Path: ...!weretis.net!feeder9.news.weretis.net!i2pn.org!i2pn2.org!.POSTED!not-for-mail
From: Richard Damon <richard@damon-family.org>
Newsgroups: comp.theory,sci.logic
Subject: Re: Why does Olcott care about simulation, anyway?
Date: Mon, 3 Jun 2024 20:59:40 -0400
Organization: i2pn2 (i2pn.org)
Message-ID: <v3lots$2uv04$14@i2pn2.org>
References: <v3j20v$3gm10$2@dont-email.me> <v3jt2s$3qblu$1@dont-email.me>
 <HlGdnbvc3Ly_YsD7nZ2dnZfqn_adnZ2d@brightview.co.uk>
 <v3l0i0$5d3$2@dont-email.me>
 <lBmcnX-HlodbjMP7nZ2dnZfqn_idnZ2d@brightview.co.uk>
 <v3lo7l$3sil$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Tue, 4 Jun 2024 00:59:40 -0000 (UTC)
Injection-Info: i2pn2.org;
	logging-data="3111940"; mail-complaints-to="usenet@i2pn2.org";
	posting-account="diqKR1lalukngNWEqoq9/uFtbkm5U+w3w6FQ0yesrXg";
User-Agent: Mozilla Thunderbird
X-Spam-Checker-Version: SpamAssassin 4.0.0
In-Reply-To: <v3lo7l$3sil$1@dont-email.me>
Content-Language: en-US
Bytes: 9629
Lines: 198

On 6/3/24 8:47 PM, olcott wrote:
> On 6/3/2024 1:56 PM, Mike Terry wrote:
>> On 03/06/2024 19:03, olcott wrote:
>>> On 6/3/2024 12:36 PM, Mike Terry wrote:
>>>> On 03/06/2024 08:58, Fred. Zwarts wrote:
>>>>> Op 03.jun.2024 om 02:16 schreef immibis:
>>>>>> The halting problem says you can't find a Turing machine that 
>>>>>> tells whether executing each other Turing machine will halt. 
>>>>>> Simulation has nothing to do with the question.
>>>>>
>>>>> Maybe because by using simulation he can shift the attention from 
>>>>> the pathological part of the Linz proof, to another halting 
>>>>> problem, namely that a simulating decider does not halt because it 
>>>>> causes infinite recursion.
>>>>
>>>> PO's simulating decider does not cause infinite recursion.  That 
>>>> only occurs in the case where the decider performs a FULL simulation 
>>>> of its input, whereas typically for PO his H/HH/... perform PARTIAL 
>>>> simulations, where the decider monitors what is being simulated and 
>>>> breaks off the simulation when a particular condition is observed.
>>>>
>>>
>>> Thanks for affirming that. You are my most technically
>>> competent and honest reviewer.
>>>
>>>> So yes, there is recursive simulation, but not /infinite/ recursion 
>>>> since at each level of simulation the simulator is free to just stop 
>>>> simulating at any time.  In practice this means that the outer 
>>>> simulator H will be the one to break out, since it will always be 
>>>> ahead of all the inner simulations of H in how far it has 
>>>> progressed.  This situation is in contrast with direct call 
>>>> recursion, where the outer caller has no control to break the 
>>>> recursion - it only regains control once the inner calls have all 
>>>> returned.
>>>>
>>>> PO does not properly understand this distinction.
>>>>
>>>
>>> *You can keep ignoring this that does not make it go away*
>>>
>>> On 10/13/2022 11:29:23 AM
>>> MIT Professor Michael Sipser agreed this verbatim paragraph is correct
>>> (He has neither reviewed nor agreed to anything else in this paper)
>>>
>>> <Professor Sipser agreed>
>>> 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.
>>> </Professor Sipser agreed>
>>>
>>> *You can ignore the above forever, that does not make it away*
>>
>> I do not ignore the above.  I recently posted an example of it: a 
>> simulating HD correctly reporting non-halting after detecting a tight 
>> loop in the computation represented by its input.
>>
>> The problem with the above is with YOU.  (You misinterpret/misapply 
>> what Sipser says.)
>>
>> And of course your entire purpose behind quoting the above is just an 
>> appeal to authority.  You know that's a fallacy, because from time to 
>> time you accuse others of doing it.
>>
>>>
>>>>>
>>>>> His own claim that D does not reach the pathological part (after 
>>>>> line 03), displays already that the simulation is unable to process 
>>>>> the pathological part. But the simulation introduces a new halting 
>>>>> problem (recursive simulation), which he thinks is an answer for 
>>>>> the original halting problem.
>>>>
>>>> You're using PO's phrase "pathological" but that is a bad 
>>>> (misleading) term because it suggests there is something WRONG/BAD 
>>>> (aka sick?) in the situation.  E.g. H processing input which is a 
>>>> description of its own source code.  There is nothing whatsoever 
>>>> wrong with that - it's just that PO gets confused by it and so 
>>>> argues to ban it.  Perhaps there  is an alternative term that 
>>>> doesn't have the deliberate connotation of "sickness".
>>>>
>>>> Mike.
>>>>
>>>
>>> *Two PhD computer science professors disagree*
>>>
>>> E C R Hehner. *Problems with the Halting Problem*, COMPUTING2011 
>>> Symposium on 75 years of Turing Machine and Lambda-Calculus, 
>>> Karlsruhe Germany, invited, 2011 October 20-21; Advances in Computer 
>>> Science and Engineering v.10 n.1 p.31-60, 2013
>>> https://www.cs.toronto.edu/~hehner/PHP.pdf
>>>
>>> E C R Hehner. *Objective and Subjective Specifications*
>>> WST Workshop on Termination, Oxford.  2018 July 18.
>>> See https://www.cs.toronto.edu/~hehner/OSS.pdf
>>>
>>> Bill Stoddart. *The Halting Paradox*
>>> 20 December 2017
>>> https://arxiv.org/abs/1906.05340
>>> arXiv:1906.05340 [cs.LO]
>>>
>>> *You can ignore the above forever, that does not make it away*
>>>
>>
>> Well, it kinda DOES.  This is just a blatant appeal to authority on 
>> your part, so it can rightly be ignored.  I'll say again - if you have 
>> some argument to make, argue it yourself in your own words rather than 
>> attempting to shut down discussion through appeal to authority.
>>
> 
> *Those were my verbatim words that professor Sipser agreed to*
> All the people that tried to show how I misinterpreted my own words
> utterly failed.
> 
> Those that claimed Professor Sipser understood my words differently than
> I did had only one basis that I remember being presented that is easily
> proven false. *They tried to get away with contradicting this*
> 
> DD correctly emulated by any HH that can possibly exist DOES NOT HALT
> DD correctly emulated by any HH that can possibly exist DOES NOT HALT
> DD correctly emulated by any HH that can possibly exist DOES NOT HALT

