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Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: dbush <dbush.mobile@gmail.com> Newsgroups: comp.theory Subject: Re: DD specifies non-terminating behavior to HHH --- RECURSIVE CHAIN --- Saving Democracy Date: Mon, 24 Feb 2025 08:11:36 -0500 Organization: A noiseless patient Spider Lines: 296 Message-ID: <vphr67$13hrc$1@dont-email.me> References: <vo6420$3mpmf$1@dont-email.me> <vpcurc$irt$5@dont-email.me> <vpd0e5$uj5$1@dont-email.me> <vpd3fg$irt$10@dont-email.me> <vpd4ih$2pvp$1@dont-email.me> <vpd6hp$2q85$3@dont-email.me> <vpd7s7$3e5k$1@dont-email.me> <vpd8pl$3h9q$1@dont-email.me> <vpd97q$3e5k$2@dont-email.me> <vpdaj5$3u9g$1@dont-email.me> <vpdatp$3e5k$3@dont-email.me> <vpddgj$3u9g$2@dont-email.me> <vpddqm$3e5k$4@dont-email.me> <vpdkhv$5kr2$1@dont-email.me> <vpdks8$5ga3$1@dont-email.me> <vpdqc8$6bqs$1@dont-email.me> <vpe1g3$7gnd$1@dont-email.me> <vpflv1$j7qb$1@dont-email.me> <vpfnhm$jena$1@dont-email.me> <vpgded$nkbd$1@dont-email.me> <vpgdn8$nlei$1@dont-email.me> <vpgh33$o4p7$1@dont-email.me> <vpghkq$o82o$1@dont-email.me> <vpgk2q$okhu$1@dont-email.me> <vpgo94$p8he$1@dont-email.me> <vpgoia$p9vl$1@dont-email.me> <vpgrdl$tdkf$1@dont-email.me> <vpgtb3$tiun$2@dont-email.me> <vpgth7$tdkf$3@dont-email.me> <vpgufr$truc$1@dont-email.me> <vpguru$tdkf$4@dont-email.me> <vpgvcv$tuuf$1@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 24 Feb 2025 14:11:36 +0100 (CET) Injection-Info: dont-email.me; posting-host="2824c1e0c122bd29eea4e0491b46b547"; logging-data="1165164"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+13/Ab/XpUqEePcejiYqCX" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:iXVPIjhLEoP8d7vhXpMOX9Q1BD0= In-Reply-To: <vpgvcv$tuuf$1@dont-email.me> Content-Language: en-US Bytes: 14449 On 2/24/2025 12:17 AM, olcott wrote: > On 2/23/2025 11:08 PM, dbush wrote: >> On 2/24/2025 12:01 AM, olcott wrote: >>> On 2/23/2025 10:45 PM, dbush wrote: >>>> On 2/23/2025 11:42 PM, olcott wrote: >>>>> On 2/23/2025 10:09 PM, dbush wrote: >>>>>> On 2/23/2025 10:20 PM, olcott wrote: >>>>>>> On 2/23/2025 9:15 PM, dbush wrote: >>>>>>>> On 2/23/2025 9:04 PM, olcott wrote: >>>>>>>>> On 2/23/2025 7:22 PM, dbush wrote: >>>>>>>>>> On 2/23/2025 8:13 PM, olcott wrote: >>>>>>>>>>> On 2/23/2025 6:15 PM, dbush wrote: >>>>>>>>>>>> On 2/23/2025 7:10 PM, olcott wrote: >>>>>>>>>>>>> On 2/23/2025 11:57 AM, dbush wrote: >>>>>>>>>>>>>> On 2/23/2025 12:30 PM, olcott wrote: >>>>>>>>>>>>>>> On 2/22/2025 8:34 PM, dbush wrote: >>>>>>>>>>>>>>>> On 2/22/2025 7:33 PM, olcott wrote: >>>>>>>>>>>>>>>>> On 2/22/2025 4:59 PM, dbush wrote: >>>>>>>>>>>>>>>>>> On 2/22/2025 5:53 PM, olcott wrote: >>>>>>>>>>>>>>>>>>> On 2/22/2025 2:59 PM, dbush wrote: >>>>>>>>>>>>>>>>>>>> On 2/22/2025 3:53 PM, olcott wrote: >>>>>>>>>>>>>>>>>>>>> On 2/22/2025 2:09 PM, dbush wrote: >>>>>>>>>>>>>>>>>>>>>> On 2/22/2025 3:03 PM, olcott wrote: >>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>> 01 int F(int i) >>>>>>>>>>>>>>>>>>>>> 02 { >>>>>>>>>>>>>>>>>>>>> 03 if (i > 10) >>>>>>>>>>>>>>>>>>>>> 04 return 0; >>>>>>>>>>>>>>>>>>>>> 05 else >>>>>>>>>>>>>>>>>>>>> 