@amWhy, @XanderHenderson: the only var symbol I like is the $\vartheta$ used for Jacobi theta functions. $\varnothing$ is new for me

What?

Thoughts on action here? A question similar to this was asked recently, closed as duplicate and ended up in a delete/undelete war, but that one was too broad, which I can't say for this one. A "lack of research effort" could be to say that $\sqrt[3]$ of both sides wasn't even considered, which would give some obvious examples stated in the comments, but I could be wrong.

@Semiclassical You can see the answer. I'm tempted to close as a PSQ of course, but it should be possible to close as a duplicate.

I've done so , but I've just realized that the author could be referring to the sequential definition of continuity, so I hope all will be well at the end.

[ SmokeDetector | MS ] Potentially bad keyword in answer, repeating characters in answer (80): How many points in a line segment? by lol on math.SE

C/D

@XanderHenderson: What you wrote is actually a proof by contrapositive, rather than contradiction. Generally speaking, proofs by contrapositive are preferred over contradiction (see here).

Still, I'm not sure it would be intuitionistically valid, as from my limited knowledge of intuitionistic logic, $a<b$ means "there is a proof of $a<b$", and $\neg(a<b)$ means "there is not a proof of $a<b$". Hence, if $a\ge b$, then $\neg(a<b)$; however, the converse is not true.

But I'm really unsure if what I wrote about intuitionistic logic is correct, so you should probably just ignore that.

@XanderHenderson Well, essentially you are using the axiom ∀a,b∈ℝ ( a = b ∨ a < b ∨ a > b ), and so given a,b∈ℝ such that a > b you get a contradiction and hence can conclude anything including "a ≤ b". So it does not rely on LEM, but rather on the soundness of that axiom. However, your intuition that there is something non-constructive going on turns out to be correct, because that very axiom is non-constructive. In fact, the proof that a Dedekind-complete ordered field exists requires LEM.

@ParamanandSingh I prefer varepsilon, but on my computer I only have to press 3 keys capslock e capslock to get it. =D

@Joe You're incorrect. The proof is not a proof by contraposition. See the explanation I just gave above.

In fact, the proof is intuitionistically valid because explosion is.

→ 6 messages moved to Basic Mathematics

Those interested in the discussion are welcome to come over to the other chat-room, as it's probably going to be a long one.

PSQ with no context provided

This one does include thoughts on question but isn't good enough that it might escape closing

@XanderHenderson: To sum up the key points: (1) ℚ is an ordered field containing ℤ, and only the axioms [ℤ ⊆ ℚ] and [ℚ = ℤ/ℤ*] distinguish ℚ from other ordered fields, and from the other axioms you can prove ∀a,b∈ℚ ( ∀c∈ℚ ( c > 0 ∧ a ≤ b+c ) ⇒ a ≤ b ), so this basic real analysis fact actually holds for all ordered fields; (2) You can prove this fact intuitionistically, because ∨elim and explosion are intuitionistic.

(3) Proof by contrapositive is not intuitionistic..

Unclear question IMO: math.stackexchange.com/q/4255305/42969 (“Why did my professor give me 0 marks for a correct result). Also the given answers are pure speculation IMO.

Psq math.stackexchange.com/q/4255348/29335

D1, D2, D3, D4

D5, D6, D7, D8

D9, D10, D11, D12

I closed this as duplicate. However some people think otherwise. Do read comments there and if necessary vote to reopen. There is also a fine answer given.

C

@MartinR I agree, by the way , noone has said anything about my speculation that $\theta$ could be given in degrees. Do you suggest to delete it so quickly ? Or shall we wait for improvements ?

@Peter The question author has already accepted an answer, therefore I doubt that the question will be improved. I already voted to delete.

@MartinR You are right, and two users with extreme high rep answered a question that was not yet clarified whatsoever.

Moreover, the claim that using L'Hospital would be circular here, annoyed me.

