User talk:Topology Expert/Archive 2

Speedy deletion of Second countablility axiom

A tag has been placed on Second countablility axiom requesting that it be speedily deleted from Wikipedia. This has been done under section A3 of the criteria for speedy deletion, because it is an article with no content whatsoever, or whose contents consist only of external links, "See also" section, book reference, category tag, template tag, interwiki link, rephrasing of the title, or an attempt to contact the subject of the article. Please see Wikipedia:Stub for our minimum information standards for short articles. Also please note that articles must be on notable subjects and should provide references to reliable sources that verify their content.

If you think that this notice was placed here in error, you may contest the deletion by adding {{hangon}} to the top of the page that has been nominated for deletion (just below the existing speedy deletion or "db" tag), coupled with adding a note on the talk page explaining your position, but be aware that once tagged for speedy deletion, if the article meets the criterion it may be deleted without delay. Please do not remove the speedy deletion tag yourself, but don't hesitate to add information to the article that would would render it more in conformance with Wikipedia's policies and guidelines. Lastly, please note that if the article does get deleted, you can contact one of these admins to request that a copy be emailed to you. --Snigbrook ^(talk) 13:27, 4 May 2008 (UTC)

Note that there is already an article second-countable space. Oded (talk) 15:32, 4 May 2008 (UTC)

It looks to me as if the creation of this page may have been an attempt to create a redirect page. The page now redirects appropriately. Michael Hardy (talk) 17:52, 5 May 2008 (UTC)

SmackBot

1. Smackbot makes over 1000 edits a day, so I really need the diff, at the very least the article name, not just "the artice on".
2. Look at the diff and look at SB's page.
3. Leaving a message for SB stops the bot. This is explained clearly at every step. PLease only do this if you need to stop the bot.

Rich Farmbrough, 09:28 5 May 2008 (GMT).

What do you mean by smackbot? I am new to Wikipedia so could you please tell me?

Thanks

Topology Expert (talk) 09:30, 5 May 2008 (UTC)

Hmm it's a robot - one of many. It does housekeeping tasks, putting dates in clean-up tags is it's main responsibility. Rich Farmbrough, 09:34 5 May 2008 (GMT).

The diff is [1]. This is in the article Locally finite collection (and not local finiteness). It is not in any way a bad edit, it just put a date on the newly placed clean-up tag {{unreferenced}}.  --Lambiam 09:43, 5 May 2008 (UTC)

To Rich Farmbrough:

Be serious.

Topology Expert (talk) 09:45, 5 May 2008 (UTC)

See WP:BOTS Rich Farmbrough, 10:55 5 May 2008 (GMT).

"Challenging" an article

I created a page on local finiteness and I don't know why someone changed it. I want to challenge this article. Also, how do I challenge an article?

Thanks for your help

TopologyExpert —Preceding unsigned comment added by Topology Expert (talk • contribs) 09:28, 5 May 2008 (UTC)

If by "challenge" you mean nominate it for deletion, the instructions are at WP:AFD. As to why someone did particular edits, you can ask about that on the article's discussion page or on the user's talk page. Normally an article is to be expected to keep getting changed forever, and one hopes the changes will improve it. Of course, some changes don't improve the article. Michael Hardy (talk) 17:49, 5 May 2008 (UTC)

The article does not cite any references or sources, that's why. Wikipedia policy is that all content of articles must be verifiable. The way of making the content verifiable is by providing references to reliable sources. See also the scientific citation guidelines, which also apply to mathematical articles.  --Lambiam 21:24, 5 May 2008 (UTC)

See also Ownership of articles. You don't "own" articles you create. The whole idea of Wikipedia is that it is a collaborative project, in which anyone can improve any article. If you have a problem with other people modifying your contributions, then you should consider starting a blog, instead of editing on Wikipedia.  --Lambiam 21:34, 5 May 2008 (UTC)

How can I site references if I just give a definition? Every book gives definitions. Secondly, the theorems I gave were made by me. They may be already known (they are reasonably simple theorems), but how do I know whether a book has this theorem or not; and which book? Lastly, next time someone edits, I will change it back. The only way to prevent me from changing it back is to give me an acceptable reason.

