Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: olcott <polcott333@gmail.com>
Newsgroups: comp.theory
Subject: Re: Defining a correct simulating halt decider
Date: Wed, 4 Sep 2024 08:04:13 -0500
Organization: A noiseless patient Spider
Lines: 78
Message-ID: <vb9lsd$3rh1t$1@dont-email.me>
References: <vb4plc$2tqeg$1@dont-email.me> <vb4u1g$2u7sn$4@dont-email.me>
 <vb59cg$3057o$1@dont-email.me>
 <f0ff8a5345087a3b89853b26af12e38d433afc7b@i2pn2.org>
 <vb7l68$3efl8$1@dont-email.me> <vb99je$3plip$2@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Wed, 04 Sep 2024 15:04:14 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="dd43bdf9b61f877c9b4c44ca800456cb";
	logging-data="4047933"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1+zEGksev0VEOxTLy2fKusZ"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:tCemXFmyywEN/0nw4Afd7pDtPWI=
Content-Language: en-US
In-Reply-To: <vb99je$3plip$2@dont-email.me>
Bytes: 4089

On 9/4/2024 4:34 AM, Fred. Zwarts wrote:
> Op 03.sep.2024 om 20:40 schreef olcott:
>> On 9/3/2024 9:42 AM, joes wrote:
>>> Am Mon, 02 Sep 2024 16:06:24 -0500 schrieb olcott:
>>>> On 9/2/2024 12:52 PM, Fred. Zwarts wrote:
>>>>> Op 02.sep.2024 om 18:38 schreef olcott:
>>>>>> A halt decider is a Turing machine that computes the mapping from its
>>>>>> finite string input to the behavior that this finite string 
>>>>>> specifies.
>>>>>> If the finite string machine string machine description specifies 
>>>>>> that
>>>>>> it cannot possibly reach its own final halt state then this machine
>>>>>> description specifies non-halting behavior.
>>> Which DDD does not.
>>
>> DDD emulated by HHH cannot possibly reach
>> its final halt state no matter what HHH does.
>>
>>>>>> A halt decider never ever computes the mapping for the computation
>>>>>> that itself is contained within.
>>> Then it is not total.
>>
>> Yes it is you are wrong.
>>
>>>>>> Unless there is a pathological relationship between the halt 
>>>>>> decider H
>>>>>> and its input D the direct execution of this input D will always have
>>>>>> identical behavior to D correctly simulated by simulating halt 
>>>>>> decider
>>>>>> H.
>>> Which makes this pathological input a counterexample.
>>
>> Which makes the pathological input a counter-example
>> to the false assumption that the direct execution of
>> a machine always has the same behavior as the machine
>> simulated by its pathological simulator.
>>
>>>>>> A correct emulation of DDD by HHH only requires that HHH emulate the
>>>>>> instructions of DDD** including when DDD calls HHH in recursive
>>>>>> emulation such that HHH emulates itself emulating DDD.
>>>>> Indeed, it should simulate *itself* and not a hypothetical other HHH
>>>>> with different behaviour.
>>>> It is emulating the exact same freaking machine code that the x86utm
>>>> operating system is emulating.
>>
>>> It is not simulating the abort because of a static variable. Why?
>>>
>>
>> void DDD()
>> {
>>    HHH(DDD);
>>    OutputString("This code is unreachable by DDD emulated by HHH");
>> }
>>
>>>>> If HHH includes code to see a 'special condition' and aborts and 
>>>>> halts,
>>>>> then it should also simulate the HHH that includes this same code and
>>>> DDD has itself and the emulated HHH stuck in recursive emulation.
>>
>>> Your HHH incorrectly changes behaviour.
>>>
>>
>> No you are wrong !!!
>>
> 
> Yes it does. HHH simulates only a few recursions, then it sees a 
> 'special condition', stops the simulation, returns to DDD and DDD halts.

void DDD()
{
   HHH(DDD); // Fred lacks the software engineering skill to understand
   OutputString("This code is unreachable from DDD emulated by HHH");
}


-- 
Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius
hits a target no one else can see." Arthur Schopenhauer