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13:02
@JonasTeuwen Can you try s/\B([+-])\B/ \1 /g ?
@JM: Gives a syntax error near (
Wait, is this sed or Perl?
13:17
How about s/\B\([+-]\)\B/ \1 /g ?
Yes, I have tried that one already, it says sed: 1: "s/B([+-])B/": unterminated substitute in regular expression (I should learn regex better)
@JonasTeuwen Tsk. I don't know of any other way to check that something isn't already surrounded by spaces...
Sorry. :(
(If you manage to figure it out, could you tell me too?)
@JM Sure! Thanks for the help :-).
Maybe I should just do all of then and then a regex that detects double spaces! 8-).
regex I know, sed not so much
I've been using Perl too long I've forgotten what doesn't work in sed()...
13:30
@robjohn Would you know the regex for emacs?
Is it different than standard regex?
I guess not.
I don't know emacs, so I don't know.
You can also do LISP regex.
Apparently it's only a subset of PCRE, since it apparently doesn't know \B.
13:33
What is it that you are trying to do? It looks like inserting spaces.
He wants to insert spaces if they aren't already there.
Exactly.
Surely it doesn't matter in compiling the document, but I would like it to look a bit nicer...
@JonasTeuwen where exactly do you want the spaces inserted?
To start with: a+b -> a + b (and with single spaces too, say a+ b -> a + b).
Someone just voted to close one of my questions as "too localised". I don't agree with that.
Today is a bad day. T_T
13:38
@MattN Wut?!
@JM T_T
Going to cry. And stab myself in the guts.
Ah, did you read Conway?
No. Why?
Sorry I can't help; not the circle I deal with... :(
Because that's what it does to me 8-).
@MattN So, what's wrong?
13:41
@JM It's okay, I think his comment actually answers my question. But I can't bring myself to do any more of this. At least not today. Will look at it again tomorrow.
@JonasTeuwen Set theory and logic are wrong. In fact, I don't even remember why I'm doing this to myself at all, studying maths that is.
Just do something else today and look again at it tomorrow.
If it really makes you feel bad you should do something else 8-).
So you might now think: No shit, Sherlock, but in my experience that's the best thing to do 8-).
Where does Sherlock come in?
Hi @Jonas @Matt
@MattN "No shit, Sherlock" is idiomatic... ;)
@JM Oh.
13:45
If you want, replace "Sherlock" with "Captain Obvious".
Luckily someone made me an offer I couldn't refuse so I have to go out tonight anyway. Which means: blissful drunkness ahead.
And a terrible hangover tomorrow! Yay!
Better than being sad.
@JonasTeuwen Spoken with experience, eh? ;)
Teddybear's absence makes me sad, too.
13:47
@JM Yep.
@MattN The sad comes after the hangover.
@MattN That is true; if your head is throbbing like a bongo drum, you won't have the energy to mope...
I think I've seen lecture notes that summed it up nicely. Let me see if I can find them.
@JonasTeuwen Are you telling me not to drink alcohol anymore?
No, I'm telling you not to drink too much.
Or at least, not if you don't feel well.
Yes; drink to enjoy, not to kill neurons. We only have so many of 'em...
Ah, here: "Observations:" at the bottom of page 3.
13:50
@JM : Serious Question : Does drinking hampers neuron growth ?
@RajeshD Most likely.
You're only alloted a certain amount of neurons at birth.
From that point, it's a steady decline. The only good thing is that we have quite a lot to start with, and extant neurons are remarkably capable of picking up slack.
I totally disagree ! Counter Example : Asaf Karagila !
What? He's only 26.
Korsakov is more something for >35 8-).
@Jonas: using sed with the following:
s/\([^ ]\)+\([^ ]\)/\1 + \2/g
seemed to work for me.
13:52
I see
@MartinSleziak I'll try that!
@JonasTeuwen Oh. I didn't know that. I thought anyone could get that after enough sustained drinking.
I was too lazy to scroll through all the transcript, you probably solve that already differently.
No, it is actually a vitamin deficit.
@MartinSleziak No, I did not.
@MartinSleziak Okay, \([^ ]\) didn't occur to me at all... :D
13:53
Again, there might be slight differences between sed under Windows and Linux.
@JonasTeuwen Wat? 0_o
Hmm, yeah unbalanced brackets [, let's see.
@JM Apparently some parts of the brain still produce new neurons in adults. Not sure if it's in any useful parts though.