The above unsigned paragraph was written by Toplogy expert.

• Topology expert, please sign your posts.
• Your style of writing did not conform to wikipedia style. Silly rabit's edits were good.
• Please read Lambiam's note about ownership of articles.
• Wikipedia forbids including original research. See WP:OR. If you come up with a theorem and you are not sure if it is known or not, then Wikepedia is not the place to publish it.
• Your declaration that you will change back any edit that does not give an acceptable reason makes me think that perhaps you have not read the very good comment by Michael Hardy above.
• Suppose you see that someone has modified the article you have created. Please
  • first try to see the merits and advantages in the change
  • if you don't see the advantages, the reason might be that as a newcomer you are not aware of style conventions, customs, and content in Wikepedia (such as the existance of a page on compactness)
  • if the edit was just a mistake, it is fine to undo it. But if different editors have different opinions about the writing of the article, then there are different mechanisms for resolution. The best is just to have a discussion on the talk page and reach an agreement.
  • please try to be cooperative. Wikipedia is a project of collaboration. We have to work well together in order to make it work. I know your intentions are good.
  • Although you are a toplogy expert, while Silly rabbit is just a silly rabbit, that silly rabbit has made over 10000 edits on more than 2800 distinct pages. Therefore, it is a silly rabbit who has some experience in Wikipedia and pehaps knows what it is doing. Perhaps we can watch that silly rabbit and learn something?

Oded (talk) 14:54, 6 May 2008 (UTC)

Topology expert. It is not reasonable that you would edit my words and leave my signature. Oded (talk) 16:24, 11 May 2008 (UTC)

Thanks for your advice. I may be inexperienced in using Wikipedia (I admit), but I am knowledgeable in mathematics. I think that certain pages (such as the one on "Supercompactness") should be deleted without debate. There are only TWO facts on supercompactness. How is that useful in a Wikipedia page. These facts may be correct, but what is the point in creating a page for only two facts? I can't see why none of my ideas are accepted. What is wrong with my reasons? If you can't see what is wrong, then you can't be a true mathematician. Please don't dispute what I have written; I am tired of arguing. If you want to keep supercompact spaces, then keep it. But just consider my opinion.

I just mean to say that I am experienced in my field and my opinions should be at least considered. I am happy to accept criticism; but consider my mathematical ideas. As a mathematician, I am certain that the theorem I made has already been published. Anyway, thanks for your advice. I will make an effort to follow it.

Topology Expert (talk) 13:35, 7 May 2008 (UTC)

Topology Expert (talk) 13:29, 7 May 2008 (UTC)

Great! I now see that there was some misunderstanding (perhaps a few).

• You are definitely right that compactness is much more important than supercompatness. That is also probably the reason why there is much more content on compactness.
• Experience in wikipedia is very relevant to making such a decision of whether to include a page or not. It is all a question about the level of detail that one wants to cover. Extreme points of view would be that (1) we want to cover only the very central concepts such as group, integral, fundamental theorem of algebra, etc, or (2) we cover every mathematical result ever published. What should we aim for? I think that basically the answer is that we should aim for the maximum level of detail that we can reliably maintain. We don't want to sacrifice accuracy for breadth and coverage. By knowing what math wikipedia has and how well it is maintained, you get an idea for what is the right breadth that can be well maintained.
• I too did not know about supercompatness before seeing the wikipedia article. But there are mathematicians out there who care about supercompactness quite a bit. As I mentioned earlier, google scholar registers about 1000 hits to supercompact space, and some of these are definitely genuine.
• Note that there are pages orthocompact and metacompact that are stubs somewhat less developed than supercompact space and perhaps of the same level of importance. I point this out for comparison — to show that having a page for supercompact seems reasonably compatible with the level of coverage of comparable subjects.
• If you still want to have supercompact deleted (which is probably not a good idea), you should be aware of the right procedure. If you see the edit comments by Silly rabbit and others in the history page and the comments in the talk page of supercompact space, you will see that they say that explain that you have chosen the wrong procedure for deletion. The correct procedure for proposing deletion in this case is Wikipedia:Afd.
• I hope this clarifies some points for you, and I hope we can continue a friendly and beneficial discussion. Apologies for the misunderstandings.

Oded (talk) 15:34, 7 May 2008 (UTC)

You cannot rely on your credentials here on Wikipedia, especially if you insist on remaining anonymous. In actual fact, all of us, Oded, Silly Rabbit, and me have mathematical credentials too. So our experience should be considered too, no? Or perhaps we should just make valid arguments and not worry about whether your credentials are greater. On Wikipedia largely people will judge you by how you edit. And thus far, your edits and comments do not, to me, show the signs of an experienced mathematician. For example, you seem to find it hard to believe that something you never heard of could be an area of interest. In actual fact, I find that is true all the time. I think an experienced mathematician is more willing than you are to accept that something "peculiar" could be very interesting to many other people. I don't mean to insult you, only to point out that behaving like an experienced mathematician is more important than claims of being one, if you want others to listen to you.

If you are not a point set topologist, I don't think you should put so much emphasis on your judgment on this type of article as that is not in your specialization. If you are, then I think the evidence is contrary to your judgment. Oded found a Proc. AMS article from 1979 on supercompact space, and despite your assertion of there being only two theorems about supercompact space, within one minute of searching, I found another Proc AMS article from 1994 on another theorem on supercompact spaces and a book by J. Van Mills (1979) on supercompactness and Wallman spaces (I will add these to the article). This is already a sign to me this is a notable enough subject. --C S (talk) 17:28, 7 May 2008 (UTC)

By the way, I should add that supercompactness is a new concept for me also (although I vaguely do recall hearing about it before). Nonetheless I think we can all appreciate it. If you look at the laundry list of spaces that are supercompact (including compact metrizable spaces), it is quite interesting that they have special subbases for which any (open) subbase covers can be reduced to 2 elements. (these subbases are hard to imagine though, even in simple cases...) --C S (talk) 18:29, 7 May 2008 (UTC)

First of all, this is to C S. I do accept that I have never heard of this concept even though I am a topologist (I specialise in other areas too). I accept that I don't know everything and perhaps I was wrong to say that supercompactness should be deleted just because I don't know that it is. So, what I am saying is this. I am changing my mind about deleting this because no one will agree. Here are my suggestions which I hope people will consider:

1. Could someone please extend this article a little bit

Topology Expert (talk) 07:40, 8 May 2008 (UTC)

I don't get it. First, you say that you agree to keep the article. A few minutes later, you put it up for AfD. Is this just to annoy us? Are you a hoax? Oded (talk) 14:44, 8 May 2008 (UTC)

This is to everyone. If you find what I say unsatisfactory, you may call me a hoax or whatever you like, but please read what I want to say. First of all, I did say that I was going to agree to keep the article. Now, "Oded" said that I should read the deletion policies and that was what I did. Now, after reading these policies, I thought that maybe I am correct to delete the article on "supercompactness" and then went ahead with the deletion process. I am sorry I didn't tell you that I was going to do that. Now, I am certain, and promise that I won't attempt to delete this article for a while. I just believe that perhaps this article should merge with the article on "Alexander Subbase Theorem". This is because, perhaps people will see the link between the two articles. Secondly, from now on I will attempt to improve the article on "Supercompactness" instead of delete it. I was thinking that maybe we could prove the theorems asserted to clarify issues? Perhaps I will do that. Also, I don't think the topic "Supercompact space" is under the category "Compactness". Perhaps we could make that so. I will also make sure that supercompactness can be linked to other concepts in topology so that people will see the benefit of it. I hope that you understand my intentions.

