Path: ...!2.eu.feeder.erje.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: "Chris M. Thomasson" Newsgroups: comp.lang.c,comp.lang.c++ Subject: Re: Can someone please verify the execution trace of this? Date: Mon, 20 May 2024 12:44:12 -0700 Organization: A noiseless patient Spider Lines: 33 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 20 May 2024 21:44:13 +0200 (CEST) Injection-Info: dont-email.me; posting-host="c64270d287de33e0b6496e257486af9b"; logging-data="165370"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19VBoQA1xrY9UMjuduFaNkG4AvihONAYZQ=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:2iut+rca8HIK+ObvcBe2XDJxmNw= Content-Language: en-US In-Reply-To: Bytes: 2843 On 5/20/2024 12:40 PM, olcott wrote: > On 5/20/2024 2:38 PM, Chris M. Thomasson wrote: [...] >> So, your thing will tell me if a program XYZ will halt or not only >> _after_ it simulates to infinity? What am I missing here? > > *The 100% totally complete every single detail scope of my post* > *The 100% totally complete every single detail scope of my post* > *The 100% totally complete every single detail scope of my post* > > typedef int (*ptr)();  // ptr is pointer to int function > 00 int H(ptr p, ptr i); > 01 int D(ptr p) > 02 { > 03   int Halt_Status = H(p, p); > 04   if (Halt_Status) > 05     HERE: goto HERE; > 06   return Halt_Status; > 07 } > 08 > 09 int main() > 10 { > 11   H(D,D); > 12   return 0; > 13 } > [...] > For every H/D pair of the above template D correctly simulated by pure > function (thus computable function) H cannot possibly reach its own > final state at line 06 and halt. > > Define H?