Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory,sci.logic Subject: Re: DDD correctly emulated by HHH is correctly rejected as non-halting. Date: Wed, 10 Jul 2024 12:53:38 -0500 Organization: A noiseless patient Spider Lines: 38 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Wed, 10 Jul 2024 19:53:39 +0200 (CEST) Injection-Info: dont-email.me; posting-host="1ca7ba779153ded89a6e04f3275941c5"; logging-data="2118299"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+/1gqrn60D6o9cE8a9iRZQ" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:yDO4KA7apMjlpF8NnzfB0YuvsAU= In-Reply-To: Content-Language: en-US Bytes: 2037 On 7/10/2024 12:45 PM, Fred. Zwarts wrote: > Op 10.jul.2024 om 17:03 schreef olcott: >> typedef void (*ptr)(); >> int HHH(ptr P); >> >> void DDD() >> { >>    HHH(DDD); >> } >> >> int main() >> { >>    HHH(DDD); >> } > > Unneeded complexity. It is equivalent to: > >        int main() >        { >          return HHH(main); >        } > Every time any HHH correctly emulates DDD it calls the x86utm operating system to create a separate process context with its own memory virtual registers and stack, thus each recursively emulated DDD is a different instance. The instance of main() can't possibly halt HHH correctly aborts and rejects as non-halting. The entirely different instance of main() that calls HHH only halts because HHH was correct to abort its simulated instance. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer