Path: ...!news.nobody.at!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Mikko <mikko.levanto@iki.fi>
Newsgroups: sci.logic
Subject: Re: Undecidability based on epistemological antinomies V2 --H(D,D)--
Date: Thu, 25 Apr 2024 11:16:33 +0300
Organization: -
Lines: 132
Message-ID: <v0d3h1$2t938$1@dont-email.me>
References: <uvq0sg$21m7a$1@dont-email.me> <uvq359$1doq3$4@i2pn2.org> <uvrbvs$2acf7$1@dont-email.me> <uvs70t$1h01f$1@i2pn2.org> <uvsgcl$2i80k$1@dont-email.me> <uvsj4v$1h01e$1@i2pn2.org> <uvubo2$34nh3$1@dont-email.me> <uvvsap$3i5q8$1@dont-email.me> <v00mf6$3nu0r$1@dont-email.me> <v02gu5$6quf$1@dont-email.me> <v038om$bitp$2@dont-email.me> <v05b0k$sivu$1@dont-email.me> <v05r5e$vvml$2@dont-email.me> <v05vl4$1165d$1@dont-email.me> <v0679k$12sq2$1@dont-email.me> <v07r2j$1h57l$1@dont-email.me> <v08gn4$1lpta$2@dont-email.me> <v0ag7u$27jkb$1@dont-email.me> <v0b8np$2d4ja$1@dont-email.me> <v0c317$2538n$1@i2pn2.org> <v0c7fn$2k0tc$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 25 Apr 2024 10:16:33 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="cc7791d62a6d3eaec3a9ae09cded4cbc";
	logging-data="3056744"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1//foYVWtA7RqdF9wbiyvKQ"
User-Agent: Unison/2.2
Cancel-Lock: sha1:sdTvsY4t/N9nBQMWHh/2rShK6mQ=
Bytes: 7680

On 2024-04-25 00:17:57 +0000, olcott said:

