• Re: How the requirements that Professor Sipser agreed to are exactly m

    From olcott@3:633/280.2 to All on Sun May 18 01:31:55 2025
    Subject: Re: How the requirements that Professor Sipser agreed to are exactly
    met --- Mike my best reviewer

    On 5/17/2025 9:27 AM, Mike Terry wrote:
    On 17/05/2025 09:55, Mikko wrote:
    On 2025-05-16 14:47:39 +0000, olcott said:

    On 5/16/2025 4:26 AM, Mikko wrote:
    On 2025-05-15 00:36:21 +0000, Mike Terry said:

    On 14/05/2025 22:31, Keith Thompson wrote:
    olcott <polcott333@gmail.com> writes:
    On 5/14/2025 3:51 PM, dbush wrote:
    On 5/14/2025 11:45 AM, olcott wrote:
    On 5/14/2025 6:20 AM, Richard Damon wrote:

    And since the DD that HHH is simulating WILL HALT when fully >>>>>>>>>> simulated (an action that HHH doesn't do)

    *NOT IN THE ACTUAL SPEC*
    <MIT Professor Sipser agreed to ONLY these verbatim words
    10/13/2022>
    ÿÿÿÿ If simulating halt decider H correctly simulates its
    ÿÿÿÿ input D until H correctly determines that its simulated D >>>>>>>>> ÿÿÿÿ would never stop running unless aborted then

    That Sipser didn't agree what you think the above means:


    If that was actually true then you could provide an
    alternative meaning for the exact words stated above.

    I keep challenging you to provide this alternative
    meaning and you dodge because you know that you are
    lying about there being any alternative meaning
    FOR THE EXACT WORDS LISTED ABOVE.

    No alternative meaning is needed, just a correct interpretation of >>>>>> the
    words (which appear to be incomplete).

    The quoted sentence is cut off, something that I suspect you didn't >>>>>> notice.ÿ Here's the full quotation from a previous article:

    <Sipser approved abstract>
    MIT Professor Michael Sipser has agreed that the following verbatim >>>>>>>> paragraph is correct (he has not agreed to anything else in this >>>>>>>> paper):

    If simulating halt decider H correctly simulates its input D
    until H
    correctly determines that its simulated D would never stop running >>>>>>>> unless aborted then H can abort its simulation of D and correctly >>>>>>>> report that D specifies a non-halting sequence of configurations. >>>>>>>> </Sipser approved abstract>

    **If** H correctly simulates its input in the manner you claim,
    **then** H can correctly report the halting status of D.ÿ (That's a >>>>>> paraphrase that probably doesn't capture the full meaning; the full >>>>>> **quotation is above.)

    To put it another way, If H correctly simulated its input in
    the manner you claim, then H could correctly report the halting
    status of D.

    I'm not surprised that Sipser would agree to that.ÿ The problem is >>>>>> that it's a conditional statement whose premise is impossible.

    If an equilateral triangle had four sides, then each of its four
    vertices would be 90 degrees.ÿ That doesn't actually mean that
    there exists an equilateral triangle with four 90-degree vertices, >>>>>> and in fact no such triangle exists.ÿ Similarly, *if* a general
    halt decider existed, then there are a lot of things we could say
    about it -- but no general halt decider can exist.

    I'm not quite 100% confident in my reasoning here.ÿ I invite any
    actual experts in computational theory (not you, PO) to criticize
    what I've written.

    I doubt that Sipser would be using your interpretation, relying on
    a false premise as a clever kind of logical loop-hole to basically
    fob someone off.

    The details of H are not known to Sipser, so he can't know whether a
    premise is false. It is possible that some simulating partial decider
    correctly simulates a part of the behaviour of some D and correctly
    determines that the unsimulated part of the behaviour never halts;
    for example, if the unsimulated part is a trivial eternal loop. That
    one premise is false about HHH with DDD is a part of what was asked.

    Mike explains all of the details of exactly how a
    correct Simulating Halt Decider is derived from
    the exact meaning of the words that professor Sipser
    agreed to IN THE PART THAT YOU IGNORED

    No, he does not. He does not even believe that it is possible to derive
    a correct Simulating Halt Decider form the exact meaning of any words.


    That's correct.

    We could build a correct /partial/ SHD though, which I explained.ÿ The
    idea behind an PSHD is ok, and a class of HP inputs could be correctly decided with a PSHD.ÿ Obviously a PSHD H could not decide its
    corresponding H^ input, as the Linz HP proof implies.ÿ Since PO's HHH / does/ decide its corresponding DD (incorrectly), it is not a PSHD, since PSHDs are not allowed to decide incorrectly. ÿ[A correctly coded PSHD
    HHH would never halt when given its (HHH^,HHH^) input.

    PO's problem is that he misunderstands the entire context of Sipser's
    words.ÿ Sipser's words concern how a PSHD H could decide some FIXED
    INPUT D it has been given.

    Mike's reviews of my work are at least ten-fold better
    than the next best reviewer. Mike is one of the few
    people here that really wants an honest dialogue. He
    carefully examined my code and has a nearly perfect
    understanding.

    https://github.com/plolcott/x86utm/blob/master/Halt7.c

    Most everyone else only seems to care about rebuttal
    at the expense of truth. Keith and Ben also seem to
    care about truth.

    <MIT Professor Sipser agreed to ONLY these verbatim words 10/13/2022>
    If simulating halt decider H correctly simulates its
    input D until H correctly determines that its simulated D
    would never stop running unless aborted then

    On 5/14/2025 7:36 PM, Mike Terry wrote: https://al.howardknight.net/?STYPE=msgid&MSGI=%3C1003cu5%242p3g1%241%40dont-email.me%3E


    Just like your SHD does not base its decision on the
    actual behavior of the infinite loop after it has
    aborted its simulation of this loop, instead it bases
    its decision on a different H/D pair that never aborts.

    HHH(DDD) does not base its decision on the actual
    behavior of DDD after it has aborted its simulation
    of DDD, instead it bases its decision on a different
    HHH/DDD pair that never aborts.

    If an otherwise correct SHD always reported on the
    behavior of its input AFTER it aborts then every
    input would be determined to be halting.

    The key question here that most experts in the theory
    of computation would be aware of is the way that functions
    computed by models of computation must work.

    Is HHH supposed to compute the mapping from its input
    on the basis of the behavior specified by this input
    or something else?

    My presentation using the concrete language of x86 leaves
    no doubt exactly what behavior that DDD specifies.

    DDD correctly simulated by HHH
    *would never stop running unless aborted*

    PO wants to interpret them as what happens
    when H is modified, and D is also modified to reference the new H.ÿ So
    he's modifying what is supposed to be a fixed input half way through his interpretation.ÿ Sipser would be holding his head in his hands if he
    knew (and cared) ... :)


    Mike.



    --
    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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