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Path: 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: Sun, 23 Feb 2025 23:45:27 -0500 Organization: A noiseless patient Spider Lines: 217 Message-ID: <vpgth7$tdkf$3@dont-email.me> References: <vo6420$3mpmf$1@dont-email.me> <8fa176d46bf5b8c36def9e32ced67a1a3f81bae1@i2pn2.org> <vpbhrk$3mfi7$1@dont-email.me> <2e999502c40f736a3f3579d23bdb2b42dc74e897@i2pn2.org> <vpcurc$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$2@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 24 Feb 2025 05:45:27 +0100 (CET) Injection-Info: dont-email.me; posting-host="2824c1e0c122bd29eea4e0491b46b547"; logging-data="964239"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19RjG1y6A4E1PzKtfRdzb28" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:V4bme/APXiqD46+INItToNUOjX4= Content-Language: en-US In-Reply-To: <vpgtb3$tiun$2@dont-email.me> 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 >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> When no_numbers_greater_than_10 is correctly simulated by F >>>>>>>>>> according to the behavior that the above machine code >>>>>>>>>> specifies then the call from no_numbers_greater_than_10 to >>>>>>>>>> F(no_numbers_greater_than_10) cannot possibly terminate >>>>>>>>>> normally by reaching its own machine address 400545 >>>>>>>>>> >>>>>>>>>> So F(no_numbers_greater_than_10)==0 is correct, and therefore >>>>>>>>>> no natural number exists that is greater than 10 >>>>>>>>>> ========== REMAINDER OF ARTICLE TRUNCATED ==========