> On 4/24/2024 6:01 PM, Richard Damon wrote:
>> On 4/24/24 11:33 AM, olcott wrote:
>>> On 4/24/2024 3:35 AM, Mikko wrote:
>>>> On 2024-04-23 14:31:00 +0000, olcott said:
>>>> 
>>>>> On 4/23/2024 3:21 AM, Mikko wrote:
>>>>>> On 2024-04-22 17:37:55 +0000, olcott said:
>>>>>> 
>>>>>>> On 4/22/2024 10:27 AM, Mikko wrote:
>>>>>>>> On 2024-04-22 14:10:54 +0000, olcott said:
>>>>>>>> 
>>>>>>>>> On 4/22/2024 4:35 AM, Mikko wrote:
>>>>>>>>>> On 2024-04-21 14:44:37 +0000, olcott said:
>>>>>>>>>> 
>>>>>>>>>>> On 4/21/2024 2:57 AM, Mikko wrote:
>>>>>>>>>>>> On 2024-04-20 15:20:05 +0000, olcott said:
>>>>>>>>>>>> 
>>>>>>>>>>>>> On 4/20/2024 2:54 AM, Mikko wrote:
>>>>>>>>>>>>>> On 2024-04-19 18:04:48 +0000, olcott said:
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>> When we create a three-valued logic system that has these
>>>>>>>>>>>>>>> three values: {True, False, Nonsense}
>>>>>>>>>>>>>>> https://en.wikipedia.org/wiki/Three-valued_logic
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> Such three valued logic has the problem that a tautology of the
>>>>>>>>>>>>>> ordinary propositional logic cannot be trusted to be true. For
>>>>>>>>>>>>>> example, in ordinary logic A ∨ ¬A is always true. This means that
>>>>>>>>>>>>>> some ordinary proofs of ordinary theorems are no longer valid and
>>>>>>>>>>>>>> you need to accept the possibility that a theory that is complete
>>>>>>>>>>>>>> in ordinary logic is incomplete in your logic.
>>>>>>>>>>>>>> 
>>>>>>>>>>>>> 
>>>>>>>>>>>>> I only used three-valued logic as a teaching device. Whenever an
>>>>>>>>>>>>> expression of language has the value of {Nonsense} then it is
>>>>>>>>>>>>> rejected and not allowed to be used in any logical operations. It
>>>>>>>>>>>>> is basically invalid input.
>>>>>>>>>>>> 
>>>>>>>>>>>> You cannot teach because you lack necessary skills. Therefore you
>>>>>>>>>>>> don't need any teaching device.
>>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> That is too close to ad homimen.
>>>>>>>>>>> If you think my reasoning is incorrect then point to the error
>>>>>>>>>>> in my reasoning. Saying that in your opinion I am a bad teacher
>>>>>>>>>>> is too close to ad hominem because it refers to your opinion of
>>>>>>>>>>> me and utterly bypasses any of my reasoning.
>>>>>>>>>> 
>>>>>>>>>> No, it isn't. You introduced youtself as a topic of discussion so
>>>>>>>>>> you are a legitimate topic of discussion.
>>>>>>>>>> 
>>>>>>>>>> I didn't claim that there be any reasoning, incorrect or otherwise.
>>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> If you claim I am a bad teacher you must point out what is wrong with
>>>>>>>>> the lesson otherwise your claim that I am a bad teacher is essentially
>>>>>>>>> an as hominem attack.
>>>>>>>> 
>>>>>>>> You are not a teacher, bad or otherwise. That you lack skills that
>>>>>>>> happen to be necessary for teaching is obvious from you postings
>>>>>>>> here. A teacher needs to understand human psychology but you don't.
>>>>>>>> 
>>>>>>> 
>>>>>>> You may be correct that I am a terrible teacher.
>>>>>>> None-the-less Mathematicians might not have very much understanding
>>>>>>> of the link between proof theory and computability.
>>>>>> 
>>>>>> Sume mathematicians do have very much understanding of that. But that
>>>>>> link is not needed for understanding and solving problems separately
>>>>>> in the two areas.
>>>>>> 
>>>>>>> When I refer to rejecting an invalid input math would seem to construe
>>>>>>> this as nonsense, where as computability theory would totally understand.
>>>>>> 
>>>>>> People working on computability theory do not understand "invalid input"
>>>>>> as "impossible input".
>>>>> 
>>>>> The proof then shows, for any program f that might determine whether
>>>>> programs halt, that a "pathological" program g, called with some input,
>>>>> can pass its own source and its input to f and then specifically do the
>>>>> opposite of what f predicts g will do. No f can exist that handles this
>>>>> case, thus showing undecidability.
>>>>> https://en.wikipedia.org/wiki/Halting_problem#
>>>>> 
>>>>> So then they must believe that there exists an H that does correctly
>>>>> determine the halt status of every input, some inputs are simply
>>>>> more difficult than others, no inputs are impossible.
>>>> 
>>>> That "must" is false as it does not follow from anything.
>>>> 
>>> 
>>> Sure it does. If there are no "impossible" inputs that entails
>>> that all inputs are possible. When all inputs are possible then
>>> the halting problem proof is wrong.
>>> 
>>> *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 
>>> 
>>> 
>>> Everyone that objects to the statement that H(D,D) correctly determines 
>>> the halt status of its inputs say that believe that H(D,D) must report 
>>> on the behavior of the D(D) that invokes H(D,D).
>> 
>> Right, because that IS the definition of a Halt Decider.
>> 
> 
> Everyone here takes the definition of a halt decider to be
> required to determine the halt status of the program that
> invokes this halt decider, knowing full well that the program
> that invokes this halt decider IS NOT ITS INPUT.
> 
> All these same people also know the computable functions only
> operate on their inputs and are not allowed to consider anything
> else.
> 
> Computable functions are the formalized analogue of the intuitive notion
> of algorithms, in the sense that a function is computable if there
> exists an algorithm that can do the job of the function, i.e. given an
> input of the function domain it can return the corresponding output.
> https://en.wikipedia.org/wiki/Computable_function
> 
> When the definition of a halt decider contradicts the definition of
> a computable function they can't both be right.

When the definitions of a term contradicts the definition of another term
then both of them are wrong. A correct definition does not contradict
anything other than a different definition of the same term.

-- 
Mikko