Re: How to write a self-referencial TM?

On Wed, 2025-05-14 at 12:45 -0500, olcott wrote:

On 5/14/2025 12:39 PM, wij wrote:

On Wed, 2025-05-14 at 12:24 -0500, olcott wrote:

On 5/14/2025 11:43 AM, wij wrote:

On Wed, 2025-05-14 at 09:51 -0500, olcott wrote:

On 5/14/2025 12:13 AM, wij wrote:

Q: Write a turing machine that performs D function (which calls itself):
 
void D() {
    D();
}
 
Easy?
 
 

 
That is not a TM.

 
It is a C program that exists. Therefore, there must be a equivalent TM.
 

To make a TM that references itself the closest
thing is a UTM that simulates its own TM source-code.

 
How does a UTM simulate its own TM source-code?
 

 
You run a UTM that has its own source-code on its tape.

 
What is exactly UTM?

 
https://en.wikipedia.org/wiki/Universal_Turing_machine

We know you don't have answer

E.g. can the HHH in POOH or x86utm reads its own source-code?
 

 
As I have said many dozens of times and Mike affirmed
HHH does emulate itself emulating DDD. It does this
through direct access to its own x86 machine language.

The TM of "HHH(DDD)" is much difficult than the problem of this post.
I think you have no right to say HHH/DDD... are TM, until you write
the sourec-code of HHH/DDD in the tape and show the transition function.