• Requiring the logically impossible is always an invalid requirement
    I think only a mod can change the subject of a topic, so it is safe.
    So yes, just be more careful when selecting your logically impossible thing, because so far none of them has qualified. Then, having found some suitable impossible requirement, in order to make your point in the subject line, you need to come up with a scenario that lists it as a requirement. That was also missing in the OP. So let's say for argument sake that a square circle (suitably defined) is impossible. What argument would plausibly list that as a requirement?
    noAxioms

    I did not provided 100% of all of the details of the mathematical definition of a square and a circle so that people having zero knowledge of math would be able to get the gist of my idea. Its really is not that hard to understand that a thing: (that must be round) and (cannot be round) cannot exist.

    Anything that is required to have (simultaneous mutually exclusive properties) cannot exist.
  • Requiring the logically impossible is always an invalid requirement
    On the surface of the Earth, imagine drawing squares centered on the North Pole with increasing length sides until the sides coincide with the circle of the equator. As ↪noAxioms said ,what can be done is all about unstated presumptions.magritte

    I am trying to form a concrete example of the logically impossible
    changing the subject to the not logically impossible is a strawman rebuttal.
  • Requiring the logically impossible is always an invalid requirement
    Not logically impossible.noAxioms

    I am not talking about squaring a circle I am talking about drawing a circle that <is> a square thus not a circle. It must be in the same two dimensional plane.

    "all points on a two dimensional surface that are equidistant from the center" and these exact same points form four straight sides of equal length in the same two dimensional plane.

    My notion of {Square-Circle} is the epitome of logically impossible.
  • Requiring the logically impossible is always an invalid requirement
    Are you referring to Squaring the circle? Are you sure about your opening statement?jgill

    I am talking about creating a perfectly round thing that
    cannot be round because it has four equal length sides,
    thus a logically impossible square circle.
  • Self Referential Undecidability Construed as Incorrect Questions
    ↪PL Olcott I think you have some interesting stuff here, but you haven't demonstrated an error on Gödel or Turing.Banno

    The key error that I and Professor demonstrated that the inability of solving the halting problem is the same as the inability for a CAD system to correctly draw a square circle both are logically impossible thus place no actual limit on computation what-so-ever.
  • Self Referential Undecidability Construed as Incorrect Questions
    ↪PL Olcott If you would show that a well-accepted and well-understood part of logic is in error, you will need a good deal of strong, formal argument to carry your case.Banno

    Once this is understood to be true
    (1) The inability to do the logically impossible never places any actual limits
    on anyone or anything

    (2) then the logical impossibility of solving the halting problem the way it is
    currently defined places no actual limit on computation.

    Introduction to the Theory of Computation 3rd Edition by Michael Sipser

    When we apply the MIT Professor Michael Sipser approved halt status critieria
    (a) 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
    (b) H can abort its simulation of D and correctly report that D specifies a non-halting sequence of configurations.

    Then H does correctly determine that halt status of every input that was
    defined to do the opposite of whatever Boolean value that H returns.
    All of the details of this are fully elboarated on the first page of this paper:

    Termination Analyzer H is Not Fooled by Pathological Input D
    https://www.researchgate.net/publication/369971402_Termination_Analyzer_H_is_Not_Fooled_by_Pathological_Input_D
  • Self Referential Undecidability Construed as Incorrect Questions
    ..and so on. I don't think it's just me.Banno

    Yes everyone that does not pay complete attention makes sure
    that they never understand what is said. I will sum up the point
    much much more concisely.

    When input D to program H does that opposite of whatever program
    H says that it will do it is logically impossible for program H to correctly
    say what input D will do.

    The inability to do the logically impossible never places any actual
    limits on anyone or anything.


    That no CAD system can possibly correctly draw a square circle places
    no actual limits on computation. Thus the halting problem proof places
    no actual limit on what can be computed.
  • Self Referential Undecidability Construed as Incorrect Questions
    My conclusion is that you're unable to present your thesis in a manner that is sufficiently clear to be evaluated.Banno

    If that was true then professor Hehner would not have totally agreed with me today.

    I am thinking the the problem is that I assumed you had more technical knowledge
    than you do. Tell me exactly how much you know about computer programming
    and I can change my words to fit your knowledge level.

    I thought the my original version of a halt decider that simply
    tries to say what another program will do when this other program
    does the opposite of whatever it says is as clear as I can get.


    That is the <same kind of thing> as Carol's question for Carol.
  • Self Referential Undecidability Construed as Incorrect Questions
    ↪PL Olcott All I'm asking is where Carol's question occurs.
    Sure, show me in C.
    Banno

    Isomorphic means <same kind of thing>.
    Carol's question for Carol and input D
    to decider H are the exact <same kind of thing>.

    In both cases their question contradicts every answer.
  • Self Referential Undecidability Construed as Incorrect Questions
    SO, Z?

    It shouldn't be this hard. I'm just checking that I've understood your point.
    Banno

    The best that I can tell is that Z is an incorrect sloppy mess that has no actual
    name and no return value. Do you not know C?

    On the other hand D and H have been fully operational code (for two years now) of the x86utm operating system that I created.
  • Self Referential Undecidability Construed as Incorrect Questions
    ↪PL Olcott Your claim is that some equivalent of Carol's question occurs in the halting program proof. It's not unreasonable to ask you to show where it occurs.Banno

    Already answered and you simply ignored.

    That Carol's question contradicts every yes/no answer that Carol can provide <is> isomorphic to input D to decider H that does that opposite of whatever Boolean value that H returns.PL Olcott
  • Self Referential Undecidability Construed as Incorrect Questions
    "Will Program Z loop forever if fed itself as input?"
    — Banno
    Banno

    I don't know and I don't care. Changing the subject is no form of rebuttal.

    // The following is written in C
    //
    01 typedef int (*ptr)(); // pointer to int function
    02 int H(ptr x, ptr y) // uses x86 emulator to simulate its input
    03
    04 int D(ptr x)
    05 {
    06   int Halt_Status = H(x, x);
    07   if (Halt_Status)
    08     HERE: goto HERE;
    09   return Halt_Status;
    10 }
    
  • Self Referential Undecidability Construed as Incorrect Questions
    Your question occurs in Z, not in H. Z is problematic, but Z is also a consequence of H, hence H is problematic.Banno

    The whole halting problem proof depends on some input D that does the
    opposite of whatever Boolean value that H returns. Changing the names
    does not change this. When you change the names I ignore them.

    This is the whole point of my and Hehner's proof
    That it is a logical impossibility for H to return a value corresponding
    to the behavior of the direct execution of D(D) does not in any way
    limit computation because the inability to do the logically impossible
    is never any actual limit to anyone or anything.
  • Self Referential Undecidability Construed as Incorrect Questions
    Have a think on it again. You have shown that Z is problematic. Sure, it is. That's what shows that H is impossible.Banno

    I have had a think in this for thousands of hours since 2004 when someone
    else directly presented me with nearly the exact same question.

    It is equally a logical impossible for any CAD system to correctly draw a square circle. The inability to do the logically impossible never places any actual limits on anyone of anything.PL Olcott
  • Self Referential Undecidability Construed as Incorrect Questions
    So sure, "the inability of a halt decider to correctly provide the halt status of an input that does the opposite of whatever halt status is provided does not place any actual limit on computation." But the impossibility of writing the program Halt does.Banno

    It is equally a logical impossible for any CAD system to correctly draw a square circle.
    The inability to do the logically impossible never places any actual limits on anyone of anything.
  • Self Referential Undecidability Construed as Incorrect Questions
    First and most obvious question is where in this the thing you called the "isomorphism from Carol's question to the halting problem proof counter- example template" is located. It's not there. But we can add it: "Will Program Z loop forever if fed itself as input?"Banno

    That Carol's question contradicts every yes/no answer that Carol can provide <is>
    isomorphic to input D to decider H that does that opposite of whatever Boolean value that H returns.
  • Self Referential Undecidability Construed as Incorrect Questions


    By skimming the paper to contrive some excuse for rebuttal you missed this:

    The bottom line of all of the above reasoning is that it is agreed that the halt status of some inputs to some halt deciders cannot possibly be correctly determined when the halt decider is required to report on the behavior of the direct execution of this input.

    The brand new insight by the PhD computer science professor and myself (since 2004) is that the inability of a halt decider to correctly provide the halt status of an input that does the opposite of whatever halt status is provided does not place any actual limit on computation.

    It is generally the case that the inability to do the logically impossible never places any actual limits on anyone of anything. That no CAD system can possibly correctly draw a square circle places no actual limits on computation.
  • Self Referential Undecidability Construed as Incorrect Questions
    PL Olcott. ok. Next.
    — Banno
    PL Olcott

    Self Referential Undecidability Construed as Incorrect Questions
    https://philpapers.org/archive/OLCSRU.pdf

    Has been reviewed by Professor Hehner and clarifications have been
    made corresponding to his review.
  • Self Referential Undecidability Construed as Incorrect Questions
    ↪PL Olcott I think you are wasting my time.Banno

    Although this forum has by far the very best people of any forum
    that I have ever participated in I still have to put checks and balances
    into the dialogue to prevent what always otherwise turns out to be
    infinite digression.

