nLab meta nForum FAQ

Getting Started

What Is This?

See Welcome to the nForum.

Where Do I Start?

You need to create an account before you can begin posting. Once your request is approved by an “administrator” you become a member. See Membership ranks and privileges for information on the different levels of membership.

I Want To Discuss Something

When you start a discussion, you have to choose a category in which to put it. There are two main choices: nLab or not-nLab. If your discussion is about something to do with the nLab, put your discussion in one of the categories following the ‘nLab’ title. If not directly about the nLab, choose one of the categories following the ‘Atrium’ title.

How is the nForum Organised?

See Out and about in the nForum.

How Do I Write Maths?

The best way to type mathematics is to use the Markdown+Itex formatter and use the itex syntax for equations. The commands summary is here.

The Maths Looks Funny

Itex gets converted to MathML. If your browser is capable of displaying MathML, that’s what you see (more specifically, if the software thinks that your browser is capable of displaying MathML). If not, the MathML is further converted to SVG or PNG. You can decide what format to see in your forum-preferences, go to the “My Details” tab and select the “itex options”.

Technical Questions

How do I make links to the nLab family?

Use the same syntax that you do in nLab, e.g. <a class='existingWikiWord' href='/nlabmeta/show/HomePage'>HomePage</a> links to HomePage on nlab and <a class='existingWikiWord' href='/nlabmeta/show/HomePage'>HomePage</a> links to HomePage on nlabmeta.

How else do I get math?

There are two methods of producing mathematics on the nForum. Which to choose depends on the “text formatter” that you use. The two methods are:

1. Use the Markdown+iTeX formatter and type mathematics just as you would on the nLab. This is the preferred method: it renders as \MathML and the source can be cut-and-pasted directly into the nLab.
2. Use one of the other formatters and use the inbuild LaTeX->png converter. To do this, enclose your mathematics in double dollars. That is, to get $x^2$ at the forum, type $$x^2$$.
3. When editing your comments, you will see that the double dollars get converted to fake XHTML tags (<latex>x^2</latex>, for example). You can type your formulae using these tags but there is no functional difference.
4. The fake tags are used for internal reasons. The only practical upshot of that is that the actual length of a comment is slightly longer than the original length. This can cause problems if the comment is near the maximum length.
5. Although mathematics (using this method) is typed with double dollars, it is presented simply as inline.

How do I type square brackets (or other “special” characters)?

Double square brackets get interpreted as wikilinks back to the n-lab. To produce actual double square brackets, you need to escape them with a backslash.