

Major (unfixable) flaw found in P!=NP paper. - amichail
http://rjlipton.wordpress.com/2010/08/09/issues-in-the-proof-that-p%E2%89%A0np/#comment-4712

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ewjordan
Until a major chorus of experts chimes in with "Yup, this is curtains for this
approach", I think it would be wise not to take too seriously any blog
comments based on quick reactions to the paper.

...just as it would be unwise to take the paper itself too seriously until a
chorus of experts tells us that it's looking pretty good.

~~~
akshayubhat
There are several indicators, the author of the comment seems to be a
researcher at an IBM R&D center.

Also the original author removed the paper from him web page. Thus which
indicates that he is probably backing out on his claim.

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hubb
removing the paper doesn't necessarily mean that at all, he probably just
wants finish editing it and getting peer feedback before he releases it
officially

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akshayubhat
well he had actually posted an updated version yesterday, so if he had to
update it he would put up a not. Regarding the legal question, i don't think
it reflect poorly any way on HP Labs. Its not like he is making cranky claims
like no one landed on moon etc. etc.

~~~
electromagnetic
I thought his paper was showing P/=NP which is the already (more generally)
accepted theory in computer fields. I'd understand it reflecting poorly if one
of HP's researchers was claiming P=NP against the accepted wisdom. It would
however reflect great if this guys paper is a proof of P/=NP or even if it's
simply a step forward.

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learner4life
It is a bit sad though for the author. The author never intended the paper to
be public. Now he joins the infamous list of people who published to prove
P!=NP or otherwise.

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zokier
Well, to be fair, he didn't actually publish it. Especially not in the
conventional meaning of scientific publishing.

~~~
nsoonhui
Not sure if he wanted to he could get past the conventional meaning of peer
review.

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gojomo
P≠NPin' ain't easy.

~~~
dunstad
I'm afraid I've missed something here. Anyone care to provide an explanation?

~~~
martincmartin
"Pimpin' ain't easy"

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tierack
Whatever comes of this paper specifically, it's been a very entertaining
couple of days to watch this unfold.

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maqr
I've been watching it the whole time, and I still have absolutely no idea
what's going on.

~~~
dschobel
_SCIENCE!!!_ </zed shaw>

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troutwine
Clearly I need to study more.

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palish
Could some math expert (cperciva?) read the paper, read this blog post, and
tell us the results?

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cperciva
I've skimmed the paper, but it's way over my head. It would take me years of
study to understand everything in this paper.

(I'm confident that I could do so if I wanted to -- but my expertise lies in
entirely different directions.)

~~~
palish
Wow.

It's so strange to realize how incredibly massive the field of mathematics is.

As a software developer, there isn't a single programming concept /
architecture / algorithm / etc that I can't learn in less than a day. _(Edit:
of course, now I regret writing this. What I meant was: I can read,
understand, and re-implement 99% of software engineering algorithms /
architectures.)_

But to know that it would take someone as insanely experienced as cpervica
_years_ of study to understand that proof... Wow.

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pmjordan
_As a software developer, there isn't a single programming concept /
architecture / algorithm / etc that I can't learn in less than a day._

That's quite a bold claim.

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palish
At this point, I have >10 years of programming experience. I've been
programming for the majority of my childhood and the entirety of my adult
life. I don't like to overestimate my own abilities, and I wish I could prove
to you that my above claim is true. I simply have enough experience where I
know for a fact that I can understand 99% of algorithms and architectures that
were designed to solve a practical real-world problem.

So you're right, "there isn't a single..." is probably pushing it. But I'd
definitely stand by the fact that I can read, understand, and re-implement 99%
of algorithms or architectures.

My point is simply that the breadth of the field of software engineering
apparently pales in comparison to that of mathematics.

Or rather --- it's very strange to me that if you are an expert in a given
branch of mathematics, then all of your lifetime of experiences cannot be
applied to an entirely different branch. If I understand cperciva correctly,
if you want to learn a particular specialized branch of mathematics, then you
basically have to start from the ground-up (years).

It would basically be equivalent to wiping your memory of all programming
knowledge, then re-learning it all, in terms of effort. It's just strange /
interesting that mathematics works that way.

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spuz
You are basically saying you could re-write the H.254 codec just by studying
it for one day? Sure you might be able to learn some of the image compression
tricks that it uses by reading the spec but to implement it efficiently
requires deep understanding of hardware architecture, instruction pipelines,
bit-twiddling algorithms and dare I say it, mathematics.

You are right that mathematics is unique in being an infinitely broad subject.
Programming as a subject is like medicine in that it is constrained by the
real world. However, I don't know about you but I'm not going to trust a
radiologist to perform surgery because he's 'understood' the concepts in one
day.

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amichail
BTW, the author has removed any mention of a proof for P!=NP from his home
page:

<http://www.hpl.hp.com/personal/Vinay_Deolalikar/>

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whakojacko
Was it ever there? I thought he always said that the paper was done on his
personal time and not related to his HP research. I read his Bio there
Sunday/Monday and dont remember seeing it. Not to mention it was still being
peer-reviewed when it was leaked.