I mean I did this: sed -f pom2.sed test.txt > out2.txt
pom2.sed contains the only line I wrote above.
Yeah. Okay, that works. So now I'll adapt it for a+ b and a +b too :-).
13:56
@MattN Hmm, must be a new development. Those textbooks were a long time ago... :)
Oh, I see.
I didn't think of that.
@JM It's quite recent.
anyway i did a useful thing today
@MattN Hah, interesting! We really know so little about the body...
14:01
@JM Indeed. Particularly worrying if you have to see a doctor : D
@JM : I did one useful thing today !
any guess
@RajeshD I suck at guessing. Please just tell...
I purchased the Rudin's Principles of mathematical analysis
First time i am buying a pure math book after school days !
@RajeshD Well, apart from "good investment; read it with pleasure", what else is there to say? :)
Surely....I hope to njoy it
14:04
I wonder at what page you will want to stab yourself in the guts.
@JonasTeuwen Shh! :D :P
@JonasTeuwen But I thought Rudin was one of the best books on the subject!?
It sure is.
Then no gut stabbing involved.
@Jonas : What is the meaning of guts ?
Ok What is this slang supposed to mean ???
14:07
@MattN It is quite hard for a first read.
Guts is no slang, right? Belly.
Guts = your insides.
It needs multiple passes to appreciate properly, yes.
I've seen people cry during the first few passes... :)
The first time I read it I was thinking like "this is horrible!" but it was actually me that was horrible.
hi all
ok got to go...i've got a train to catch tonight...bye
14:12
@Srivatsan Hi.
@RajeshD Bye.
Hm, curious. I don't understand this at all.
My meta post, it's getting downvotes, but nobody has explained why.
@Srivatsan Link?
But Rahul's mockup doesn't have downvotes, no?
Here: meta.math.stackexchange.com/q/3550/13425. Actually, there's one explanation.
@JM Yes, I was coming to that, JM.
Thanks.
14:18
Since there is no explanation, I am trying to second guess these people. =)
Why is it that there is someone disagreeing with me, but not Rahul? Do you have any ideas?
@Srivatsan Yes, that's the puzzling bit...
Hypothetically, let's say the question gets a net total of -10 votes, and Rahul's gets +10 votes. I wonder what we would do then... =)
@MattN You're welcome, Matt.
Have you started answering questions again, JM?
@Srivatsan Only a few. I still have to write that answer to my own question that I promised...
Hm, which is one that again?
I already have something written, but it could use a good deal of streamlining...
14:30
jan 12? You weren't active then, were you? I haven't seen this question till now.
@Srivatsan I think I went on break a few days after that...
Oh ok.
In the meantime, I wrote a new entry on my blog...
14:44
It feels a bit awkward using mathematica. It is proprietary software (small issue) but I'll also have a vendor lock-in (big issue).
@JonasTeuwen FWIW: it was a hell of a long time before I upgraded. I skipped two versions.
Hmm :-). The problem is that there is not enough money to have those developers work on OSS :-(.
I was actually apprehensive for a while; it seemed at one point they threw in the kitchen sink...
@JonasTeuwen Yeah, rather unfortunate...
Uh, could you rephrase that? My head can't parse that. 8-).
@JonasTeuwen There was a big jump in the number of functions from version five to version six. It seemed at the time that they wanted it to cook and launder for you as well... :D
14:51
Oh :D.
They have only send me version 8.
Plus the workbench, but not sure what that is.
Yes, that's the latest. I skipped six and seven.
@JonasTeuwen That's an IDE for heavy-duty programming. If you aren't writing long code, you won't need it so much.
Oh right.
@JM Surprise! Version seven of Mathematica would allow you to compute things as well; that is, in addition to the cooking and laundering.
@Srivatsan :D
@J.M. I think I have an answer to your question. (Which I'm ripping off of one of robjohn's answers which he got more votes on than I did. Payback time.)
15:01
@anon Chip away! I'll do a comparison with the original solution afterwards.
Wait a minute. The robjohn answer is in the third link you provided @J.M.!
Ah, hmm... :)
At least the LHS of Gautschi's inequality follows from what robjohn has. I'm having trouble seeing it for the RHS.
For $0<s<1$, we have $$\Gamma(x+s)\le\Gamma(x)^{1-s}\Gamma(x+1)^s=\Gamma(x)x^s.$$ If we multiply both sides of this by $x^{1-s}\,\Gamma(x+s)^{-1}$ and use $x\Gamma(x)=\Gamma(x+1)$ one obtains the left-hand side of the Gautschis inequality.