    If you agree we can go on to the next point if you don't agree
    then you lack the mandatory prerequisites required for the next point.
  • Self Referential Undecidability Construed as Incorrect Questions
    PL Olcott. ok. Next.Banno

    Ah so you are totally convinced that Carol's question
    posed to Carol is a self-contradictory thus incorrect question?
  • Self Referential Undecidability Construed as Incorrect Questions
    Well, no. I’m pointing out that you only have a problem here if you restrict yourself to yes/no with no revision.Banno

    So in other words you think that a Turing machine halt decider might
    reply: "I don't know let me think about it?"

    The thought experiment must stipulate that any answer besides
    [yes, no] is a wrong answer to preserve the mathematical mapping
    from Carol's question to a Turing machine halt decider.

    The question was written by a PhD computer science professor to
    make the computer science of the halting problem easier to understand.
  • Self Referential Undecidability Construed as Incorrect Questions
    But that's not right - you've been given several correct answers.Banno

    In other words you do not understand that it is an incorrect question.
    We go back one more step.

    Do you understand why this is not true or false?
    "This sentence is not true."
  • Self Referential Undecidability Construed as Incorrect Questions
    So an {epistemological antinomies} (why the curly brackets?) is, for example, the liar. Where is there an example of the Liar being used in a diagonalization? What might that look like? OR do you mean something else?Banno

    We need to go back to more basic things.
    Do you understand why this question has no correct answer?
    The question is: >>>Is this sentence true: "This sentence is not true." ???<<<

    If that is too difficult then do you understand why this is not true or false?
    "This sentence is not true."
  • Self Referential Undecidability Construed as Incorrect Questions
    Here's where we are up to: can you explain how you reject diagonalisation for Gödel but not for Cantor? Or do you reject Cantor's argument, too?Banno

    I am just saying that when diagonalisation is evaluating {epistemological antinomies}
    it always makes sure to ignore all of the details. It never even notices that they are
    {epistemological antinomies}. Diagonalisation only looks for a 1 or a 0 on the
    diagonal and makes sure to ignore absolutely everything else.
  • Self Referential Undecidability Construed as Incorrect Questions
    ↪PL Olcott I don't see this conversation progressing.Banno

    Only because when I make a correct point you simply
    ignore rather than acknowledge it.

    I form a perfect incorrect question and then you change the words
    and form a strawman rebuttal of those changed words.

    The question is: >>>Is this sentence true: "This sentence is not true."<<<
  • Self Referential Undecidability Construed as Incorrect Questions
    ↪PL Olcott Well, we've dealt with that already, and as ↪Antony Nickles showed, it's problematic for you to insist on a yes or no answer.Banno

    Not when we are mathematically mapping Carol's question to an input D to a halt decider H that does the opposite of whatever Boolean value that H returns. It is impossible for Carol to correctly answer her question for the same reason and in the same way that it is impossible for H to return the correct halt status of D.

    Also, "This sentence is not true" is not a question.Banno
    The question is: >>>Is this sentence true: "This sentence is not true."<<<

    And further the liar does not play a role in the issue at hand, Gödel incompleteness and Halting.Banno

    Gödel says that it does.
    The most important aspect of Gödel's 1931 Incompleteness theorem
    are these plain English direct quotes of Gödel from his paper:
    ...there is also a close relationship with the “liar” antinomy,14 ...
    ...14 Every epistemological antinomy can likewise be used for a similar undecidability proof...

    The Liar Antinomy <is> an epistemological antinomy.
    So Gödel agrees that incorrect questions are a thing.
  • Self Referential Undecidability Construed as Incorrect Questions
    a question is not the sort of thing that is apt to contradiction.Banno

    Then correctly answer this question:
    Is this sentence (true or false): "This sentence is not true."
  • Self Referential Undecidability Construed as Incorrect Questions
    After all, what I said above is the case; that is the reason for the halting problem. One way to treat this is as a reductio, showing that your approach has problems.Banno

    When I stopped tolerating infinite digression it ceased.
  • Self Referential Undecidability Construed as Incorrect Questions
    The reason that the halting problem persists is that the number of possible Turing machines is not enumerable; but any Turing machine designed to check for a halt can only check at most an enumerable number of Turing machines. It therefore cannot check if every Turing machine will halt.Banno