Topology Expert (talk) 08:11, 9 May 2008 (UTC)

Exercises in articles

I removed the "Exercises" section of the local finiteness articles because it is a longstanding agreement that exercises do not belong in encyclopedia articles. The content criterion is located at the policy page WP:NOT: specifically, Wikipedia is not a textbook. All information from the exercises is now contained in the article itself. A reader wishing to test his or her knowledge may still do so, but the article cannot designate these special parts of the text as exercises. silly rabbit (talk) 11:44, 9 May 2008 (UTC)

I see you have readded the exercises. A better place for this material might be Wikibooks rather than Wikipedia. silly rabbit (talk) 11:51, 9 May 2008 (UTC)

"Silly rabit", could I suggest writing

I removed the "Exercises" section of the [[locally finite collection | local finiteness]] articles because

etc., so that others participating in the discussion can immediately see what you're talking about? Michael Hardy (talk) 15:51, 9 May 2008 (UTC)

"Silly rabit", I think it's too extreme to say without qualification that "exercises do not belong in encyclopedia articles". Having an "exercises" section, explicitly so labeled, may not be in accord with Wikipedia usages, but in the course of explaining a topic, one may parethetically mention that some gap in the argument may be left as an exercise for the reader since it's routine, or one may mention that it is useful to anyone trying to learn the subject to solve a particular problem. Those sorts of things happen. Michael Hardy (talk) 21:26, 9 May 2008 (UTC)

Per WP:MSM#Writing style in mathematics, the reader is not to be addressed or ordered about. Exercise sections do not belong in encyclopedia articles. Neither do any instructions to the reader. "This is an encyclopedia, not a collection of mathematical texts." There *are* wikimedia foundation projects where this sort of thing is not only acceptable, but encouraged. Wikipedia is not one of them. JackSchmidt (talk) 15:32, 10 May 2008 (UTC)

Have you considered putting the exercises into a lesson plan on Wikiversity instead? Maybe in Topic:Topology? -- KathrynLybarger (talk) 15:41, 10 May 2008 (UTC)

response/exercises/math typesetting

Hi Topo. Thanks for your message. I don't know much about wikibooks, but I would imagine that exercises would fit very well there, and if you have corrections to make there, go ahead. I saw your new article about the comb space. I've made some minor corrections to the typesetting. Please look them over. A good way to typeset math is with <math>...</math>. For example:

$f^{-1}:A\to B$ or $f:A\mapsto B$.

$A\cup B\times C$.

Also $\infty$ or ∞ for infinity.

There is still more typesetting to fix in that article, I only did about a third. Also, I fixed the definition of the deleted comb. Please check that I got it right. Cheers, Oded (talk) 14:29, 12 May 2008 (UTC)

---

Topo,

"I am not actually familiar with how to write mathematical symbols so I will have to learn."

Let me know if you need pointers to where to learn about this.

"Also, the definition you gave for the deleted comb space is basically the same as mine, written in a different way."

There was one minor issue that I changed the ordering to correspond better to the previous line, so that the reader could easily see the difference. But more importantly, the last part what we had previously was {0X1}, and I changed this to $\{0\}\times \{0,1\}$.

"I noticed that you seem to be experienced in measure theory so perhaps you will know whether more pages are required on the subject. I don't know how much detail is necessary, but perhaps we could merge some related pages together."

I think WP math is going to expand. I would tend to generally be against merging articles unless there is a very good case (i.e., the subject is virtually identical). I see no problem with short articles. Also, each time that one merges or changes the name of an article, this has the potential to mess up some links.

"I think that the definition of an outer measure and the definition of the lebesgue measure fit together nicely so perhaps we could add a little bit about how the outer measure relates to the lebesgue measure? I am not so sure about this since I am not very familiar with Wikipedia. Could you please give me your opinion on this?"

The construction of Lebesgue measure in Lebesgue measure does mention the connection. Also, the outer measure article mentions Lebesgue measure. So I think it is ok.

