Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: Re: DDD simulated by HHH cannot possibly halt (Halting Problem) Date: Sat, 5 Apr 2025 01:18:06 -0500 Organization: A noiseless patient Spider Lines: 31 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 05 Apr 2025 08:18:06 +0200 (CEST) Injection-Info: dont-email.me; posting-host="97eba1022354d338380a8cae376e9e02"; logging-data="1627428"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18TP+l0F/JIRqCK8uRvcz95" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:FQQyWsTReEdi8ktLuXJoyjNadMA= X-Antivirus-Status: Clean X-Antivirus: Norton (VPS 250404-6, 4/4/2025), Outbound message Content-Language: en-US In-Reply-To: On 4/4/2025 3:12 AM, Mikko wrote: > On 2025-04-04 01:27:15 +0000, olcott said: > >> void DDD() >> { >>     HHH(DDD); >>     return; >> } >> >> Do you really think that anyone knowing the C >> programming language is too stupid to see that >> DDD simulated by HHH cannot possibly return? > > Anyone knowing the C language can see that if DDD() does not halt > it means that HHH(DDD) does not halt. The knowledge that that > means that HHH is not a decider is possible but not required. > *Perpetually ignoring this is not any actual rebuttal at all* *Simulating termination analyzer Principle* It is always correct for any simulating termination analyzer to stop simulating and reject any input that would otherwise prevent its own termination. The only rebuttal to this is rejecting the notion that deciders must always halt. -- Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer