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On 2024-05-30 11:33:03 +0000, Richard Damon said:also the function "Description" doesn't have to 'know' all of the descriptions - one per machine is enough.
On 5/30/24 6:11 AM, immibis wrote:At this point we may assume the axiom of choice.On 30/05/24 05:48, olcott wrote:>On 5/29/2024 9:55 PM, Richard Damon wrote:>On 5/29/24 10:36 PM, olcott wrote:>On 5/29/2024 9:25 PM, Richard Damon wrote:>On 5/29/24 9:55 PM, olcott wrote:>When the category is examined all at once then there is no need>
to look at each individual element.
So, which one or ones gave the correct answer for their input?
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*Formalizing the Linz Proof structure*
∃H ∈ Turing_Machines
∀x ∈ *Turing_Machines_Descriptions*
∀y ∈ Finite_Strings
such that H(x,y) = Halts(x,y)
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When we formalize it that way then some simulating halt deciders
get the correct answer.
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*Everyone else implicitly assumes this incorrect formalization*
∃H ∈ Turing_Machines
∀x ∈ *Turing_Machines*
∀y ∈ Finite_Strings
such that H(x,y) = Halts(x,y)
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Nope.
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You just don't understand the meaning of a "Description" in the problem.
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A deciders compute the mapping FROM ITS INPUTS
to it own accept or reject state
Deciders cannot take ACTUAL TURING MACHINES AS INPUTS
Deciders can only take FINITE STRINGS AS INPUTS
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If you want to be pedantic, you made the mistake.
It's actually H(DescriptionOf(x),y) = Halts(x,y)
DescriptionOf is an injective function that converts Turing machines into finite strings.
OR in his formal language:
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∃H ∈ Turing_Machines, and for
∀M ∈ Turing_Machines, which have a description Wm, and
∀w ∈ Finite_Strings
such that H(Wm,w) = Halts(M,w)
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The problem is that there doesn't exist a FUNCTION "Description" as one machine can have an potentially infinite number of descriptions.
It is more that there is an inverse function, Described where we could say that M = Described(Wm)
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