Path: ...!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 12:49:13 -0500 Organization: A noiseless patient Spider Lines: 72 Message-ID: References: <991dde3a60e1485815b789520c7149e7842d18f2@i2pn2.org> <-GOdnZvgEPn-84j1nZ2dnZfqn_SdnZ2d@brightview.co.uk> <2qydnbbWA6CAGIv1nZ2dnZfqn_SdnZ2d@brightview.co.uk> <87frhjamvt.fsf@bsb.me.uk> <313c6e5a3816ff483563120b589b22d1bc190c2f@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 19:49:14 +0200 (CEST) Injection-Info: dont-email.me; posting-host="4d3877b25e07ae675aebb853b858fd37"; logging-data="3551034"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+EbBBSXiUq5kFjf3MSEqXO" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:5vOsnBMT7LnDyVM18cbY8/EZcK0= X-Antivirus-Status: Clean Content-Language: en-US X-Antivirus: Norton (VPS 250506-4, 5/6/2025), Outbound message In-Reply-To: <313c6e5a3816ff483563120b589b22d1bc190c2f@i2pn2.org> Bytes: 5201 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. >>>>> >>>> >>>> >>>>      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. >>>> >>>> >>>> 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. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer