Path: ...!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: olcott Newsgroups: comp.theory Subject: Re: Functions computed by Turing Machines MUST apply finite string transformations to inputs --- MT Date: Tue, 6 May 2025 15:38:25 -0500 Organization: A noiseless patient Spider Lines: 66 Message-ID: References: <-GOdnZvgEPn-84j1nZ2dnZfqn_SdnZ2d@brightview.co.uk> <2qydnbbWA6CAGIv1nZ2dnZfqn_SdnZ2d@brightview.co.uk> <87frhjamvt.fsf@bsb.me.uk> <313c6e5a3816ff483563120b589b22d1bc190c2f@i2pn2.org> <5acc22f83441f7be0be1dbb0bb3dbb26a90a7b38@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 06 May 2025 22:38:26 +0200 (CEST) Injection-Info: dont-email.me; posting-host="4d3877b25e07ae675aebb853b858fd37"; logging-data="3903396"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19d/1Il7kArNlwplkMVLjV3" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:Zj5fu/YEB1AL7e8QymwSXAMrawY= X-Antivirus: Norton (VPS 250506-6, 5/6/2025), Outbound message Content-Language: en-US X-Antivirus-Status: Clean In-Reply-To: <5acc22f83441f7be0be1dbb0bb3dbb26a90a7b38@i2pn2.org> Bytes: 5243 On 5/6/2025 3:25 PM, joes wrote: > Am Tue, 06 May 2025 12:49:13 -0500 schrieb olcott: >> On 5/6/2025 6:23 AM, Richard Damon wrote: >>> On 5/5/25 10:36 PM, olcott wrote: >>>> On 5/5/2025 8:23 PM, Richard Damon wrote: >>>>> On 5/4/25 9:23 PM, olcott wrote: >>>>>> On 5/4/2025 8:04 PM, Ben Bacarisse wrote: >>>>>>> Mike Terry writes: >>>>>>> ... >>>>>>>> As explained above, UTM(⟨Ĥ⟩ ⟨Ĥ⟩) simulates Ĥ run with input Ĥ >>>>>>>> (having the same halting behaviour) and Ĥ run with input Ĥ HALTS. >>>>>>>> So embedded_H does not "gather enough information to deduce that >>>>>>>> UTM(⟨Ĥ⟩ ⟨Ĥ⟩) would never halt".  THAT IS JUST A FANTASY THAT YOU >>>>>>>> HAVE. >>>>>>>> UTM(⟨Ĥ⟩ ⟨Ĥ⟩) DOES halt, so embedded_H can't possibly gather >>>>>>>> information that genuinely implies it DOESN'T halt.  The >>>>>>>> explanation is obvious: embedded_H gathers information that *YOU* >>>>>>>> believe implies that UTM(⟨Ĥ⟩ ⟨Ĥ⟩) >>>>>>>> would never halt, but *YOU ARE SIMPLY WRONG*. >>>>>>> >>>>>>> He used to claim that false ("does not halt") was the correct >>>>>>> answer, >>>>>>> /even though/ the computation in question halts!  Those were >>>>>>> simpler days.  Of course cranks will never admit to having been >>>>>>> wrong about anything other than a detail or two, so anyone who >>>>>>> could be bothered could try to get him to retract that old claim. >>>>>>> >>>>>> >>>>> 10/13/2022> >>>>>> >>>>> 10/13/2022> >>>>>> >>>>>> When Ĥ is applied to ⟨Ĥ⟩ >>>>>> Ĥ.q0 ⟨Ĥ⟩ ⊢* embedded_H ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥ.qy ∞ >>>>>> Ĥ.q0 ⟨Ĥ⟩ ⊢* embedded_H ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥ.qn >>>>>> >>>>>> In other words embedded_H ⟨Ĥ⟩ ⟨Ĥ⟩ is correct to reject its input if >>>>>> >>>>>> Ĥ.q0 ⟨Ĥ⟩ ⊢* UTM ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥ.qy ∞ >>>>>> Ĥ.q0 ⟨Ĥ⟩ ⊢* UTM ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥ.qn Would not halt. >>>>> >>>>> Nope, because that isn't the input that it was given. >>>> >>>> *Wrong* >>>> >>>>      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 >>>> >>>> *simulated D would never stop running unless aborted* >>>> simulated D (the actual input) >>>> never stop running unless aborted (hypothetical H/D pair) >>>> >>> No, that is changing the input. >>> >> *would never stop running unless aborted* means the hypothetical same >> HHH that DD calls except that this HHH does not abort. > Yes, that is not the same HHH. > Yet is the HHH that Professor Sipser agreed would be the correct measure of the behavior of the actual input. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer