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    • This forum is intended as a discussion place for the n-Lab. It's probably a long way from ideal (you mean you want to be able to type maths?) but it's a start.

      To begin with, just start a new discussion in the General category. I'll sort out some other categories if and when it becomes clear that they are needed.

    • I just tried to use the WikiWord feature but came a cropper on HTML entities. I tried Froölicher spaces but the ö seemed to get escaped and appear as is on the page. Anyone know how to fix this?

    • Following Eric's reply to my query, here's how to do links on this forum. Basically it depends on one's choice of filter. If you use 'Text' then just type the raw link:

      http://ncatlab.org/nlab/

      If you use Markdown, the correct syntax is

      [nLab](http://ncatlab.org/nlab/)

      For Textile, use

      "nLab":http://ncatlab.org/nlab/

      Finally, for Html just use the HTML code:

      nLab

      It seems that Vanilla regards raw HTML as potentially dangerous and won't allow it to go through without passing through a filter and all the filters escape HTML code (with the exception of the Html filter, though even that tries to weed out dangerous code).

    • This will probably get me back into negative credit with Urs ...

      The n-Lab should have an FAQ page and the conclusions of discussions should get added to it. To find out what the consensus was on something should not involve having to search through several sites - when you may not even be sure that it was discussed at all. The onus should probably be on the original questor to write up the solution on the FAQ (which, of course, can then be edited by the solvators if they feel they've been misquoted).

    • (Copied over from the n-Cafe as the thread quickly got diverted)

      One of the aims of the nLab is to provide a space for collaborative work to take place. This raises the question of authorship. It would probably be a good idea to get something in place on this before anyone attempts anything serious rather than after.

      Here’s a hypothetical. Someone starts a page on some topic with the intention of doing a little original research on said topic. Various people also contribute, to a greater or lesser degree. At some point, it is felt that something significant has been done and there is something worth publishing there. Assuming that we are still working with the current publishing model, what would people feel would be an acceptable procedure at this juncture? The point about the assumption being that the current model only permits three levels of authorship on a paper:

      1. Author

      2. Mentioned in the acknowledgments

      3. Not mentioned at all

      On the other hand, the revision system of a wiki allows for a much more fine level of distinction. So we would need a translation from the wiki levels of authorship to those of a paper.

      Now, I don’t expect this to get sorted out straightaway, and I expect that whatever consensus is reached at the beginning will be quickly seen to be a complete travesty once someone actually tries to implement it. So what I would actually like to see is something that allows for this.

      What I have in mind is that the original author (who, let me remind you, intended there to be original work) to put up some sort of disclaimer/terms-of-use on the page along the lines of:

      “This page (and its sub-pages) have been created for the express purpose of doing original work. It may happen that a snapshot of these pages will be submitted for publication. At that time, an author list will be decided upon. This author list will be decided by [Original author and Certain Others] subject to the guidelines laid down at [Guidance for Publication].”

      The “Certain Others” should be a team of respected arbitrators (two names instantly spring to mind) whom everyone trusts to be fair and reasonable. The “Guidelines” obviously should contain a description of what the community regards as being a contribution worthy of authorship or of acknowledgment (for example, adding a full stop at the end of a sentence probably doesn’t warrant an acknowledgment, but sorting out some horrendous notation or checking references probably does).

      The discussion I would like to see first is as to the overall model. I don’t think that this is the place to discuss the actual guidelines - if this model is acceptable then the obvious thing to do is create a page on the wiki and see what the eventual consencus is.

    • (Copied over from the n-Cafe entry as it didn't get noticed there - maybe for a good reason)

      Here’s another question, slightly related to the “authorship” one I just posted.

      How much is someone allowed to set the direction for a page? I don’t mean “left-to-right” before anyone gives a spurious reply. For example, if someone is intending on using the nLab for collaborative research then they may wish to set a goal or slogan or something for the page. This sort of thing should be laid out in a “code of conduct”, I guess, so that both the original author and any contributors know what is allowed.

    • The hopefully unique experience of crashing the n-Lab three times in one weekend (please, everyone, use belts and braces), made me think about mirrors. Admittedly this may be something for a little further down the line and may be more a general Instiki thing than n-Lab, but it may be worth thinking about it now.

      A mirror (or more) would be there so that if the main site crashes, people can still use the n-Lab. Now, having a complete copy of the n-Lab seems a recipe for disaster as there will be conflicts in edits from different sites. However there could well be some value in having static mirrors so that people can still use the n-Lab as a reference, and they can still plan their edits for when the original becomes live again.

      A static mirror can be set up easily by exporting the html. However, it should be kept up to date, probably daily, for which exporting the html every time seems a little overkill. Suitable use of wget can get around this but this still downloads a whole page for a small change.

      Obviously the best solution for bandwidth purposes would be for instiki to be able to export dated diffs. However, that's a feature request and Jacques may like to know whether or not there's any demand for it before investigating so ...

      Do mirrors seem like a good idea?

    • How do others compose long(ish) articles? I'm an inveterate previewer but doing that "live" involves lots of commits which feels expensive both in terms of bandwidth and database (since the system saves every single one of them).

      I guess we could ask Jacques for a "preview" feature on instiki, but that doesn't get round the bandwidth problem.

      Any ideas?

    • Is there a bug in the handling of theorem numbering? The last paragraph of this page refers to "Theorem 3" but it should really be "Theorem 6."

    • What are these really saying? Are they just something generic provided by the software that Andrew never changed? They talk about some ‘community’ that's going to tell me what I can and cannot do and which from that context clearly does not include me!
    • This comment is invalid XHTML+MathML+SVG; displaying source. <div> This is a bit small to put in a forum post, but it would be confusing to put it in the relevant page, and at least I know that Andrew will see it here. (^_^)<p>Andrew, I reverted your edit to the explanation on query boxes. The reason is to remove the space from the explanation, which can cause formatting problems. I think it best to keep technical explanations as legible as possible. Of course, there's nothing wrong with the other way, which (as you know) is how they give it in the Maruku documentation, except that it would be harder for a novice to read about.<p>Incidentally, I checked that they produce identical compiled XHTML.</p></p> </div>

    • I don't understand the rules for itex's "aligned" environment. Sometimes it seems to right-align the first column and left-align the second, which is what I would expect. But other times it seems to randomly decide to center both columns. Is there some subtlety of the syntax I am not aware of?

    • I'm curious as to how far back the n-lab should go. I just created "constant morphism" but was debating whether or not that was too basic. I then found that Toby had edited it and made a Wikilink to "constant function". I'm curious as to what people think is the baseline for the n-lab.

      I figure that something like "constant function" is a prerequisite for most of the n-lab. On the other hand, it might be an idea to have some "examples" pages showing how lots of the structure works for particular categories. Then "constant function" to link to the examples page for Set. This is a bit more pedagogical than perhaps we are at the moment.

    • Is it just me, or is ncatlab.org down?
    • How do I make asterisks in itex? Writing "*" gets translated to <em> tags in the wrong places, but \ast doesn't work either.
    • How hard would it be to add to instiki the capability to have actual redirects, like Wikipedia does?

    • According to my sources, "heuristic" refers to a process of discovery; essentially by trial and error. On the n-Lab it seems to be getting used as an adjective to mean something like "not very technical". Am I misreading something here?

      To make the point a little more general, the n-Lab is fairly international and so in its expression it should strive to be as simple as possible. We have enough jargon within the mathematics so I think that we should aim for simple language elsewhere. Maybe I notice this more than others since, as one of the few native English speakers who contributes, when I encounter a word or phrase that doesn't make sense (linguistically, not mathematically) then I can be fairly confident that it is the word or phrase that is incorrect and not my grasp of the English language. Or if it is me that has it wrong then it is highly likely that others will also be confused and so the offending term should be mollified to make it clearer.

      So, now's your chance to object before I purge the n-Lab of the word "heuristic" and other grammatical nonsense!

    • How does one do a bibliography on the n-Lab? Within a given article, I mean.

    • You can now use formulae on this forum. To do so, encase the formula in double dollars: &#36;&#36;x^2 + y^2&#36;&#36; produces x^2 + y^2.

      It's experimental, but then I guess we're not going to be using it too much on this forum (though please do try it out so I can iron out the bugs) as this isn't a forum about mathematics.

      It doesn't work too well with the preview feature. That's not a bug, that's a feature (remember that you can always edit your post after posting).

      If you edit your post then you'll find that your formula gets put between <latex> tags. That's because the plugin converts the dollars to fake html tags before storing it in the database. It makes it easier to tell other plugins to ignore the formula.

