Path: ...!weretis.net!feeder9.news.weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Mikko Newsgroups: comp.theory Subject: Re: Every D correctly simulated by H never reaches its final state and halts Date: Mon, 20 May 2024 11:08:20 +0300 Organization: - Lines: 106 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 10:08:21 +0200 (CEST) Injection-Info: dont-email.me; posting-host="338f00df9c13dbf24a97640fc9b87ad2"; logging-data="4092392"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19JOyZxBO+2xENKLr/sPamm" User-Agent: Unison/2.2 Cancel-Lock: sha1:Bg9ZC+rtwUCnked61hvdFXrAJ9Y= Bytes: 5079 On 2024-05-19 13:59:09 +0000, olcott said: > On 5/19/2024 8:43 AM, Mikko wrote: >> On 2024-05-19 12:36:08 +0000, olcott said: >> >>> On 5/19/2024 5:37 AM, Mikko wrote: >>>> On 2024-05-18 14:38:53 +0000, olcott said: >>>> >>>>> On 5/18/2024 4:45 AM, Mikko wrote: >>>>>> On 2024-05-17 15:55:03 +0000, olcott said: >>>>>> >>>>>>> On 5/17/2024 4:08 AM, Mikko wrote: >>>>>>>> On 2024-05-17 07:25:52 +0000, Fred. Zwarts said: >>>>>>>> >>>>>>>>> Op 17.mei.2024 om 03:15 schreef olcott: >>>>>>>>>> The following is self-evidently true on the basis of the >>>>>>>>>> semantics of the C programming language. >>>>>>>>>> >>>>>>>>>> typedef int (*ptr)();  // ptr is pointer to int function >>>>>>>>>> 00 int H(ptr x, ptr x); >>>>>>>>>> 01 int D(ptr x) >>>>>>>>>> 02 { >>>>>>>>>> 03   int Halt_Status = H(x, x); >>>>>>>>>> 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 } >>>>>>>>>> >>>>>>>>>> In the above case a simulator is an x86 emulator that correctly >>>>>>>>>> emulates at least one of the x86 instructions of D in the order >>>>>>>>>> specified by the x86 instructions of D. >>>>>>>>>> >>>>>>>>>> This may include correctly emulating the x86 instructions of H >>>>>>>>>> in the order specified by the x86 instructions of H thus calling >>>>>>>>>> H(D,D) in recursive simulation. >>>>>>>>>> >>>>>>>>>> Any H/D pair matching the above template where >>>>>>>>>> D(D) is simulated by the same H(D,D) that it calls >>>>>>>>>> cannot possibly reach its own line 06 and halt. >>>>>>>>>> >>>>>>>>>> *This is a simple software engineering verified fact* >>>>>>>>>> >>>>>>>>> >>>>>>>>> Note that olcott defines 'verified fact' as 'proven fact', but he is >>>>>>>>> unable to show the proof. So, it must be read as 'my belief'. >>>>>>>> >>>>>>>> A "proven fact" without a proof is not worse than a "verified fact" >>>>>>>> without a verification. >>>>>>>> >>>>>>> >>>>>>> *I updated my wording* >>>>>>> It is self-evidently true to anyone having sufficient knowledge >>>>>>> of the semantics of the C programming language. >>>>>> >>>>>> No, it is not. I would know if it were. >>>>>> >>>>> >>>>> If you do not understand that a single valid counter-example >>>>> would refute my claim then you don't know enough about proofs. >>>> >>>> Your claim >>>> >>> >>> Most people to not know the difference between deductive proof >>> ]and inductive evidence. >> >> Most people don't read comp.theory so here we needn't care. >> > > If anyone is trying to prove me wrong they > must first understand what an actual proof is. > > Several people here seem to think that ad hominem personal > attacks and insults are the basis for a valid rebuttal. > > Richard has stated that he thinks that an example of > {D never simulated by H} ∈ {every D simulated by H} More generally, everybody who knows what ∈ usually means, thinks that {} ∈ X is true unless it is a syntax error. > On 5/1/2024 7:28 PM, Richard Damon wrote: > Message-ID: > http://al.howardknight.net/?STYPE=msgid&MSGI=%3Cv0ummt%242qov3%242%40i2pn2.org%3E > > >>>>>>> It is self-evidently true to anyone having sufficient knowledge >>>>>>> of the semantics of the C programming language. >>>> >>>> is a little unclear about the meaning of "It" but I think it >>>> is false for any reasonable interpretation. Can I call myself >>>> a counter-example? As this question seems unanswered I thing it is best to say that you haven't proven that I am not a counter-example and therefore that a counter-example does not exist. -- Mikko