06 return F(i+1); >>>>>>>>>>>>>>>>>>>>> 07 } >>>>>>>>>>>>>>>>>>>>> 08 >>>>>>>>>>>>>>>>>>>>> 09 int no_numbers_greater_than_10() >>>>>>>>>>>>>>>>>>>>> 10 { >>>>>>>>>>>>>>>>>>>>> 11 return F(0); >>>>>>>>>>>>>>>>>>>>> 12 } >>>>>>>>>>>>>>>>>>>>> 13 >>>>>>>>>>>>>>>>>>>>> 14 int main() >>>>>>>>>>>>>>>>>>>>> 15 { >>>>>>>>>>>>>>>>>>>>> 16 F((int)no_numbers_greater_than_10); >>>>>>>>>>>>>>>>>>>>> 17 return 0; >>>>>>>>>>>>>>>>>>>>> 18 } >>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>>> So if the address of no_numbers_greater_than_10 is >>>>>>>>>>>>>>>>>>>>>> greater than 10 then 0 is returned right away, >>>>>>>>>>>>>>>>>>>>>> otherwise as most 10 recursive calls will be made >>>>>>>>>>>>>>>>>>>>>> before the condition is matched and 0 is returned. >>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>>> This doesn't change the fact that >>>>>>>>>>>>>>>>>>>>>> no_numbers_greater_than_10 correctly >>>>>>>>>>>>>>>>>>>>>> simulated by F cannot possibly return so >>>>>>>>>>>>>>>>>>>>>> F(no_numbers_greater_than_10) >>>>>>>>>>>>>>>>>>>>>> is correct to report non-halting, which means that >>>>>>>>>>>>>>>>>>>>>> there is no natural >>>>>>>>>>>>>>>>>>>>>> number greater than 10. >>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>>> Agreed? >>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>> I think that you will find more bugs when you try to >>>>>>>>>>>>>>>>>>>>> provide the line number by line number execution >>>>>>>>>>>>>>>>>>>>> trace. >>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>> #1 bug F never simulates anything. >>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>> It is a verified fact that >>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>> F never simulates anything when i > 10. >>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Remember, you agreed that the behavior of X simulated >>>>>>>>>>>>>>>>>> by Y is defined by replacing the code of Y with an >>>>>>>>>>>>>>>>>> unconditional simulator and running Y(X): >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> On 2/22/2025 1:02 PM, olcott wrote: >>>>>>>>>>>>>>>>>> > On 2/22/2025 11:10 AM, dbush wrote: >>>>>>>>>>>>>>>>>> >> On 2/22/2025 11:43 AM, olcott wrote: >>>>>>>>>>>>>>>>>> >>> The first point is DD correctly simulated by HHH >>>>>>>>>>>>>>>>>> cannot >>>>>>>>>>>>>>>>>> >>> possibly terminate normally by reaching its own >>>>>>>>>>>>>>>>>> "return" >>>>>>>>>>>>>>>>>> >>> instruction. >>>>>>>>>>>>>>>>>> >> >>>>>>>>>>>>>>>>>> >> In other words, if the code of HHH is replaced >>>>>>>>>>>>>>>>>> with an unconditional simulator then it can be shown >>>>>>>>>>>>>>>>>> that DD is non- halting and therefore HHH(DD)==0 is >>>>>>>>>>>>>>>>>> correct. >>>>>>>>>>>>>>>>>> >> >>>>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>>>> > Wow finally someone that totally gets it. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> So the behavior of no_numbers_greater_than_10 >>>>>>>>>>>>>>>>>> simulated by F is defined by replacing the code of F >>>>>>>>>>>>>>>>>> with an unconditional simulated and running >>>>>>>>>>>>>>>>>> F(no_numbers_greater_than_10). >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> The finite string input to F proves that there are no >>>>>>>>>>>>>>>>>> instructions in no_numbers_greater_than_10 that can >>>>>>>>>>>>>>>>>> break the recursive simulation. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Try to show how no_numbers_greater_than_10 correctly >>>>>>>>>>>>>>>>>> simulated by F can possibly halt. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Then is ceases to be analogous to HHH(DD) because >>>>>>>>>>>>>>>>> no_numbers_greater_than_10() always terminates normally >>>>>>>>>>>>>>>>> by reaching its own "return" instruction. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> In other words, when we actually run >>>>>>>>>>>>>>>> no_numbers_greater_than_10() it reaches its own "return" >>>>>>>>>>>>>>>> instruction. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> That means we've now established that the direct >>>>>>>>>>>>>>>> execution of a program (which includes all the functions >>>>>>>>>>>>>>>> it calls UNMODIFIED) defines whether or not it halts. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Likewise, when we actually run DD() unmodified it also >>>>>>>>>>>>>>>> reaches its own "return" instruction. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Therefore HHH(DD)==0 is wrong. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> _DD() >>>>>>>>>>>>>>> [00002133] 55 push ebp ; housekeeping >>>>>>>>>>>>>>> [00002134] 8bec mov ebp,esp ; housekeeping >>>>>>>>>>>>>>> [00002136] 51 push ecx ; make space for local >>>>>>>>>>>>>>> [00002137] 6833210000 push 00002133 ; push DD >>>>>>>>>>>>>>> [0000213c] e882f4ffff call 000015c3 ; call HHH(DD) >>>>>>>>>>>>>>> [00002141] 83c404 add esp,+04 >>>>>>>>>>>>>>> [00002144] 8945fc mov [ebp-04],eax >>>>>>>>>>>>>>> [00002147] 837dfc00 cmp dword [ebp-04],+00 >>>>>>>>>>>>>>> [0000214b] 7402 jz 0000214f >>>>>>>>>>>>>>> [0000214d] ebfe jmp 0000214d >>>>>>>>>>>>>>> [0000214f] 8b45fc mov eax,[ebp-04] >>>>>>>>>>>>>>> [00002152] 8be5 mov esp,ebp >>>>>>>>>>>>>>> [00002154] 5d pop ebp >>>>>>>>>>>>>>> [00002155] c3 ret >>>>>>>>>>>>>>> Size in bytes:(0035) [00002155] >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> When DD is correctly simulated by HHH according to the >>>>>>>>>>>>>>> behavior >>>>>>>>>>>>>>> that the above machine code specifies then the call from DD >>>>>>>>>>>>>>> to HHH(DD) cannot possibly return and this correctly >>>>>>>>>>>>>>> simulated >>>>>>>>>>>>>>> DD cannot possibly terminate normally by reaching its >>>>>>>>>>>>>>> own machine >>>>>>>>>>>>>>> address 00002155. >>>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> Similarly: >>>>>>>>>>>>>> >>>>>>>>>>>>>> 0000000000400534 <no_numbers_greater_than_10>: >>>>>>>>>>>>>> 400534: 55 push %rbp >>>>>>>>>>>>>> 400535: 48 89 e5 mov %rsp,%rbp >>>>>>>>>>>>>> 400538: b8 34 05 40 00 mov $0x400534,%eax >>>>>>>>>>>>>> 40053d: 48 89 c7 mov %rax,%rdi >>>>>>>>>>>>>> 400540: e8 a8 ff ff ff callq 4004ed <F> >>>>>>>>>>>>>> 400545: 5d pop %rbp >>>>>>>>>>>>>> 400546: c3 retq >>>>>>>>>>>>>> >>>>>>>>>>>>>> ========== REMAINDER OF ARTICLE TRUNCATED ==========