Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: olcott <polcott333@gmail.com>
Newsgroups: comp.lang.c,comp.lang.c++
Subject: Re: Can someone please verify the execution trace of this?
Date: Mon, 20 May 2024 14:40:32 -0500
Organization: A noiseless patient Spider
Lines: 113
Message-ID: <v2g8vg$551c$4@dont-email.me>
References: <v2b78t$2vima$1@dont-email.me>
 <v2df79$3ghfd$1@raubtier-asyl.eternal-september.org>
 <v2di7v$3gujt$1@dont-email.me>
 <v2eada$3p6sk$1@raubtier-asyl.eternal-september.org>
 <v2edbr$3pl2i$1@dont-email.me>
 <v2eluk$3r1qu$1@raubtier-asyl.eternal-september.org>
 <v2enl9$3r9t0$1@dont-email.me>
 <v2erbb$3rt3e$1@raubtier-asyl.eternal-september.org>
 <v2fnqq$1hhg$1@dont-email.me>
 <v2fpgi$1vq6$1@raubtier-asyl.eternal-september.org>
 <v2fs3s$2i1u$1@dont-email.me>
 <v2g0fd$3hp3$1@raubtier-asyl.eternal-september.org>
 <v2g0oc$3j0c$1@dont-email.me> <v2g55d$4cjb$1@dont-email.me>
 <v2g7fv$4nu0$4@dont-email.me> <v2g7vf$51fq$1@dont-email.me>
 <v2g882$52r2$1@dont-email.me> <v2g8c6$51fq$2@dont-email.me>
 <v2g8jq$551c$1@dont-email.me> <v2g8s8$51fq$5@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Mon, 20 May 2024 21:40:33 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="629f9cefad5d4023792ce8f8ed8d9594";
	logging-data="169004"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1+MVinVCN4uWmqgctQ6ZBbm"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:wzNMQAhWFBZlmoZOgynMACJqq6o=
Content-Language: en-US
In-Reply-To: <v2g8s8$51fq$5@dont-email.me>
Bytes: 5688

On 5/20/2024 2:38 PM, Chris M. Thomasson wrote:
> On 5/20/2024 12:34 PM, olcott wrote:
>> On 5/20/2024 2:30 PM, Chris M. Thomasson wrote:
>>> On 5/20/2024 12:28 PM, olcott wrote:
>>>> On 5/20/2024 2:23 PM, Chris M. Thomasson wrote:
>>>>> On 5/20/2024 12:15 PM, olcott wrote:
>>>>>> On 5/20/2024 1:35 PM, Chris M. Thomasson wrote:
>>>>>>> On 5/20/2024 10:20 AM, olcott wrote:
>>>>>>>> On 5/20/2024 12:15 PM, Bonita Montero wrote:
>>>>>>>>> Am 20.05.2024 um 18:01 schrieb olcott:
>>>>>>>>>> On 5/20/2024 10:16 AM, Bonita Montero wrote:
>>>>>>>>>>> Am 20.05.2024 um 16:47 schrieb olcott:
>>>>>>>>>>>
>>>>>>>>>>>> It is a simple question about the behavior of C functions.
>>>>>>>>>>>> This group's purpose is the C/C++ language.
>>>>>>>>>>>
>>>>>>>>>>> Your question is generic to most languages and you're
>>>>>>>>>>> not asking how to do that in C or how to improve that.
>>>>>>>>>>> And you're asking the same thing for years.
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Yes I am very persistent. I keep asking until
>>>>>>>>>> I get an answer.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> After some time you should recognize you're doing circles.
>>>>>>>>>
>>>>>>>>
>>>>>>>> I am asking a straight forward question that people
>>>>>>>> keep ignoring it has nothing to do will my circles:
>>>>>>>> Ask until answered stops when answered.
>>>>>>>>
>>>>>>>
>>>>>>> Think of your halt decider running a black box program. 
>>>>>>
>>>>>> *It is not even a halt decider in this post it is merely a simulator*
>>>>> [...]
>>>>>
>>>>> Humm... So, what is your main point? You cannot decide if a program 
>>>>> will halt, _unless_ you code the test program?
>>>>>
>>>>
>>>> My ONLY point has been to put the people that have continued to
>>>> lie about the behavior of D correctly simulated by H in their place.
>>>> Several people have consistently lied about this for two years.
>>>>
>>>
>>> My only point is that one cannot 100% totally decide if a black box 
>>> program will halt, or not.
>>
>> I am not asking about any black box program.
>> D is fully specified and the only relevant detail about H is that
>>
>> it correctly simulates 1 to ∞ steps of D thus including 0 to ∞
>> recursive simulations of H simulating itself simulating D.
>>
>> *From this we can conclude*
>> *D correctly simulated by H never reaches its own line 06 and halts*
>>
>>
>>
> 
> So, your thing will tell me if a program XYZ will halt or not only 
> _after_ it simulates to infinity? What am I missing here?

*The 100% totally complete every single detail scope of my post*
*The 100% totally complete every single detail scope of my post*
*The 100% totally complete every single detail scope of my post*

typedef int (*ptr)();  // ptr is pointer to int function
00 int H(ptr p, ptr i);
01 int D(ptr p)
02 {
03   int Halt_Status = H(p, p);
04   if (Halt_Status)
05     HERE: goto HERE;
06   return Halt_Status;
07 }
08
09 int main()
10 {
11   H(D,D);
12   return 0;
13 }

In the above case a simulator is an x86 emulator that correctly emulates 
at least one of the x86 instructions of D in the order specified by the 
x86 instructions of D.

This may include correctly emulating the x86 instructions of H in the 
order specified by the x86 instructions of H thus calling H(D,D) in 
recursive simulation.

Execution Trace
Line 11: main() invokes H(D,D);

keeps repeating (unless aborted)
Line 01:
Line 02:
Line 03: simulated D(D) invokes simulated H(D,D) that simulates D(D)

Simulation invariant:
D correctly simulated by H cannot possibly reach past its own line 03.

For every H/D pair of the above template D correctly simulated by pure
function (thus computable function) H cannot possibly reach its own
final state at line 06 and halt.


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