D: ; CODE XREF: start_search+BA j .text:0040BD6D mov eax, dword_669C6C .text:0040BD72 mov ecx, dword_669C68 .text:0040BD78 push -1 .text:0040BD7A push -1 .text:0040BD7C push -1 .text:0040BD7E push eax .text:0040BD7F push ecx .text:0040BD80 lea edx, [ebp+var_440] .text:0040BD86 push edx .text:0040BD87 call gen_quiet_moves .text:0040BD8C mov eax, [ebp+var_440] .text:0040BD92 add esp, 24 .text:0040BD95 xor ecx, ecx .text:0040BD97 test eax, eax .text:0040BD99 jz short loc_40BDB5 .text:0040BD9B lea edx, ds:66BC70h[esi*4] .text:0040BDA2 .text:0040BDA2 loc_40BDA2: ; CODE XREF: start_search+113 j .text:0040BDA2 add ecx, 1 .text:0040BDA5 mov [edx], eax .text:0040BDA7 mov eax, [ebp+ecx*4+var_440] .text:0040BDAE add edx, 4 .text:0040BDB1 test eax, eax .text:0040BDB3 jnz short loc_40BDA2 .text:0040BDB5 .text:0040BDB5 loc_40BDB5: ; CODE XREF: start_search+F9 j .text:0040BDB5 add ecx, esi .text:0040BDB7 mov list_root[ecx*4], 0 .text:0040BDC2 .text:0040BDC2 loc_40BDC2: ; CODE XREF: start_search+80 j .text:0040BDC2 mov esi, list_root .text:0040BDC8 xor edi, edi .text:0040BDCA test esi, esi .text:0040BDCC mov [ebp+num_moves], edi .text:0040BDCF jz short loc_40BE4C .text:0040BDD1 mov [ebp+num_moves], offset list_root .text:0040BDD8 .text:0040BDD8 loc_40BDD8: ; CODE XREF: start_search+1A7 j .text:0040BDD8 lea eax, [ebp+undo] .text:0040BDDB push eax .text:0040BDDC push esi .text:0040BDDD call make_move .text:0040BDE2 push offset pos_info_entry .text:0040BDE7 call evaluate .text:0040BDEC mov ecx, dword_667C20 .text:0040BDF2 lea edx, ds:0[ecx*8] .text:0040BDF9 mov ecx, offset dword_667BF8 .text:0040BDFE sub ecx, edx .text:0040BE00 mov eax, [ecx] .text:0040BE02 mov ecx, [ecx+4] .text:0040BE05 and eax, pos_info_entry .text:0040BE0B and ecx, dword_669C84 .text:0040BE11 add esp, 0Ch .text:0040BE14 or eax, ecx .text:0040BE16 jnz short loc_40BE1C .text:0040BE18 mov bl, 1 .text:0040BE1A jmp short loc_40BE1E .text:0040BE1C ; --------------------------------------------------------------------------- .text:0040BE1C .text:0040BE1C loc_40BE1C: ; CODE XREF: start_search+176 j .text:0040BE1C xor bl, bl .text:0040BE1E .text:0040BE1E loc_40BE1E: ; CODE XREF: start_search+17A j .text:0040BE1E lea eax, [ebp+undo] .text:0040BE21 push eax .text:0040BE22 push esi .text:0040BE23 call unmake_move .text:0040BE28 add esp, 8 .text:0040BE2B test bl, bl .text:0040BE2D jz short loc_40BE39 .text:0040BE2F mov list_root[edi*4], esi .text:0040BE36 add edi, 1 ; num_moves++ .text:0040BE39 .text:0040BE39 loc_40BE39: ; CODE XREF: start_search+18D j .text:0040BE39 mov eax, [ebp+num_moves] .text:0040BE3C mov esi, [eax+4] .text:0040BE3F add eax, 4 ; i++ .text:0040BE42 test esi, esi ; list_root[i].move!=0 .text:0040BE44 mov [ebp+num_moves], eax .text:0040BE47 jnz short loc_40BDD8 .text:0040BE49 mov [ebp+num_moves], edi .text:0040BE4C .text:0040BE4C loc_40BE4C: ; CODE XREF: start_search+12F j .text:0040BE4C xor esi, esi .text:0040BE4E cmp edi, 1 ; if (num_moves <= 1) .text:0040BE51 mov list_root[edi*4], esi ; list_root[num_moves].move = 0 .text:0040BE58 ja short loc_40BE64 .text:0040BE5A mov G_max_depth, 4 ; max_depth = 4; .text:0040BE64 .text:0040BE64 loc_40BE64: ; CODE XREF: start_search+1B8 j .text:0040BE64 push esi .text:0040BE65 push offset dword_667A28 .text:0040BE6A call setjmp .text:0040BE6F add esp, 8 .text:0040BE72 test eax, eax ; if (setjmp(jmp_buffer) != 0) return; .text:0040BE74 jz short loc_40BE87 .text:0040BE76 mov eax, offset byte_664E08 .text:0040BE7B call sub_4092E0 .text:0040BE80 pop edi .text:0040BE81 pop esi .text:0040BE82 pop ebx .text:0040BE83 mov esp, ebp .text:0040BE85 pop ebp .text:0040BE86 retn .text:0040BE87 ; --------------------------------------------------------------------------- .text:0040BE87 .text:0040BE87 loc_40BE87: ; CODE XREF: start_search+1D4 j .text:0040BE87 call ds:GetTickCount ; start_timer .text:0040BE8D mov start_time, eax .text:0040BE92 mov eax, dword_66C490 .text:0040BE97 add eax, 1 ; All of this stuff is trans_inc_date .text:0040BE9A and eax, 3 .text:0040BE9D mov ecx, eax .text:0040BE9F cmp ecx, esi .text:0040BEA1 mov dword_66C490, eax .text:0040BEA6 jge short loc_40BEAB .text:0040BEA8 add ecx, 4 .text:0040BEAB .text:0040BEAB loc_40BEAB: ; CODE XREF: start_search+206 j .text:0040BEAB add ecx, 1 .text:0040BEAE shl ecx, 8 .text:0040BEB1 mov dword_66C498, ecx .text:0040BEB7 lea ecx, [eax-1] .text:0040BEBA cmp ecx, esi .text:0040BEBC jge short loc_40BEC1 .text:0040BEBE add ecx, 4 .text:0040BEC1 .text:0040BEC1 loc_40BEC1: ; CODE XREF: start_search+21C j .text:0040BEC1 add ecx, 1 .text:0040BEC4 shl ecx, 8 .text:0040BEC7 mov dword_66C49C, ecx .text:0040BECD lea ecx, [eax-2] .text:0040BED0 cmp ecx, esi .text:0040BED2 jge short loc_40BED7 .text:0040BED4 add ecx, 4 .text:0040BED7 .text:0040BED7 loc_40BED7: ; CODE XREF: start_search+232 j .text:0040BED7 add ecx, 1 .text:0040BEDA shl ecx, 8 .text:0040BEDD add eax, -3 .text:0040BEE0 cmp eax, esi .text:0040BEE2 mov dword_66C4A0, ecx .text:0040BEE8 jge short loc_40BEED .text:0040BEEA add eax, 4 .text:0040BEED .text:0040BEED loc_40BEED: ; CODE XREF: start_search+248 j .text:0040BEED add eax, 1 .text:0040BEF0 shl eax, 8 .text:0040BEF3 mov dword_66C4A4, eax .text:0040BEF8 xor eax, eax .text:0040BEFA lea ebx, [ebx+0] .text:0040BF00 .text:0040BF00 loc_40BF00: ; CODE XREF: start_search+274 j .text:0040BF00 mov killer1[eax], esi ; (Pos_info + i)->killer1 = 0; .text:0040BF06 mov killer2[eax], esi ; (Pos_info + i)->killer2 = 0; .text:0040BF0C add eax, 32 .text:0040BF0F cmp eax, 8192 .text:0040BF14 jb short loc_40BF00 .text:0040BF16 mov eax, 256 .text:0040BF1B mov ecx, 768 .text:0040BF20 mov edi, offset History .text:0040BF25 rep stosd ; memset(History, 256, 12 * 64 * sizeof(int)); .text:0040BF27 mov eax, dword_667C40 .text:0040BF2C and eax, dword_66C488 .text:0040BF32 mov ecx, dword_667C44 .text:0040BF38 shl eax, 4 .text:0040BF3B add eax, dword_66C480 .text:0040BF41 cmp [eax], ecx .text:0040BF43 jnz short loc_40BF4F .text:0040BF45 movzx edx, word ptr [eax+4] .text:0040BF49 mov dword_66C478, edx .text:0040BF4F .text:0040BF4F loc_40BF4F: ; CODE XREF: start_search+2A3 j .text:0040BF4F cmp [eax+10h], ecx .text:0040BF52 jnz short loc_40BF5E .text:0040BF54 movzx edx, word ptr [eax+14h] .text:0040BF58 mov dword_66C478, edx .text:0040BF5E .text:0040BF5E loc_40BF5E: ; CODE XREF: start_search+2B2 j .text:0040BF5E cmp [eax+20h], ecx .text:0040BF61 jnz short loc_40BF6D .text:0040BF63 movzx edx, word ptr [eax+24h] .text:0040BF67 mov dword_66C478, edx .text:0040BF6D .text:0040BF6D loc_40BF6D: ; CODE XREF: start_search+2C1 j .text:0040BF6D cmp [eax+30h], ecx .text:0040BF70 jnz short loc_40BF7B .text:0040BF72 movzx eax, word ptr [eax+34h] .text:0040BF76 mov dword_66C478, eax .text:0040BF7B .text:0040BF7B loc_40BF7B: ; CODE XREF: start_search+2D0 j .text:0040BF7B mov eax, [ebp+num_moves] .text:0040BF7E cmp eax, 2 .text:0040BF81 jb loc_40C039 .text:0040BF87 add eax, -1 .text:0040BF8A mov [ebp+var_8], eax .text:0040BF8D js loc_40C039 .text:0040BF93 .text:0040BF93 loc_40BF93: ; CODE XREF: start_search+393 j .text:0040BF93 lea ebx, ds:0[eax*4] .text:0040BF9A mov edi, list_root[ebx] .text:0040BFA0 cmp edi, dword_66C478 .text:0040BFA6 lea edx, dword_66C074[ebx] .text:0040BFAC jnz short loc_40BFB5 .text:0040BFAE mov ecx, 7FFFFFFFh .text:0040BFB3 jmp short loc_40BFE1 .text:0040BFB5 ; --------------------------------------------------------------------------- .text:0040BFB5 .text:0040BFB5 loc_40BFB5: ; CODE XREF: start_search+30C j .text:0040BFB5 mov ecx, edi .text:0040BFB7 and ecx, 63 .text:0040BFBA mov ecx, dword_667A90[ecx*4] .text:0040BFC1 test ecx, ecx .text:0040BFC3 jz short loc_40BFDF .text:0040BFC5 mov esi, edi .text:0040BFC7 shr esi, 6 .text:0040BFCA and esi, 63 .text:0040BFCD shl ecx, 4 .text:0040BFD0 sub ecx, dword_667A90[esi*4] .text:0040BFD7 add ecx, 2147483391 .text:0040BFDD jmp short loc_40BFE1 .text:0040BFDF ; --------------------------------------------------------------------------- .text:0040BFDF .text:0040BFDF loc_40BFDF: ; CODE XREF: start_search+323 j .text:0040BFDF xor ecx, ecx .text:0040BFE1 .text:0040BFE1 loc_40BFE1: ; CODE XREF: start_search+313 j .text:0040BFE1 ; start_search+33D j .text:0040BFE1 cmp ecx, [edx] .text:0040BFE3 mov esi, eax .text:0040BFE5 jnb short loc_40C01F .text:0040BFE7 mov eax, ebx .text:0040BFE9 lea esp, [esp+0] .text:0040BFF0 .text:0040BFF0 loc_40BFF0: ; CODE XREF: start_search+37A j .text:0040BFF0 mov ebx, dword_66BC74[eax] .text:0040BFF6 mov edx, [edx] .text:0040BFF8 mov list_root[eax], ebx .text:0040BFFE mov dword_66C070[eax], edx .text:0040C004 add esi, 1 .text:0040C007 lea eax, ds:0[esi*4] .text:0040C00E cmp ecx, dword_66C074[eax] .text:0040C014 lea edx, dword_66C074[eax] .text:0040C01A jb short loc_40BFF0 .text:0040C01C mov eax, [ebp+var_8] .text:0040C01F .text:0040C01F loc_40C01F: ; CODE XREF: start_search+345 j .text:0040C01F sub eax, 1 .text:0040C022 mov list_root[esi*4], edi .text:0040C029 mov dword_66C070[esi*4], ecx .text:0040C030 mov [ebp+var_8], eax .text:0040C033 jns loc_40BF93 .text:0040C039 .text:0040C039 loc_40C039: ; CODE XREF: start_search+2E1 j .text:0040C039 ; start_search+2ED j
--Setjmp is called after the move generation, as in Fruit
--Something very strange: whereas in Strelka a failed setjmp call simply results in a return, in Rybka 1.0 it involves a function call, like in Fruit (there it is search_update_current()). The weird part is, it appears to be calling parse_position(). That is what the "call sub_4092E0" is for. Why would Rybka 1.0 be parsing the position after a setjmp call?
--The timer is started after the setjmp call
--depth is limited to 4 when there's only 1 legal move (commented out in Strelka, as noted in the other thread).
--I noted earlier that the history initialization was different. Strelka and Rybka 1.0 are the same here, using memset(History, 256, 12 * 64 * sizeof(int)); But what I didn't notice is, 256 is out of range for an unsigned char. So that code is the same as Fruit's memset(History, 0, 12 * 64 * sizeof(int)); Why would Rybka 1.0 have 256? Is it the optimizer gone wild, or a deliberate attempt at obfuscation?
Can you explain how the above material demonstrates an equivalence between Rybka and Fruit?
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Terry McCracken
- Posts: 16465
- Joined: Wed Aug 01, 2007 4:16 am
- Location: Canada
Re: Rybka 1.0 vs. Strelka
No, it's a terrible question and it has already been answered at length!Graham Banks wrote:Good question. Terry?chrisw wrote:Terry,Terry McCracken wrote:Maybe not Bob...it gets lost fairly quickly.Zach Wegner wrote:The topic came up in another thread about the issue of comparing Strelka to Fruit vs. comparing Rybka 1.0 to Fruit. I am doing some disassembling of Rybka 1.0, so I will post the assembly that is equivalent to the last piece of code I had in Fruit. Just to let you know, this is by no means complete. I have filled in most of the function names and some of the variable names, but there is a lot left to do. This is just the result of a few day's work, more will come later.
