From Newsgroup: comp.lang.c++

On 9/29/2025 8:42 PM, Richard Heathfield wrote:

On 30/09/2025 02:29, olcott wrote:

The instance of DD that HHH is simulating does call
an instance of HHH: dip shit.

No, genius, it doesn't. DD isn't running, so it's in no position to call anything. Simulating a call is not the same as calling.

typedef int (*ptr)();
int HHH(ptr P);

int DD()
{
int Halt_Status = HHH(DD);
if (Halt_Status)
HERE: goto HERE;
return Halt_Status;
}

When DD is simulated by HHH according to the semantics of the
x86 language then *the finite string input to HHH does specify*

that HHH simulates DD and then simulates an instance of itself
simulating an instance of DD that calls yet another instance
of HHH in recursive simulation again.

*the finite string input to HHH does specify*
pick's up where Rice's theorem left off.

In computability theory, Rice's theorem states that
all non-trivial semantic properties of programs are
undecidable. A semantic property is one about the
program's behavior ...
https://en.wikipedia.org/wiki/Rice%27s_theorem

All Turing machine deciders only compute the mapping
from their finite string inputs to an accept state
or reject state on the basis that this input finite
string specifies a semantic or syntactic property.
--
Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius
hits a target no one else can see." Arthur Schopenhauer
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