From: gudi on
http://www.hindu.com/2010/08/12/stories/2010081257181300.htm


Narasimham
From: Marko Amnell on

"gudi" <mathma18(a)hotmail.com> wrote in message
15d2dc9d-3aa1-401e-84b0-e47be585d770(a)v35g2000prn.googlegroups.com...
> http://www.hindu.com/2010/08/12/stories/2010081257181300.htm
>
>
> Narasimham

Vinay Deolalikar claims he has a proof that P != NP.
But the experts don't buy it. The best online discussion
of the subject is over at Richard Lipton's blog:

http://rjlipton.wordpress.com/

A consensus has formed that is best expressed
by Terence Tao:

------------------------------------------------------------

I think there are several levels to the basic question
"Is the proof correct?":

1.Does Deolalikar's proof, after only minor changes,
give a proof that P NP?

2.Does Deolalikar's proof, after major changes, give
a proof that P NP?

3.Does the general proof strategy of Deolalikar (exploiting
independence properties in random -SAT or similar structures)
have any hope at all of establishing non-trivial complexity
separation results?

After all the collective efforts seen here and elsewhere, it now
appears (though it is perhaps still not absolutely definitive) that
the answer to #1 is "No" (as seen for instance in the issues
documented in the wiki), and the best answer to #2 we currently
have is "Probably not, unless substantial new ideas are added."
But I think the question #3 is still not completely resolved, and
still worth pursuing (though not at the hectic internet speed of
the last few days.)

http://rjlipton.wordpress.com/

-----------------------------------------------------------

Despite the many objections of experts, Deolalikar is
standing by his claim to have a proof and is trying
to respond to the criticisms. His homepage now states
vis-�-vis his paper on P vs NP that: "Please note that
the final version of the paper is under preparation
and will be submitted to journal review."



From: Marko Amnell on

"Marko Amnell" <marko.amnell(a)kolumbus.fi> wrote in message
8ci5e3F347U1(a)mid.individual.net...

> A consensus has formed that is best expressed
> by Terence Tao:

Oops. Some characters were lost when I copy and
pasted Tao's comment. Here is a more readable version:

------------------------------------------------------------

I think there are several levels to the basic question
"Is the proof correct?":

1.Does Deolalikar's proof, after only minor changes,
give a proof that P != NP?

2.Does Deolalikar's proof, after major changes, give
a proof that P != NP?

3.Does the general proof strategy of Deolalikar (exploiting
independence properties in random k-SAT or similar structures)
have any hope at all of establishing non-trivial complexity
separation results?

After all the collective efforts seen here and elsewhere, it now
appears (though it is perhaps still not absolutely definitive) that
the answer to #1 is "No" (as seen for instance in the issues
documented in the wiki), and the best answer to #2 we currently
have is "Probably not, unless substantial new ideas are added."
But I think the question #3 is still not completely resolved, and
still worth pursuing (though not at the hectic internet speed of
the last few days.)

http://rjlipton.wordpress.com/



From: Marko Amnell on

"Marko Amnell" <marko.amnell(a)kolumbus.fi> wrote in message
8ci5e3F347U1(a)mid.individual.net...
>
> "gudi" <mathma18(a)hotmail.com> wrote in message
> 15d2dc9d-3aa1-401e-84b0-e47be585d770(a)v35g2000prn.googlegroups.com...
>> http://www.hindu.com/2010/08/12/stories/2010081257181300.htm
>>
>>
>> Narasimham
>
> Vinay Deolalikar claims he has a proof that P != NP.
> But the experts don't buy it.

And the last nail in the coffin seems to have
been hammered in today, with the release of
a letter from Neil Immerman, an expert on
Finite Model Theory, one of the theories used
by Deolalikar in his purported proof, in
which Immerman identifies a fatal flaw
in Deolalikar's argument:
http://rjlipton.wordpress.com/2010/08/12/fatal-flaws-in-deolalikars-proof/

TechCrunch has a pretty good article on
what just happened:
http://techcrunch.com/2010/08/12/fuzzy-math/

What did happen is that a week ago, Vinay Deolalikar,
a computer scientist at Hewlett-Packard in Palo Alto,
California, sent a copy of an article to several leading
experts in theoretical computer science, in which he
claimed to have solved the P vs NP problem, perhaps
the most important open problem in the field.

What happened then was something unprecendented.
Two days later, someone leaked Deolalikar's article to
the public. Online, hundreds of computer scientists,
mathematicians and engineers tore apart Deolalikar's article,
finding numerous flaws in the argument. It was, as some
have said, the most public peer review process in the
history of the world. You can see a list of some of the
flaws on a wiki page created to cover the event:
http://michaelnielsen.org/polymath1/index.php?title=Deolalikar_P_vs_NP_paper

There has never been anything like it. It did remind
me a bit of the online discussions back in 1993 when
Andrew Wiles announced that he had proved
Fermat's Last Theorem. At the time, various experts
came forward to analyse Wiles's paper online, and
post summaries, analyses and explanations on Usenet.
But the scale of the discussion in places like sci.math
about Wiles was dwarfed by the scale of the discussion
about Deolalikar's proof over the last five days.
Back in 1993, there was no blogosphere like today.