Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: "Chris M. Thomasson" Newsgroups: comp.lang.c Subject: Re: Proving the: Simulating termination analyzer Principle Date: Wed, 9 Apr 2025 16:39:24 -0700 Organization: A noiseless patient Spider Lines: 55 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Thu, 10 Apr 2025 01:39:26 +0200 (CEST) Injection-Info: dont-email.me; posting-host="a1d36cabcbafabd2745ccb32a63424ad"; logging-data="1800183"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/cEEJbOk5DSGxtd25imMOO0dPD172pStA=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:Nj4bUJHAjv8Ivd2mQUrbx5U5IBA= In-Reply-To: Content-Language: en-US On 4/9/2025 10:18 AM, olcott wrote: > On 4/9/2025 1:00 AM, Chris M. Thomasson wrote: >> On 4/5/2025 8:26 PM, olcott wrote: >>> On 4/5/2025 7:59 PM, Richard Heathfield wrote: >>>> If it is claimed always to give the right answer, it becomes >>>> possible (as shown above in the chevrons) to write a program for >>>> which it will not be able to work out the right answer - reductio ad >>>> absurdum. >>>> >>>> Your 'principle' doesn't matter a jot. >>>> >>> >>> Except that it gives the correct >>> *Simulating termination analyzer Principle* >>> answer for the Halting Problems impossible input. >>> The computer science of termination analyzers might agree. >>> >> >> is this pseudo-code akin to your decider? >> >> bool >> halts() >> { >>      return (rand_normal() < .5f); >> } >> >> ? >> > > Not at all it has been fully operational software for > about three years: > https://github.com/plolcott/x86utm/blob/master/Halt7.c > > typedef void (*ptr)(); > int HHH(ptr P); > > int DD() > { >   int Halt_Status = HHH(DD); >   if (Halt_Status) >     HERE: goto HERE; >   return Halt_Status; > } > > int main() > { >   HHH(DD); > } > > Some version of HHH has been able to return the correct > halt status for some version of DD for about three years. > HHH is always correct for inputs in its domain. > Is your decider 100% correct for any "black box" program?