most recent 30 from http://mathoverflow.net 2013-05-23T02:18:32Z http://mathoverflow.net/feeds/user/29570 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/126129/question-on-dacosta-logic Jaykov Foukzon 2013-03-31T19:28:09Z 2013-03-31T19:36:33Z

<p>Does it da'Costa Logic solved paradoxes of Cantor's naive set theory?</p>

http://mathoverflow.net/questions/125640/question-on-godel-completeness-theorem Jaykov Foukzon 2013-03-26T17:31:10Z 2013-03-27T01:42:41Z

<p>Let Th be a formal theory. Suppose that Con (Th). Does it Godel completeness theorem confirms that the corresponding model M_Th of the Th <em>really</em> exists?</p>

http://mathoverflow.net/questions/124720/standard-model-of-zfc Jaykov Foukzon 2013-03-16T19:16:22Z 2013-03-17T00:32:21Z

<p>Is ZFC+Con(ZFC) powerful enough to show there isn't any standard model of ZFC? What you think about it?</p>

http://mathoverflow.net/questions/123814/reflection-principles Jaykov Foukzon 2013-03-06T21:37:59Z 2013-03-07T14:57:04Z

<p>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? I asking also for an explanation of the paradox in the link</p> <p>cs.nyu.edu/pipermail/fom/2007-October/012035.html</p> <p>of the case when ZFC is replaced on S=ZFC+(ZFC has omega-model)? </p>

http://mathoverflow.net/questions/117983/what-are-integration-on-fractal Jaykov Foukzon 2013-01-03T19:32:16Z 2013-01-04T16:08:37Z

<p>Who can explain the proof of the formula (2.12) given here: J. Phys. A: Math. Gen. 20 (1987) 3861-3875. Printed in the UK <a href="http://ru.scribd.com/doc/118425928/Svozil-Quantum-Field-Theory-on-Fractal-Space-time" rel="nofollow">http://ru.scribd.com/doc/118425928/Svozil-Quantum-Field-Theory-on-Fractal-Space-time</a> It is easy to prove that in general case this formula is wrong!!! </p>

http://mathoverflow.net/questions/117894/what-are-chris-mortensen-number-systems Jaykov Foukzon 2013-01-02T19:21:47Z 2013-01-02T20:39:50Z

<p>What are Chris Mortensen number systems?</p>

http://mathoverflow.net/questions/126129/question-on-dacosta-logic Jaykov Foukzon 2013-04-02T10:38:55Z 2013-04-02T10:38:55Z

@Noah S. Thanks.I am asking about paraconsistent set theory with unrestricted comprehension schema.

http://mathoverflow.net/questions/125640/question-on-godel-completeness-theorem Jaykov Foukzon 2013-03-30T16:31:18Z 2013-03-30T16:31:18Z

@Henry Cohn Thanks! Statement &quot;Consistent theory T&quot; has a clear substantial sense and it means that on any step of the proof we cannot prove the formula 1=0. But construction of proofs is real physical process and for example, if &quot;10 ^ {10 ^ {10000} exists&quot; has not the same substantial sense as well as &quot;2 exists&quot; then and statement Con (T) obviously has not any sense.

http://mathoverflow.net/questions/125640/question-on-godel-completeness-theorem/125642#125642 Jaykov Foukzon 2013-03-29T19:40:36Z 2013-03-29T19:40:36Z

&gt; I really think that &quot;is $T $ consistent?&quot; and &quot;what do symbols mean?&quot; are unrelated.) $T $ consistent has clear substantial sense and it means that on any step of the proof we cannot prove the formula 1=0. But construction of proofs is real physical process and if &quot;10 ^ {10 ^ {10000} exists&quot; has not the same substantial sense as well as &quot;2 exists&quot; then and statement Con (T) has not any sense.

http://mathoverflow.net/questions/125640/question-on-godel-completeness-theorem/125642#125642 Jaykov Foukzon 2013-03-29T18:07:13Z 2013-03-29T18:07:13Z

