Logic — math, philosophy & computational aspects

Archive for November, 2009

fuzzy logic by neuron structure

we can express the fuzzy logic by neuron structure of neural network, and logic operation such as logic OR, logic AND, logic NEGATION in fuzzy logic can present excitatory neuron, forward inhibitory neuron and backward inhibitory neuron in the biological neuron structure. this means the fuzzy logic  and neural network, two approaching methods which mimic human brain, present connection with human logic and neuran structure. basically, as like we can express overall logic by three basic fuzzy operations, w

 can express all neuran by three biological neural structures. so we can say that the neuran structures of the fuzzy logic and the neural network’s are the same. but the difference of two approaching methods is that neural network emphasizes parallel structure and learning ability, on the other hand, fuzzy logic can express uncertain problems logically, and can guess by fuzzy inference.
I expect you to response about above article.  

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Errors

I  would like to collect what the readers think are the most common
logical errors in the world today (outside of the academic world) and
how they might be most easily recognized.  If you (the reader) would
please email me (jmer…@mitre.org) what you think, I would appreciate it.

If an interest is expressed by sufficient numbers, and I get sufficient
answers to warrant it, I’ll post the accumulation.

Thank you.

Jim Meritt

James W. Meritt:  m23…@mwunix.mitre.org – or – jmer…@mitre.org
The opinions above are mine.  If anyone else wants to share them, fine.
They may say so if they wish. The facts "belong" to noone and simply are.

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Complexity Theory

Question:
Is E2 (The second Grzegorw… class) a subset of P (poly time.) ?
Certainly if it is, it is a proper class, as P has x#y.
If this is not known, what is the ‘opinion’ ?
Thanks in advance,
Kevin.

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axiomatisability of monadic second order theories

Question:  does anyone know whether the following theories are
axiomatisable?

(1)  The monadic (second order) theory of partial orders.

(2)  The monadic (second order) theory of trees.

Thanks

Philip Kremer

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Intuitionism

Every time I read something by an intuitionist, I get the impression
that the writer is either unable or unwilling to distinguish between
the notions of truth and decidability.  On the other hand I’ve never
read anything that says this, either by an intuitionist claiming that
there is no difference; or by a critic criticising the intuitionist’s
lack of appreciation of the difference.  The closest I’ve seen is a
claim that intuitionistic logic is a modal logic of "provability".

So have I just missed these writings or aren’t there any such?  If
not, why don’t intuitionists argue that there is no difference between
truth and decidability, or argue that logic should not be concerned
with truth, or do something similar that shows at least that they
understand the difference between the two concepts?  Surely this would
be better than just offering an argument on the non-validity of the
law of the excluded middle based on an undecidable property.  To me at
least, these arguments have always looked a bit silly.

                                        David Gudeman
gude…@cs.arizona.edu

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ampliative deduction

Valid deductive inference is subject to a seeming paradox.  (1) The
content of the conclusion is already stated or ‘contained’ in the
premises (otherwise the negated conclusion would not contradict the
premises), and so such arguments are ‘non-ampliative’. But (2) such
arguments can give us something new and useful (even knowledge which
is ‘new’ in that we did not realise it followed from the premises) and
so would seem to be in some sense ampliative.

Some of the logicians who have discussed this issue in a traditional
context are CS Peirce, JS Mill, G Frege, M Dummett and W Salmon.

The same issue could be re-constructed (and perhaps illuminated) in
the context of inference in symbolic AI systems, and I would be
interested in any views or references on this.

Email preferred: email: D.M.Peter…@cs.bham.ac.uk

Donald Peterson.

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Intuitionism and provability

It seems to me that one could use a Goedel type argument to show
that even intuitionists need to distiguish between provability,
in some fixed system, and something like ‘truth’. Has anybody
ever worked this out in some detail?

Peter

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Help needed: infinitary languages

Hello all:
        I need help to answer the following question ( or indications where
it appears: I have looked in the classical books about infinitary languages,
but until now I havent find it ) :

Is it possible to express “there are at least \omega_{1} elements”
in L_{\omega_{2} \omega_{1}}?

Is it possible to express `there are exactly \omega_{1} elements”
in L_{\omega_{2} \omega_{1}} ?

        Thanks in advance
                        Claudio

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Looking for an email address …

Has anybody got the email address of Dana Scott?
I would appreciate if you can help me. Thanks in advance.
                                   Farrukh

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Validity Accuracy Reliability

        Please tell me the scientific meanings of Validity, Reliability,
and Accuracy.  This is an assignment for my computer class in which
we have to get responses to complete this project.  Your response would be
greatly appreciated.  Thanks!

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