XPost: comp.theory, sci.logic, sci.math

Halting problem undecidability and infinitely nested simulation (V3)

A simulating halt decider H bases it halt status decision on what the
behavior of its input would be if H was a UTM. If H correctly determines
that its simulated input would never reach its final state then H aborts
this simulation and transitions to its final reject state. Otherwise H transitions to its final accept state as soon as its simulation completes.

Simulating halt deciders determine whether or not the Linz halt criteria possibly can met:
the Turing machine will halt whenever it enters a final state. (Linz:1990:234)
on the basis of matching infinite behavior patterns. Failure to match is construed as halting.

The following simplifies the syntax for the definition of the Linz
Turing machine Ĥ, it is now a single machine with a single start state.
A copy of Linz H is embedded at Ĥ.qx.

Ĥ.q0 ⟨Ĥ⟩ ⊢* Ĥ.qx ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥ.qy ∞
Ĥ.q0 ⟨Ĥ⟩ ⊢* Ĥ.qx ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥ.qn

When Ĥ is applied to ⟨Ĥ⟩
Ĥ copies its input ⟨Ĥ1⟩ to ⟨Ĥ2⟩ then embedded_H simulates ⟨Ĥ1⟩ ⟨Ĥ2⟩

Then these steps would keep repeating:
Ĥ1 copies its input ⟨Ĥ2⟩ to ⟨Ĥ3⟩ then embedded_H simulates ⟨Ĥ2⟩ ⟨Ĥ3⟩
Ĥ2 copies its input ⟨Ĥ3⟩ to ⟨Ĥ4⟩ then embedded_H simulates ⟨Ĥ3⟩ ⟨Ĥ4⟩
Ĥ3 copies its input ⟨Ĥ4⟩ to ⟨Ĥ5⟩ then embedded_H simulates ⟨Ĥ4⟩ ⟨Ĥ5⟩...

This shows that the simulated input to embedded_H ⟨Ĥ⟩ ⟨Ĥ⟩ would never reach its final state conclusively proving that this simulated input
never halts. This enables embedded_H to abort the simulation of its
input and correctly transition to Ĥ.qn.

Because a halt decider is a decider embedded_H is only accountable for computing the mapping from ⟨Ĥ⟩ ⟨Ĥ⟩ to Ĥ.qy or Ĥ.qn on the basis of the
actual behavior specified by these inputs. embedded_H is not accountable
for the behavior of the computation that it is contained within: Ĥ
applied to ⟨Ĥ⟩ because this is not an actual input to embedded_H.


Halting problem undecidability and infinitely nested simulation (V3) https://www.researchgate.net/publication/358009319_Halting_problem_undecidability_and_infinitely_nested_simulation_V3



--
Copyright 2021 Pete Olcott

Talent hits a target no one else can hit;
Genius hits a target no one else can see.
Arthur Schopenhauer

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)