Well. Then explain to me that you particularly mean when tell that number $10 ^ {10 ^ {10000}} $ exist. It something real or only a symbol?

http://mathoverflow.net/questions/125640/question-on-godel-completeness-theorem/125642#125642 Jaykov Foukzon 2013-03-29T08:31:12Z 2013-03-29T08:31:12Z

Noah &gt; In particular, can you please explain what you mean by &quot;really exists?&quot; &quot;Really exists&quot; means exist as real infinite physical object or infinite physical process. For example E.Nelson in fact asserts that such object or process does not exist, i.e. РА has no any standard models.

http://mathoverflow.net/questions/125640/question-on-godel-completeness-theorem/125642#125642 Jaykov Foukzon 2013-03-28T16:44:40Z 2013-03-28T16:44:40Z

&gt; then at some level you must be rejecting infinite sets, which is fine, In it there is no necessity. Nevertheless it is possible to assume that real-life infinite sets, are not obliged to correspond to the classical logic.

http://mathoverflow.net/questions/125640/question-on-godel-completeness-theorem/125685#125685 Jaykov Foukzon 2013-03-28T15:31:49Z 2013-03-28T15:31:49Z

Andrej Bauer. &gt;but &quot;really exist&quot; might mean &quot;exists constructively&quot;. Well. Thus &quot;really exist&quot; completely depend on logic.

http://mathoverflow.net/questions/125640/question-on-godel-completeness-theorem/125642#125642 Jaykov Foukzon 2013-03-26T19:38:21Z 2013-03-26T19:38:21Z

&gt;Let me elaborate a bit on why having computationally simple models &gt;is relevant. It's not just that such models are &quot;less complicated&quot; &gt;than standard set-theoretic constructions, as I state above; it's &gt;that we don't even need to talk about set theory, at all, to get &gt;them! The models in question are uniformly It agree.But nevertheless there are known mathematicians which think that such constructive process will suffer contradictions <a href="https://web.math.princeton.edu/~nelson/papers/warn.pdf" rel="nofollow">web.math.princeton.edu/~nelson/papers/warn.pdf</a>

http://mathoverflow.net/questions/124720/standard-model-of-zfc Jaykov Foukzon 2013-03-22T16:23:53Z 2013-03-22T16:23:53Z

Noah S. You rave. My question is put clearly and no any relation to my statements in other places has. Moreover I never addressed to whom or with intentions to check my proofs and the more so their sketches.

http://mathoverflow.net/questions/124720/standard-model-of-zfc Jaykov Foukzon 2013-03-17T03:18:39Z 2013-03-17T03:18:39Z

Joel David Hamkins.Yes of course.

http://mathoverflow.net/questions/124720/standard-model-of-zfc Jaykov Foukzon 2013-03-16T21:01:52Z 2013-03-16T21:01:52Z

I'm asking does it follow from ZFC+ there exists some model of ZFC

http://mathoverflow.net/questions/124720/standard-model-of-zfc Jaykov Foukzon 2013-03-16T20:57:32Z 2013-03-16T20:57:32Z

Timothy Chow &gt;What you're asking is, as long as there exists some model of ZFC, does it follow that no models are standard? Yes of course.

http://mathoverflow.net/questions/123814/reflection-principles Jaykov Foukzon 2013-03-06T23:11:36Z 2013-03-06T23:11:36Z

jdh.hamkins.org I asking also for an explanation of the paradox in the link <a href="http://www.cs.nyu.edu/pipermail/fom/2007-October/012035.html" rel="nofollow">cs.nyu.edu/pipermail/fom/2007-October/012035.html</a> of the case S=ZFC+ omega-model?

http://mathoverflow.net/questions/123814/reflection-principles Jaykov Foukzon 2013-03-06T23:02:47Z 2013-03-06T23:02:47Z

wff being &quot;over M&quot; meant an wff with bounded quantifiers restrict by M.

http://mathoverflow.net/questions/123814/reflection-principles Jaykov Foukzon 2013-03-06T22:39:53Z 2013-03-06T22:39:53Z

Bew_{S}(A_M) mean that A_M is provable in S.