(Actually to go from weak to strong inequality you might have to do some kind of endpoint discussion, but that's just book-keeping.) Thoughts anyone?
15:24
@anon I don't have the photocopy of Gautschi's paper on hand now; I'll check it tomorrow.
But IIRC Gautschi did something like that.
Took me a while to realize a proper mapping. :) There's probably a more informative coloring scheme, but I'll figure that out later.
Wow, that looks pretty cool! I think it's stretched a lot because it's not an isometric realization, but there's really no way around that because the parallelogram has a flat metric.
Also, there's really no good way to map the double pole... :)
I settled on the least messy position.
Anyway, thanks for the challenge. :) I'll try it out on the other functions tomorrow, and maybe update my blog post.
Now imagine slowly shifting the fundamental domain (parallelogram) by a continuous parameter multiple (time) of the first period ($t=0$ to $t=1$) and then of the second period, and making it an animation! Also, smoother coloration. Probably not feasible on a PC but one can dream.
I like how twisty it is.
Crap, my pen exploded everywhere on my bed. This isn't looking very pretty.
"Exploded"?
15:39
You've never had a pen explode before? (It doesn't technically explode per se, it's just the phrase that's used.)
You'll need to soak it. Longer it stays, the harder it gets to remove.
I never liked pens. I used to write everything in ball point pen but a few months ago I discovered that I much prefer pencil. Especially to write proofs. : )
@anon I've had leaky fountain pens, but I haven't seen any other way to spill ink...
I hate pencils. And chalk. Ugh. Mental fingernail-on-chalkboard feeling every single time I use either of those things.
How did you make it explode?
15:41
Dunno.
I have to go clean my hand, brb.
@anon I don't like hard pencils either. If you use soft ones that won't happen.
I use number 1 for sketches, and number 2 for writing.
I assume explode means it just leaked. But that doesn't explain why it's "all over" his bed.
@MattN The "all over" made me think of something rather violent, too...
@JM Is 1 the hardest? Or the softest? They use letters here, H is hard, B is soft, HB is somewhere in between.
15:44
@MattN Ah, different system apparently. 1 is the softest, 3 is the hardest.
Can an identity element has zero divisors in a ring?
Pencils give me that feeling regardless of softness. And it's on my sheets because I'm sitting in bed.
@Daniil: Only in the trivial ring.
Actually, no, because a zero divisor should be nonzero I think.
Hello!
(I assume you're asking if the identity can be a zero divisor.)
sup unNaturhal
Ok, so I do not really understand the this definition of characteristic of a ring: such number n that (1+1+...+1) = (id added n times) = 0
15:48
That's because n=0 in that ring, Daniil ;)
I used to use the following definition: n is a characteristic of a ring R if for ever a in R: a+a+...+a = (element a added n times ) = 0
that second definition is equivalent to the first, of course
@Srivatsan: here is a comparison of $c_d$ and $\dfrac{1}{\sqrt{2\pi d}}$: i.sstatic.net/ZwbZw.png
but in the basic situation that means that n*1 = n = 0 :|
15:50
Sorry for the interruption...
Yo robjohn. Scroll up a bit and look at the gamma function inequality J.M. and I were talking about; he has a question about it on MSE that links to your answer.
@Daniil: Yes, n=0 in a ring of characteristic n. Problem?
:3156878 That's very cool.
@Daniil I'm a bit late and anon has already answered but let me say something anyway: If $e$ is a zero divisor then there is an element $a \neq 0$ such that $e \cdot a = 0$. But $e \cdot a = a \neq 0$ which would be a contradiction.
Is it odd $d$, even $d$ or all $d$?
robjohn: Interruption? Just post it, yeash.
15:51
@anon Just a sec, lemme look
@anon Assume we have $F_4$. Char($F_4$) = 2, right?
or am I missing something
Yes.
But $2 \neq 0$ in $F_4$, innit?
@MattN yeah, that's why I was confused
No, 2=0 in F_4.
@anon The LHS inequality is just the log convexity of $\Gamma(x)$ and the RHS equality follows from $\Gamma(x+1)=x\Gamma(x)$.
15:53
Yes.
but you knew that.
F4 is just {0,1,x,1+x} with x^2=x+1 and 1+1=0.
