Re: Why does Olcott care about simulation, anyway?

On 03/06/2024 08:58, Fred. Zwarts wrote:

Op 03.jun.2024 om 02:16 schreef immibis:

The halting problem says you can't find a Turing machine that tells whether executing each other Turing machine will halt. Simulation has nothing to do with the question.

 Maybe because by using simulation he can shift the attention from the pathological part of the Linz proof, to another halting problem, namely that a simulating decider does not halt because it causes infinite recursion.

PO's simulating decider does not cause infinite recursion.  That only occurs in the case where the decider performs a FULL simulation of its input, whereas typically for PO his H/HH/... perform PARTIAL simulations, where the decider monitors what is being simulated and breaks off the simulation when a particular condition is observed.
So yes, there is recursive simulation, but not /infinite/ recursion since at each level of simulation the simulator is free to just stop simulating at any time.  In practice this means that the outer simulator H will be the one to break out, since it will always be ahead of all the inner simulations of H in how far it has progressed.  This situation is in contrast with direct call recursion, where the outer caller has no control to break the recursion - it only regains control once the inner calls have all returned.
PO does not properly understand this distinction.

 His own claim that D does not reach the pathological part (after line 03), displays already that the simulation is unable to process the pathological part. But the simulation introduces a new halting problem (recursive simulation), which he thinks is an answer for the original halting problem.

You're using PO's phrase "pathological" but that is a bad (misleading) term because it suggests there is something WRONG/BAD (aka sick?) in the situation.  E.g. H processing input which is a description of its own source code.  There is nothing whatsoever wrong with that - it's just that PO gets confused by it and so argues to ban it.  Perhaps there  is an alternative term that doesn't have the deliberate connotation of "sickness".
Mike.