Hello All! I want you to kindly consider reopening this question :math.stackexchange.com/questions/3973870/… . As I have serious queries in the answer of question which was linked to my question and I have mentioned about that in my question

@user21820 Thanks. That confirms my intuition that there was something fishy about trichotomy, just not quite the thing I thought it was. :D

I have made some edits to my previous question that was not opened:math.stackexchange.com/questions/3973870/… . I have edited what I was unable to understand in answer and comments. Kindly have a look at it.

@XanderHenderson To add one more line: The computable reals forms a model of Th(ℝ), but that model is not computable (because equality of computable reals is not computable).

@TeresaLisbon thank-you for your replies to your meta thread re reviews. I will be interested to see what other responses you get to that!

Didn't notice this bountied PSQ somehow!

@postmortes Thanks, I asked it with some sincerity, but it may end up being a more personal requirement than a network-wide arrangement. If so, I'll find ways to open up a little more. I think it's a need of mine to not be as one-dimensional as I am now.

Teresa, please review my comment to you on meta. You are way overthinking. Do you also want a meta site to the meta math.se site? meta.meta.math.se, for questions about how the meta site functions? and then a meta.meta.meta.math.se. We all need to learn to make the best decisions we can with the information we have at the time. Mods face the same dilemma. There is likely no way one can guarantee being perfectly correct, always.

@ArcticChar You are now in a position where, in addition to posting requests for deletion, you can on many posts, include your vote to delete. E.g., the latter three in the row I linked. Admittedly, I am referring to posts from August 25th which may have only been recently

....closed.So my comment may not be relevant; I'll look more carefully at dates of closure, @ArcticChar

@TeresaLisbon Thanks, @Xander!

@amWhy I can vote on all of them (those posts have been closed for more than 1 week) But I only have 5 votes and I voted on 4 of those.

@ArcticChar Oh my gosh. I forgot that delete votes start with 5, and increase later. Thanks for the info. Also, rest assured I've covered them all with my vote to delete. I'll also add that you have good judgement regarding the questions you post for deletion.

Still needs one more close vote: math.stackexchange.com/q/4255348/29335

→ 1 message moved to ­Trash

@amWhy (This is my reply to the meta concern as well) I knew that this question would come up, so I thought about it by trying to compare it with a people-government type situation. The people "elect" the government, certain servants choose to serve the government in what way they can, and they are responsible for the running and upkeep of the community by providing feedback to the people on their actions. Similarly, the people provide feedback to the government and its servants regarding...

... their services. I just felt that we are doing (as government servants) what we think is our job, of closing posts etc. I just felt that we may not be hearing as much feedback from people that we want to hear. I may be overthinking this, but I can't help it. I've asked this question because if someone was to come to me tomorrow and say : "I want to review your reviewing, I can't trust it!" then I want them to have a forum where they can say something, either to us, or to a higher authority.

@TeresaLisbon Feedback about review actions are posted often to meta.se. In any case, even in your analogy, the only folks government officials listen to are those who they seek donation money from, and votes.

@amWhy I think we differ on how much feedback we want to receive. I mentioned in my post that the feedback to review actions on meta was too small, but as I see it now, that is probably a personal opinion. Even postmortes pointed this out. Is this the case? By the way, I felt it was too small because I feel like I close so, so many questions everyday, and I feel like I fall into patterns of thinking that are too fixated and could very easily be wrong, likewise others.

@TeresaLisbon They already do: flags, meta.math, and the thread "undelete and reopen thread". If you are not comfortable with your decisions, and need others to approve (you are rarely going to get full approval from everyone, of you every action, every day, then I'd suggest sitting on the sidelines for a while. Real life doesn't stop for everyone to gain approval before living life.

@TeresaLisbon The pattern you fall into is flip flopping. Yay, nay, wait, nay, yay, wait....

