Re: D correctly simulated by H cannot possibly reach its own line 06 and halt

Op 31.mei.2024 om 17:54 schreef olcott:

On 5/31/2024 10:37 AM, Fred. Zwarts wrote:

Op 31.mei.2024 om 16:25 schreef olcott:

On 5/31/2024 2:50 AM, Fred. Zwarts wrote:

Op 31.mei.2024 om 00:01 schreef olcott:

On 5/30/2024 4:54 PM, joes wrote:

Am Thu, 30 May 2024 09:55:24 -0500 schrieb olcott:
>

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 left hand-side are line numbers of correct C code.
This code does compile and does conform to c17.
>
Everyone with sufficient knowledge of C can easily determine that D
correctly emulated by any *pure function* H (using an x86 emulator)
cannot possibly reach its own simulated final state at line 06 and halt.

Yeah, of course not, if H doesn’t halt.
>

>
To actually understand my words (as in an actual honest dialogue)
you must pay careful attention to every single word. Maybe you
had no idea that *pure functions* must always halt.
>
Or maybe you did not know that every computation that never reaches
its own final state *DOES NOT HALT* even if it stops running because
it is no longer simulated.

>
Since the claim is that H is also a computation, it holds for H, as well. That means that H *DOES NOT HALT* even if it stops running because it is no longer simulated.
>

>
*pure function H definitely halts you are confused*
>

>
You can assume a unicorn, but that does not make it existent. You can assume a simulating H that is a pure function and halts, but that does not make them existent. The set of such H is empty.

 You simply ignored my proof that you are wrong.
 D correctly simulated by pure function HH cannot possibly reach
its own final state at line 06 in any finite number of steps of
correct simulation.

I do not ignore your claim. It is in fact exactly your claim that D does not reach line 04 that proves that the simulation of HH does not reach its own final state.
HH correctly simulated by HH cannot possibly reach its own final state and return to D in any finite number of steps of correct simulation.
You simply ignore that proof. So, again: If HH would halt, then the correct simulation of HH would halt, too. Then HH would return to D and the simulated D would continue with line 04. This contradicts your claim, which proves that HH does not halt.
If this is not true, prove it. Show the trace starting where the simulation of HH halts and HH returns to D and show that the next 10 instructions are not the continuation to line 04. If you cannot show the trace of where HH returns to D, you fail to prove that the simulation of HH halts.
Remember: halting means reaching the final state. The final state of the simulated HH is the return to D.