"I also wanted to ask whether I could change the name of the article on 'locally connected spaces'. When I first created this article I thought that this concept has a connection with the concept of components of a topological space so I decided to add that in. I don't think there is a page written on 'components' anyway so maybe we could change the name of the article to 'Components and locally connected spaces' which is a much more appropriate name. Could you please tell me how to do this?"

I don't think this is a good idea. I don't think that these topics should share an article. I think that the stuff on connected components should be in an article connected component (topology). Now the latter redirects to connected space, but if that page does not accomodate well the material that you'd like to add, then it would be appropriate to replace the redirect with an article.

"I also noticed that there is not much written on the concept of the uniform norm. They have only used this in the context of function spaces but perhaps the more general reader would also prefer a view relating to the product topology. I am happy to write a page on that if necessary."

Can you please clarify. It is not clear to me what you'd like to add.

Also, I should mention that it is very important to include references to books or articles where the reader can read more on the material or just verify the article. We all make mistakes from time to time, and having a reference to check is important from that aspect as well. In fact, no WP article is considered in good shape if there are no references.

Cheers, Oded (talk) 15:18, 13 May 2008 (UTC)

---

Topo,

"Sorry for the late response. I meant (when I said that I was going to add a page on the uniform topology), was that there are pages on how the uniform topology fits in the context of functions spaces, but there is no page relating to the uniform topology on R^{ωSuperscript text}. Some readers (particularly students), may prefer to read about the properties of the uniform topology on R^{ωSuperscript text}. Of course, I am not saying that we should delete the original pages, but maybe we can add a page on this. I am not so sure whether Wikipedia is a learning tool (i.e, information should be written with examples so that people can learn), so maybe we shouldn't add an extra page relating to the uniform topology on R^{ωSuperscript text}. But in my opinion, some people may want to also read how the uniform topology can be imposed on R^{ωSuperscript text} and some of its properties. Of course, the uniform topology is most used in functional analysis. Could you please give me your opinion on this?"

I don't see a reason to specialize to $R^{\omega }$. Doesn't this apply more generally to $X^{I}$ where $X$ is a metric space and $I$ is any set? Have you seen this being called the uniform norm or uniform topology in a textbook or math paper? If I understand what you are referring to, then this is not a norm at all. A discussion of these spaces (in the context of point-set topology) seems worthwhile, but I'm not sure what would be the correct name for such an article. If you can site a few sources and see what they call it, that could help.

"Also, I recently added some information regarding the relevance of the 'induced homomorphism' in algebraic topology (about two pages on a word file). But, David Eppstein deleted what I wrote. Therefore, I asked him why he did this but perhaps you may know what was wrong with what I wrote (since you are familiar with Wikipedia). Thankyou for your help."

David explained his reasons in the edit summary. One reason he mentioned is that your style was not compatible with wikipedia standards. I suggest that you read a few articles in the math part of WP to get some feeling of what is accepted style, and that you try to immitate the style in your writing. For example, I suggest the following articles: group (mathematics), Dilworth theorem (somewhat less polished), Fundamental group. You don't need to start out writing a perfect article (in fact, it would usually be a bad idea to attempt this). But what you write should roughly conform to WP style, so that other editors do not have to thoroughly revise it later. For example, the article Gromov-Hausdorff convergence is an example of a good starting point for a more comprehensive article. I think I agree with David that the style in which you wrote that section is not the WP style (more like a textbook).

The other reason that David mentions is that he thinks this biases the article to much to a certain direction. This reasoning is somewhat problematic. Generally in WP lack of information about one aspect of a subject is not a reason not to include other information. However, I'm not sure that what you wrote really fits under induced homomorphism. Its proper place is fundamental group, and indeed this topic is covered there. It would be unreasonable to have a discussion in the article induced homomorphism about all the different types of induced homomorphisms, how they are used, etc. Perhaps this is what David meant and I think I agree.

Oded (talk) 18:25, 17 May 2008 (UTC)

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