@amWhy You're right ,thanks for being frank. I think this is a personal problem after all, this need to gain validation from everybody when you are not going to get it. At the same time, what about those who are , for example concerned that EoQS moderation was over done? Remember the comment on the "clumsily formulated" questions that said "we need an EoQS for reviewers" it went for a few days, and came back, and had so many up votes , I just wonder if that's not just a flash in the pan.

Hence my suggestion to wait on the sidelines awhile. You bend the way the wind blows.

People don't like it when they can't always do as they want. Too often, they comeback with: Okay, if your going to monitor x, y, z, I want monitoring of a, b, c. It's angry retaliation, drawing false comparisons. You need to be careful of others false analogies; rather than acknowledge a problem, some want to turn around and say those who disapprove of their behaviour, .... Well I disapprove of yours! So there!. Childish defense mechanisms. I really have nothing more to say, @Teresa.

@amWhy I am a child in some way, but here's what I don't understand : you're right, the feedback mechanism IS there! There's everything that you suggest. Why is it then, that I'm actually receiving so little feedback? For example, consider the EoQS related confusion that Xander sorted for me recently. I just don't feel confident because I'm not receiving enough feedback over it, and I was wondering if the public sentiment is that the absence of a public-to-reviewer channel is keenly felt.

I get tired of going down this road with you so frequently. I do appreciate you are trying to help this site, without doing harm. But you need to understand claims of harm "back at you" are often merely defense mechanisms. And I know user who take advantage of you, in this way; you are so easy to sway, manipulate.

@TeresaLisbon If you need praise regularly, doing what we're doing in CURED, you aren't going to get praise. We try to support each other, but the real test of ones integrity is being true to who you are and want to be and what you believe in, even in a desert of feedback. You get get feedback, upvotes, green checkmarks, etc., easily enough. If Needing every thing you do to be cherished on this site, then go for it seeking rep.

You know plenty of people you can ask, individually, for feedback. But I too am confused as are many others, because I really don't know what your goals and priorities are for you, and wrt this site. Just as we seek not to have askers chronically needing coddling to be sure of answers, it is non productive for everyone to have to coddle long term users, or the perpetual need for approval.

@amWhy I get what you're trying to say. I think I have to go back to the drawing board. But I know one thing : I can defend the fact that I close certain kinds of questions and this is not going to change. I know that certain ideals I have are set in stone. But there are always these fringes, you like to see them and keep evaluating yourself and how open you are to some possibilities. By the way, I don't think I receive negative feedback at all, which is why when I do, it rattles me.

I'm growing up, please bear with me till then. I will hope that I can be firmer in what I do. I will use all channels of feedback I can use. Meanwhile, I'll delete my question , I'm not well prepared enough to ask it.

@TeresaLisbon Yes, I acknowledge all you say. Negative feedback comes in many forms. Not formal assessments.

@TeresaLisbon You can leave it. Of course I will be patient. We're all growing. And I am sincerely impressed at your commitment to keep an open mind, etc.

No need to delete your meta question.

@amWhy No, I think I'm not the right person to be asking it, so I just deleted it. I am not, in particular, in a position to answer your question there well i.e. I'm not in a position to defend a stance of mine. Like, the problem for me is that I'm constantly concerned about the fact that I cannot defend every.single.xyz.action of mine, while I see people like Xander doing it so well, I almost feel jealous in some sense. Like, every.single.action they make seems to have some excellence...

... just some absolutely convincing bit of logic to it, and I'm not really able to bring any emotional pull I have to the table. When I can't validate something or am unable to come to a compromise on a certain issue, I believe that I'm not the one to be taking it up : that must be another's job. So when I couldn't address your meta post, I decided that my post missed something, something that would put a hole straight through other arguments that are for it.

I assure you, even @Xander has made mistakes, has regrets...

@amWhy Yes, but I'm sort of not able to let go of the fact that I need to defend every action I take, at least when called upon. Even yesterday, if you recall the conversation with Peter and user21820, I didn't find what is wrong with the question till it was pointed out to me, and it felt so obvious that I was looking at it in an extremely one-dimensional fashion. It pained me, in some sense. I want to be able to develop that ability to see things in different ways, in some sense , rather...