      It currently works with the markdown and Html filters but not the Text or Textile ones.

    • Following on from the discussion on the cafe, I've discovered that tikz (a fairly sophisticated LaTeX picture package) can be converted to SVG. Basically, running htlatex (from the TeX4ht package) on a latex document with tikz pictures in produces SVG versions of the pictures. There are a few limitations, mainly to do with text, but it seems to work.

      However, including SVGs in Instiki doesn't seem to work exactly. Compare the picture in the sandbox with the original SVG:

      Sandbox Original SVG

      For more examples, see the page of my talk on Comparative Smootheology at the Ottawa conference which is here.

      The trick, from the pgf manual, is to load the correct output driver before loading the Ti_k_Z package. The line is:

      \def\pgfsysdriver{pgfsys-tex4ht.def}

      I got this hint originally from someone's user page on Wikipedia, but it's covered fully in the PGF manual.

    • I was always quite frustrated with the small textarea for the "Edit page" in Instiki. So I've made a Stylish extension for Firefox, which makes this textarea bigger. It can be installed at this page.

      It would be nice to put this into the CSS for Instiki, except I needed to adjust the "id=content" div, and one only wants to do it on the edit pages, not on all pages (otherwise you'd get wide text on all pages, which is probably not desirable). In Stylish you can select the "edit" pages by stipulating that the theme only applies to url's with /edit in their title. Does anyone know of a workaround to this?

      There are a few other things I find frustrating too. I'd like to be able to adjust that sidebar, to remind us of how to insert query boxes, etc.

      Any thoughts on customizing the nLab?
    • Right now I'm thinking that it would be better for us to change strategy: instead of trying to get a working TikZ system for the nLab via Tex4ht, we should instead just start coding in basic TikZ commands directly into itex2mml. This approach has numerous advantages:

      1. It doesn't require a TeX system on the server. This means (a) it will be much faster and (b) it will be portable, so we would probably gain the support of Jacques.

      2. We can start implementing things right away, starting with the "draw" command. We can setup the nLab to run the current working version of itex2mml.

      The disadvantages are:

      1. We have to start coding things into itex2mml.

      2. It is unlikely we'd ever get all of TikZ to be exportable to SVG (we'd probably get less out than we could with Tex4ht). I doubt SVG is up to the task, from what I've seen of it (how could the web designers ever expect such a crappy format to take off?? ). Tex4ht could do more since all it has to do is transform low-level commands in the dvi file into svg, which can always in principle be done. I am talking about "removing the bottom man" and coding directly from high-level into medium-level (i.e. directly from TikZ to SVG without going down to pgf or dvi first).
    • You may have noticed the nLab is sporting a serif font scheme for text and math, for one day! I installed this in the CSS just to raise awareness of what's possible. You can override it in Firefox.

      The math fonts it tries to select are, in this order:
      Georgia, DejaVu Serif, BitStream Vera Serif, Linux Libertine, Constantia, Cambria Math, STIXNonUnicode, STIXSize1, STIXGeneral, Symbol

      The text fonts are, in this order:
      Georgia, DejaVu Serif, BitStream Vera Serif, Linux Libertine, Constantia, Cambria, Times New Roman

      I personally find this a more pleasing scheme; the Stix math fonts look terrible on my system (very dim). No doubt others will think differently! How does it look to you?
    • There's some discussion on the Café starting here.

    • I see from the Sandbox that Toby has been experimenting with ways to get forward slashes in names. Whatever his method is, it seems to work within the n-Lab.

      However, it doesn't (necessarily) work externally. My RSS feed reader showed that someone had created a page called 'Sandbox/test' but when I clicked on it then I got the 'Internal Error' page.

      Did Toby's method involve escaping the slash? If so, the problem is that you want it to remain escaped right until the end. However, when stuff goes through scripts and readers and gets passed from one page to another then it tends to get decoded and re-encoded many times. So it's hard to predict how many times you need to escape the escaping - if it's even possible to do that at all.

      We shouldn't overlook Murphy's Law when designing schemes like the naming scheme. Sticking to the basic character set makes the system a whole lot more robust (quite apart from Google rankings).

    • I think it's time to sum up our discussions on graphics in Instiki. I'm getting a little lost as to what we're aiming for.

      1. MathML+SVG is not ideally implemented yet so any method that produces mixed diagrams (i.e. graphics and text) is going to be imperfect and the resulting diagrams will need tweaking.

