Arbital Markdown

[summary: Arbital uses Markdown with many custom extensions to help you create awesome explanations. Become a pro editor by learning how to create todos, greenlinks, page summaries, [arbital_note notes], hidden text, and insert LaTeX!]

The Arbital editor uses Markdown syntax for editing the pages. If you've used Reddit or any of the StackOverflow, it's the same syntax. Here is a helpful intro to Markdown syntax.

[toc:]

Arbital Markdown syntax

Arbital adds a few extra features to Markdown syntax.

Table of contents

[toc:] creates a table of contents, like the one above.

Greenlinks

[todo: Add note about the Intrasite Link button on the toolbar.]

You can quickly link to a page by using [id] or, even better, [alias] syntax. For example:
<a href="arbital_markdown.html">Arbital Markdown</a> => Arbital Markdown
[Arbital\_markdown] => Arbital Markdown

%%hidden(Advanced): If you want the inserted title to be lower-cased, add a dash:
<a href="value_alignment_problem.html">Value alignment problem</a> => Value alignment problem
<a href="value_alignment_problem.html">Value alignment problem</a> => Value alignment problem

If you want to specify what text shows up as the link, use [alias text]. For example:
<a href="arbital_markdown.html">Custom link</a> => Custom link

If you link to a page that doesn't exist, the link will show up red:
[definitely\_doesnt\_exist Doesn't exist] => [definitely_doesnt_exist Doesn't exist]

If you want to just create a red link with some text:
[ create a page for this concept later] => [ create a page for this concept later]

If you want to mention someone use [@userId] or [@userAlias]:
<a href="AlexeiAndreev.html">Alexei Andreev</a> => Alexei Andreev
<a href="AlexeiAndreev.html">Alexei Andreev</a> => Alexei Andreev
NOTE: the user will get an update if the mention is in a comment. %%

Summaries

You can set the page's summary, which shows up in greenlink popovers and other places. For example:
[summary: Summary of the page goes here. *Markdown* is okay!]
Or to set a specific summary:
[summary(Technical): Very technical summary. *Markdown* is okay!]
Make sure that the entire summary block is in a paragraph of its own.

Hidden text

You can create hidden text:

%%hidden(Button text):
Hidden text goes here.
%%

%%hidden(Button text): Surprise! %%

You can use this for hiding problem answers and asking the user to solve the problem themselves before clicking the button to see the correct answer. Button text is required.

[arbital_note Notes]

You can create notes, which are snippets of text hidden behind a question mark. You can put footnotes or other text that might be interesting to some users, but not to everyone. For example:
%note:Fun note text!% will show up as: %note:Fun note text!%

%%%comment:
[1]: this is not something we want to advertise at this time.  
You can embed [3r votes] from other pages. For example:  
`[vote: 3r]` creates this voting bar:  
[vote: 3r]
%%%

Todos, [arbital_inline_comments comments], and [arbital_fixme fixmes]

You can leave todo markers for yourself or other authors. For example:
[todo: finish this section] [todo: finish this section]
%%todo: You can put any funky *markdown* syntax here including `[Arbital\_greenlink links]`. %%
This will only appear in the top quality bar when expanded, not the page text. Red links and "todo" markers count towards the todo score, which you will see next to the pages on the Explore and your Profile pages. %%todo: You can put any funky markdown syntax here including links. %%

Similarly, you can leave comments or fixmes for other authors, but without increasing the todo count. For example:
[comment: there has got to be a better metaphor for this] [fixme: this needs to be fixed, but I've got it] [comment: there has got to be a better metaphor for this] [fixme: this needs to be fixed, but I've got it] <pre>%%comment: You can put any funky *markdown* syntax here. You can vary the number of %s to envelop other similar blocks. %%</pre>
Again, this doesn't show up for the reader in any way.

%%comment:
You can put any funky *markdown* syntax here. You can vary the number of %s to envelop other similar blocks.
%%

[todo: questions and path generation]

[todo: conditional text]

LaTeX

If you're new to LaTeX you may want to read the Wikibooks guide

You can use \$ to create inline mathematical expressions, e.g. $~$ax^2 + bx + c \= 0$~$ will be displayed as: $~$ax^2 + bx + c = 0$~$
And \$\$ to create centered math expressions, e.g. $$~$\\lim\_{N \\to \\infty} \\sum\_{k\=1}^N f(t\_k) \\Delta t$~$$ will be displayed as: $$~$\lim_{N \to \infty} \sum_{k=1}^N f(t_k) \Delta t$~$$

The editor can get a little slow if you are editing very LaTeX-heavy pages. If this is an issue for you, let us know, and in the meantime you can disable MathJax on the settings page.