    That simply changes the subject away from an input deriving a self-contradictory
    thus incorrect question for a specific decider. The most favorite rebuttal tactic of
    all of my reviewers is to make sure to always change the subject before there is
    ever any closure on any point.
  • Self Referential Undecidability Construed as Incorrect Questions
    PL Olcott That post doesn't tell me anything.Banno

    The reason why the halting problem is not solvable is that its specification does
    not forbid self-contradictory questions. When we change the specification such
    the self-contradictory questions cannot exist then the conventional proofs fail to
    show that the halting problem is not solvable.
  • Self Referential Undecidability Construed as Incorrect Questions
    ↪PL Olcott You seem to me to be doing no more than recursive assertion. It is because it is because it is because...Banno

    {epistemological antinomy} is the end all be all of why for these things.
    Professor Hehner calls this exact same idea {inconsistent specification} and
    I call this exact same idea {self-contradictory question}. Gödel calls it
    {epistemological antinomy}.

    When ordinary people hear the term {epistemological antinomy} they translate
    it into {some complex thing that I don't understand} in their or internal dialogue.
    That is why I use the much clearer term {self-contradictory question}.
  • Self Referential Undecidability Construed as Incorrect Questions
    Do you also reject the uncountability of the reals?Banno

    We can map every real to an integer and it does seem that we have some reals left over.
    If we imagine that there can be such a thing as immediately adjacent points on a
    number line, then these points would map to the integers. 1.0 + infinitesimal would
    be the next point on a number line.
  • Self Referential Undecidability Construed as Incorrect Questions
    You would presumably, for consistency's sake, say the same for Turing Machines,Banno

    Not at all and now I show my words are sustained by Gödel's words.
    The last paragraph is proven by all that comes before it.


    My unique take on Gödel 1931 Incompleteness (also self-referential)
    Any expression of the language of formal system F that asserts its
    own unprovability in F to be proven in F requires a sequence of
    inference steps in F that prove they themselves do not exist.

    It is not at all that F is in any way incomplete.
    It is simply that self-contradictory statements cannot be proven
    because they are erroneous.

    The most important aspect of Gödel's 1931 Incompleteness theorem are
    these plain English direct quotes of Gödel from his paper
    ...there is also a close relationship with the “liar” antinomy,14 ...
    ...14 Every epistemological antinomy can likewise be used for a similar undecidability proof...
    ...We are therefore confronted with a proposition which asserts its own unprovability. 15 ...
    (Gödel 1931:43-44)

    Gödel, Kurt 1931.
    On Formally Undecidable Propositions of Principia Mathematica And Related Systems

    https://mavdisk.mnsu.edu/pj2943kt/Fall%202015/Promotion%20Application/Previous%20Years%20Article%2022%20Materials/godel-1931.pdf

    Antinomy
    It is a term often used in logic and epistemology,
    when describing a paradox or unresolvable contradiction.
    https://www.newworldencyclopedia.org/entry/Antinomy

    Quoted from above
    ...14 Every epistemological antinomy can likewise be used for a similar
    undecidability proof...

    ...We are therefore confronted with a proposition which asserts its own
    unprovability...

    Thus in my simple version we can see WHY {a proposition that asserts
    its own unprovability} in F cannot be proven in F. It is because such
    a proposition is an {epistemological antinomy} in F.


    I have also showed that an input D that does the opposite of whatever
    program H says is an {epistemological antinomy} for H.
  • Self Referential Undecidability Construed as Incorrect Questions
    Well, no. He carefully shows why G is unprovable.Banno

    Not at all. Diagonalization only shows THAT an expression
    is unprovable, it abstracts away WHY. If we were to formalize
    this question: "What time is it (yes or no)?" diagonalization
    could show THAT it cannot be correctly answered and have
    no idea that the reason WHY it cannot be answered is a type
    mismatch error. Diagonalization makes sure to discard these
    details.
  • Self Referential Undecidability Construed as Incorrect Questions
    As long as you acknowledge that, again, the “solution set” is YOUR requirement, not revealing anything but the answer you dictate. What you have imposed as “correct” suppresses any other interpretation and thus only has one set of answers.Antony Nickles

    Yes this makes it exactly the same as the halting problem's input D
    that does the opposite of whatever Boolean value that decider H says.

    Since the analogy of Carol's question is much easier to understand
    it provides great leverage in understanding the error of the halting
    problem proofs

    The whole purpose of Carol's question was to show that the halting
    problem specification derives a self-contradictory thus incorrect
    question for some program/input pairs.

