Path: ...!weretis.net!feeder9.news.weretis.net!news.quux.org!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: Re: Every sufficiently competent C programmer knows Date: Tue, 11 Mar 2025 12:09:39 -0500 Organization: A noiseless patient Spider Lines: 71 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 11 Mar 2025 18:09:39 +0100 (CET) Injection-Info: dont-email.me; posting-host="21ad3ceb157a21d404b41b865b615184"; logging-data="2190047"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19KkcbEpPqKrbp6NVs/OGr2" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:8quHAZEtpHSy5GnAupNqrMzj3/g= X-Antivirus: Norton (VPS 250311-0, 3/10/2025), Outbound message In-Reply-To: Content-Language: en-US X-Antivirus-Status: Clean Bytes: 3314 On 3/11/2025 11:41 AM, Fred. Zwarts wrote: > Op 11.mrt.2025 om 14:31 schreef olcott: >> On 3/11/2025 5:28 AM, Mikko wrote: >>> On 2025-03-10 23:41:13 +0000, olcott said: >>> >>>> typedef void (*ptr)(); >>>> int HHH(ptr P); >>>> >>>> void Infinite_Loop() >>>> { >>>>    HERE: goto HERE; >>>>    return; >>>> } >>>> >>>> void Infinite_Recursion() >>>> { >>>>    Infinite_Recursion(); >>>>    return; >>>> } >>>> >>>> void DDD() >>>> { >>>>    HHH(DDD); >>>>    return; >>>> } >>>> >>>> int DD() >>>> { >>>>    int Halt_Status = HHH(DD); >>>>    if (Halt_Status) >>>>      HERE: goto HERE; >>>>    return Halt_Status; >>>> } >>>> >>>> That when HHH correctly emulates N steps of the >>>> above functions that none of these functions can >>>> possibly reach their own "return" instruction >>>> and terminate normally. >>> >>> Every competent programmer knows that the information given is >>> insufficient to determine whether HHH emulates at all, and whether >>> it emulates correctly if it does. >>> >>>> Since HHH does see that same pattern that competent >>>> C programmers see it correctly aborts its emulation >>>> and rejects these inputs as non terminating. >>> >>> Whether HHH does see those patterns cannot be inferred from the >>> information >>> given. Only about DDD one can see that it halts if HHH returns. In >>> addition, >>> the given information does not tell whether HHH can see patterns that >>> are >>> not there. >>> >>> How many competent programmers you have asked? >>> >> >> Two C programmers with masters degrees in computer science >> agree that DDD correctly emulated by HHH cannot possibly >> reach its own "return" instruction and terminate normally. >> > > It is clear that that HHH cannot possibly simulate itself up to the end. I say that the cat is black and you say No you are wrong because the dog is white. -- Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer