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From: olcott <polcott333@gmail.com>
Newsgroups: comp.lang.c++,comp.lang.c
Subject: Re: D correctly simulated by H never halts
Date: Wed, 29 May 2024 14:16:27 -0500
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On 5/29/2024 1:51 PM, Chris M. Thomasson wrote:
> On 5/29/2024 6:34 AM, olcott wrote:
>> On 5/28/2024 11:54 PM, Chris M. Thomasson wrote:
>>> On 5/28/2024 8:29 PM, olcott wrote:
>>>> On 5/28/2024 10:05 PM, Chris M. Thomasson wrote:
>>> [...]
>>>>> too vague? Oh that is rich.
>>>>
>>>> I had to start specifying the x86 language because dozens of reviewers
>>>> believed that D correctly simulated by H was supposed to report on the
>>>> behavior of non-input: int main() { D(D); }
>>>>
>>>> It was only that I could show that this would require simulating
>>>> the x86 instructions of D incorrectly or in the wrong order that
>>>> I could prove that they were wrong. Their mistake was my primary
>>>> rebuttal for two years.
>>>>
>>>
>>> How do you simulate cmpxchg8b?
>>
>> That is not an x86 instruction it is an x64 instruction
>> https://phoenixnap.com/kb/x64-vs-x86
> 
> You are wrong. cmpxchg8b is an x86 instruction. A 64-bit DWCAS on a 
> 32-bit system.
> 

OK great. I am wrong about a detail totally unrelated to my work.
The details related to my work I am correct and checked every which
way many hundreds of times.

The only detail relevant to this group is STEP ONE of my four step proof.

typedef int (*ptr)();  // ptr is pointer to int function in C
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       }

The above template refers to an infinite set of H/D pairs where D is
correctly simulated by either pure simulator H or pure function H. This
was done because many reviewers used the shell game ploy to endlessly
switch which H/D pair was being referred to.

H correctly simulates 1 to ∞ steps of D with either pure function H or
pure simulator H. In none of these cases does the correctly simulated D
ever reach its own simulated final state and halt.

*In actual finite memory C the H/D pair would eventually crash*

*Correct Simulation Defined*
    This is provided because many reviewers had a different notion of
    correct simulation that diverges from this notion.

    A simulator is an x86 emulator that correctly emulates 1 to N of the
    x86 instructions of D in the order specified by the x86 instructions
    of D. This may include M recursive emulations of H emulating itself
    emulating D.

*Fully operational code proves recursive emulation*

When we see that D correctly simulated by pure simulator H would remain
stuck in infinite recursive simulation then we also know that less than
an infinite number of steps is not enough steps for D correctly
simulated by pure function H to reach its own simulated 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