Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: dbush Newsgroups: comp.theory Subject: Re: How the requirements that Professor Sipser agreed to are exactly met Date: Mon, 12 May 2025 19:40:01 -0400 Organization: A noiseless patient Spider Lines: 154 Message-ID: References:

MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 13 May 2025 01:40:02 +0200 (CEST) Injection-Info: dont-email.me; posting-host="525f3751cca56668838a1ae1f1e0ddfb"; logging-data="1441986"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+7Ebyf+sca1IwEnvqs1xtS" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:wknTsw2JIaJNoNzWzJokH1s6o+I= In-Reply-To: Content-Language: en-US On 5/12/2025 7:36 PM, olcott wrote: > On 5/12/2025 6:24 PM, dbush wrote: >> On 5/12/2025 6:41 PM, olcott wrote: >>> On 5/12/2025 5:30 PM, dbush wrote: >>>> On 5/12/2025 6:28 PM, olcott wrote: >>>>> On 5/12/2025 4:54 PM, dbush wrote: >>>>>> On 5/12/2025 5:46 PM, olcott wrote: >>>>>>> On 5/12/2025 4:39 PM, dbush wrote: >>>>>>>> On 5/12/2025 5:12 PM, olcott wrote: >>>>>>>>> On 5/12/2025 3:29 PM, dbush wrote: >>>>>>>>>> On 5/12/2025 4:17 PM, olcott wrote: >>>>>>>>>>> On 5/12/2025 2:53 PM, dbush wrote: >>>>>>>>>>>> On 5/12/2025 2:27 PM, olcott wrote: >>>>>>>>>>>>> On 5/12/2025 1:20 PM, dbush wrote: >>>>>>>>>>>>>> On 5/12/2025 2:17 PM, olcott wrote: >>>>>>>>>>>>>>> Introduction to the Theory of Computation 3rd Edition >>>>>>>>>>>>>>> by Michael Sipser (Author) >>>>>>>>>>>>>>> 4.4 out of 5 stars 568 rating >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> https://www.amazon.com/Introduction-Theory-Computation- >>>>>>>>>>>>>>> Michael- Sipser/ dp/113318779X >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> int DD() >>>>>>>>>>>>>>> { >>>>>>>>>>>>>>> int Halt_Status = HHH(DD); >>>>>>>>>>>>>>> if (Halt_Status) >>>>>>>>>>>>>>> HERE: goto HERE; >>>>>>>>>>>>>>> return Halt_Status; >>>>>>>>>>>>>>> } >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> DD correctly simulated by any pure simulator >>>>>>>>>>>>>>> named HHH cannot possibly terminate thus proving >>>>>>>>>>>>>>> that this criteria has been met: >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>> 10/13/2022> >>>>>>>>>>>>>>> If simulating halt decider H correctly simulates its >>>>>>>>>>>>>>> input D until H correctly determines that its >>>>>>>>>>>>>>> simulated D >>>>>>>>>>>>>>> would never stop running unless aborted then >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> H can abort its simulation of D and correctly report >>>>>>>>>>>>>>> that D >>>>>>>>>>>>>>> specifies a non-halting sequence of configurations. >>>>>>>>>>>>>>> >>>>>>>>>>>>>> words 10/13/2022> >>>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> Which is not what you thought he agreed to: >>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> On Monday, March 6, 2023 at 2:41:27 PM UTC-5, Ben >>>>>>>>>>>>>> Bacarisse wrote: >>>>>>>>>>>>>> > I exchanged emails with him about this. He does not >>>>>>>>>>>>>> agree with anything >>>>>>>>>>>>>> > substantive that PO has written. I won't quote him, as >>>>>>>>>>>>>> I don't have >>>>>>>>>>>>>> > permission, but he was, let's say... forthright, in his >>>>>>>>>>>>>> reply to me. >>>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> *Ben already acknowledged that the requirements have been met* >>>>>>>>>>>>> >>>>>>>>>>>>> On 10/17/2022 10:23 AM, Ben Bacarisse wrote: >>>>>>>>>>>>> > ...D(D) would not halt unless H stops the simulation. >>>>>>>>>>>>> > H /can/ correctly determine this silly criterion (in >>>>>>>>>>>>> this one case)... >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Which is not what Sipser agreed to, as stated above. >>>>>>>>>>>> >>>>>>>>>>>> He agreed, as all others would, that H must determine if >>>>>>>>>>>> UTM(D) halts. >>>>>>>>>>> >>>>>>>>>>> That is not what Ben's words mean. >>>>>>>>>>> >>>>>>>>>>> On 10/14/2022 7:44 PM, Ben Bacarisse wrote: >>>>>>>>>>> > I don't think that is the shell game. PO really /has/ an H >>>>>>>>>>> > (it's trivial to do for this one case) that correctly >>>>>>>>>>> determines >>>>>>>>>>> > that P(P) *would* never stop running *unless* aborted. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> 10/13/2022> >>>>>>>>>>> H correctly determines that its simulated D >>>>>>>>>>> would never stop running unless aborted... >>>>>>>>>>> >>>>>>>>>>> *its simulated D* >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Which Sipser (and everyone else) takes to mean UTM(D), >>>>>>>>> >>>>>>>>> *its simulated D* cannot be *correctly* understood >>>>>>>>> to mean a D simulated by anything else other than >>>>>>>>> a hypothetical H that never aborts. >>>>>>>> >>>>>>>> False. It cannot be *correctly* understood to be anything else >>>>>>>> but the algorithm D simulated completely by a UTM, >>>>>>> >>>>>>> An H that never aborts a UTM. >>>>>> >>>>>> In which case you don't have algorithm D. You instead have >>>>>> algorithm Dn. >>>>>> >>>>> >>>>> *its simulated D would never stop running unless aborted* >>>>> can only mean one thing. >>>> >>>> And what it means is changing the input. >>>> >>>> Changing the input is not allowed. >>> >>> So professor Sisper was wrong? >>> >> >> He didn't agree to what you think he did: >> >> On Monday, March 6, 2023 at 2:41:27 PM UTC-5, Ben Bacarisse wrote: >> > I exchanged emails with him about this. He does not agree with >> anything >> > substantive that PO has written. I won't quote him, as I don't have >> > permission, but he was, let's say... forthright, in his reply to me. >> >> >> On 8/23/2024 5:07 PM, Ben Bacarisse wrote: >> > I suspect he was tricked because PO used H and D as the names without >> > making it clear that D was constructed from H in the usual way (Sipser >> > uses H and D in at least one of his proofs). Of course, he is >> clued in >> > enough know that, if D is indeed constructed from H like that, the >> > "minor remark" becomes true by being a hypothetical: if the moon is >> made >> > of cheese, the Martians can look forward to a fine fondue. But, >> > personally, I think the professor is more straight talking than that, >> > and he simply took as a method that can work for some inputs. That's >> > the only way is could be seen as a "minor remark" with being >> accused of >> > being disingenuous. >> >> On 8/23/2024 9:10 PM, Mike Terry wrote: >> > So that PO will have no cause to quote me as supporting his case: >> what >> > Sipser understood he was agreeing to was NOT what PO interprets it as >> > meaning. Sipser would not agree that the conclusion applies in PO's >> > HHH(DDD) scenario, where DDD halts. >> > > This can only have one meaning: > *its simulated D would never stop running unless aborted* And that meaning is "changing the input" Changing the input is not allowed.