    When we show this then the inability of some H to say what
    input D will do when D is defined to the opposite of whatever
    H says is simply an incorrect question for H.

    If some program/input pairs are incorrect questions then the lack
    of the ability of H to provide a correct answer is the same as the
    lack of the ability of a baker to bake a perfect angel food cake using
    only house brick for ingredients.
  • Self Referential Undecidability Construed as Incorrect Questions
    Exactly. That's what I attempted to explain to PL Olcott, but it is impossible to agree with him, because according to his point, there will always be an incorrect answer because the question is 'posed' to Carol. It seems that poor Carol is guilty of everything regarding this tricky dilemma!javi2541997

    Can Carol correctly answer “no” to this [yes/no] question?

    Was written by a PhD computer science professor as an analogy to the
    conventional halting problem proofs where an input D has been defined
    to do the opposite of whatever program H says.

    His purpose in doing this was to show that because the question
    "Does your input halt on its input? is self-contradictory for some
    program/input pairs that for these pairs it is an incorrect question.

    We still agree with everyone else that when an input D does the
    opposite of whatever program H says that H cannot correctly say
    what input D will do.

    The key distinction that we make is that this does not place any actual
    limit on computation. That H cannot answer an incorrect question is the
    same as the fact that a baker cannot bake a perfect angle food cake
    using only house bricks for ingredients. It is incorrect for us to say that
    her baking skills are limited on that basis.
  • Self Referential Undecidability Construed as Incorrect Questions
    Carol does not need to be “indicating… an incorrect answer”, she could be indicating there IS NO sense of correctness in this “question”Antony Nickles

    Her answer of "no" indicates that she cannot correctly answer "no"
    yet because "no" is the correct answer her answer of "no" is incorrect.


    Can Carol correctly answer “no” to this [yes/no] question?
    The revised question requires Carol to answer from the solution set.
    Any lack of answer from {yes, no} or answer from {yes,no} is not a
    correct answer.

    Carol's question was written by a PhD computer science professor to show
    that the halting problem specification is inconsistent.

    I have spoken with him directly many times and he agrees with me that an
    equivalent way of saying this is that input D to decider H makes this question:
    "Does your input halt on its input?" a self-contradictory thus incorrect question
    for H when D is defined to do the opposite of whatever H says.
  • Self Referential Undecidability Construed as Incorrect Questions
    G is not a deduction in F. That would be silly.

    Rather, Gödel shows using arithmatization and the diagonalization that the structure of F is such that there must be WFF such as G. He's not using the deductive power of F to prove that G is unprovable.
    Banno

    In other words Gödel uses a convolulted mess to show THAT G IS unprovable in F
    in F while carefully hiding WHY G is unprovable in F.

    Antinomy It is a term often used in logic and epistemology, when describing a paradox or
    unresolvable contradiction.
    https://www.newworldencyclopedia.org/entry/Antinomy

    Gödel acknowledges that his G is {a proposition which asserts its own unprovability}
    and also acknowledges that any {epistemological antinomy} (self-contradictory G) will do.

    ...14 Every epistemological antinomy can likewise be used for a similar undecidability proof...
    ...We are therefore confronted with a proposition which asserts its own unprovability. 15 ...
    (Gödel 1931:43-44)

    Gödel, Kurt 1931.
    On Formally Undecidable Propositions of Principia Mathematica And Related Systems

    https://mavdisk.mnsu.edu/pj2943kt/Fall%202015/Promotion%20Application/Previous%20Years%20Article%2022%20Materials/godel-1931.pdf
  • Self Referential Undecidability Construed as Incorrect Questions
    But there is no proof of G in F. That's the point of G.Banno

    The reason that there is no proof of G in F
    (everyone always make sure to ignore the reason)


    is that to prove there is no proof G in F requires a sequence of
    inference steps that prove that they themselves do not exist.

    Gödel makes sure to hide the reason behind Gödel numbers
    and diagonalization.
  • Self Referential Undecidability Construed as Incorrect Questions
    Gödel does not prove in F that some statement in F is not provable.Banno

    Yes he does and he does it in a ridiculously convoluted way because Peano Arithematic is woefully inexpressive for this task.

    ...We are therefore confronted with a proposition which asserts its own unprovability. 15 ... (Gödel 1931:43-44)PL Olcott

    G := (F ⊬ G) is a propostion in F that asserts its own unprovability in F stripped of the extraneous mess of Gödel numbers.

    F ⊢ GF ↔ ¬ProvF (┌GF┐). // This one is similar to mine
    https://plato.stanford.edu/entries/goedel-incompleteness/#FirIncTheCom