Re: Undecidability based on epistemological antinomies V2 --Mendelson--

On 4/22/24 10:03 AM, olcott wrote:

On 4/22/2024 3:26 AM, Mikko wrote:

On 2024-04-21 14:34:44 +0000, olcott said:
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On 4/21/2024 2:50 AM, Mikko wrote:

On 2024-04-20 16:37:27 +0000, olcott said:
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On 4/20/2024 2:41 AM, Mikko wrote:

On 2024-04-19 02:25:48 +0000, olcott said:
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On 4/18/2024 8:58 PM, Richard Damon wrote:

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Godel's proof you are quoting from had NOTHING to do with undecidability,

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*Mendelson (and everyone that knows these things) disagrees*
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https://sistemas.fciencias.unam.mx/~lokylog/images/Notas/la_aldea_de_la_logica/Libros_notas_varios/L_02_MENDELSON,%20E%20-%20Introduction%20to%20Mathematical%20Logic,%206th%20Ed%20-%20CRC%20Press%20(2015).pdf

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On questions whether Gödel said something or not the sumpreme authority
is not Mendelson but Gödel.
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When some authors affirm that undecidability and incompleteness
are the exact same thing then whenever Gödel uses the term
incompleteness then he is also referring to the term undecidability.

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That does not follow. Besides, a reference to the term "undecidability"
is not a reference to the concept 'undecidability'.
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In other words you deny the identity principle thus X=X is false.

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It is not a good idea to lie where the truth can be seen.
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  >>>"undecidability" is not a reference to the concept 'undecidability'.
That is the best that I could make about the above quote. There is no
standard practice of using different kind of quotes that I am aware of.

Except that undeciability and incompleteness are not the EXACT same thing.
They CAN'T be, because they apply to different class of objects.
Of course, you are too stupid to understand that, because you logic is based on making category errors.

 

An undecidable sentence of a theory K is a closed wf ℬ of K such that
neither ℬ nor ¬ℬ is a theorem of K, that is, such that not-⊢K ℬ and
not-⊢K ¬ℬ. (Mendelson: 2015:208)

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So that is what "undecideble" means in Mendelson: 2015. Elsewhere it may
mean something else.
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 It never means anything else.

LIE.
It also means (as the ORIGINAL definition) a computation problem for which no computation can be created that always gives the correct answer.

 

Incomplete(F) ≡ ∃x ∈ L ((L ⊬  x) ∧ (L ⊬ ¬x))

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So not the same.
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 Not provable or refutable in a formal system is exactly
the same as not provable of refutable in a formal system.
I think that you are playing head games.
 

But that isn't what the above says, itr says that F HAS a statement that is not provable or refutable, while undecidable (when applied to a statement) says THAT STATEMENT is not provable or refutable.
SYSTEMS are not STATEMENTS, so you are shows to be just wrong.