      2. Drawing diagrams in (La)TeX is not a simple affair and the packages that do so are extremely complicated (under the hood/bonnet). Jacques is, understandably, reluctant to implement a hack in itex but is similarly reluctant to implement the whole machinery.

      3. On the other hand, he is willing (may already have done so) to implement a system that allows for alternatives: a picture for the screen and another for the LaTeX output. Indeed, this is already in place if the LaTeX picture is a PDF.

      4. So we need converters. Inkscape will export TikZ so one can convert from SVG to TikZ. I don't know how "nice" the resulting TikZ is, though.

      5. On the other hand, the best bet for TikZ to SVG is TeX4ht and this results in fairly horrendous SVG.

      6. When putting diagrams into Instiki, due to the poor interaction of MathML and SVG then one oughtn't to stack thinks too deeply. It's reasonable to have MathML embedded in SVG or vice versa, but to have MathML embedded in SVG embedded in MathML is asking for trouble. Since the worst seems to be MathML in SVG (for visual reasons rather than technical), it's best to have only simple mathematics embedded in a diagram (probably a good guideline anyway).

      7. Big diagrams can be put on separate pages and included in, but there is potential for reuse within the page so small diagrams should stay inline. Well-formed SVG is more compact than MathML so although the raw syntax looks a little out of place, it's not so bad.

    • I think it would be useful to have some way of marking which sections of the n-lab are original research, which exposition, and which something else. Something a little finer than on a per-page basis, as well.

      Then it would be nice to have some way for people to say that they've read the OR bits and that they:

      • Have found a flaw
      • Don't believe it (but can't say exactly why)
      • Believe it (but haven't rigorously gone through it)
      • Have looked for a flaw but haven't found one

      (Note that I don't put "Have verified it" in my list).

      Any suggestions? Is this worthwhile?

      (Hmm, something here is killing lists ... have to track that down and kill it instead)

    • In my opinion, we should start thinking about how to migrate from Instiki to Mediawiki.

      It is becoming increasingly clear that Instiki is not scalable. There is some very good content going up there and Instiki does not have the developer support we need for a long term solution. Mediawiki has a large base that will ensure continued updates and improvements to the software.

    • I've hacked the feeds for this forum a little so that there are now "all comments" feeds.

      It's not perfect yet: I get the right thing in Live Bookmarks, but in my feed reader (RNews) then I run into problems because the comments' titles are those of the discussion, so lots of comments have the same title. My feed reader collapses these to the first comment (I wouldn't mind so much if it collapsed them to the last comment!).

      There are two possible solutions to this. Either make the feed entry titles unique (perhaps adding the comment number to it) or offering a reversed feed (in addition to the current one) so that when the feed reader collapses entries with the same title then the most recent comment is the one that survives.

      Neither is completely simple so I thought I'd canvas opinion first. Also, given the plethora of feed readers out there then the fact that it seems to work in Live Bookmarks and almost works in RNews doesn't mean that it will work in everything so please try it and see if it works for you.

    • I'm putting this here so that it doesn't distract from the fascinating 'redirects' thread.

      I've noticed that lists on this forum don't appear how I want them to, and now that Toby's noticed it too then I thought it was worth investigating. I thought at first one of the filters was killing them, but turns out it's bad stylesheet design.

      I'm using Toby's post on instructions on redirects as a test page. The first list there is unordered (was it meant to be?) and the other two are ordered.

      The stylesheets that I've provided work as follows (several are named "default" unfortunately):

      • basic vanilla: works fine
      • Dizzy: works fine
      • Vanilla sky: lists are fine, but there seems to be something missing here!
      • Tonka: no lists
      • vaneablack: all lists are bulleted (is this the default for the forum?)
      • default (first, rather pink): no lists
      • default (second): works fine
      • default (third): no lists
      • default (fourth): works fine
      • quik_red: works fine
      • cloud6: works fine

      Of course, some of them have other issues. I just downloaded a bunch off the vanilla website and picked one for the default (not sure which it is off the top of my head. I switched recently to test the background transparency of the mathematics).

      If you don't like any of these, then I'm happy to install others. If there's a particular shade of lurid pink that you can't do without either design your own or see if someone else has one you like. The repository is here (I'm not sure of the distinction between a "theme" and a "style").

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