Path: news.eternal-september.org!eternal-september.org!feeder3.eternal-september.org!news.quux.org!news.nk.ca!rocksolid2!i2pn2.org!.POSTED!not-for-mail From: Richard Damon Newsgroups: comp.theory Subject: Re: Functions computed by Turing Machines MUST apply finite string transformations to inputs --- MT Date: Mon, 5 May 2025 21:23:45 -0400 Organization: i2pn2 (i2pn.org) Message-ID: References: <991dde3a60e1485815b789520c7149e7842d18f2@i2pn2.org> <-GOdnZvgEPn-84j1nZ2dnZfqn_SdnZ2d@brightview.co.uk> <2qydnbbWA6CAGIv1nZ2dnZfqn_SdnZ2d@brightview.co.uk> <87frhjamvt.fsf@bsb.me.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 6 May 2025 01:28:11 -0000 (UTC) Injection-Info: i2pn2.org; logging-data="3311256"; mail-complaints-to="usenet@i2pn2.org"; posting-account="diqKR1lalukngNWEqoq9/uFtbkm5U+w3w6FQ0yesrXg"; User-Agent: Mozilla Thunderbird X-Spam-Checker-Version: SpamAssassin 4.0.0 Content-Language: en-US In-Reply-To: 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. Ĥ doesn't use a UTM (unless H is actually such a machine). H is allowed to abort its emulaiton if UTM (Ĥ) (Ĥ) would never halt, but UTM (Ĥ) (Ĥ) sees that Ĥ (Ĥ) ⊢* embedded_H ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥ.qn since embedded_H is the same as H and your H does do that, and thus H never had the needed proof to do that, so it made an error. You are just showing that you idea of "logic" is based on just lying about what words mean. > >>> I know you'll not understand what I've just said, because it is all too >>> abstract and you don't understand the concepts involved, and >>> consequently >>> you probably don't agree with my Sipser interpretation, and even if >>> you did >>> I doubt you would be able to work out its consequences.  So I don't >>> expect >>> to be posting any further. >> >> Not you then!  I sympathise, though my reason for not talking to him is >> his unacceptable insults. >> > >