Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: "Fred. Zwarts" <F.Zwarts@HetNet.nl>
Newsgroups: comp.theory
Subject: Re: Turing Machine computable functions MUST apply finite string
 transformations to inputs
Date: Fri, 2 May 2025 10:43:01 +0200
Organization: A noiseless patient Spider
Lines: 54
Message-ID: <vv20im$lg4h$1@dont-email.me>
References: <TuuNP.2706011$nb1.2053729@fx01.ams4>
 <87cyd5182l.fsf@nosuchdomain.example.com> <vu6lnf$39fls$2@dont-email.me>
 <vugddv$b21g$2@dont-email.me> <vui4uf$20dpc$1@dont-email.me>
 <vuivtb$2lf64$3@dont-email.me> <vungtl$2v2kr$1@dont-email.me>
 <vuoaac$3jn5n$5@dont-email.me> <vuq81v$1hjka$1@dont-email.me>
 <vutefq$gmbi$3@dont-email.me>
 <991dde3a60e1485815b789520c7149e7842d18f2@i2pn2.org>
 <vuti3c$jq57$1@dont-email.me> <vutmr6$nvbg$2@dont-email.me>
 <vutv7r$v5pn$4@dont-email.me> <vuu73m$151a8$3@dont-email.me>
 <vuuej8$1cqp7$1@dont-email.me> <vuur2n$1qe3m$2@dont-email.me>
 <vv0352$2ur4q$1@dont-email.me> <vv0kpi$3djh5$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Fri, 02 May 2025 10:43:02 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="20e0c4296e2d221d792ddfac2ba55e92";
	logging-data="704657"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/2tslj6ReH2C8GnV9DkxNz"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:O5CAyrdsjPljQS7kswModLQZ4H8=
Content-Language: nl, en-GB
In-Reply-To: <vv0kpi$3djh5$1@dont-email.me>

Op 01.mei.2025 om 22:15 schreef olcott:
> On 5/1/2025 10:14 AM, André G. Isaak wrote:
>> On 2025-04-30 21:50, olcott wrote:
>>> On 4/30/2025 7:17 PM, André G. Isaak wrote:
>>
>>>> You are still hopelessly confused about your terminology.
>>>>
>>>> Computable functions are a subset of mathematical functions, and 
>>>> mathematical functions are *not* the same thing as C functions. 
>>>> Functions do not apply "transformations". They are simply mappings, 
>>>> and a functions which maps every pair of natural numbers to 5 is a 
>>>> perfectly legitimate, albeit not very interesting, function.
>>>>
>>>> What makes this function a *computable function* is that fact that 
>>>> it is possible to construct a C function (or a Turing Machine, or 
>>>> some other type of algorithm) such as int foo(int x, int y) {return 
>>>> 5;} which computes that particular function; but the C function and 
>>>> the computable function it computes are entirely separate entities.
>>>
>>> computes the sum of two integers
>>> by transforming the inputs into an output.
>>> int sum(int x, int y) { return x + y; }
>>>
>>> Computes no function because it ignores its inputs.
>>> int sum(int x, int y) { return 5; }
>>
>> All you're demonstrating here is that you have no clue what a function 
>> is, nor, apparently, do you have any desire to learn.
>>
>> André
>>
> 
> What I am explaining is that a halt decider
> must compute the mapping FROM THE INPUTS ONLY
> by applying a specific set of finite string
> transformations to the inputs.
> 
> int DD()
> {
>    int Halt_Status = HHH(DD);
>    if (Halt_Status)
>      HERE: goto HERE;
>    return Halt_Status;
> }
> 
A correct decider would use finite string transformations and conclude 
that the input describes a halting program. This is possible, because 
the direct execution and world-class simulators perform those 
transformations correctly. A program that is not able to do the correct 
finite string transformation is just an erroneous program, even if it 
does not crash by violations of the x86 code.
The input to HHH describes a halting program, but HHH has a bug so that 
it does not complete the finite string transformations, but it aborts 
them prematurely.