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From: Richard Heathfield <rjh@cpax.org.uk>
Newsgroups: comp.theory
Subject: Re: Every sufficiently competent C programmer knows
Date: Tue, 11 Mar 2025 17:35:02 +0000
Organization: Fix this later
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On 11/03/2025 17:01, olcott wrote:
> On 3/11/2025 8:42 AM, Richard Heathfield wrote:
>> On 11/03/2025 13:26, olcott wrote:
>>> On 3/11/2025 5:01 AM, Richard Heathfield wrote:
>>
>> <snip>
>>
>>>> And yet I can't even /see/ HHH, let alone judge what it does 
>>>> or does not do correctly. All I see is a call to it.
>>>>
>>>
>>> It is stipulated that HHH correctly emulates N
>>> steps of the x86 machine code of its input functions.
>>> This may or may not include HHH emulating itself
>>> emulating an input.typedef void (*ptr)();
> int HHH(ptr P);
> 
> void Infinite_Loop()
> {
>    HERE: goto HERE;
>    return;
> }
> 
> void Infinite_Recursion()
> {
>    Infinite_Recursion();
>    return;
> }
> 
> void DDD()
> {
>    HHH(DDD);
>    return;
> }
> 
> int DD()
> {
>    int Halt_Status = HHH(DD);
>    if (Halt_Status)
>      HERE: goto HERE;
>    return Halt_Status;
> }

Yeah, I got all that.

> That when HHH correctly emulates N steps of the
> above functions that none of these functions can
> possibly reach their own "return" instruction
> and terminate normally.

We can't know that without seeing the code.

>> Not good enough. Show us the code. It may contain a bug that 
>> you haven't spotted.
>>
> 
> The above is a semantic tautology thus making bugs
> impossible.

Clearly you haven't done much programming. Bugs are very possible.


> 
> https://github.com/plolcott/x86utm/blob/master/Halt7.c

Ah! At last, source for HHH.

u32 HHH(ptr P)
{
   u32* Aborted;
   u32* execution_trace;
   u32  End_Of_Code;
   goto SKIP;

DATA1:
#ifdef _WIN32

<grin> I see.

Nice talking to you.

>>>> I suggest that Mr Olcott should supply the missing source 
>>>> code if he wishes to be taken seriously.

He has now done so: < 
https://github.com/plolcott/x86utm/blob/master/Halt7.c>

It's illegible, of course, but that turns out not to matter.


>>> Not required for the above thought experience where
>>> every relevant behavior has been fully specified. This
>>> is merely another lame attempt on your part to perpetually
>>> dodge the point.
>>
>> Dodge what point? You must be confusing me with someone else, 
>> because I have no idea what your point is, unless it's to 
>> demonstrate that you have read up on the Halting Problem. Jolly 
>> good tick VG, but it's a done deal, it's in the literature, and 
>> you're almost a century too late.
>>
> 
> If you as not Richard Damon pretending to be someone
> else, great!!!

I as indeed not Richard Damon pretending to be someone else but, 
in the time it has taken you to establish that, you have 
succeeded in losing my interest because you clearly have nothing 
to say that's worth hearing. Bye-de-bye.

-- 
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
Sig line 4 vacant - apply within