Gautschi actually proved an inequality on incomplete gamma, and then took limits afterwards. I really should aim to post that answer by tomorrow.
OK, in general, if I understand correctly: $char(F_{p^n}) = p$, I don't think I fully understand why
It's obvious when n=1
$\mathbb{F}_{p^n}$ can be constructed as $\mathbb{F}_{p}[X]$ modulo an irreducible monic polynomial of degree $n$ (it doesn't matter which such polynomial). Now if you add any n polynomials in this ring, each coefficient vanishes separately.
16:11
@MartinSleziak For when you get back: how about I create a room to post stuff only related to the book? It's kind of noisy in here.
@robjohn Why did you remove the image?
@Srivatsan I linked to it in the other message.
So: c_d is always larger than its asymptotically close cousin?
@Srivatsan It seems so
(I mean: for all $d$, odd and even.)
Completely unrelated: I didn't know copy-pasting a block of text from a book and paper could feel so good =)
16:15
@Srivatsan where is that?
@robjohn In my new answer: math.stackexchange.com/q/102966. Might not be so interesting to you though.
@Srivatsan were you able to simply copy and paste? no additional work?
@anon thank you
@robjohn No, quite a bit of additional work. I meant: copy-paste with no mental effort. I typed out the paragraph from the textbook. I copy-pasted from the pdf, which obviously gets the text right but not the math; so I did a pass correcting it.
Okay. I wasn't sure if the format on the webpage was MathJax compatible.
16:20
The day I can copy-paste from a math PDF and get proper $\TeX$...
@JM Hm, ya, I am looking forward to it too.
Could someone help me to solve this absolute value?
$\left|\frac{2-x}{x+3}\right|\ge-\cos\left(4\right)$
On that note, probably my only peeve now with the DLMF is: why aren't they on MathJax already?!
Can somebody please check my proof regarding the fact that Galois fields have order of $p^n$: mathbin.net/88055
@JM Should I not answer the question then?
16:23
@robjohn It would still be great to have different answers. :) Hopefully it's different from Gautschi's route...
(...and as I said, I only posted it because J. Math Phys. doesn't have an electronic archive yet. Which is a shame.)
16:44
@JM: Here is anon's screenshot of a post with mine. What is the difference? Why do I have a "history" link and anon does not?
I suspect some SE extension plugin or something, but I don't recall more details or its correct name.
@Srivatsan How do you make these "screen shots," Srivatsan?
@Srivatsan first of all, there is such plugin. Second, wth my name is there? :D
@Skullpatrol Every OS gives you a way to take a screenshot. In Mac, it's Ctrl-Shift-F4...
the plugin is called SE modifications
@Ilya Yes, I think I installed it long back. Now I don't remember what to look for =)
@Ilya Ah, aren't you, like, flattered? :=)
Do you have SE modifications installed?
16:51
still yes. in chrome!
@Srivatsan How about Windows IE?
@Ilya Can you do me a favour? Go to any thread with answers posted: click on the "history" link under the question and under any of the answers. Can you tell me what you get?
@Skullpatrol "Snipping tool", if I remember right. Just google for screenshot in windows.
@Skullpatrol or MSDOS
@Srivatsan Thank you for the tip.
I use this: windows.microsoft.com/en-US/windows-vista/…, but there might be other (possibly even better) ways.
You are welcome.
16:55
@Srivatsan: for question it gave the history of edits, for answers - page not found
@Ilya Right; same here. Thanks. I will file this as a bug.
It's a bug, right? Not by design? =)
oh man...
should I post it for you? :D
@Ilya Thanks for the offer. But why this offer?
@Ilya Yeah, I am cowering in fear. :=)
17:01
Excuse me... An absolute value, is ever greater than a negativ number, right?
@Srivatsan MUAHAHAHA
@unNaturhal absolute value is non-negative
@Ilya I will muster enough strength to post this. Yeah, I can do this!
So, this function:
$\left|\frac{2-x}{x+3}\right|\ge-1$
Is verified $\forall x\in\Re$, right?
little son?
17:07
@Srivatsan: take a look on the photo of Robert
@unNaturhal we usually use \mathbb for R: $\mathbb R$. Yes, it holds for all $x$ but $-3$ because in that case it is undefined
Little son is very cute, I must say.
@Srivatsan oh, you not ))
I'm reading Solaris, it's cool
I must not say?
