Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: dbush Newsgroups: comp.theory Subject: Re: Every sufficiently competent C programmer knows --- Paraphrase of Sipser's agreement Date: Sat, 15 Mar 2025 18:35:28 -0400 Organization: A noiseless patient Spider Lines: 164 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 15 Mar 2025 23:35:28 +0100 (CET) Injection-Info: dont-email.me; posting-host="22e85aca536ab619b45b62b85c20fbc6"; logging-data="472184"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+kWyK13tjmmtGTAsGcbWjJ" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:NaMzvMUD7bK5E4Qud0ORWssMG5w= In-Reply-To: Content-Language: en-US Bytes: 8072 On 3/15/2025 5:27 PM, olcott wrote: > On 3/15/2025 5:12 AM, Mikko wrote: >> On 2025-03-14 14:39:30 +0000, olcott said: >> >>> On 3/14/2025 4:03 AM, Mikko wrote: >>>> On 2025-03-13 20:56:22 +0000, olcott said: >>>> >>>>> On 3/13/2025 4:22 AM, Mikko wrote: >>>>>> On 2025-03-13 00:36:04 +0000, olcott said: >>>>>> >>>>>>> >>>>>>> void DDD() >>>>>>> { >>>>>>>    HHH(DDD); >>>>>>>    return; >>>>>>> } >>>>>>> >>>>>>> int DD() >>>>>>> { >>>>>>>    int Halt_Status = HHH(DD); >>>>>>>    if (Halt_Status) >>>>>>>      HERE: goto HERE; >>>>>>>    return Halt_Status; >>>>>>> } >>>>>>> >>>>>>> When HHH correctly emulates N steps of the >>>>>>> above functions none of them can possibly reach >>>>>>> their own "return" instruction and terminate normally. >>>>>> >>>>>> Nevertheless, assuming HHH is a decider, Infinite_Loop and >>>>>> Infinite_Recursion >>>>>> specify a non-terminating behaviour, DDD specifies a terminating >>>>>> behaviour >>>>> >>>>> _DDD() >>>>> [00002172] 55         push ebp      ; housekeeping >>>>> [00002173] 8bec       mov  ebp,esp  ; housekeeping >>>>> [00002175] 6872210000 push 00002172 ; push DDD >>>>> [0000217a] e853f4ffff call 000015d2 ; call HHH(DDD) >>>>> [0000217f] 83c404     add  esp,+04 >>>>> [00002182] 5d         pop  ebp >>>>> [00002183] c3         ret >>>>> Size in bytes:(0018) [00002183] >>>>> >>>>> What is the sequence of machine language >>>>> instructions of DDD emulated by HHH such that DDD >>>>> reaches its machine address 00002183? >>>> >>>> Irrelevant off-topic distraction. >>> >>> Proving that you don't have a clue that Rice's Theorem >>> is anchored in the behavior that its finite string input >>> specifies. The depth of your knowledge is memorizing >>> quotes from textbooks. >> >> Another irrelevant off-topic distraction, this time involving >> a false claim. >> >> One can be a competent C programmer without knowing anyting about Rice's >> Theorem. >> > > YES. > >> Rice's Theorem is about semantic properties in general, not just >> behaviours. >> The unsolvability of the halting problem is just a special case. >> > > A property about Turing machines can be represented as the language of > all Turing machines, encoded as strings, that satisfy that property. > http://kilby.stanford.edu/~rvg/154/handouts/Rice.html > > Does THE INPUT TO simulating termination analyzer > HHH encode a C function that reaches its "return" > instruction [WHEN SIMULATED BY HHH] (The definition > of simulating termination analyzer) ??? > > >     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. > > But 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: > Fritz Feldhase writes: > > > On Monday, March 6, 2023 at 3:56:52 AM UTC+1, olcott wrote: > >> On 3/5/2023 8:33 PM, Fritz Feldhase wrote: > >> > On Monday, March 6, 2023 at 3:30:38 AM UTC+1, olcott wrote: > >> > > > >> > > I needed Sipser for people [bla] > >> > > > >> > Does Sipser support your view/claim that you have refuted the halting theorem? > >> > > >> > Does he write/teach that the halting theorem is invalid? > >> > > >> > Tell us, oh genius! > >> > > >> Professor Sipser only agreed that [...] > > > > So the answer is no. Noted. > > > >> Because he has >250 students he did not have time to examine anything > >> else. [...] > > > > Oh, a CS professor does not have the time to check a refutation of the > > halting theorem. *lol* > 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: > joes writes: > >> Am Wed, 21 Aug 2024 20:55:52 -0500 schrieb olcott: > >>> Professor Sipser clearly agreed that an H that does a finite simulation >>> of D is to predict the behavior of an unlimited simulation of D. >> >> If the simulator *itself* would not abort. The H called by D is, >> by construction, the same and *does* abort. > > We don't really know what context Sipser was given. I got in touch at > the time so do I know he had enough context to know that PO's ideas were > "wacky" and that had agreed to what he considered a "minor remark". > > Since PO considers his words finely crafted and key to his so-called > work I think it's clear that Sipser did not take the "minor remark" he > agreed to to mean what PO takes it to mean! My own take if that he > (Sipser) read it as a general remark about how to determine some cases, > i.e. that D names an input that H can partially simulate to determine > it's halting or otherwise. We all know or could construct some such > cases. > > 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.