Re: Analysis of Flibble’s Latest: Detecting vs. Simulating Infinite Recursion ZFC

On 25/05/2025 16:55, olcott wrote:

On 5/25/2025 5:19 AM, Richard Heathfield wrote:

On 24/05/2025 17:13, olcott wrote:

No HHH can report on the behavior of its caller

>
 From Halt7.c:
>
void DDD()
{
   HHH(DDD);
   return;
}
>
Since (as you say) no HHH can report on the behaviour of its caller, and since (as your code shows) DDD is HHH's caller, we deduce that HHH cannot report on DDD.
>
So HHH is not (according to you) a halt analyser for DDD.
>
I'm not sure you've left anything to discuss, have you?
>

 HHH(DDD) does correctly reject
*ITS INPUT THUS NOT ITS CALLER*
as non-halting.

Its input, as you show by the notation HHH(DDD), is DDD. So it's reporting on DDD.
 > HHH(DDD) does correctly reject
 > *ITS INPUT THUS NOT ITS CALLER*
 > as non-halting.
But as this code shows:
 >> void DDD()
 >> {
 >>    HHH(DDD);
 >>    return;
 >> }
DDD calls HHH. Therefore DDD is HHH's caller.
DDD is HHH's caller AND its input.
"No HHH can report on the behavior of its caller", so HHH cannot report on DDD.
But here:
 > HHH(DDD) does correctly reject
 > *ITS INPUT THUS NOT ITS CALLER*
 > as non-halting.
we have HHH reporting on its caller, DDD. But "No HHH can report on the behavior of its caller", so HHH cannot report on DDD... but it clearly does.
--
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
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