The interesting thing that I found is that for this piece of code, Rybka 1.0 is more similar to Fruit than Strelka. Here are the differences:Code: Select all
.text:0040BCA0 start_search proc near ; CODE XREF: start_go+35F p .text:0040BCA0 .text:0040BCA0 var_44C = dword ptr -44Ch .text:0040BCA0 var_440 = dword ptr -440h .text:0040BCA0 undo = dword ptr -40h .text:0040BCA0 var_8 = dword ptr -8 .text:0040BCA0 num_moves = dword ptr -4 .text:0040BCA0 .text:0040BCA0 push ebp .text:0040BCA1 mov ebp, esp .text:0040BCA3 sub esp, 440h .text:0040BCA9 push ebx .text:0040BCAA push esi .text:0040BCAB push edi .text:0040BCAC push offset dword_669C60 .text:0040BCB1 mov dword_667A0C, -500 .text:0040BCBB mov dword_667A10, 500 .text:0040BCC5 call evaluate .text:0040BCCA add esp, 4 .text:0040BCCD test al, al .text:0040BCCF jz short loc_40BD25 .text:0040BCD1 mov ecx, dword_669C6C .text:0040BCD7 mov eax, dword_669C68 .text:0040BCDC not ecx .text:0040BCDE push ecx .text:0040BCDF not eax .text:0040BCE1 push eax .text:0040BCE2 push offset list_root .text:0040BCE7 call gen_evasions .text:0040BCEC mov ecx, list_root .text:0040BCF2 add esp, 12 .text:0040BCF5 xor eax, eax .text:0040BCF7 test ecx, ecx .text:0040BCF9 jz short loc_40BD15 .text:0040BCFB jmp short loc_40BD00 .text:0040BCFB ; --------------------------------------------------------------------------- .text:0040BCFD align 10h .text:0040BD00 .text:0040BD00 loc_40BD00: ; CODE XREF: start_search+5B j .text:0040BD00 ; start_search+73 j .text:0040BD00 mov list_root[eax*4], ecx .text:0040BD07 mov ecx, dword_66BC78[eax*8] .text:0040BD0E add eax, 1 .text:0040BD11 test ecx, ecx .text:0040BD13 jnz short loc_40BD00 .text:0040BD15 .text:0040BD15 loc_40BD15: ; CODE XREF: start_search+59 j .text:0040BD15 mov list_root[eax*4], 0 .text:0040BD20 jmp loc_40BDC2 .text:0040BD25 ; --------------------------------------------------------------------------- .text:0040BD25 .text:0040BD25 loc_40BD25: ; CODE XREF: start_search+2F j .text:0040BD25 mov edx, dword_667B9C .text:0040BD2B mov eax, dword_667B98 .text:0040BD30 mov ecx, dword_667B94 .text:0040BD36 push edx .text:0040BD37 mov edx, dword_667B90 .text:0040BD3D push eax .text:0040BD3E push ecx .text:0040BD3F push edx .text:0040BD40 push offset dword_66C070 .text:0040BD45 mov eax, offset list_root .text:0040BD4A call gen_captures .text:0040BD4F xor esi, esi .text:0040BD51 add esp, 20 .text:0040BD54 cmp list_root, esi .text:0040BD5A jz short loc_40BD6D .text:0040BD5C lea esp, [esp+0] .text:0040BD60 .text:0040BD60 loc_40BD60: ; CODE XREF: start_search+CB j .text:0040BD60 add esi, 1 .text:0040BD63 cmp list_root[esi*4], 0 .text:0040BD6B jnz short loc_40BD60 .text:0040BD6D .text:0040BD6D loc_40BD6D: ; CODE XREF: start_search+BA j .text:0040BD6D mov eax, dword_669C6C .text:0040BD72 mov ecx, dword_669C68 .text:0040BD78 push -1 .text:0040BD7A push -1 .text:0040BD7C push -1 .text:0040BD7E push eax .text:0040BD7F push ecx .text:0040BD80 lea edx, [ebp+var_440] .text:0040BD86 push edx .text:0040BD87 call gen_quiet_moves .text:0040BD8C mov eax, [ebp+var_440] .text:0040BD92 add esp, 24 .text:0040BD95 xor ecx, ecx .text:0040BD97 test eax, eax .text:0040BD99 jz short loc_40BDB5 .text:0040BD9B lea edx, ds:66BC70h[esi*4] .text:0040BDA2 .text:0040BDA2 loc_40BDA2: ; CODE XREF: start_search+113 j .text:0040BDA2 add ecx, 1 .text:0040BDA5 mov [edx], eax .text:0040BDA7 mov eax, [ebp+ecx*4+var_440] .text:0040BDAE add edx, 4 .text:0040BDB1 test eax, eax .text:0040BDB3 jnz short loc_40BDA2 .text:0040BDB5 .text:0040BDB5 loc_40BDB5: ; CODE XREF: start_search+F9 j .text:0040BDB5 add ecx, esi .text:0040BDB7 mov list_root[ecx*4], 0 .text:0040BDC2 .text:0040BDC2 loc_40BDC2: ; CODE XREF: start_search+80 j .text:0040BDC2 mov esi, list_root .text:0040BDC8 xor edi, edi .text:0040BDCA test esi, esi .text:0040BDCC mov [ebp+num_moves], edi .text:0040BDCF jz short loc_40BE4C .text:0040BDD1 mov [ebp+num_moves], offset list_root .text:0040BDD8 .text:0040BDD8 loc_40BDD8: ; CODE XREF: start_search+1A7 j .text:0040BDD8 lea eax, [ebp+undo] .text:0040BDDB push eax .text:0040BDDC