This is ungrammatical semi-coherent dribble. What's a countable
ZFC-set?
Okay, now the next bit is ungrammatical:
x$Y if and only if x there is an element set Y.
x$Y ↔ x∈X
That's ungrammatical. It doesn't make any sense.
Okay, so you just meant the membership relation. Now for your predicate
x#Y. What makes you think this is definable in the first-order language
of set theory?
You write "Let T be the collection of all sets X such that ZFC proves exists unique X psi(X), where psi(X) is a 1-place open formula." In the phrase "ZFC proves exists unique X psi(X)", X does not appear as a free variable. Are you assuming that every theorem of ZFC is true and letting X be the unique set such that psi(X)?
On Thursday, January 17, 2013 9:54:13 AM UTC+2, Rupert wrote:You write "Let T be the collection of all sets X such that ZFC proves exists unique X psi(X), where psi(X) is a 1-place open formula." In the phrase "ZFC proves exists unique X psi(X)", X does not appear as a free variable. Are you assuming that every theorem of ZFC is true and letting X be the unique set such that psi(X)?Yes.
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I work not with the formula, but with a collection of equivalent formulas which define unique set. Thus the answer always the unique
I work not with the formula, but with a collection of equivalent formulas which define unique set. Thus the answer always the unique,see formula (2.14).
And where in your opinion I used language of the second order?
On Thursday, January 17, 2013 11:28:55 AM UTC+2, Rupert wrote:
On Thursday, January 17, 2013 9:53:52 AM UTC+1, JAYKOV wrote:
On Thursday, January 17, 2013 10:36:15 AM UTC+2, JAYKOV wrote:
On Thursday, January 17, 2013 10:19:58 AM UTC+2, Rupert wrote:
On Thursday, January 17, 2013 9:12:40 AM UTC+1, JAYKOV wrote:
On Thursday, January 17, 2013 9:54:13 AM UTC+2, Rupert wrote:You write "Let T be the collection of all sets X such that ZFC proves exists unique X psi(X), where psi(X) is a 1-place open formula." In the phrase "ZFC proves exists unique X psi(X)", X does not appear as a free variable. Are you assuming that every theorem of ZFC is true and letting X be the unique set such that psi(X)?Yes.
Okay. So you are working in a metatheory which has a truth predicate, and you are taking it as an axiom that every theorem of ZFC is true. (This set is *not* definable in the first-order language of set theory.)
Then you go on to define the predicate "ZFC proves X is not a member of Y". The problem here is that this is really a predicate that should apply to open formulas, not sets. You would get different answers depending on which formula you used to define the set.
----------------------------------------------------------------------------------------------------------------I work not with the formula, but with a collection of equivalent formulas which define unique set. Thus the answer always the unique,see formula (2.14).
Your argument fails because your "Russell set" R is not definable in the first-order language of set theory, so you don't get the desired contradiction.And where in your opinion I used language of the second order?
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It would be true if I worked in ZFC, but I worked in ZFC#, but there your argument false. If you work in ZFC#, predicate Prov (x, y) already sufficient.
It would be true if I worked in ZFC, but I worked in ZFC#, but there your argument false. If you work in ZFC#, predicate Prov (x, y) already sufficient. See Proposition 2.1.
It would be true if I worked in ZFC, but I worked in ZFC#, but there your argument false. If you work in ZFC#, predicate Prov (x, y) already sufficient. See Proposition 2.1 and formula 2.17.
In passing I want to pay your attention to following circumstance. A hypothesis consistency of ZFC is extremely unnatural. This hypothesis as it is known demands real existence of the corresponding model, satisfying to axioms of ZFC.And who being in senses, it can be charged, what something such is available in this remarkable world?
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What you means under formula ~Con(ZFC}? Is it like formula {2.6}?
If it so then your argument again the false
If it so then your argument again the false
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Well. But if you mean direct definition: ~Con (ZFC) <-->ZFC|-A&~A it cannot be done in the first-order language of set theory alone.Therefore yours contr example does not valid
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Yes certainly. But in this case we deal with Th * = ZFC+E(standard model of ZFC). In standard model of ZFC
in fact arithmetic formula ~Con (ZFC) is fail.
On Tuesday, January 29, 2013 10:31:23 PM UTC+2, JAYKOV wrote:
On Tuesday, January 29, 2013 7:30:05 PM UTC+2, Rupert wrote:
On Tuesday, January 29, 2013 4:10:28 AM UTC+1, JAYKOV wrote:
On Monday, January 28, 2013 4:28:06 PM UTC+2, Rupert wrote:
On Sunday, January 27, 2013 11:15:30 PM UTC+1, JAYKOV wrote:If it so then your argument again the false
Well, you are the one making an argument. And you have not convinced me, for reasons I have given.