~~~
ctbarna
He posted something saying that it wasn't meant to be released yet. He had
sent it to some experts on August 6th and it made its way into the wild on
August 8th. He posted what he said was an "updated" draft. It was there this
morning but is no longer.

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akshayubhat
The mention of the paper has been removed from the authors homepage.

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phreeza
Your title is a bit drastic, where does anyone say its unfixable in the post?

edit: sorry, was viewing this from a mobile phone, which didn't skip ahead to
the comment.

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amichail
Charanjit Jutla says "unfixable" twice.

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igravious
Yes but you've linked to a comment to the main blog post. Which is a bit
untoward. A comment on a blog is hardly authoritative. I did a double-take
until I realized you weren't linking to the main post. The main blog post says
(and I quote) _Still there remains the key question: is the proof correct? In
one sense the present paper almost surely has mistakes—not just from the above
objections but what one could expect of any first-draft in a breakthrough
situation. The real questions are, is the proof strategy correct, and are the
perceived gaps fixable?_

edit: the commenter Charanjit Jutla seems to know his stuff but I still
maintain that an offhand comment does not warrant the definitive titling of
your submission.

~~~
kvs
Do a quick search on the blogs and the names of people posting comments on it.
They are authoritative sources, just because it is on a blog (run by a well
known complexity theorist) doesn't mean it's less important. I am quite
surprised to see so many comments from these guys and such a discussion happen
in public.

~~~
studer
They don't necessarily agree with each other, though, so I'm not so sure how
"authoritative" individual blog comments are (see e.g. Bradfield's followup to
Jutla -- _"And I don’t understand your comment about it not being known
whether mu-calculus has a hierarchy of expressibility in alternation. It’s 15
years since I (and independently Lenzi) proved that it did!"_ )

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jmatt
All these academics that lay low then pop up with problems and call
Deolalikar's contribution unfixable infuriate me.

They bring out the worst in the same way that bad QA employees do. They create
no wealth and add little value. They slow down and confuse the process. But in
the end they are still necessary. There is something to be said about how one
reports such problems. Most here know a great QA person that reports relevant
problems in a intelligent manner and is there to help find solutions. Versus
the QA person that just cranks out an endless stream of wonky insane problems.
All make you look bad and all are difficult to reproduce, understand or
address.

It's my understanding that his approach is a radical and new way to attempt to
solve the P!=NP problem. So it's no surprise that at first glance the vast
majority of average math and computer scientists would think it was not a
valid approach. And, again no surprise to me, that has ended up to be the
case. I don't pretend to understand this flaw or Deolalikar's paper. But I do
understand the type of person that posts comments like that...

It looks like the math community has settle on a wiki to unofficially collect
news and information on the paper:

[http://michaelnielsen.org/polymath1/index.php?title=Deolalik...](http://michaelnielsen.org/polymath1/index.php?title=Deolalikars_P!%3DNP_paper)

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brent
The claim is that the proof is unfixable. Proofs are either right or wrong.
Good academics are supposed to checks proofs of their colleagues. There is no
claim as to the merit of contributions made by Deolalikar. So, why exactly do
these academics infuriate you?

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jmatt
_So, why exactly do these academics infuriate you?_

I'm quite clear if you read more than one sentence.

It's the way this guy responded to a comment of a blog about the paper. It
just seems like a bad place to post a real unfixable flaw to the paper.
Assuming the commenter is right (also possibly a bad assumption) why not put
some effort into your response that will be read by every computer science and
math person you'll ever work with in the future. For instance how does one
respond, follow up, contact this guy? I have to go google him wtf. It's the
equivalent to nitpicking. In the end someone else will have to pick up the
pieces of what he said and analyze it and rewrite it and repost it. So to me
he seems like the guy from QA that no one wants to work with - a bad team
player.

~~~
flatline
I'm sure that QA guy loves working with you, too...