push esi .text:0040BDDD call make_move .text:0040BDE2 push offset pos_info_entry .text:0040BDE7 call evaluate .text:0040BDEC mov ecx, dword_667C20 .text:0040BDF2 lea edx, ds:0[ecx*8] .text:0040BDF9 mov ecx, offset dword_667BF8 .text:0040BDFE sub ecx, edx .text:0040BE00 mov eax, [ecx] .text:0040BE02 mov ecx, [ecx+4] .text:0040BE05 and eax, pos_info_entry .text:0040BE0B and ecx, dword_669C84 .text:0040BE11 add esp, 0Ch .text:0040BE14 or eax, ecx .text:0040BE16 jnz short loc_40BE1C .text:0040BE18 mov bl, 1 .text:0040BE1A jmp short loc_40BE1E .text:0040BE1C ; --------------------------------------------------------------------------- .text:0040BE1C .text:0040BE1C loc_40BE1C: ; CODE XREF: start_search+176 j .text:0040BE1C xor bl, bl .text:0040BE1E .text:0040BE1E loc_40BE1E: ; CODE XREF: start_search+17A j .text:0040BE1E lea eax, [ebp+undo] .text:0040BE21 push eax .text:0040BE22 push esi .text:0040BE23 call unmake_move .text:0040BE28 add esp, 8 .text:0040BE2B test bl, bl .text:0040BE2D jz short loc_40BE39 .text:0040BE2F mov list_root[edi*4], esi .text:0040BE36 add edi, 1 ; num_moves++ .text:0040BE39 .text:0040BE39 loc_40BE39: ; CODE XREF: start_search+18D j .text:0040BE39 mov eax, [ebp+num_moves] .text:0040BE3C mov esi, [eax+4] .text:0040BE3F add eax, 4 ; i++ .text:0040BE42 test esi, esi ; list_root[i].move!=0 .text:0040BE44 mov [ebp+num_moves], eax .text:0040BE47 jnz short loc_40BDD8 .text:0040BE49 mov [ebp+num_moves], edi .text:0040BE4C .text:0040BE4C loc_40BE4C: ; CODE XREF: start_search+12F j .text:0040BE4C xor esi, esi .text:0040BE4E cmp edi, 1 ; if (num_moves <= 1) .text:0040BE51 mov list_root[edi*4], esi ; list_root[num_moves].move = 0 .text:0040BE58 ja short loc_40BE64 .text:0040BE5A mov G_max_depth, 4 ; max_depth = 4; .text:0040BE64 .text:0040BE64 loc_40BE64: ; CODE XREF: start_search+1B8 j .text:0040BE64 push esi .text:0040BE65 push offset dword_667A28 .text:0040BE6A call setjmp .text:0040BE6F add esp, 8 .text:0040BE72 test eax, eax ; if (setjmp(jmp_buffer) != 0) return; .text:0040BE74 jz short loc_40BE87 .text:0040BE76 mov eax, offset byte_664E08 .text:0040BE7B call sub_4092E0 .text:0040BE80 pop edi .text:0040BE81 pop esi .text:0040BE82 pop ebx .text:0040BE83 mov esp, ebp .text:0040BE85 pop ebp .text:0040BE86 retn .text:0040BE87 ; --------------------------------------------------------------------------- .text:0040BE87 .text:0040BE87 loc_40BE87: ; CODE XREF: start_search+1D4 j .text:0040BE87 call ds:GetTickCount ; start_timer .text:0040BE8D mov start_time, eax .text:0040BE92 mov eax, dword_66C490 .text:0040BE97 add eax, 1 ; All of this stuff is trans_inc_date .text:0040BE9A and eax, 3 .text:0040BE9D mov ecx, eax .text:0040BE9F cmp ecx, esi .text:0040BEA1 mov dword_66C490, eax .text:0040BEA6 jge short loc_40BEAB .text:0040BEA8 add ecx, 4 .text:0040BEAB .text:0040BEAB loc_40BEAB: ; CODE XREF: start_search+206 j .text:0040BEAB add ecx, 1 .text:0040BEAE shl ecx, 8 .text:0040BEB1 mov dword_66C498, ecx .text:0040BEB7 lea ecx, [eax-1] .text:0040BEBA cmp ecx, esi .text:0040BEBC jge short loc_40BEC1 .text:0040BEBE add ecx, 4 .text:0040BEC1 .text:0040BEC1 loc_40BEC1: ; CODE XREF: start_search+21C j .text:0040BEC1 add ecx, 1 .text:0040BEC4 shl ecx, 8 .text:0040BEC7 mov dword_66C49C, ecx .text:0040BECD lea ecx, [eax-2] .text:0040BED0 cmp ecx, esi .text:0040BED2 jge short loc_40BED7 .text:0040BED4 add ecx, 4 .text:0040BED7 .text:0040BED7 loc_40BED7: ; CODE XREF: start_search+232 j .text:0040BED7 add ecx, 1 .text:0040BEDA shl ecx, 8 .text:0040BEDD add eax, -3 .text:0040BEE0 cmp eax, esi .text:0040BEE2 mov dword_66C4A0, ecx .text:0040BEE8 jge short loc_40BEED .text:0040BEEA add eax, 4 .text:0040BEED .text:0040BEED loc_40BEED: ; CODE XREF: start_search+248 j .text:0040BEED add eax, 1 .text:0040BEF0 shl eax, 8 .text:0040BEF3 mov dword_66C4A4, eax .text:0040BEF8 xor eax, eax .text:0040BEFA lea ebx, [ebx+0] .text:0040BF00 .text:0040BF00 loc_40BF00: ; CODE XREF: start_search+274 j .text:0040BF00 mov killer1[eax], esi ; (Pos_info + i)->killer1 = 0; .text:0040BF06 mov killer2[eax], esi ; (Pos_info + i)->killer2 = 0; .text:0040BF0C add eax, 32 .text:0040BF0F cmp eax, 8192 .text:0040BF14 jb short loc_40BF00 .text:0040BF16 mov eax, 256 .text:0040BF1B mov ecx, 768 .text:0040BF20 mov edi, offset History .text:0040BF25 rep stosd ; memset(History, 256, 12 * 64 * sizeof(int)); .text:0040BF27 mov eax, dword_667C40 .text:0040BF2C and eax, dword_66C488 .text:0040BF32 mov ecx, dword_667C44 .text:0040BF38 shl eax, 4 .text:0040BF3B add eax, dword_66C480 .text:0040BF41 cmp [eax], ecx .text:0040BF43 jnz short loc_40BF4F .text:0040BF45 movzx edx, word ptr [eax+4] .text:0040BF49 mov dword_66C478, edx .text:0040BF4F .text:0040BF4F loc_40BF4F: ; CODE XREF: start_search+2A3 j .text:0040BF4F cmp [eax+10h], ecx .text:0040BF52 jnz short loc_40BF5E .text:0040BF54 movzx edx, word ptr [eax+14h] .text:0040BF58 mov dword_66C478, edx .text:0040BF5E .text:0040BF5E loc_40BF5E: ; CODE XREF: start_search+2B2 j .text:0040BF5E cmp [eax+20h], ecx .text:0040BF61 jnz short loc_40BF6D .text:0040BF63 movzx edx, word ptr [eax+24h] .text:0040BF67 mov dword_66C478, edx .text:0040BF6D .text:0040BF6D loc_40BF6D: ; CODE XREF: start_search+2C1 j .text:0040BF6D cmp [eax+30h], ecx .text:0040BF70 jnz short loc_40BF7B .text:0040BF72 movzx eax, word ptr [eax+34h] .text:0040BF76 mov dword_66C478, eax .text:0040BF7B .text:0040BF7B loc_40BF7B: ; CODE XREF: start_search+2D0 j .text:0040BF7B mov eax, [ebp+num_moves] .text:0040BF7E cmp eax, 2 .text:0040BF81 jb loc_40C039 .text:0040BF87 add eax, -1 .text:0040BF8A mov [ebp+var_8], eax .text:0040BF8D js loc_40C039 .text:0040BF93 .text:0040BF93 loc_40BF93: ; CODE XREF: start_search+393 j .text:0040BF93 lea ebx, ds:0[eax*4] .text:0040BF9A mov edi, list_root[ebx] .text:0040BFA0 cmp edi, dword_66C478 .text:0040BFA6 lea edx, dword_66C074[ebx] .text:0040BFAC jnz short loc_40BFB5 .text:0040BFAE mov ecx, 7FFFFFFFh .text:0040BFB3 jmp short loc_40BFE1 .text:0040BFB5 ; --------------------------------------------------------------------------- .text:0040BFB5 .text:0040BFB5 loc_40BFB5: ; CODE XREF: start_search+30C j .text:0040BFB5 mov ecx, edi .text:0040BFB7 and ecx, 63 .text:0040BFBA mov ecx, dword_667A90[ecx*4] .text:0040BFC1 test ecx, ecx .text:0040BFC3 jz short loc_40BFDF .text:0040BFC5 mov esi, edi .text:0040BFC7 shr esi, 6 .text:0040BFCA and esi, 63 .text:0040BFCD shl ecx, 4 .text:0040BFD0 sub ecx, dword_667A90[esi*4] .text:0040BFD7 add ecx, 2147483391 .text:0040BFDD jmp short loc_40BFE1 .text:0040BFDF ; --------------------------------------------------------------------------- .text:0040BFDF .text:0040BFDF loc_40BFDF: ; CODE XREF: start_search+323 j .text:0040BFDF xor ecx, ecx .text:0040BFE1 .text:0040BFE1 loc_40BFE1: ; CODE XREF: start_search+313 j .text:0040BFE1 ; start_search+33D j .text:0040BFE1 cmp ecx, [edx] .text:0040BFE3 mov esi, eax .text:0040BFE5 jnb short loc_40C01F .text:0040BFE7 mov eax, ebx .text:0040BFE9 lea esp, [esp+0] .text:0040BFF0 .text:0040BFF0 loc_40BFF0: ; CODE XREF: start_search+37A j .text:0040BFF0 mov ebx, dword_66BC74[eax] .text:0040BFF6 mov edx, [edx] .text:0040BFF8 mov list_root[eax], ebx .text:0040BFFE mov dword_66C070[eax], edx .text:0040C004 add esi, 1 .text:0040C007 lea eax, ds:0[esi*4] .text:0040C00E cmp ecx, dword_66C074[eax] .text:0040C014 lea edx, dword_66C074[eax] .text:0040C01A jb short loc_40BFF0 .text:0040C01C mov eax, [ebp+var_8] .text:0040C01F .text:0040C01F loc_40C01F: ; CODE XREF: start_search+345 j .text:0040C01F sub eax, 1 .text:0040C022 mov list_root[esi*4], edi .text:0040C029 mov dword_66C070[esi*4], ecx .text:0040C030 mov [ebp+var_8], eax .text:0040C033 jns loc_40BF93 .text:0040C039 .text:0040C039 loc_40C039: ; CODE XREF: start_search+2E1 j .text:0040C039 ; start_search+2ED j
--Setjmp is called after the move generation, as in Fruit
--Something very strange: whereas in Strelka a failed setjmp call simply results in a return, in Rybka 1.0 it involves a function call, like in Fruit (there it is search_update_current()). The weird part is, it appears to be calling parse_position(). That is what the "call sub_4092E0" is for. Why would Rybka 1.0 be parsing the position after a setjmp call?