To be absolutely sure that every action you've taken is a phenomenon known only to magalomaniacs, the arrogant, the self-delusional. So be careful what you wish for. ;D

...than be stuck to a single narrative of "I can't tell the user what to improve, so they must be right and I must be wrong".

@amWhy You're right, before we veer too off-topic, I have to grow up in short. Hopefully, I'm doing that.

@TeresaLisbon As long as we learn a bit more in every attempt and encounter, your doing well.

@amWhy I hope so! Thanks for conversing with me, by the way. I hope I can help all CURED folks someday, the way you helped me today.

@TeresaLisbon You already have. :-)

@amWhy Thanks! I'll now move to the review queue. It's been another day of learning.

(I'll put the bad questions up here)

@TeresaLisbon See you!

@amWhy See you too!

C/D

D

@Peter Open for D

cv-pls education PSQ Complex equation homework. Please solve this. a^4 + a^3 + a^2 + 1 = 0. Find the value of a^2020 + 2a^2010 +3a^2000‭ - Akif Ismail‭ 2021-09-20 17:16:40Z

[ SmokeDetector | MS ] Offensive answer detected (78): Finding the general formula for Dn by John Mollard on math.SE

C/D

@Peter Open for deletion.

@amWhy Horrable, slandoris, LIES!

@XanderHenderson ;D

C2

cv-pls inner-products I don't understand what this person is asking for... Alternative ways to write a dot product?‭ - qsfzy‭ 2021-09-20 18:48:53Z

i guess something about algorithms for the dot product?

but that seems really trivial

i guess there is the whole long discussion here: algowiki-project.org/en/Dot_product

but i can't see how factoring would make that any better

inorite?

also i don't know what a Julia function is

The "obvious" algorithm consists of two multiplications and an addition (the multiplications being the "expensive" operations). The proposed alternative requires two multiplications, a division, and an addition. Why should the latter be preferred?

unless it just means "coded in Julia"

This has to be a duplicate, but I am unable to find a good target. (Besides: read the comments.)

cv-pls probability PSQ. Roll an n-sided die, your result is m. Roll an m-sided die. Continue until m = 1. What is the expected number of rolls?‭ - nilypp‭ 2021-09-20 16:52:25Z

not an answer, one more delete vote needed

@JoséCarlosSantos sir i didn't find this type of question in the search engine.So I posted the question.I was planning to delete this question. But shaun has already answered the question

@KReiser It's now deleted.

@Xander This suggested edit was not an audit. I rejected as vandalism, but how can we flag such mean spirited edit suggestions? As of yet, there is no flagging capacity in that queue.

@jasmine As I wrote, I was unable to find a duplicate.

@amWhy The best you can do is flag the post with a custom flag explaining the problem.

@XanderHenderson The post on which there is a suggested edit?

@amWhy Yes, indeed.

When mods check a flagged post, do you have direct access to suggested edits, approved or rejected?

Not directly, but it appears in the post's timeline. If you explain that an editor attempted to vandalize the post, we can see. I think it should be visible in the timeline for everyone, but I don't know if that is true.

@Xander Thanks. Most vandalized posts are obvious audits, but I've seen some very harmful attempts to edit. It's hardly an every day occurrence, but when it happens, me no like it.

How long will it take math.se to reach 1.5 million questions? Currently need ~64,300 more questions surviving deletion. I remember when @quid and many users picked days (once a day was picked, no one else could pick it), to determine who was most accurate in guessing the day we reached 1 million questions.

@MartinSleziak was helpful, in giving a rough estimate of the rate of question asking around then. that contest is no doubt in the transcripts of "whatever, quid".

We're not close enough to 1.5 million to make it timesly, but stay tuned!!

Consider closing. Pure PSQ + three questions.