Re: DD specifies non-terminating behavior to HHH --- RECURSIVE CHAIN --- Saving Democracy

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Sujet : Re: DD specifies non-terminating behavior to HHH --- RECURSIVE CHAIN --- Saving Democracy
De : dbush.mobile (at) *nospam* gmail.com (dbush)
Groupes : comp.theory
Date : 22. Feb 2025, 19:21:07
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vpd4ih$2pvp$1@dont-email.me>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
User-Agent : Mozilla Thunderbird
On 2/22/2025 1:02 PM, olcott wrote:
On 2/22/2025 11:10 AM, dbush wrote:
On 2/22/2025 11:43 AM, olcott wrote:
On 2/22/2025 5:01 AM, joes wrote:
Am Fri, 21 Feb 2025 21:55:32 -0600 schrieb olcott:
On 2/20/2025 4:00 AM, joes wrote:
>
>
Not even the variable Root in line 502 of Halt7.c?
https://github.com/plolcott/x86utm/blob/master/Halt7.c You are not even
in the correct function.
1059
>
>
Unless we go through a 100% precise sequence of steps
my reviewers will always consistently dodge the point
as they have done for several years.
>
typedef void (*ptr)();
int HHH(ptr P);
>
int DD()
{
   int Halt_Status = HHH(DD);
   if (Halt_Status)
     HERE: goto HERE;
   return Halt_Status;
}
>
int main()
{
   HHH(DD);
}
>
The first point is DD correctly simulated by HHH cannot
possibly terminate normally by reaching its own "return"
instruction.
>
In other words, if the code of HHH is replaced with an unconditional simulator then it can be shown that DD is non-halting and therefore HHH(DD)==0 is correct.
>
 Wow finally someone that totally gets it.
 
Let's test that on another case.
>
01 int F(int i)
02 {
03      if (i<10) {
04          return 0;
05      } else {
06          return F(i+1);
07      }
08 }
09
10 int no_numbers_greater_than_10()
11 {
12      return F(0);
13 }
14
15 int main()
16 {
17   no_numbers_greater_than_10();
18   return 0;
19 }
Actually, let's update main:
int main()
{
    F((int)no_numbers_greater_than_10);
    return 0;
}

>
The function no_numbers_greater_than_10() checks if any natural number exists that is greater than 10.  It does this by checking all natural numbers one at a time.  If one such number exists it halts and return 0.   If no such number exists, it will run forever as no such number will satisfy the condition.
>
 Your code is incomplete. I added main() with line numbers.
 
We can see that no_numbers_greater_than_10 correctly simulated by F cannot possibly terminate normal by reaching its own "return" instruction.  This means that F correctly reports that no_numbers_greater_than_10 is non-halting.  It further means, since no_numbers_greater_than_10  doesn't halt that there is no natural number greater than 10.
>
Agreed?
 Here the execution trace that I see:
15, 16, 17, 10, 11, 12, 01, 02, 03, 04, 12, 18, 19
 
Just as you say we're not talking about the direct execution of DD, we're also not talking about the direct execution of no_numbers_greater_than_10.  We're talking about no_numbers_greater_than_10 correctly simulated by F.
It's a verified fact that no_numbers_greater_than_10 correctly simulated by F cannot possibly return so F(no_numbers_greater_than_10) is correct to report non-halting, which means that there is no natural number greater than 10.
Agreed?

Date Sujet#  Auteur
18 Apr 26 o 

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