# Help:Questions

i.e. Things not working as they should.

## Contents

## Treating Long Proofs

On this page is a 1-genus case of Ringel-Youngs theorem and it would make sense to create a page dedicated to the said theorem. However, the proof is quite long and spans over a number of articles over time, totaling to around 100 pages. What should I do in that case? Should I provide an outline of the proof along with the references? Or do something else entirely? --Stixme (talk) 03:39, 22 January 2018 (EST)

- Outline of proof to start with. What we would hope to do would be to break it into conceptual sections. Each of the subproofs would be given its own page, and that page would be linked to from the main proof page.

- We haven't done any seriously long proofs. If you want a model to copy, the biggest so far (that I can remember off the top of my head) is probably the Poincaré Conjecture, which (to a certain extent) is still at the outline stage. --prime mover (talk) 08:45, 22 January 2018 (EST)

## [Answered] Eqn template

Just a note.

The delimiter $|$ doesn't seem to be valid in the eqn template, so I used \vert instead, but this behaves pretty weirdly, e.g.

\(\displaystyle \) | \(\le\) | \(\displaystyle \left\vert { a_{m+1} } \right\vert + \left\vert { a_{m+2} } \right\vert + \cdots + \left\vert { a_n } \right\vert\) | Triangle Inequality |

is fine, but

\(\displaystyle \) | \(\le\) | \(\displaystyle \left\vert {a_{m+1} } \right\vert + \left\vert {a_{m+2} } \right\vert + \cdots + \left\vert {a_n} \right\vert\) | Triangle Inequality |

is not.

Argh, also this:

\(\displaystyle \left\vert { \frac{a_n}{ n^s } } \right\vert\) | \(=\) | \(\displaystyle \frac{ \left\vert { a_n } \right\vert }{ n^\sigma }\) |
{{eqn|l= |
o=\leq | r= \frac{ \left\vert { a_n } \right\vert }{ n^{\sigma_0} }
{{eqn|l= |
o= = | r= \left\vert { \frac{a_n}{ n^{s_0} } } \right\vert |

can't make it work at all. Linus44

- Placing two }'s side-by-side will prematurely close {{eqn}} template. This has been a topic of discussion on the main page ... we're still looking for a fix. --Joe (talk) 15:23, 15 February 2011 (CST)

- Ok, thanks Linus44 15:30, 15 February 2011 (CST)

- You missed some closing braces

\(\displaystyle \left\vert { \frac{a_n}{ n^s } } \right\vert\) | \(=\) | \(\displaystyle \frac{ \left\vert { a_n } \right\vert }{ n^\sigma }\) | |||||||||||

\(\displaystyle \) | \(\leq\) | \(\displaystyle \frac{ \left\vert { a_n } \right\vert }{ n^{\sigma_0} }\) | |||||||||||

\(\displaystyle \) | \(=\) | \(\displaystyle \left\vert { \frac{a_n}{ n^{s_0} } } \right\vert\) |

{{begin-eqn}} {{eqn|l= \left\vert { \frac{a_n}{ n^s } } \right\vert |o= = |r= \frac{ \left\vert { a_n } \right\vert }{ n^\sigma } }} {{eqn|l= |o=\leq |r= \frac{ \left\vert { a_n } \right\vert }{ n^{\sigma_0} } }} <------------------------------------------------------------------ here {{eqn|l= |o= = |r= \left\vert { \frac{a_n}{ n^{s_0} } } \right\vert }} <------------------------------------------------------------------ and here {{end-eqn}}

--Joe (talk) 15:32, 15 February 2011 (CST)

- I tried 4 times to add the same reply but I kept getting a midair collision. Stroll on. --prime mover 15:35, 15 February 2011 (CST)

## How do you post something on a discussion page?

How do you post something on a discussion page? --1is0? May 4, 2013

- By pressing the link at the top of the page that says "Discussion". If it's blue, it means there's already such a page, to which you are welcome to add material. If it's red, then the page does not yet exist because nobody has posted anything to it yet. Your contribution will then be the first on that page. --prime mover (talk) 22:58, 4 May 2013 (UTC)

## Does the site have a standard quantifier convention?

For unbounded quantification, I've seen \(\forall x:\forall y:\exists a :(\dots)\) when I would have written simply \(\forall x\forall y\exists a(\dots)\)

For bounded quantification, I've seen something similar (use of colons). However, I would simply write the quantification without the colons. --Robertbiggs34 (talk) 19:26, 27 May 2013 (UTC)

Also, when using bounded quantification and using the same quantifier over the same set (i.e. \( \forall x\in \R \,\forall y\in\R\)) do we shorten this to \(\forall x,y\in\R\) or \(\forall x.y\in\R\)? --Robertbiggs34 (talk) 19:30, 27 May 2013 (UTC)

- We use commas. I am not the style master here, so I can't answer the rest too well. I don't think colons should be needed between quantifiers, at least for unbounded quantification, but Prime.mover would be the one to answer definitively. --Dfeuer (talk) 19:33, 27 May 2013 (UTC)

- $\forall x: \forall y: \exists a : \left({\ldots}\right)$ is the convention, consistent with colon meaning (loosely) "such that".