17:09
@Srivatsan no, you not must say
@Srivatsan ok. let us take a look on equivalence class $$\text{I have to say}\in[\text{I must say}]$$ so my point was that you don't have to
I not understand. =)
But wait: I am pasting links in the post.
@Ilya, $x\neq-3$ is defined in another condition of the system of equations..
It's the same right?
uhu
#
D-:
17:13
@unNaturhal he is agreeing with you :)
anyway, I meant that it's right
@Daniil hey, don't use your Dark Russian Power
@Daniil Lol xD
But... The absolute value of an entire fraction, is ever greather than a negative value, right?
ever = always?
$\left|\frac{x-2x^2+1}{x}\right|\ge n$ (where $n$ is a random negative number)
Yes, sorry :P
17:19
yes
Ok, thank u :D
But now I have another problem...
...which is...
To solve this:
$\left|\frac{2-x}{x+3}\right|\ge-\cos\left(4\right)$
I have to set up a system like this:
$\begin{cases}\frac{2-x}{x+3}\le\cos\left(4\right)\\\frac{2-x}{x+3}\ge-\cos\left(4\right)\end{cases}$
(It's so funny MathJax when you know the commands xD)
@unNaturhal pretty much yeah
$\cos4$ is negative, so yes
17:27
@Ilya: Done.
Thanks for your -ahem- encouragement.
Aren't B's almost the maximum grade?
@Srivatsan don't cough my friend, drink a tea with honey )
@MattN Hello.
@Ilya Oooookey, thanks!
@Daniil xD
@Ilya Hello.
@Srivatsan well-well. now I'm not flattened
17:29
@Ilya What? I thought you didn't want your name there? So I picked a neutral party. =)
(Ah, sorry about the switch and bait. :D)
Gah, I spent. See you guys in a few hours.
@Srivatsan T_T
@Ilya Ah man, it should've been bait and switch. :=)
@JM Good night.
@Ilya But... The theory says that the first condition to set up in the system, takes the second member without the sign?
17:33
@Srivatsan T_T
@unNaturhal whut?
@unNaturhal If you want to solve |x| < y, then you need to solve x < y and x > -y
@Daniil why not to explain him how to solve $|x|\geq y$?
@Ilya, and if, you have > instead of < and -y instead of y?
$\left|x\right|\ge-y$
@unNaturhal ?
That inequality, follows the same rule?
17:40
$|x|\geq - y$ iff $x\geq - y$ or $x\leq y$
#
D-:
Or is represented by?
I don't understand you
AND betwen two functions is practically a system of the two equation. And OR what is it?
17:43
@unNaturhal if |x| > y then x > y and x < -y
now, is there really a difference between y and -y?
Nope :P
@Daniil if $|-22|>1$ then $-22>1$ and $-22<-1$?
there is OR
Садись, два ))
Well, you know what I meant ;)
In order to solve |x| > y you need to solve x > y or x < -y
wait
uhh
God, I really need to get my shit together
Heh. Someone downvoted my question.
yes, |x|>y implies (x>y or x<-y)
Anyway. Thanks @JonasTeuwen and @JM for earlier today. I don't feel too bad anymore.
Going out for drinkies now so see you later folks.
"the proof may be found or adapted from your textbook therefore I'll vote to close as too localized" This rationale doesn't make sense to me - that paintbrush touches a large percentage of meaningful MSE questions.
18:24
@anon Which post is this?
I guess I will see the closed questions
Matt N.'s latest question. (I paraphrased the first comment according to my interpretation of it.)
@anon Ya, that seems like a pretty whimsical reason to close a question.
18:37
Have you played arXiv vs. snarXiv?
Yes. I tend to fail miserably.
The presence of dollar signs helps me out though.
That seems to be a small hole (in the game) :=)
@MattN Let me know, if you create the room.
- which book is this room about?
18:52
MattN studies Just-Weese: Discovering Modern Set theory, vol 1 the basics.
He invited me to join him.
Here's Google Books link.
You are joining em in studying? Or you are teaching em? Not that these are disjoint activities, but still..
I guess something in between.
IIRC I started to read volume 2 once; but then I found out I should review some stuff from Vol. 1, too.
But it is true that I should know at least half of the material presented there. Anyway, it will probably do no harm to me if I go through it.
Sure sure.
Both of you have a copy of the book?
Cool.
18:57
I have both volumes.
Ah, this talk about studying reminds me: I never enquired Matt about eir exam.

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