Re: How to write a self-referencial TM?

On 5/18/2025 4:58 PM, André G. Isaak wrote:

On 2025-05-18 14:57, olcott wrote:
 

TM description is a misnomer in that they never
merely describe some of the details of the TM
(as all mere descriptions always do).
>
Instead they specify ALL of the details, thus have
always actually been a TM specification language more
commonly understood as the source-code for a TM.

 You seem to be getting bogged down in a relatively inconsequential terminological issue here which contributes nothing to the overall debate.
 

It is not inconsequential. It is the misnomer that an
input is merely described that enables people to believe
that DDD simulated by HHH must have the same behavior
as DDD simulated by HHH1 even when they SPECIFY different
behavior.

In English, both 'description' and 'specification' can refer to something which is either complete or only partial.
 

Description typically means partial and
specification typically means complete.

When people talk about passing a UTM a description of a TM, it is understood that this refers to a *complete* description rather than a partial one.
 

If this was true then they would understand that
the input to HHH(DDD) specifies behavior that is
not the same behavior as DDD().
_DDD()
[00002172] 55         push ebp      ; housekeeping
[00002173] 8bec       mov ebp,esp   ; housekeeping
[00002175] 6872210000 push 00002172 ; push DDD
[0000217a] e853f4ffff call 000015d2 ; call HHH(DDD)
[0000217f] 83c404     add esp,+04
[00002182] 5d         pop ebp
[00002183] c3         ret
Size in bytes:(0018) [00002183]
They would understand that no matter how many
instructions of DDD are emulated by HHH according
to the rules of the x86 language that this
correctly emulated DDD cannot possibly halt.

If you prefer the term 'specification', you're free to use it, but there's no sense in which 'description' is a misnomer.
 André
 

--
Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius
hits a target no one else can see." Arthur Schopenhauer