leslie townes

 Mathematics

Associated with Math.SE; for both general discussion & math qu...
15:38
people who study that stuff eventually go nuts, or are nuts to begin with. no exceptions
15:37
it's nice for my sense of humor to be appreciated
15:35
which is why you combine it with the krein milman theorem.
15:32
nah, every time they do that they are secretly applying the krein milman theorem and the boolean prime ideal theorem.
15:10
it would also be helpful to see a concrete example of something that this principle would be applicable to :)
15:09
so it is likely that any difficulty of proving something by normal induction on the natural numbers will not be removed by some space age general induction principle
15:08
its maybe worth keeping in the background, all of these schema for proving things, are just schema for proving things. there are difficult and open problems that might conceivably be provable by induction on natural numbers, or maybe not. a problem generally is not simplified, or made more complicated, by the availability of approaches to solving it
15:03
it might help to eliminate any reference to P or other abstraction and give an example of something you would like to prove
yst 19:32
and let that be a lesson to you
yst 19:32
yeah, people are just objecting to lang's treatment of the axiom of choice.
yst 19:13
i put all of the blame on serge lang
yst 19:05
i could not tell the difference.
yst 19:05
from the POV of someone who cannot see deleted posts, it very much looks the same to post a new amended question, vs. amending a previously posted question.
yst 19:04
i do think that MSE orthodoxy is to amend something rather than repost something, but i do not have high enough reputation to see what the originally posted now deleted thing was.
yst 19:04
oh, just ignore ted. he is salty.
yst 19:01
this all strikes me as unusual, as far as it goes with selecting a route from AC to zorn's lemma. although i do not remmeber how it is normally done. i am guessing that it is not done in this way
yst 18:51
it is the hat from which we can produce a great many rabbits
yst 18:51
in his algebra book i think he takes it as fundamental. it might be how he presents the axiom of choice in the book. i could be misremembering things. but that is how it is often used in algebra.
yst 18:50
at a high level, what is lang proving zorn's lemma from? is it a choice principle? is it something like a krein milman theorem (e.g. a selection theorem pulling elements from sets with certain properties)
yst 18:48
i chatted with lang a couple of times, never about math. he was a very unusual person
yst 18:48
okay, yeah, that seems kind of weird to me. i would want to know more about what f is. this probably isn't your fault. it is lang's fault.
yst 18:47
full disclosure, i am not fully devoted to this. my son is running around yelling as i type this.
yst 18:46
is "extreme point" here relative to a particular f, or is it some absolute notion?
yst 18:41
and also makes me think that "extreme point" is not the usual thing but some weird fever dream from the mind of serge lang
yst 18:41
what's kind of weird about all of this is that maybe lang is working in a slightly less than familiar context. if you said to be "zorn's lemma" and "extreme point" i would be thinking something like the krein milman theorem, where zorn's lemma or something equivalent to it is what you are using to prove the theorem. here, we are proving zorn's lemma, which raises the spectre of what we are assuming.
yst 18:38
:)
yst 18:38
anyway, i salute you for attempting to read a textbook by serge lang.
yst 18:38
although there is no satisfying some people :)
yst 18:37
but to be clear i think it is already fine as written, as far as meeting the threshold, for "i would not vote to close this."
yst 18:37
ben it looks fine to me as written although it feels out of order. if the statement is that "every element of M is an extreme point" the next thing my mind wants is what M is. not, like, four bullet points later. i might also want to know if an "extreme point" in an "inductively ordered poset" is the same thing as what i might be familiar with from the vector space context, or what an "extreme point" is.
yst 13:56
i was trying to get my daughter to appreciate the number line the other day (she was doing some subtraction problems) and she just refused to hear it. she didn't want to be bothered with "weird pictures." i didn't either, believe me. but i grew up.
yst 13:43
e.g. the = set is roughly the boundary of either of the > or < sets, and the > set can be obtained from the < set (or vice versa) by complementation and removing boundary points.
yst 13:40
before diving into any algebraic specifics. people will always mess those up anyway
yst 13:40
yeah, there is a fundamental thing, which is that the mutually exclusive conditions f(x) < g(x), f(x) = g(x), f(x) > g(x) always divide the real line into disjoint regions, and under normal highschool type circumstances the set f(x) = g(x) is a set of "points," and the other sets are intervals separated by those points, and you can use information about any one of these sets to sort of guess at the structure of the others.
yst 12:40
we might be well into a regime where sane people might use a continuous approximation. :)
yst 12:38
and i love that we now have 10^5.
yst 12:37
interesting. it hadn't occurred to me to use a formula involving binomial coefficients, mainly because i was working in an environment that did not have them built in, but also because that (-1)^n stuff suggests maybe the formula involves cancellation of numbers that are larger than they "need to be" to get the result. i was iterating a single function over a list, which only ever dealt with accumulation of nonnegative numbers.
Fri 22:31
you need a really big abacus
Fri 22:31
i think
Fri 22:31
eventually you run into just needing to do arithmetic with really big numbers, and that becomes the limiting thing
Fri 22:30
the only thing stopping me from doing it in assembly is feeling like i can't do really big numbers better than haskell
Fri 21:58
mine was like 40 minutes but i was gaming and shilling crypto in other windows while it was going
Fri 21:57
no optimization, just zipping a list with translates of the list and +
Fri 21:52
anank how did you implement your s(n,k)? i had mine go by n, computing the full list s(n,k) by iterating that pascal recursion thing over s(n-1,k) on a list that got 6 things longer with each iteration
Fri 21:38
it might be more productive than what society is currently doing, at least we'd learn about coin flips
Fri 21:35
hahah let's boil the oceans and put AI levels of compute into s(10^k,3*10^k)
Fri 21:21
yeah, that's basically where i am with mine. let's declare victory
Fri 21:11
@anankElpis i dont think my setup can do s(100000,300000), can yours?
Fri 20:54
mod 100,000, anyway
Fri 20:53
we agree!