Path: ...!news.mixmin.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: olcott <polcott333@gmail.com> Newsgroups: comp.theory Subject: Re: Overview of proof that the input to HHH(DDD) specifies non-halting behavior --- Mike --- in our head Date: Wed, 14 Aug 2024 08:56:10 -0500 Organization: A noiseless patient Spider Lines: 58 Message-ID: <v9id1q$f16v$9@dont-email.me> References: <v9edol$3metk$1@dont-email.me> <v9fe61$3rqao$1@dont-email.me> <v9flkh$3se8c$3@dont-email.me> <v9fr90$3u3of$1@dont-email.me> <v9ftsp$3uffi$1@dont-email.me> <v9g0im$3u3of$5@dont-email.me> <v9g22t$3uffi$3@dont-email.me> <v9g6rb$cql$1@dont-email.me> <v9g7d3$gmc$1@dont-email.me> <v9gaup$17ve$1@dont-email.me> <v9gbl8$1i21$1@dont-email.me> <v9hrq3$ccps$1@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Wed, 14 Aug 2024 15:56:11 +0200 (CEST) Injection-Info: dont-email.me; posting-host="0b9b77ee625b8578b747fee4cc5a1452"; logging-data="492767"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19zrVqQNh8+3skB8oOZqtpV" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:Ifk3JqWt9Rd5KqErIEtzUSPiTBY= Content-Language: en-US In-Reply-To: <v9hrq3$ccps$1@dont-email.me> Bytes: 3471 On 8/14/2024 4:01 AM, Fred. Zwarts wrote: > Op 13.aug.2024 om 21:20 schreef olcott: >> >> A simulation of N instructions of DDD by HHH according to >> the semantics of the x86 language is necessarily correct. > We can agree that HHH made a good start for the simulation with a > correct simulation of the first N steps, but failed to complete the > simulation by not reaching the end of the simulation. > No wrong. That N instructions were emulating correctly is the whole point. Anything else is a distraction from this point. > Note that the semantics of the x86 language does not depend on who or > what is using it. The direct execution uses the same semantics and it > correctly shows that the end of the program can be reached according to > this semantics. So, when the simulator does not reach the end, it > deviates from the semantics of the input, when it processes the same input. _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] The is a hypothetical mental exercise and can be accomplished even if the only DDD in the world was simply typed into a word processor and never run. HHH can be purely imaginary yet must emulate the above code and itself according to the semantics of the x86 language. In this case HHH is a pure emulator. (a) On this basis we know that such an HHH would emulate the first four instructions of DDD. (b) This includes a calls from the emulated DDD to an emulated HHH(DDD). (c) This emulated HHH would emulate the first four instructions of DDD. (b) and (c) keep repeating. We can do that all in our head never needing any actually existing HHH. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer