Path: ...!feeds.phibee-telecom.net!3.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: Re: Proof that DDD specifies non-halting behavior --- point by point Date: Thu, 15 Aug 2024 21:26:49 -0500 Organization: A noiseless patient Spider Lines: 91 Message-ID: References: <561f876601b0329c0260bac26f8b6dfb6e28647f@i2pn2.org> <190847da05ab48555c036a799e768f555461eb43@i2pn2.org> <31884066c1cc49b47c3d4ea6009d04f2edca2795@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 16 Aug 2024 04:26:49 +0200 (CEST) Injection-Info: dont-email.me; posting-host="0832828dca420f70d701da47ce3141da"; logging-data="1367136"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+w8ef1BrhlI7ETw5OxiM+4" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:DgnNPqBCanNhMVlFD3jPBQGhPfM= In-Reply-To: <31884066c1cc49b47c3d4ea6009d04f2edca2795@i2pn2.org> Content-Language: en-US Bytes: 4741 On 8/15/2024 8:57 PM, Richard Damon wrote: > On 8/15/24 10:58 AM, olcott wrote: >> On 8/15/2024 3:19 AM, Mikko wrote: >>> On 2024-08-14 04:04:23 +0000, Richard Damon said: >>> >>>> On 8/13/24 11:48 PM, olcott wrote: >>>>> On 8/13/2024 10:21 PM, Richard Damon wrote: >>>>>> On 8/13/24 10:38 PM, olcott wrote: >>>>>>> On 8/13/2024 9:29 PM, Richard Damon wrote: >>>>>>>> On 8/13/24 8:52 PM, olcott wrote: >>>>>>>>> void DDD() >>>>>>>>> { >>>>>>>>>    HHH(DDD); >>>>>>>>>    return; >>>>>>>>> } >>>>>>>>> >>>>>>>>> _DDD() >>>>>>>>> [00002172] 55         push ebp      ; housekeeping >>>>>>>>> [00002173] 8bec       mov ebp,esp   ; housekeeping >>>>>>>>> [00002175] 6872210000 push 00002172 ; push DDD >>>>>>>>> [0000217a] e853f4ffff call 000015d2 ; call HHH(DDD) >>>>>>>>> [0000217f] 83c404     add esp,+04 >>>>>>>>> [00002182] 5d         pop ebp >>>>>>>>> [00002183] c3         ret >>>>>>>>> Size in bytes:(0018) [00002183] >>>>>>>>> >>>>>>>>> A simulation of N instructions of DDD by HHH according to >>>>>>>>> the semantics of the x86 language is necessarily correct. >>>>>>>>> >>>>>>>> >>>>>>>> Nope, it is just the correct PARTIAL emulation of the first N >>>>>>>> instructions of DDD, and not of all of DDD, >>>>>>> >>>>>>> That is what I said dufuss. >>>>>> >>>>>> Nope. You didn't. I added clairifying words, pointing out why you >>>>>> claim is incorrect. >>>>>> >>>>>> For an emulation to be "correct" it must be complete, as partial >>>>>> emulations are only partially correct, so without the partial >>>>>> modifier, they are not correct. >>>>>> >>>>> >>>>> A complete emulation of one instruction is >>>>> a complete emulation of one instruction >>>> >>>> >>>> >>>>> >>>>>>> >>>>>>>> >>>>>>>>> A correct simulation of N instructions of DDD by HHH is >>>>>>>>> sufficient to correctly predict the behavior of an unlimited >>>>>>>>> simulation. >>>>>>>> >>>>>>>> Nope, if a HHH returns to its caller, >>>>>>> >>>>>>> *Try to show exactly how DDD emulated by HHH returns to its caller* >>>>>>> (the first one doesn't even have a caller) >>>>>>> Use the above machine language instructions to show this. >>>>>>> >>>>>> >>>>>> Remember how English works: >>>>>> >>>>>> When you ask "How DDD emulated by HHH returns to its callers". >>>>> >>>>> Show the exact machine code trace of how DDD emulated >>>>> by HHH (according to the semantics of the x86 language) >>>>> reaches its own machine address 00002183 >>>> >>>> No. The trace is to long, and since you HHH doesn't meet your >>>> requirements (since it isn't a pure function) you can't give me a >>>> compldte input to trace. >>> >>> The trace is regular enough that we could define a formal language for >>> the trace and construct an analyzer program to detect deviations from >>> x86 semnatics and hidden inputs. >>> >> >> There are no deviations. The x86utm operating system is >> built from libx86emu that has had decades of development >> effort. HHH really does emulate itself emulating DDD. >> > > And then ignores that emulation, counter-factual but you don't care. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer