Re: Can someone please verify the execution trace of this?

On 5/20/2024 8:14 AM, Marcel Mueller wrote:

Am 18.05.24 um 23:40 schrieb olcott:

In the above case a simulator is an x86 emulator that correctly emulates
at least one of the x86 instructions of D in the order specified by the
x86 instructions of D.
>
This may include correctly emulating the x86 instructions of H in the
order specified by the x86 instructions of H thus calling H(D,D) in
recursive simulation.

 There is no recursion.
H is an undefined reference. There is nothing to simulate.
 And even if H would be defined, the implementation of H might never call *x or *y.
 

Line 03: simulated D(D) invokes simulated H(D,D) that simulates D(D)
>
*Simulation invariant*
D correctly simulated by H cannot possibly reach past its own line 03.

 So this is proven not to be true in general.
  Marcel

https://en.wikipedia.org/wiki/Pure_function#
*Try to find any way that*
For every H/D pair of the template below where D correctly simulated
by pure function (thus computable function) H can possibly reach its
own final state at line 06 and halt.
typedef int (*ptr)();  // ptr is pointer to int function
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 }
In the above case a simulator is an x86 emulator that correctly emulates
at least one of the x86 instructions of D in the order specified by the
x86 instructions of D.
This may include correctly emulating the x86 instructions of H in the
order specified by the x86 instructions of H thus calling H(D,D) in
recursive simulation.
Execution Trace
Line 11: main() invokes H(D,D);
keeps repeating (unless aborted)
Line 01:
Line 02:
Line 03: simulated D(D) invokes simulated H(D,D) that simulates D(D)
Simulation invariant:
D correctly simulated by H cannot possibly reach past its own line 03.
For every H/D pair of the above template D correctly simulated by pure
function (thus computable function) H cannot possibly reach its own
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