It does.

Has been proven.

You just don't know the meaning of the words you are using.

DD(DD) HALTS if HH(DD,DD) returns 0, and for your design, the only other 
case is an HH that isn't a decider.

What you actually seem to be claiming is that no HH can correctly 
simulate the DD built on it to a final state, or equivalently, No HH can 
prove that the DD built on it will Halt.

Neither of these show that DD doesn't Halt, only that HH's simulation 
can't get there.


> 
> typedef int (*ptr)();  // ptr is pointer to int function in C
> 00       int HH(ptr p, ptr i);
> 01       int DD(ptr p)
> 02       {
> 03         int Halt_Status = HH(p, p);
> 04         if (Halt_Status)
> 05           HERE: goto HERE;
> 06         return Halt_Status;
> 07       }
> 
> _DD()
> [00001c22] 55         push ebp
> [00001c23] 8bec       mov ebp,esp
> [00001c25] 51         push ecx
> [00001c26] 8b4508     mov eax,[ebp+08]
> [00001c29] 50         push eax        ; push DD 1c22
> [00001c2a] 8b4d08     mov ecx,[ebp+08]
> [00001c2d] 51         push ecx        ; push DD 1c22
> [00001c2e] e80ff7ffff call 00001342   ; call HH
> [00001c33] 83c408     add esp,+08
> [00001c36] 8945fc     mov [ebp-04],eax
> [00001c39] 837dfc00   cmp dword [ebp-04],+00
> [00001c3d] 7402       jz 00001c41
> [00001c3f] ebfe       jmp 00001c3f
> [00001c41] 8b45fc     mov eax,[ebp-04]
> [00001c44] 8be5       mov esp,ebp
> [00001c46] 5d         pop ebp
> [00001c47] c3         ret
> Size in bytes:(0038) [00001c47]
> 
>> [Perhaps Hehner/Stoddart are just idiots who got things wrong, or much 
>> more likely you've completely misinterpreted what they're saying, or 
>> you've misunderstood the context or whatever and you are the idiot.  
========== REMAINDER OF ARTICLE TRUNCATED ==========