--The timer is started after the setjmp call
--depth is limited to 4 when there's only 1 legal move (commented out in Strelka, as noted in the other thread).
--I noted earlier that the history initialization was different. Strelka and Rybka 1.0 are the same here, using memset(History, 256, 12 * 64 * sizeof(int)); But what I didn't notice is, 256 is out of range for an unsigned char. So that code is the same as Fruit's memset(History, 0, 12 * 64 * sizeof(int)); Why would Rybka 1.0 have 256? Is it the optimizer gone wild, or a deliberate attempt at obfuscation?
Can you explain how the above material demonstrates an equivalence between Rybka and Fruit?
You people really have a problem imo.
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Dann Corbit
- Posts: 12777
- Joined: Wed Mar 08, 2006 8:57 pm
- Location: Redmond, WA USA
Re: Wanted: some opposition to the provided evidence
According to the evidence provided, I see two possibilities.tiger wrote:Zach is showing code snippets where Rybka 1.0 is actually more similar to Fruit than Strelka 2.0.
A few days ago there was some vocal opposition to the idea that Rybka 1.0 coud be a derived work of Fruit 2.1.
Where is the opposition now?
There are several skilled people ready to explain why many programmers think (without daring to tell it) that Rybka started its life as Fruit 2.1.
The evidence is now being shown factually. Feel free to contradict it factually.
// Christophe
1. The Rybka author took Fruit code and modified it.
2. The Ryka author studied Fruit code and took the ideas in it.
Item 1 is illegal and item 2 is legal. There is obviously no way to differentiate which one was done. I assume that there are no patents on any of Fruit's algorithms. If this is the case, then it is not wrong, immoral or unethical to read the code, study the code, improve the code, rewrite the code, alter the code, etc. and then write your own version.
The code is not identical. The similar parts that have been demonstrated are all trivial anyway.
Everyone who wrote a chess program borrowed ideas from other people. People who claim otherwise are liars. Either that or they do not use alpha-beta, null move pruning, hash tables, etc.
I think that the mud slinging contest is a silly farce.
Slingers: "LOOK HE COPIED!"
Of course, we *all* did. Let's be honest. Everyone who failed to learn from Fruit's code is an idiot.
The only salient question is *how* Vas copied (e.g. learning ideas or copying code is not provable unless the code is identical and the code is not identical even in its most similar parts).
Mechanical estimates of how much code is similar are very unimpressive to me, especially when you consider that strcpy, printf, etc are going to be embedded in most programs.
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chrisw
Re: Wanted: some opposition to the provided evidence
Dann,Dann Corbit wrote:According to the evidence provided, I see two possibilities.tiger wrote:Zach is showing code snippets where Rybka 1.0 is actually more similar to Fruit than Strelka 2.0.
A few days ago there was some vocal opposition to the idea that Rybka 1.0 coud be a derived work of Fruit 2.1.
Where is the opposition now?
There are several skilled people ready to explain why many programmers think (without daring to tell it) that Rybka started its life as Fruit 2.1.
The evidence is now being shown factually. Feel free to contradict it factually.
// Christophe
1. The Rybka author took Fruit code and modified it.
2. The Ryka author studied Fruit code and took the ideas in it.
Item 1 is illegal and item 2 is legal. There is obviously no way to differentiate which one was done. I assume that there are no patents on any of Fruit's algorithms. If this is the case, then it is not wrong, immoral or unethical to read the code, study the code, improve the code, rewrite the code, alter the code, etc. and then write your own version.
The code is not identical. The similar parts that have been demonstrated are all trivial anyway.
Everyone who wrote a chess program borrowed ideas from other people. People who claim otherwise are liars. Either that or they do not use alpha-beta, null move pruning, hash tables, etc.
I think that the mud slinging contest is a silly farce.
Slingers: "LOOK HE COPIED!"
Of course, we *all* did. Let's be honest. Everyone who failed to learn from Fruit's code is an idiot.
The only salient question is *how* Vas copied (e.g. learning ideas or copying code is not provable unless the code is identical and the code is not identical even in its most similar parts).
Mechanical estimates of how much code is similar are very unimpressive to me, especially when you consider that strcpy, printf, etc are going to be embedded in most programs.
It is being claimed that the code fragment disassembly of Rybka 1 (?) posted by Zach is the same as a disassembly of Fruit. We await the evidence ...
Chris
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Zach Wegner
- Posts: 1922
- Joined: Thu Mar 09, 2006 12:51 am
- Location: Earth
Re: Wanted: some opposition to the provided evidence
Chris,chrisw wrote:Dann,
It is being claimed that the code fragment disassembly of Rybka 1 (?) posted by Zach is the same as a disassembly of Fruit. We await the evidence ...
Chris
The evidence of course exists. It's hard for me to post it right now because I'm at work. There's no need for everyone to repeatedly request this evidence, as it will be posted. I'd prefer to wait and organize everything into a webpage, but since people are asking, I can post a comparison of the given disassembly with Fruit. Of course I can't do a side-by-side comparison here...
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tiger
- Posts: 819
- Joined: Sat Mar 11, 2006 3:15 am
- Location: Guadeloupe (french caribbean island)
Re: Wanted: some opposition to the provided evidence
mclane wrote:yes rolf. its an international conspiracy. and you are the one who can look through. you - without any programming skill, you tell us the top secret,Rolf wrote: Look, how Bob is now running hot in his campaign. Funny, but I thought it all the time. This isnt science what Bob is showing. It's like his absolution of the mean IBM fraud (from science position) against Kasparov.
evaluate our positions and help us through the nights.
messias.
what do you want us to do ?
shall we wear white clothes ?
shall we pray with you, the pope, for your grace to help us in the dilemma.
shall we all take hand by hand and feel free ?
hosianna. hosianna.
what a mean campaign this is.
and how holy your holyness.
let us fall on the floor and pray 10 ave marias.
amazing grace, how sweet our lord.
exactly.This isnt science what Bob is showing
its the way you say it.
YOU know the truth my lord.
you give us light and future, you make the flowers grow and the sun go up and down.
you are the master of our joy.
here is a meeting of the conspiracy-club that tried to fool you:
there they sat and planned to fool our gracious Lord Rolf.
and he was so strong to look through.
no. its a believe. a believe in evil.This isnt science what Bob is showing
only you pope rolf know the truth. and can you help us my lord ?
Hey, nice picture you have posted. Isn't it David Levy at the left of Frans Morsch? And the back of vdH?
What was the event?
// Christophe
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Terry McCracken
- Posts: 16465
- Joined: Wed Aug 01, 2007 4:16 am
- Location: Canada
Re: Wanted: some opposition to the provided evidence
Bob is a top expert, also Bob started completely from scratch, so did Christophe!Dann Corbit wrote:According to the evidence provided, I see two possibilities.tiger wrote:Zach is showing code snippets where Rybka 1.0 is actually more similar to Fruit than Strelka 2.0.
A few days ago there was some vocal opposition to the idea that Rybka 1.0 coud be a derived work of Fruit 2.1.
Where is the opposition now?
There are several skilled people ready to explain why many programmers think (without daring to tell it) that Rybka started its life as Fruit 2.1.
The evidence is now being shown factually. Feel free to contradict it factually.
// Christophe
1. The Rybka author took Fruit code and modified it.
2. The Ryka author studied Fruit code and took the ideas in it.
Item 1 is illegal and item 2 is legal. There is obviously no way to differentiate which one was done. I assume that there are no patents on any of Fruit's algorithms. If this is the case, then it is not wrong, immoral or unethical to read the code, study the code, improve the code, rewrite the code, alter the code, etc. and then write your own version.
The code is not identical. The similar parts that have been demonstrated are all trivial anyway.
Everyone who wrote a chess program borrowed ideas from other people. People who claim otherwise are liars. Either that or they do not use alpha-beta, null move pruning, hash tables, etc.
I think that the mud slinging contest is a silly farce.
Slingers: "LOOK HE COPIED!"
Of course, we *all* did. Let's be honest. Everyone who failed to learn from Fruit's code is an idiot.
The only salient question is *how* Vas copied (e.g. learning ideas or copying code is not provable unless the code is identical and the code is not identical even in its most similar parts).
Mechanical estimates of how much code is similar are very unimpressive to me, especially when you consider that strcpy, printf, etc are going to be embedded in most programs.
Zach is also giving further evidence in another thread for Vas to answer and Vas alone and Vas should answer!
It's that simple. No one is trying to destroy Rybka or hurt Vas.
But the roots of Rybka are being fully investigated, and this process should be allowed to continue unimpeded.