Path: ...!news.misty.com!weretis.net!feeder9.news.weretis.net!news.quux.org!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: "Fred. Zwarts" Newsgroups: comp.theory Subject: Re: DDD simulated by HHH cannot possibly halt (Halting Problem) --- mindless robots Date: Mon, 14 Apr 2025 19:15:59 +0200 Organization: A noiseless patient Spider Lines: 69 Message-ID: References: <852f89c9196e0261b8156050fea4572fe886933f@i2pn2.org> <63af93cb608258cc3e12b9bab3a2efa0b7ee7eee@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 14 Apr 2025 19:16:02 +0200 (CEST) Injection-Info: dont-email.me; posting-host="a048a74c664ee603a5cdc0003a866577"; logging-data="1796143"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18DPobRmBWp4+vMd0Pr1zfp" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:cfsrQfLi+jgmp2HB9oYXZRgaZjg= Content-Language: nl, en-GB In-Reply-To: Bytes: 5568 Op 14.apr.2025 om 13:56 schreef olcott: > On 4/14/2025 4:25 AM, joes wrote: >> Am Sun, 13 Apr 2025 21:11:56 -0500 schrieb olcott: >>> On 4/13/2025 6:11 PM, Richard Damon wrote: >>>> On 4/13/25 5:00 PM, olcott wrote: >>>>> On 4/13/2025 3:00 PM, dbush wrote: >>>>>> On 4/13/2025 3:59 PM, olcott wrote: >>>>>>> On 4/13/2025 3:54 AM, joes wrote: >>>>>>>> Am Fri, 11 Apr 2025 10:56:32 -0500 schrieb olcott: >>>>>>>>> On 4/11/2025 3:24 AM, Richard Heathfield wrote: >>>>>>>>>> On 11/04/2025 08:57, Mikko wrote: >> >>>>>>>>>> Mr Olcott can have his principle if he likes, but only by EITHER >>>>>>>>>> proving it (which, as you say, he has not yet done) OR by taking >>>>>>>>>> it as axiomatic, leaving the world of mainstream computer science >>>>>>>>>> behind him, >>>>>>>>>> constructing his own computational 'geometry' so to speak, and >>>>>>>>>> abandoning any claim to having overturned the Halting Problem. >>>>>>>>>> Navel contemplation beckons. >>>>>>>>>> Axioms are all very well, and he's free to invent as many as he >>>>>>>>>> wishes, but nobody else is obliged to accept them. >>>>>>>>>> >>>>>>>>> *Simulating termination analyzer Principle* >>>>>>>>> It is always correct for any simulating termination analyzer to >>>>>>>>> stop simulating and reject any input that would otherwise prevent >>>>>>>>> its own termination. >>>>>>>> Sure. Why doesn’t the STA simulate itself rejecting its input? >>>>>>>> >>>>>>> Because that is a STUPID idea and categorically impossible because >>>>>>> the outermost HHH sees its needs to stop simulating before any inner >>>>>>> HHH can possibly see this. >>>>>>> >>>>>> In other words, you agree that Linz and others are correct that no H >>>>>> exists that satisfies these requirements: >>>>>> Given any algorithm (i.e. a fixed immutable sequence of instructions) >>>>>> X described as with input Y: >>>>>> A solution to the halting problem is an algorithm H that computes the >>>>>> following mapping: >>>>>> (,Y) maps to 1 if and only if X(Y) halts when executed directly >>>>>> (,Y) maps to 0 if and only if X(Y) does not halt when executed >>>>>> directly >>>>>> >>>>> No stupid! Those freaking requirements are wrong and* >>>>> anchored in the ignorance  of rejecting the notion of a simulating >>>>> termination analyzer OUT-OF-HAND WITHOUT REVIEW. >>>> No, those "freeking requirement" *ARE* the requirements >>> AND AS STUPID AS {REQUIRING} A GEOMETRIC SQUARE CIRCLE IN THE SAME >>> TWO-DIMENSIONAL PLANE. >> Nothing is stupid about wanting a halt decider. It’s just not obvious >> that it’s impossible. >> > > When people insist that a termination analyzer reports > on behavior other than the behavior that its finite string > input specifies this is isomorphic to requiring a perfectly > geometric square circle in the same two dimensional plane, > simply logically impossible, thus an incorrect requirement. It is very clear what its finite string input specifies: when exactly this same finite string input is used in direct execution or in world-class simulators, we see that it specifies a halting program according to the unique semantics of the x86 language. It is not clear what a geometric square circle is. So, your comparison fails. But I think we agree that there is no algorithm that can determine for all possible inputs whether the input specifies a program that (according to the semantics of the machine language) halts when directly executed. Correct?