---------------------------------------------------------------------------------------------------------------------------------------------------Well. But if you mean direct definition: ~Con (ZFC) <-->ZFC|-A&~A it cannot be done in the first-order language of set theory alone.Therefore yours contr example does not valid
~Con(ZFC) can be formulated in the first-order language of set theory, in fact, the first-order language of number theory.
--------------------------------------------------------------------------------------------------------------------------------------------------Yes certainly. But in this case we deal with Th * = ZFC+E(standard model of ZFC). In standard model of ZFC
in fact arithmetic formula ~Con (ZFC) is fail.
REMARK:In order to deduce "ZFC is inconsistent" from ZFC",i.e., ZFC |- ~con(ZFC), one needs
_something more_ than the consistency of ZFC, e.g., that ZFC has an
omega-model (i.e., a model in which the integers are the standard
integers).
On Tuesday, January 29, 2013 10:36:24 PM UTC+2, JAYKOV wrote:
On Tuesday, January 29, 2013 10:31:23 PM UTC+2, JAYKOV wrote:
On Tuesday, January 29, 2013 7:30:05 PM UTC+2, Rupert wrote:
On Tuesday, January 29, 2013 4:10:28 AM UTC+1, JAYKOV wrote:
On Monday, January 28, 2013 4:28:06 PM UTC+2, Rupert wrote:
On Sunday, January 27, 2013 11:15:30 PM UTC+1, JAYKOV wrote:If it so then your argument again the false
Well, you are the one making an argument. And you have not convinced me, for reasons I have given.
---------------------------------------------------------------------------------------------------------------------------------------------------Well. But if you mean direct definition: ~Con (ZFC) <-->ZFC|-A&~A it cannot be done in the first-order language of set theory alone.Therefore yours contr example does not valid
~Con(ZFC) can be formulated in the first-order language of set theory, in fact, the first-order language of number theory.
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Yes certainly. But in this case we deal with Th * = ZFC+E(standard model of ZFC). In standard model of ZFC
in fact arithmetic formula such that ~Con (ZFC) is fail.
Yes. But this
_means_ that Th has omega model. Otherwise you cannot define predicate Pr_Th ([Phi]).About what claim it is concrete You speak above?
It is not of great importance. Condition
Е(omega model of ZFC) is assumed in this paper initially. See AbstractAbstract In this article we derived an importent example of the inconsistentcountable set. Main result is: ~ (ZFC +Е (omega model of ZFC))
Th contains (ZFC +Е(omega model of ZFC))
No. I assumed Con(ZFC+E(omega model of ZFC)).But Con(ZFC+E(omega model of ZFC)).and
~Con(ZFC+E(omega model of ZFC)).does not valid in omega model of ZFC simultaneously.
No. Obviously there it is meant also that Phi must be true in omega model.
It is the corrected version 4 and corresponding corrections are brought.
Well, that's not what you said. There is no hope of communicating effectively unless you say what you mean.
So what exactly is the assertion that you want to make?
Yes of course.
On Saturday, February 16, 2013 5:55:48 PM UTC+1, JAYKOV wrote:
On Thursday, February 14, 2013 7:10:38 PM UTC+2, Rupert wrote:
On Thursday, February 14, 2013 5:28:27 PM UTC+1, JAYKOV wrote:
On Wednesday, February 13, 2013 12:59:39 PM UTC+2, Rupert wrote:
Explain in more details.Predicate (2.19) is done by first order language.
Explain in more details
. Predicate (2.19) is done by first order languages.Okay. Explain in more details.
But in the
formula (2.14) there is a typing error.
Why you so think? Predicate (2.19) is done by first order languages.
In that sense that definitions (2.20) and (2.16) is equivalent
Well. I will write this point with the maximum detail.
I think that already there is no error, but as much as possible detailed statement is necessary.
I confirm that Godel's completeness theorem does not leave any chances for ZFC to be consistent
Well.Let con(ZFC) be a sentence in ZFC asserting that ZFC has an omega-model M. Let A_M be an wff over M. Let S be the theory ZFC+con(ZFC). Is the reflection for S: Bew_{S}(A_M) --> A_M is satisfied?
Let S be the theory ZFC+con(ZFC). Is the reflection for S: Bew_{S}(A_M) --> A_M is satisfied?
But then to you also it should
is equivalent
Short:
Let W={q_n(x)} be the set (countable) of the all one-place open wff q(x) such that conditions ( * ) or ( ** ) is satisfied. Let Y be the quotient set (countable) of W by <--->,i.e. Y=W/<--->. Let q_n,n=1,2,... be the element of W and [q_n]_k,k =1,2,...be the respective element of Y={[q_n]_k},n=1,2,....,k =1,2,... . {Psi_n,k}=Y.
(*) + (**)<----->Th#|-E!x_n[\Phy_(x_n)] see Definition 2.2.
Well, which one?
Take at first (2)
I am sorry.
There a typing error. Correctly so