@JacobSchlather also. =)

Remember: a^x grows to infinity if a > 1 and decays to zero if a < 1.

s/he left

e^infinity is not infinity

it's nothing

@anon Kids these days... ;)

@QED e^(nothing) is some other nothing... =)

how do we get people to stop thinking of "infinity" as a number

(Or the same nothing.)

@QED but I can exponentiate minus infinity... :-)

@QED Good luck with that. You do know how people play "Let's see who thinks of a bigger number", right? "I say infinity." "Then I say infinity plus one." "In that case, I say infinity plus infinity." =)

@Srivatsan infinity times infinity

Ah man, I was outnumbered... =)

lolol

No one else wants to close this q? math.stackexchange.com/questions/87143/…

lemme look

Grading homework is a lot of work :).

@robjohn Do read my second comment there. =)

@QED How do you like this tag summary for infinity? Somewhere beyond the numbers lies the concept of Infinity. But what exactly does "infinity" mean? What rules does it obey? What interesting properties does it have?

I don't really like that

@Srivatsan I was going to say that it seemed more like 65988

@QED I imagined so. I myself feel a bit queasy...

@robjohn You can pick a different question when you close it. In fact, I am encouraging you to pick a different question. 65988 seems good...

I don't think infinity should be a tag actually

how do you do that cool trick?

[tag:infinity] should work.

just testing if the code thingie works

@QED It should never really be a tag, but always strive to be one.

lol

Jurors needed: math.stackexchange.com/questions/87166.

two little martingales sitting in a tree...

One more body part for the hangman

@QED If you really want the tag gone, you can write an answer here. meta.math.stackexchange.com/questions/1363

Thanks, @robjohn. I presume you chose 95988.

65988, yes

I should learn about martingales and not just watch them with binoculars.

Then I could vote to close the other question :-)

And if it is ok with you, can you upvote my comment so that it is not buried under the other comments?

@robjohn Well, I know about martingales, but it is pretty clear that the two questions are the same..

comment unburied. I feel like a hangman, birdwatcher, and graverobber all at the same time.

@robjohn Thanks, robjohn.

This question is tagged geometry. I could perhaps see analytic-geometry, if it exists.

It does.

I wonder if geometry is too general a tag.

It is defintely NOT diophantine.

I have fixed it :-)

@robjohn Is there a rep threshold for posting an answer to your own question?

@JacobSchlather Here?

@Srivatsan I don't know. I will look.

@robjohn Don't inconvenience yourself, robjohn. I am working on a post right now, but I will look soon.

I don't see anything, but there are many things I don't know about the site.

@robjohn Yes, it does throw surprises at us now and then.

It is hard to duck when surprises are thrown.

Does anyone know how to left align rather than right align?

Did you try \yourmother{left}?

I'm using \begin{align}.

No, not yet. You? And I don't think am going to.

I did not try that either.

@AsafKaragila: I posted it as is, math.stackexchange.com/questions/87179/…

I'll read and then try and answer.

Sure, thanks!

@Matt: Where do you study forcing from? Your notation is horrid.

@AsafKaragila A lecture.

Who's the teacher?

You can find his book, going to be published in December, here: math.uzh.ch/index.php?file&key1=18667

(I'm doing one course at uni, not at ETH.)

Hmmm.

I'm not sure if you should study forcing from a book about combinatorial set theory. Perhaps a book about forcing can do a better job.

@AsafKaragila: I've just started to read the book, it's quite enjoyable. Especially for a Springer book. : )

@AsafKaragila: I have some lecture notes as well.

That is a good thing.

More or less.

I'd rather have a book.

I still suggest forcing with either Kunen or Jech to begin with.

I got Kunen from the library. : )

I wish there was a just a PDF will everything in it

@QED I prefer paper. : ) In fact, paperback. Hardcovers are too heavy.

me too

Anyway. I do not like the guy's notation.

I don't have any opinion as I don't know any better.

Of course not. I am just saying.

I edited the LaTeX a bit in your question. Use & signs to set align pivots in the lines of your {align} environment.

Now you can transform all the other multiple $$ lines into align.

Thanks!

Why do I want to replace $$ with aligns?

It's a cleaner look.

Ack! the profile page just barfed.

It came back.

My kitty pooped, and now the whole house stinks. :-\

It looked almost all text, with interspersed images. ugly.

@AsafKaragila tell me about it...

She has some digestive problems, I think.

Our kitten seems to have just settled her digestive tract down. She doesn't smell so awful now, when she poops.

Or I am getting used to it :-(

One of ours had diarrhea on and off, a particularly smelly one. Turned out he had Tritrichomonas foetus, some parasite.

@AsafKaragila: I fixed the alignment.

I think I should go to sleep. Good night folks!

Wait!

@Matt: I posted an answer.

@AsafKaragila too late, it seems.

bbl

@AsafKaragila I'm back

Oh good, I was about to go to bed :-)

I guess I can stay a bit longer though.

If you need to sleep you can

it's just something I was somewhat curious about and after idling googling wild automorphisms I couldn't seem to find anything talking about the situation without choice

Well, there are many things somewhat open without the axiom of choice.

okay

The axiom of choice is a very strong axiom. Just the fact that it is preserved under forcing extensions is a lot.

Hello

Oh look, a whole other Matt.

hi

I get every notification for an @Matt in this room

Its quite annoying

@JacobSchlather I would imagine that most automorphisms of C as a field over Q would require some choice of Hamel basis. In the absence of AC it may not exist.

Right

Many assertions which follow almost trivially from the axiom of choice are not only much weaker than the axiom of choice, but are also "choice principles" for themselves which do not imply or follow by many other such principles.

Interesting

Is my use of D[]dx here correct? imgur.com/F2GuL

Or did I somehome make that notation up out of thin air?

lol

I've never seen the notation before matt

For example, the assertion "There exists a class function C(x) such that |C(x)|=|x| and if |x|=|y| then C(x)=C(y)" follows trivially from AC. It does not hold in many models in which AC is absent and I have yet to see anyone even treat that as a choice principle. I took that as an interest, but so far I have no leads on how to approach this problem in a useful way.

All right

so do you know if there are models of ZF where the only automorphisms of C are the identity and complex conjugation?

Have you seen this MO thread?

I have not

that answers my question in the first sentence

:-)

Thanks

that was what I was mainly curious about

Asaf, what do you think of the notation I posted?

It looks like maybe I was going for eulers notation: en.wikipedia.org/wiki/Notation_for_differentiation

I have never seen this notation before. D[f] is often used as the Differential operator. I'd imagine that differential forms for partial derivatives exist but I am unfamiliar with that field.

How about this: imgur.com/6jmeL

Better?

Yeah.

Usually, however, it is common to use \partial for the partial derivative.

This gives the backwards-cursive-lowercase d letter.