- It's also $\forall x, y \in \R$ which is consistent with comma being used to separate entities in a list. I've never seen a dot used in this context, it looks perverse to me.

- What we
*don't*sanction is the use of a comma to mean "such that", so when we see $\forall x \in S, P \left({x}\right)$ we immediately change it to $\forall x \in S: P \left({x}\right)$, and so on.

- What we

- Commas are probably the most ill-used punctuation mark in natural language as well as mathematics, so it's something we're used to.

- Incidentally, please use dollar-sign delimiters instead of
`<math>`

because the latter are not fully supported by MathJax (and dollars are more compact and quicker to type than the alternatives). --prime mover (talk) 19:42, 27 May 2013 (UTC)

- Incidentally, please use dollar-sign delimiters instead of

- Vector Space Axioms is a good illustration of PW style. --GFauxPas (talk) 20:12, 27 May 2013 (UTC)

Hello, new user here. Are there preferences concerning the use of formalized quantifiers or natural language? --Xario (talk) 07:02, 12 December 2018 (EST)

- Formalized quantifiers are best, unless what you are building looks highly confusing. --prime mover (talk) 07:59, 12 December 2018 (EST)

## Is it possible to download your definitions as a data file?

There are a lot of technical definitions here that would be great for inclusion (with attribution, of course) in the multilingual dictionary at http://kamusigold.org. Is there any way to siphon them in one go?

- Interesting and ambitious concept. There is an "Export Pages" tool which lives under Special pages (see LH menu). It compromises the capabilities of anyone else to use the database while it's happening though, because of the load on the application, so try not to do this often. --prime mover (talk) 13:01, 27 September 2016 (EDT)
- Thanks. I tried with the top level for the Definitions category, and got back a beautiful xml page that will be a snap to parse. However, there are a ton of sub-categories and sub-subs and sub-sub-subs, which are not captured in the top level export. By my count, there are close to 750 definition categories (many with only one member) - downloading them one at a time would be a mission. Might there be a way to consolidate the task?
- I would happily run this at 6am Europe/ 9pm Pacific. In my experience with web traffic, that's when the web's circadian rhythms hit bottom.

- We used to do a daily xml dump of the whole site. I can re-enable it if it would help. You should be able to just fetch it and parse out the definitions. --Joe (talk)

- That would be great. Please let me know the whens and wheres, and I'll do a one-time fetch. Maybe come back about once a year to see what's new, but this certainly won't be something we are running daily. --Malangali (talk) 03:33, 30 September 2016 (EDT)

## Floor function theorem

How to prove that the amount of integers between $1,\ldots,n$ which are divided by $1\le k\le n$ is $\left\lfloor\dfrac{n}{k}\right\rfloor$ ? Simcha Waldman (talk) 08:59, 6 September 2017 (EDT)

- At $\mathsf{Pr} \infty \mathsf{fWiki}$ we do not currently provide personal assistance, but there are some other things you can do:
- Create a page for the theorem, and leave the proof for someone else to fill in (which may take some time). Be sure to choose a good name. I suggest Amount of Multiples of Number less than Number in terms of Floor Function, but you can choose.
- Ask your question on a Q&A forum (which is not related to $\mathsf{Pr} \infty \mathsf{fWiki}$) or see if it's already answered there.

- We are in the process of writing detailed instructions for how to request a proof. --barto (talk) 09:41, 6 September 2017 (EDT)

- I don't understand the question. Do you mean this? Pigeonhole Principle --prime mover (talk) 12:34, 6 September 2017 (EDT)

## Book page style

I was going to add the contents for a book on group theory I'm reading, the formatting for different books varies quite a bit e.g. Book:David_Joyner/Adventures_in_Group_Theory, Book:P.M._Cohn/Algebra/Volume_1/Second_Edition, Book:Gilbert_A._Bliss/Lectures_on_the_Calculus_of_Variations. Is there an established format for new additions? --Linus44 (talk) 06:21, 24 June 2018 (EDT)

- As it appears in the contents list of the book in question, basically. I used to generate the contents in full detail, but as I no longer have a scanner that performs efficiently, I have to type the damn things in, and so I am currently entering just the main chapter headings rather than trying to include the full reproduction of the contents lists as they appear. --prime mover (talk) 10:22, 24 June 2018 (EDT)

## QUD-Box to the right?

I know it's a small thing but it kinda bugs me that the boxes are not on the right hand side below the proof. Shouldn't it be also kinda easy with "align=right" or "float=left" in the template? Or am I missing something? --Xario (talk) 11:16, 12 December 2018 (EST)

- Everything hangs to the left on $\mathsf{Pr} \infty \mathsf{fWiki}$. We aim for short sentences, and it is rare for anything to spread over into the right hand side of the screen. Hence we put our
`{{qed}}`

on the left. House style. --prime mover (talk) 12:39, 12 December 2018 (EST)