Editing Meta:How to contribute (section)

== How to get started? ==

=== Creating or editing a page ===

To create a page, just go to the URL you would like to create, ''e.g.'' [https://www.lambda-lab.org/wiki/My_new_page https://www.lambda-lab.org/wiki/My new page]. Make sure you respect the [[#Naming conventions|naming conventions]].

To edit a page, go to this page and click on the ''Edit'' link below the title. You can also edit a section only by clicking on the ''[edit]'' link next to the section title. It is sometimes easier to edit the source code of the page instead of using MediaWiki's [https://www.mediawiki.org/wiki/Extension:VisualEditor VisualEditor], which can be done by clicking the ''Edit source'' link. Notice that there are ''protected'' pages, ''i.e.'' pages that unauthorised users cannot edit.

If you plan to spend some time modifying a page or a section, you can use [[Template:Working on page]] or [[Template:Working on section]] to display a warning for other users.

=== Generalities on MediaWiki ===

The λLab uses [https://www.mediawiki.org/ MediaWiki] (the software running Wikipedia for example). The pages are formatted according to the syntax of {{quotes|wikicode}}, a summary of which is provided below. This syntax is partly hidden when using [https://www.mediawiki.org/wiki/Extension:VisualEditor VisualEditor], which is enabled by default on the λLab.

==== Templates ====

One of its key features is ''transclusion'', allowing to insert the content of a page (usually a ''template'') into another page. To insert the content of [[Template:Example]] into the current page and pass it some arguments, the general syntax is <code><nowiki>{{Example|argument 1|argument 2|foo=named argument}}</nowiki></code>. Templates allow to extend MediaWiki's features and to store some parts of frequently used code. The most useful templates are described on the current page.

* Here is a list of <span class="plainlinks">[https://www.lambda-lab.org/wiki/Special:AllPages?namespace=10 all available templates]</span>. 
* For most templates, the page [[Template:Template name]] contains (or will contain) a documentation.

==== Categories ====

MediaWiki allows to give categories to pages. Please don't use this feature until a hierarchy of categories is set up.

=== Typesetting text ===

Text can be formatted using ''wikicode'', the markup used by MediaWiki. See MediaWiki's help pages [https://www.mediawiki.org/wiki/Help:Formatting on markup] and [https://www.mediawiki.org/wiki/Help:Links on hyperlinks]. There are additional features:
* To put text between quotes, use <code><nowiki>{{quotes|text}}</nowiki></code>. This will produce: {{quotes|text}}.

=== Typesetting math ===

To typeset math, use the templates [[Template:$|$]] (for inline math) and [[Template:$$|$$]] (for displayed math).
For example, <code><nowiki>{{$|F : \mathbf C \to \mathbf D}} and {{$$|\sum_{i{{=}}1}^{N} a_i \cdot x^i.}}</nowiki></code> produces: {{$|F : \mathbf C \to \mathbf D}} and {{$$|\sum_{i{{=}}1}^{N} a_i \cdot x^i.}}

Notice the <code><nowiki>{{=}}</nowiki></code> producing an = sign (this is needed inside template arguments).

An important remark is that '''the λLab does not run LaTeX''', but some web libraries that use LaTeX-like syntax. Hence all your preferred LaTeX commands are not available. More precisely:
* Currently, the default behaviour of [[Template:$|$]] and [[Template:$$|$$]] is that they use MediaWiki's [https://www.mediawiki.org/wiki/Extension:Math Math extension], which runs [https://www.mathjax.org/ MathJax] on server-side (and caches the result). See [https://www.mediawiki.org/wiki/Extension:Math/Syntax here] a list of available commands.
* We also have [https://katex.org/ KaTeX] installed, which is executed client-side (hence being slower) but supports more functions (see the [https://katex.org/docs/support_table support table]). If needed, KaTeX rendering can be enabled by <code><nowiki>{{$ or $$|some math...|k=1}}</nowiki></code>.

If using a template is too painful for you, we have been enabling the usual LaTeX syntax: <code>\(...\)</code> for inline math, <code>\[...\]</code> for displayed math. This is rendered through KaTeX.

This behaviour may be modified in the future if we find better options: '''please do ''only'' use syntax described here, and not MediaWiki's built-in <code><nowiki><math></nowiki></code> tags!'''

=== Definitions, Theorems, etc. (and proofs) ===

Theorems are produced with [[Template:Theorem box]]. The syntax is as follows:
<pre>
{{Theorem box
| type=lemma (or definition, or whatever you want)
| id=a unique identifier (as for a \label{...} in TeX)
| title=... (this line is optional)
| content=...
}}
</pre>
The result is as follows:
{{Theorem box
| type=lemma
| id=unique-id
| title=title
| content=Content...
}}

Proofs are produced with [[Template:Proof]]. The syntax is <code><nowiki>{{Proof|...}}</nowiki></code>. The template has an optional <code>title</code> argument, to replace the default title of the proof.

To reference to a theorem, use [[Template:Theorem ref]] as follows: <code><nowiki>{{Theorem ref|the identifier of the theorem}}</nowiki></code>. For example, see {{Theorem ref|unique-id}}. The template has an optional <code>text</code> argument, to replace the default text of the reference; for example {{Theorem ref|unique-id|text=this}} also links to the lemma above.

=== Bibliographical references ===

Bibliographical reference should be grouped in a ''References'' section at the bottom of each page. This section should consist in one or several list(s) of references:
* [Reference 1] with a comment if needed.
* [Reference 2]
* etc.
Individual references can be typeset in a BibTeX-like syntax using the following templates: [[Template:Bib Article|Bib Article]], [[Template:Bib Book|Bib Book]], [[Template:Bib InCollection|Bib InCollection]], [[Template:Bib InProceedings|Bib InProceedings]], [[Template:Bib Misc|Bib Misc]] and [[Template:Bib Thesis|Bib Thesis]]. If you think one of these templates should be improved or a similar template is missing, feel free to [[Meta:Feature requests|request it]].

In the body of a page, references can be cited with [[Template:Cite]]. A cited reference must be present in the References section.

=== Special mathematical features ===

==== Commutative diagrams ====

Commutative diagrams can be produced with <code><nowiki>{{Diagram|...}}</nowiki></code>, with [https://redgregory.notion.site/Diagrams-With-KaTeX-9166ebfa650a463dbdf67357143ebaed KaTeX's diagram syntax].

==== Proof trees ====

Proof trees can be produced in an [https://ctan.org/pkg/ebproof ebproof]-like syntax thanks to [[Template:Proof tree]]. The following example:
<pre>
{{Proof tree
| hypo \vdash F
| infer 1 \vdash G
| hypo \vdash H
| infer 2 style:(double) label:(R) \vdash G \oplus H 
}}
</pre>
produces the following result:
{{Proof tree
| hypo \vdash F
| infer 1 \vdash G
| hypo \vdash H
| infer 2 style:(double) label:(R) \vdash G \oplus H 
}}

This is an experimental feature: please [[Meta:Bugs|report bugs]] and [[Meta:Feature requests|request enhancements]]!