Path: ...!news.mixmin.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Mikko <mikko.levanto@iki.fi>
Newsgroups: comp.theory
Subject: Re: DDD correctly emulated by HHH is Correctly rejected as non-halting V2
Date: Tue, 23 Jul 2024 09:32:57 +0300
Organization: -
Lines: 67
Message-ID: <v7niqp$13ghd$1@dont-email.me>
References: <v6rg65$32o1o$3@dont-email.me> <v6v2t1$3pmjn$3@dont-email.me> <3fc6548531f91ed14a27420caf9679a634573ed0@i2pn2.org> <v70lmo$61d8$1@dont-email.me> <8a6e6d9ff49aabe2525ce5729a439c807de4768a@i2pn2.org> <34Ocnd4voeWlDAn7nZ2dnZfqnPudnZ2d@brightview.co.uk> <v725d7$hlvg$1@dont-email.me> <aa7643b6d8c46d2c4dd5ef92ae3650afe114adbb@i2pn2.org> <v734ct$mjis$2@dont-email.me> <056325e336f81a50f4fb9e60f90934eaac823d22@i2pn2.org> <v73gk2$obtd$1@dont-email.me> <e2958e7ea04d53590c79b53bfb4bc9dff468772b@i2pn2.org> <v742r2$s48s$2@dont-email.me> <210383b2ee318f68a96d94aec314ee8b93f79b7f@i2pn2.org> <v75u22$19j7l$4@dont-email.me> <fde630817c49562bc765bdbc98e16a1582bcad53@i2pn2.org> <v78mda$1smtm$2@dont-email.me> <v7d5cl$2t3ja$1@dont-email.me> <v7ds0o$30pvh$3@dont-email.me> <v7fs29$3f4g7$1@dont-email.me> <v7gd17$3hlc2$2@dont-email.me> <v7ikn4$1jv5$1@dont-email.me> <v7j2pg$3o7r$3@dont-email.me> <v7l3di$idv1$1@dont-email.me> <v7lnrf$luh0$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Tue, 23 Jul 2024 08:32:58 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="b538c18a808e7b1dbb2e6c99920961e5";
	logging-data="1163821"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX19cAnWSg9qinNLVzHcuVWp1"
User-Agent: Unison/2.2
Cancel-Lock: sha1:8Lu+ua3sJjchcD96STlEPZ0gsTM=
Bytes: 4292

On 2024-07-22 13:46:21 +0000, olcott said:

> On 7/22/2024 2:57 AM, Mikko wrote:
>> On 2024-07-21 13:34:40 +0000, olcott said:
>> 
>>> On 7/21/2024 4:34 AM, Mikko wrote:
>>>> On 2024-07-20 13:11:03 +0000, olcott said:
>>>> 
>>>>> On 7/20/2024 3:21 AM, Mikko wrote:
>>>>>> On 2024-07-19 14:08:24 +0000, olcott said:
>>>>>> 
>>>>>>> When we use your incorrect reasoning we would conclude
>>>>>>> that Infinite_Loop() is not an infinite loop because it
>>>>>>> only repeats until aborted and is aborted.
>>>>>> 
>>>>>> You and your HHH can reason or at least conclude correctly about
>>>>>> Infinite_Loop but not about DDD. Possibly because it prefers to
>>>>>> say "no", which is correct about Infinte_loop but not about DDD.
>>>>>> 
>>>>> 
>>>>> *Because this is true I don't understand how you are not simply lying*
>>>>> int main
>>>>> {
>>>>>    DDD();
>>>>> }
>>>>> 
>>>>> Calls HHH(DDD) that must abort the emulation of its input
>>>>> or {HHH, emulated DDD and executed DDD} never stop running.
>>>> 
>>>> You are the lying one.
>>>> 
>>>> If HHH(DDD) abrots its simulation and returns true it is correct as a
>>>> halt decider for DDD really halts.
>>>> 
>>> 
>>> (b) We know that a decider is not allowed to report on the behavior
>>> computation that itself is contained within.
>> 
>> No, we don't. There is no such prohibition.
>> 
> 
> Turing machines never take actual Turing machines as inputs.
> They only take finite strings as inputs and an actual executing
> Turing machine is not itself a finite string.

The definition of a Turing machine does not say that a Turing machine
is not a finite string. It is an abstract mathematical object without
a specification of its exact nature. It could be a set or a finite
string. Its exact nature is not relevant to the theory of computation,
which only cares about certain properties of Turing machines.

> Therefore It is not allowed to report on its own behavior.

Anyway, that does not follow. The theory of Turing machines does not
prohibit anything.

> Another different TM can take the TM description of this
> machine and thus accurately report on its actual behavior.

If a Turing machine can take a description of a TM as its input
or as a part of its input it can also take its own description.
Every Turing machine can be given its own description as input
but a Turing machine may interprete it as something else.

-- 
Mikko